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rocksdb/utilities/backup/backup_engine.cc

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// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#ifndef ROCKSDB_LITE
#include <algorithm>
#include <atomic>
#include <cinttypes>
#include <cstdlib>
#include <exception>
#include <functional>
#include <future>
#include <limits>
#include <map>
#include <mutex>
#include <optional>
#include <sstream>
#include <string>
#include <thread>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include "env/composite_env_wrapper.h"
#include "env/fs_readonly.h"
#include "env/fs_remap.h"
#include "file/filename.h"
#include "file/line_file_reader.h"
#include "file/sequence_file_reader.h"
#include "file/writable_file_writer.h"
#include "logging/logging.h"
#include "monitoring/iostats_context_imp.h"
#include "options/options_helper.h"
#include "port/port.h"
#include "rocksdb/advanced_options.h"
#include "rocksdb/env.h"
#include "rocksdb/rate_limiter.h"
#include "rocksdb/statistics.h"
#include "rocksdb/transaction_log.h"
#include "table/sst_file_dumper.h"
#include "test_util/sync_point.h"
#include "util/cast_util.h"
#include "util/channel.h"
#include "util/coding.h"
#include "util/crc32c.h"
#include "util/math.h"
#include "util/rate_limiter.h"
#include "util/string_util.h"
#include "utilities/backup/backup_engine_impl.h"
#include "utilities/checkpoint/checkpoint_impl.h"
namespace ROCKSDB_NAMESPACE {
namespace {
using ShareFilesNaming = BackupEngineOptions::ShareFilesNaming;
constexpr BackupID kLatestBackupIDMarker = static_cast<BackupID>(-2);
inline uint32_t ChecksumHexToInt32(const std::string& checksum_hex) {
std::string checksum_str;
Slice(checksum_hex).DecodeHex(&checksum_str);
return EndianSwapValue(DecodeFixed32(checksum_str.c_str()));
}
inline std::string ChecksumStrToHex(const std::string& checksum_str) {
return Slice(checksum_str).ToString(true);
}
inline std::string ChecksumInt32ToHex(const uint32_t& checksum_value) {
std::string checksum_str;
PutFixed32(&checksum_str, EndianSwapValue(checksum_value));
return ChecksumStrToHex(checksum_str);
}
const std::string kPrivateDirName = "private";
const std::string kMetaDirName = "meta";
const std::string kSharedDirName = "shared";
const std::string kSharedChecksumDirName = "shared_checksum";
const std::string kPrivateDirSlash = kPrivateDirName + "/";
const std::string kMetaDirSlash = kMetaDirName + "/";
const std::string kSharedDirSlash = kSharedDirName + "/";
const std::string kSharedChecksumDirSlash = kSharedChecksumDirName + "/";
} // namespace
void BackupStatistics::IncrementNumberSuccessBackup() {
number_success_backup++;
}
void BackupStatistics::IncrementNumberFailBackup() { number_fail_backup++; }
uint32_t BackupStatistics::GetNumberSuccessBackup() const {
return number_success_backup;
}
uint32_t BackupStatistics::GetNumberFailBackup() const {
return number_fail_backup;
}
std::string BackupStatistics::ToString() const {
char result[50];
snprintf(result, sizeof(result), "# success backup: %u, # fail backup: %u",
GetNumberSuccessBackup(), GetNumberFailBackup());
return result;
}
void BackupEngineOptions::Dump(Logger* logger) const {
ROCKS_LOG_INFO(logger, " Options.backup_dir: %s",
backup_dir.c_str());
ROCKS_LOG_INFO(logger, " Options.backup_env: %p", backup_env);
ROCKS_LOG_INFO(logger, " Options.share_table_files: %d",
static_cast<int>(share_table_files));
ROCKS_LOG_INFO(logger, " Options.info_log: %p", info_log);
ROCKS_LOG_INFO(logger, " Options.sync: %d",
static_cast<int>(sync));
ROCKS_LOG_INFO(logger, " Options.destroy_old_data: %d",
static_cast<int>(destroy_old_data));
ROCKS_LOG_INFO(logger, " Options.backup_log_files: %d",
static_cast<int>(backup_log_files));
ROCKS_LOG_INFO(logger, " Options.backup_rate_limit: %" PRIu64,
backup_rate_limit);
ROCKS_LOG_INFO(logger, " Options.restore_rate_limit: %" PRIu64,
restore_rate_limit);
ROCKS_LOG_INFO(logger, "Options.max_background_operations: %d",
max_background_operations);
}
namespace {
// -------- BackupEngineImpl class ---------
class BackupEngineImpl {
public:
BackupEngineImpl(const BackupEngineOptions& options, Env* db_env,
bool read_only = false);
~BackupEngineImpl();
IOStatus CreateNewBackupWithMetadata(const CreateBackupOptions& options,
DB* db, const std::string& app_metadata,
BackupID* new_backup_id_ptr);
IOStatus PurgeOldBackups(uint32_t num_backups_to_keep);
IOStatus DeleteBackup(BackupID backup_id);
void StopBackup() { stop_backup_.store(true, std::memory_order_release); }
IOStatus GarbageCollect();
// The returned BackupInfos are in chronological order, which means the
// latest backup comes last.
void GetBackupInfo(std::vector<BackupInfo>* backup_info,
bool include_file_details) const;
Status GetBackupInfo(BackupID backup_id, BackupInfo* backup_info,
bool include_file_details = false) const;
void GetCorruptedBackups(std::vector<BackupID>* corrupt_backup_ids) const;
IOStatus RestoreDBFromBackup(
const RestoreOptions& options, BackupID backup_id,
const std::string& db_dir, const std::string& wal_dir,
const std::list<const BackupEngineImpl*>& locked_restore_from_dirs) const;
IOStatus VerifyBackup(BackupID backup_id,
bool verify_with_checksum = false) const;
IOStatus Initialize();
ShareFilesNaming GetNamingNoFlags() const {
return options_.share_files_with_checksum_naming &
BackupEngineOptions::kMaskNoNamingFlags;
}
ShareFilesNaming GetNamingFlags() const {
return options_.share_files_with_checksum_naming &
BackupEngineOptions::kMaskNamingFlags;
}
void TEST_SetDefaultRateLimitersClock(
const std::shared_ptr<SystemClock>& backup_rate_limiter_clock,
const std::shared_ptr<SystemClock>& restore_rate_limiter_clock) {
if (backup_rate_limiter_clock) {
static_cast<GenericRateLimiter*>(options_.backup_rate_limiter.get())
->TEST_SetClock(backup_rate_limiter_clock);
}
if (restore_rate_limiter_clock) {
static_cast<GenericRateLimiter*>(options_.restore_rate_limiter.get())
->TEST_SetClock(restore_rate_limiter_clock);
}
}
private:
void DeleteChildren(const std::string& dir,
uint32_t file_type_filter = 0) const;
IOStatus DeleteBackupNoGC(BackupID backup_id);
// Extends the "result" map with pathname->size mappings for the contents of
// "dir" in "env". Pathnames are prefixed with "dir".
IOStatus ReadChildFileCurrentSizes(
const std::string& dir, const std::shared_ptr<FileSystem>&,
std::unordered_map<std::string, uint64_t>* result) const;
struct FileInfo {
FileInfo(const std::string& fname, uint64_t sz, const std::string& checksum,
const std::string& id, const std::string& sid, Temperature _temp)
: refs(0),
filename(fname),
size(sz),
checksum_hex(checksum),
db_id(id),
db_session_id(sid),
temp(_temp) {}
FileInfo(const FileInfo&) = delete;
FileInfo& operator=(const FileInfo&) = delete;
int refs;
// Relative path from backup dir
const std::string filename;
const uint64_t size;
// crc32c checksum as hex. empty == unknown / unavailable
std::string checksum_hex;
// DB identities
// db_id is obtained for potential usage in the future but not used
// currently
const std::string db_id;
// db_session_id appears in the backup SST filename if the table naming
// option is kUseDbSessionId
const std::string db_session_id;
Temperature temp;
std::string GetDbFileName() const {
std::string rv;
// extract the filename part
size_t slash = filename.find_last_of('/');
// file will either be shared/<file>, shared_checksum/<file_crc32c_size>,
// shared_checksum/<file_session>, shared_checksum/<file_crc32c_session>,
// or private/<number>/<file>
assert(slash != std::string::npos);
rv = filename.substr(slash + 1);
// if the file was in shared_checksum, extract the real file name
// in this case the file is <number>_<checksum>_<size>.<type>,
// <number>_<session>.<type>, or <number>_<checksum>_<session>.<type>
if (filename.substr(0, slash) == kSharedChecksumDirName) {
rv = GetFileFromChecksumFile(rv);
}
return rv;
}
};
// TODO: deprecate this function once we migrate all BackupEngine's rate
// limiting to lower-level ones (i.e, ones in file access wrapper level like
// `WritableFileWriter`)
static void LoopRateLimitRequestHelper(const size_t total_bytes_to_request,
RateLimiter* rate_limiter,
const Env::IOPriority pri,
Statistics* stats,
const RateLimiter::OpType op_type);
static inline std::string WithoutTrailingSlash(const std::string& path) {
if (path.empty() || path.back() != '/') {
return path;
} else {
return path.substr(path.size() - 1);
}
}
static inline std::string WithTrailingSlash(const std::string& path) {
if (path.empty() || path.back() != '/') {
return path + '/';
} else {
return path;
}
}
// A filesystem wrapper that makes shared backup files appear to be in the
// private backup directory (dst_dir), so that the private backup dir can
// be opened as a read-only DB.
class RemapSharedFileSystem : public RemapFileSystem {
public:
RemapSharedFileSystem(const std::shared_ptr<FileSystem>& base,
const std::string& dst_dir,
const std::string& src_base_dir,
const std::vector<std::shared_ptr<FileInfo>>& files)
: RemapFileSystem(base),
dst_dir_(WithoutTrailingSlash(dst_dir)),
dst_dir_slash_(WithTrailingSlash(dst_dir)),
src_base_dir_(WithTrailingSlash(src_base_dir)) {
for (auto& info : files) {
if (!StartsWith(info->filename, kPrivateDirSlash)) {
assert(StartsWith(info->filename, kSharedDirSlash) ||
StartsWith(info->filename, kSharedChecksumDirSlash));
remaps_[info->GetDbFileName()] = info;
}
}
}
const char* Name() const override {
return "BackupEngineImpl::RemapSharedFileSystem";
}
// Sometimes a directory listing is required in opening a DB
IOStatus GetChildren(const std::string& dir, const IOOptions& options,
std::vector<std::string>* result,
IODebugContext* dbg) override {
IOStatus s = RemapFileSystem::GetChildren(dir, options, result, dbg);
if (s.ok() && (dir == dst_dir_ || dir == dst_dir_slash_)) {
// Assume remapped files exist
for (auto& r : remaps_) {
result->push_back(r.first);
}
}
return s;
}
// Sometimes a directory listing is required in opening a DB
IOStatus GetChildrenFileAttributes(const std::string& dir,
const IOOptions& options,
std::vector<FileAttributes>* result,
IODebugContext* dbg) override {
IOStatus s =
RemapFileSystem::GetChildrenFileAttributes(dir, options, result, dbg);
if (s.ok() && (dir == dst_dir_ || dir == dst_dir_slash_)) {
// Assume remapped files exist with recorded size
for (auto& r : remaps_) {
result->emplace_back(); // clean up with C++20
FileAttributes& attr = result->back();
attr.name = r.first;
attr.size_bytes = r.second->size;
}
}
return s;
}
protected:
// When a file in dst_dir is requested, see if we need to remap to shared
// file path.
std::pair<IOStatus, std::string> EncodePath(
const std::string& path) override {
if (path.empty() || path[0] != '/') {
return {IOStatus::InvalidArgument(path, "Not an absolute path"), ""};
}
std::pair<IOStatus, std::string> rv{IOStatus(), path};
if (StartsWith(path, dst_dir_slash_)) {
std::string relative = path.substr(dst_dir_slash_.size());
auto it = remaps_.find(relative);
if (it != remaps_.end()) {
rv.second = src_base_dir_ + it->second->filename;
}
}
return rv;
}
private:
// Absolute path to a directory that some extra files will be mapped into.
const std::string dst_dir_;
// Includes a trailing slash.
const std::string dst_dir_slash_;
// Absolute path to a directory containing some files to be mapped into
// dst_dir_. Includes a trailing slash.
const std::string src_base_dir_;
// If remaps_[x] exists, attempt to read dst_dir_ / x should instead read
// src_base_dir_ / remaps_[x]->filename. FileInfo is used to maximize
// sharing with other backup data in memory.
std::unordered_map<std::string, std::shared_ptr<FileInfo>> remaps_;
};
class BackupMeta {
public:
BackupMeta(
const std::string& meta_filename, const std::string& meta_tmp_filename,
std::unordered_map<std::string, std::shared_ptr<FileInfo>>* file_infos,
Env* env, const std::shared_ptr<FileSystem>& fs)
: timestamp_(0),
sequence_number_(0),
size_(0),
meta_filename_(meta_filename),
meta_tmp_filename_(meta_tmp_filename),
file_infos_(file_infos),
env_(env),
fs_(fs) {}
BackupMeta(const BackupMeta&) = delete;
BackupMeta& operator=(const BackupMeta&) = delete;
~BackupMeta() {}
void RecordTimestamp() {
// Best effort
Status s = env_->GetCurrentTime(&timestamp_);
if (!s.ok()) {
timestamp_ = /* something clearly fabricated */ 1;
}
}
int64_t GetTimestamp() const { return timestamp_; }
uint64_t GetSize() const { return size_; }
uint32_t GetNumberFiles() const {
return static_cast<uint32_t>(files_.size());
}
void SetSequenceNumber(uint64_t sequence_number) {
sequence_number_ = sequence_number;
}
uint64_t GetSequenceNumber() const { return sequence_number_; }
const std::string& GetAppMetadata() const { return app_metadata_; }
void SetAppMetadata(const std::string& app_metadata) {
app_metadata_ = app_metadata;
}
IOStatus AddFile(std::shared_ptr<FileInfo> file_info);
void AddExcludedFile(const std::string& relative_file) {
excluded_files_.emplace_back(relative_file);
}
IOStatus Delete(bool delete_meta = true);
bool Empty() const { return files_.empty(); }
std::shared_ptr<FileInfo> GetFile(const std::string& filename) const {
auto it = file_infos_->find(filename);
if (it == file_infos_->end()) {
return nullptr;
}
return it->second;
}
const std::vector<std::shared_ptr<FileInfo>>& GetFiles() const {
return files_;
}
const std::vector<BackupExcludedFileInfo>& GetExcludedFiles() const {
return excluded_files_;
}
// @param abs_path_to_size Pre-fetched file sizes (bytes).
IOStatus LoadFromFile(
const std::string& backup_dir,
const std::unordered_map<std::string, uint64_t>& abs_path_to_size,
RateLimiter* rate_limiter, Logger* info_log,
std::unordered_set<std::string>* reported_ignored_fields);
IOStatus StoreToFile(
bool sync, int schema_version,
const TEST_BackupMetaSchemaOptions* schema_test_options);
std::string GetInfoString() {
std::ostringstream ss;
ss << "Timestamp: " << timestamp_ << std::endl;
char human_size[16];
AppendHumanBytes(size_, human_size, sizeof(human_size));
ss << "Size: " << human_size << std::endl;
ss << "Files:" << std::endl;
for (const auto& file : files_) {
AppendHumanBytes(file->size, human_size, sizeof(human_size));
ss << file->filename << ", size " << human_size << ", refs "
<< file->refs << std::endl;
}
return ss.str();
}
const std::shared_ptr<Env>& GetEnvForOpen() const {
if (!env_for_open_) {
// Lazy initialize
// Find directories
std::string dst_dir = meta_filename_;
auto i = dst_dir.rfind(kMetaDirSlash);
assert(i != std::string::npos);
std::string src_base_dir = dst_dir.substr(0, i);
dst_dir.replace(i, kMetaDirSlash.size(), kPrivateDirSlash);
// Make the RemapSharedFileSystem
std::shared_ptr<FileSystem> remap_fs =
std::make_shared<RemapSharedFileSystem>(fs_, dst_dir, src_base_dir,
files_);
// Make it read-only for safety
remap_fs = std::make_shared<ReadOnlyFileSystem>(remap_fs);
// Make an Env wrapper
env_for_open_ = std::make_shared<CompositeEnvWrapper>(env_, remap_fs);
}
return env_for_open_;
}
private:
int64_t timestamp_;
// sequence number is only approximate, should not be used
// by clients
uint64_t sequence_number_;
uint64_t size_;
std::string app_metadata_;
std::string const meta_filename_;
std::string const meta_tmp_filename_;
// files with relative paths (without "/" prefix!!)
std::vector<std::shared_ptr<FileInfo>> files_;
std::vector<BackupExcludedFileInfo> excluded_files_;
std::unordered_map<std::string, std::shared_ptr<FileInfo>>* file_infos_;
Env* env_;
mutable std::shared_ptr<Env> env_for_open_;
std::shared_ptr<FileSystem> fs_;
IOOptions iooptions_ = IOOptions();
}; // BackupMeta
void SetBackupInfoFromBackupMeta(BackupID id, const BackupMeta& meta,
BackupInfo* backup_info,
bool include_file_details) const;
inline std::string GetAbsolutePath(
const std::string& relative_path = "") const {
assert(relative_path.size() == 0 || relative_path[0] != '/');
return options_.backup_dir + "/" + relative_path;
}
inline std::string GetPrivateFileRel(BackupID backup_id, bool tmp = false,
const std::string& file = "") const {
assert(file.size() == 0 || file[0] != '/');
return kPrivateDirSlash + std::to_string(backup_id) + (tmp ? ".tmp" : "") +
"/" + file;
}
inline std::string GetSharedFileRel(const std::string& file = "",
bool tmp = false) const {
assert(file.size() == 0 || file[0] != '/');
return kSharedDirSlash + std::string(tmp ? "." : "") + file +
(tmp ? ".tmp" : "");
}
inline std::string GetSharedFileWithChecksumRel(const std::string& file = "",
bool tmp = false) const {
assert(file.size() == 0 || file[0] != '/');
return kSharedChecksumDirSlash + std::string(tmp ? "." : "") + file +
(tmp ? ".tmp" : "");
}
inline bool UseLegacyNaming(const std::string& sid) const {
return GetNamingNoFlags() ==
BackupEngineOptions::kLegacyCrc32cAndFileSize ||
sid.empty();
}
inline std::string GetSharedFileWithChecksum(
const std::string& file, const std::string& checksum_hex,
const uint64_t file_size, const std::string& db_session_id) const {
assert(file.size() == 0 || file[0] != '/');
std::string file_copy = file;
if (UseLegacyNaming(db_session_id)) {
assert(!checksum_hex.empty());
file_copy.insert(file_copy.find_last_of('.'),
"_" + std::to_string(ChecksumHexToInt32(checksum_hex)) +
"_" + std::to_string(file_size));
} else {
file_copy.insert(file_copy.find_last_of('.'), "_s" + db_session_id);
if (GetNamingFlags() & BackupEngineOptions::kFlagIncludeFileSize) {
file_copy.insert(file_copy.find_last_of('.'),
"_" + std::to_string(file_size));
}
}
return file_copy;
}
static inline std::string GetFileFromChecksumFile(const std::string& file) {
assert(file.size() == 0 || file[0] != '/');
std::string file_copy = file;
size_t first_underscore = file_copy.find_first_of('_');
return file_copy.erase(first_underscore,
file_copy.find_last_of('.') - first_underscore);
}
inline std::string GetBackupMetaFile(BackupID backup_id, bool tmp) const {
return GetAbsolutePath(kMetaDirName) + "/" + (tmp ? "." : "") +
std::to_string(backup_id) + (tmp ? ".tmp" : "");
}
// If size_limit == 0, there is no size limit, copy everything.
//
// Exactly one of src and contents must be non-empty.
//
// @param src If non-empty, the file is copied from this pathname.
// @param contents If non-empty, the file will be created with these contents.
// @param src_temperature Pass in expected temperature of src, return back
// temperature reported by FileSystem
IOStatus CopyOrCreateFile(const std::string& src, const std::string& dst,
const std::string& contents, uint64_t size_limit,
Env* src_env, Env* dst_env,
const EnvOptions& src_env_options, bool sync,
RateLimiter* rate_limiter,
std::function<void()> progress_callback,
Temperature* src_temperature,
Temperature dst_temperature,
uint64_t* bytes_toward_next_callback,
uint64_t* size, std::string* checksum_hex);
IOStatus ReadFileAndComputeChecksum(const std::string& src,
const std::shared_ptr<FileSystem>& src_fs,
const EnvOptions& src_env_options,
uint64_t size_limit,
std::string* checksum_hex,
const Temperature src_temperature) const;
// Obtain db_id and db_session_id from the table properties of file_path
Status GetFileDbIdentities(Env* src_env, const EnvOptions& src_env_options,
const std::string& file_path,
Temperature file_temp, RateLimiter* rate_limiter,
std::string* db_id, std::string* db_session_id);
struct CopyOrCreateResult {
~CopyOrCreateResult() {
// The Status needs to be ignored here for two reasons.
// First, if the BackupEngineImpl shuts down with jobs outstanding, then
// it is possible that the Status in the future/promise is never read,
// resulting in an unchecked Status. Second, if there are items in the
// channel when the BackupEngineImpl is shutdown, these will also have
// Status that have not been checked. This
// TODO: Fix those issues so that the Status
io_status.PermitUncheckedError();
}
uint64_t size;
std::string checksum_hex;
std::string db_id;
std::string db_session_id;
IOStatus io_status;
Temperature expected_src_temperature = Temperature::kUnknown;
Temperature current_src_temperature = Temperature::kUnknown;
};
// Exactly one of src_path and contents must be non-empty. If src_path is
// non-empty, the file is copied from this pathname. Otherwise, if contents is
// non-empty, the file will be created at dst_path with these contents.
struct CopyOrCreateWorkItem {
std::string src_path;
std::string dst_path;
Temperature src_temperature;
Temperature dst_temperature;
std::string contents;
Env* src_env;
Env* dst_env;
EnvOptions src_env_options;
bool sync;
RateLimiter* rate_limiter;
uint64_t size_limit;
Statistics* stats;
std::promise<CopyOrCreateResult> result;
std::function<void()> progress_callback;
std::string src_checksum_func_name;
std::string src_checksum_hex;
std::string db_id;
std::string db_session_id;
CopyOrCreateWorkItem()
: src_path(""),
dst_path(""),
src_temperature(Temperature::kUnknown),
dst_temperature(Temperature::kUnknown),
contents(""),
src_env(nullptr),
dst_env(nullptr),
src_env_options(),
sync(false),
rate_limiter(nullptr),
size_limit(0),
stats(nullptr),
src_checksum_func_name(kUnknownFileChecksumFuncName),
src_checksum_hex(""),
db_id(""),
db_session_id("") {}
CopyOrCreateWorkItem(const CopyOrCreateWorkItem&) = delete;
CopyOrCreateWorkItem& operator=(const CopyOrCreateWorkItem&) = delete;
CopyOrCreateWorkItem(CopyOrCreateWorkItem&& o) noexcept {
*this = std::move(o);
}
CopyOrCreateWorkItem& operator=(CopyOrCreateWorkItem&& o) noexcept {
src_path = std::move(o.src_path);
dst_path = std::move(o.dst_path);
src_temperature = std::move(o.src_temperature);
dst_temperature = std::move(o.dst_temperature);
contents = std::move(o.contents);
src_env = o.src_env;
dst_env = o.dst_env;
src_env_options = std::move(o.src_env_options);
sync = o.sync;
rate_limiter = o.rate_limiter;
size_limit = o.size_limit;
stats = o.stats;
result = std::move(o.result);
progress_callback = std::move(o.progress_callback);
src_checksum_func_name = std::move(o.src_checksum_func_name);
src_checksum_hex = std::move(o.src_checksum_hex);
db_id = std::move(o.db_id);
db_session_id = std::move(o.db_session_id);
src_temperature = o.src_temperature;
return *this;
}
CopyOrCreateWorkItem(std::string _src_path, std::string _dst_path,
const Temperature _src_temperature,
const Temperature _dst_temperature,
std::string _contents, Env* _src_env, Env* _dst_env,
EnvOptions _src_env_options, bool _sync,
RateLimiter* _rate_limiter, uint64_t _size_limit,
Statistics* _stats,
std::function<void()> _progress_callback = {},
const std::string& _src_checksum_func_name =
kUnknownFileChecksumFuncName,
const std::string& _src_checksum_hex = "",
const std::string& _db_id = "",
const std::string& _db_session_id = "")
: src_path(std::move(_src_path)),
dst_path(std::move(_dst_path)),
src_temperature(_src_temperature),
dst_temperature(_dst_temperature),
contents(std::move(_contents)),
src_env(_src_env),
dst_env(_dst_env),
src_env_options(std::move(_src_env_options)),
sync(_sync),
rate_limiter(_rate_limiter),
size_limit(_size_limit),
stats(_stats),
progress_callback(_progress_callback),
src_checksum_func_name(_src_checksum_func_name),
src_checksum_hex(_src_checksum_hex),
db_id(_db_id),
db_session_id(_db_session_id) {}
};
struct BackupAfterCopyOrCreateWorkItem {
std::future<CopyOrCreateResult> result;
bool shared;
bool needed_to_copy;
Env* backup_env;
std::string dst_path_tmp;
std::string dst_path;
std::string dst_relative;
BackupAfterCopyOrCreateWorkItem()
: shared(false),
needed_to_copy(false),
backup_env(nullptr),
dst_path_tmp(""),
dst_path(""),
dst_relative("") {}
BackupAfterCopyOrCreateWorkItem(
BackupAfterCopyOrCreateWorkItem&& o) noexcept {
*this = std::move(o);
}
BackupAfterCopyOrCreateWorkItem& operator=(
BackupAfterCopyOrCreateWorkItem&& o) noexcept {
result = std::move(o.result);
shared = o.shared;
needed_to_copy = o.needed_to_copy;
backup_env = o.backup_env;
dst_path_tmp = std::move(o.dst_path_tmp);
dst_path = std::move(o.dst_path);
dst_relative = std::move(o.dst_relative);
return *this;
}
BackupAfterCopyOrCreateWorkItem(std::future<CopyOrCreateResult>&& _result,
bool _shared, bool _needed_to_copy,
Env* _backup_env, std::string _dst_path_tmp,
std::string _dst_path,
std::string _dst_relative)
: result(std::move(_result)),
shared(_shared),
needed_to_copy(_needed_to_copy),
backup_env(_backup_env),
dst_path_tmp(std::move(_dst_path_tmp)),
dst_path(std::move(_dst_path)),
dst_relative(std::move(_dst_relative)) {}
};
using BackupWorkItemPair =
std::pair<CopyOrCreateWorkItem, BackupAfterCopyOrCreateWorkItem>;
struct RestoreAfterCopyOrCreateWorkItem {
std::future<CopyOrCreateResult> result;
std::string from_file;
std::string to_file;
std::string checksum_hex;
RestoreAfterCopyOrCreateWorkItem() : checksum_hex("") {}
RestoreAfterCopyOrCreateWorkItem(std::future<CopyOrCreateResult>&& _result,
const std::string& _from_file,
const std::string& _to_file,
const std::string& _checksum_hex)
: result(std::move(_result)),
from_file(_from_file),
to_file(_to_file),
checksum_hex(_checksum_hex) {}
RestoreAfterCopyOrCreateWorkItem(
RestoreAfterCopyOrCreateWorkItem&& o) noexcept {
*this = std::move(o);
}
RestoreAfterCopyOrCreateWorkItem& operator=(
RestoreAfterCopyOrCreateWorkItem&& o) noexcept {
result = std::move(o.result);
checksum_hex = std::move(o.checksum_hex);
return *this;
}
};
bool initialized_;
std::mutex byte_report_mutex_;
mutable channel<CopyOrCreateWorkItem> files_to_copy_or_create_;
std::vector<port::Thread> threads_;
std::atomic<CpuPriority> threads_cpu_priority_;
// Certain operations like PurgeOldBackups and DeleteBackup will trigger
// automatic GarbageCollect (true) unless we've already done one in this
// session and have not failed to delete backup files since then (false).
bool might_need_garbage_collect_ = true;
// Adds a file to the backup work queue to be copied or created if it doesn't
// already exist.
//
// Exactly one of src_dir and contents must be non-empty.
//
// @param src_dir If non-empty, the file in this directory named fname will be
// copied.
// @param fname Name of destination file and, in case of copy, source file.
// @param contents If non-empty, the file will be created with these contents.
IOStatus AddBackupFileWorkItem(
std::unordered_set<std::string>& live_dst_paths,
std::deque<BackupAfterCopyOrCreateWorkItem>& backup_items_to_finish,
std::deque<BackupWorkItemPair>* excludable_items, BackupID backup_id,
bool shared, const std::string& src_dir,
const std::string& fname, // starts with "/"
const EnvOptions& src_env_options, RateLimiter* rate_limiter,
FileType file_type, uint64_t size_bytes, Statistics* stats,
uint64_t size_limit = 0, bool shared_checksum = false,
std::function<void()> progress_callback = {},
const std::string& contents = std::string(),
const std::string& src_checksum_func_name = kUnknownFileChecksumFuncName,
const std::string& src_checksum_str = kUnknownFileChecksum,
const Temperature src_temperature = Temperature::kUnknown);
// backup state data
BackupID latest_backup_id_;
BackupID latest_valid_backup_id_;
std::map<BackupID, std::unique_ptr<BackupMeta>> backups_;
std::map<BackupID, std::pair<IOStatus, std::unique_ptr<BackupMeta>>>
corrupt_backups_;
std::unordered_map<std::string, std::shared_ptr<FileInfo>>
backuped_file_infos_;
std::atomic<bool> stop_backup_;
// options data
BackupEngineOptions options_;
Env* db_env_;
Env* backup_env_;
// directories
std::unique_ptr<FSDirectory> backup_directory_;
std::unique_ptr<FSDirectory> shared_directory_;
std::unique_ptr<FSDirectory> meta_directory_;
std::unique_ptr<FSDirectory> private_directory_;
static const size_t kDefaultCopyFileBufferSize = 5 * 1024 * 1024LL; // 5MB
bool read_only_;
BackupStatistics backup_statistics_;
std::unordered_set<std::string> reported_ignored_fields_;
static const size_t kMaxAppMetaSize = 1024 * 1024; // 1MB
std::shared_ptr<FileSystem> db_fs_;
std::shared_ptr<FileSystem> backup_fs_;
IOOptions io_options_ = IOOptions();
public:
std::unique_ptr<TEST_BackupMetaSchemaOptions> schema_test_options_;
};
// -------- BackupEngineImplThreadSafe class ---------
// This locking layer for thread safety in the public API is layered on
// top to prevent accidental recursive locking with RWMutex, which is UB.
// Note: BackupEngineReadOnlyBase inherited twice, but has no fields
class BackupEngineImplThreadSafe : public BackupEngine,
public BackupEngineReadOnly {
public:
BackupEngineImplThreadSafe(const BackupEngineOptions& options, Env* db_env,
bool read_only = false)
: impl_(options, db_env, read_only) {}
~BackupEngineImplThreadSafe() override {}
using BackupEngine::CreateNewBackupWithMetadata;
IOStatus CreateNewBackupWithMetadata(const CreateBackupOptions& options,
DB* db, const std::string& app_metadata,
BackupID* new_backup_id) override {
WriteLock lock(&mutex_);
return impl_.CreateNewBackupWithMetadata(options, db, app_metadata,
new_backup_id);
}
IOStatus PurgeOldBackups(uint32_t num_backups_to_keep) override {
WriteLock lock(&mutex_);
return impl_.PurgeOldBackups(num_backups_to_keep);
}
IOStatus DeleteBackup(BackupID backup_id) override {
WriteLock lock(&mutex_);
return impl_.DeleteBackup(backup_id);
}
void StopBackup() override {
// No locking needed
impl_.StopBackup();
}
IOStatus GarbageCollect() override {
WriteLock lock(&mutex_);
return impl_.GarbageCollect();
}
Status GetLatestBackupInfo(BackupInfo* backup_info,
bool include_file_details = false) const override {
ReadLock lock(&mutex_);
return impl_.GetBackupInfo(kLatestBackupIDMarker, backup_info,
include_file_details);
}
Status GetBackupInfo(BackupID backup_id, BackupInfo* backup_info,
bool include_file_details = false) const override {
ReadLock lock(&mutex_);
return impl_.GetBackupInfo(backup_id, backup_info, include_file_details);
}
void GetBackupInfo(std::vector<BackupInfo>* backup_info,
bool include_file_details) const override {
ReadLock lock(&mutex_);
impl_.GetBackupInfo(backup_info, include_file_details);
}
void GetCorruptedBackups(
std::vector<BackupID>* corrupt_backup_ids) const override {
ReadLock lock(&mutex_);
impl_.GetCorruptedBackups(corrupt_backup_ids);
}
using BackupEngine::RestoreDBFromBackup;
IOStatus RestoreDBFromBackup(const RestoreOptions& options,
BackupID backup_id, const std::string& db_dir,
const std::string& wal_dir) const override {
// TSAN reports a lock inversion (potential deadlock) if we acquire read
// locks in different orders. Assuming the implementation of RWMutex
// allows simultaneous read locks, there should be no deadlock, because
// there is no write lock involved here. Nevertheless, to appease TSAN and
// in case of degraded RWMutex implementation, we lock the BackupEngines
// including this one and those in options.alternate_dirs in a consistent
// order.
// However, locked_restore_from_dirs is kept in "search" order.
std::list<const BackupEngineImpl*> locked_restore_from_dirs;
std::vector<port::RWMutex*> mutexes;
// Add `this`
locked_restore_from_dirs.emplace_back(&impl_);
mutexes.push_back(&mutex_);
// Add alternates
for (BackupEngineReadOnlyBase* be : options.alternate_dirs) {
BackupEngineImplThreadSafe* bets =
static_cast_with_check<BackupEngineImplThreadSafe>(
be->AsBackupEngine());
locked_restore_from_dirs.emplace_back(&bets->impl_);
mutexes.push_back(&bets->mutex_);
}
// Acquire read locks in pointer order
std::sort(mutexes.begin(), mutexes.end());
std::vector<ReadLock> locks(mutexes.begin(), mutexes.end());
// Impl
return impl_.RestoreDBFromBackup(options, backup_id, db_dir, wal_dir,
locked_restore_from_dirs);
}
using BackupEngine::RestoreDBFromLatestBackup;
IOStatus RestoreDBFromLatestBackup(
const RestoreOptions& options, const std::string& db_dir,
const std::string& wal_dir) const override {
// Defer to above function, which locks
return RestoreDBFromBackup(options, kLatestBackupIDMarker, db_dir, wal_dir);
}
IOStatus VerifyBackup(BackupID backup_id,
bool verify_with_checksum = false) const override {
ReadLock lock(&mutex_);
return impl_.VerifyBackup(backup_id, verify_with_checksum);
}
BackupEngine* AsBackupEngine() override { return this; }
// Not public API but needed
IOStatus Initialize() {
// No locking needed
return impl_.Initialize();
}
// Not public API but used in testing
void TEST_SetBackupMetaSchemaOptions(
const TEST_BackupMetaSchemaOptions& options) {
impl_.schema_test_options_.reset(new TEST_BackupMetaSchemaOptions(options));
}
// Not public API but used in testing
void TEST_SetDefaultRateLimitersClock(
const std::shared_ptr<SystemClock>& backup_rate_limiter_clock = nullptr,
const std::shared_ptr<SystemClock>& restore_rate_limiter_clock =
nullptr) {
impl_.TEST_SetDefaultRateLimitersClock(backup_rate_limiter_clock,
restore_rate_limiter_clock);
}
private:
mutable port::RWMutex mutex_;
BackupEngineImpl impl_;
};
} // namespace
IOStatus BackupEngine::Open(const BackupEngineOptions& options, Env* env,
BackupEngine** backup_engine_ptr) {
std::unique_ptr<BackupEngineImplThreadSafe> backup_engine(
new BackupEngineImplThreadSafe(options, env));
auto s = backup_engine->Initialize();
if (!s.ok()) {
*backup_engine_ptr = nullptr;
return s;
}
*backup_engine_ptr = backup_engine.release();
return IOStatus::OK();
}
namespace {
BackupEngineImpl::BackupEngineImpl(const BackupEngineOptions& options,
Env* db_env, bool read_only)
: initialized_(false),
threads_cpu_priority_(),
latest_backup_id_(0),
latest_valid_backup_id_(0),
stop_backup_(false),
options_(options),
db_env_(db_env),
backup_env_(options.backup_env != nullptr ? options.backup_env : db_env_),
read_only_(read_only) {
if (options_.backup_rate_limiter == nullptr &&
options_.backup_rate_limit > 0) {
options_.backup_rate_limiter.reset(
NewGenericRateLimiter(options_.backup_rate_limit));
}
if (options_.restore_rate_limiter == nullptr &&
options_.restore_rate_limit > 0) {
options_.restore_rate_limiter.reset(
NewGenericRateLimiter(options_.restore_rate_limit));
}
db_fs_ = db_env_->GetFileSystem();
backup_fs_ = backup_env_->GetFileSystem();
}
BackupEngineImpl::~BackupEngineImpl() {
files_to_copy_or_create_.sendEof();
for (auto& t : threads_) {
t.join();
}
LogFlush(options_.info_log);
for (const auto& it : corrupt_backups_) {
it.second.first.PermitUncheckedError();
}
}
IOStatus BackupEngineImpl::Initialize() {
assert(!initialized_);
initialized_ = true;
if (read_only_) {
ROCKS_LOG_INFO(options_.info_log, "Starting read_only backup engine");
}
options_.Dump(options_.info_log);
auto meta_path = GetAbsolutePath(kMetaDirName);
if (!read_only_) {
// we might need to clean up from previous crash or I/O errors
might_need_garbage_collect_ = true;
if (options_.max_valid_backups_to_open !=
std::numeric_limits<int32_t>::max()) {
options_.max_valid_backups_to_open = std::numeric_limits<int32_t>::max();
ROCKS_LOG_WARN(
options_.info_log,
"`max_valid_backups_to_open` is not set to the default value. "
"Ignoring its value since BackupEngine is not read-only.");
}
// gather the list of directories that we need to create
std::vector<std::pair<std::string, std::unique_ptr<FSDirectory>*>>
directories;
directories.emplace_back(GetAbsolutePath(), &backup_directory_);
if (options_.share_table_files) {
if (options_.share_files_with_checksum) {
directories.emplace_back(
GetAbsolutePath(GetSharedFileWithChecksumRel()),
&shared_directory_);
} else {
directories.emplace_back(GetAbsolutePath(GetSharedFileRel()),
&shared_directory_);
}
}
directories.emplace_back(GetAbsolutePath(kPrivateDirName),
&private_directory_);
directories.emplace_back(meta_path, &meta_directory_);
// create all the dirs we need
for (const auto& d : directories) {
IOStatus io_s =
backup_fs_->CreateDirIfMissing(d.first, io_options_, nullptr);
if (io_s.ok()) {
io_s =
backup_fs_->NewDirectory(d.first, io_options_, d.second, nullptr);
}
if (!io_s.ok()) {
return io_s;
}
}
}
std::vector<std::string> backup_meta_files;
{
IOStatus io_s = backup_fs_->GetChildren(meta_path, io_options_,
&backup_meta_files, nullptr);
if (io_s.IsNotFound()) {
return IOStatus::NotFound(meta_path + " is missing");
} else if (!io_s.ok()) {
return io_s;
}
}
// create backups_ structure
for (auto& file : backup_meta_files) {
ROCKS_LOG_INFO(options_.info_log, "Detected backup %s", file.c_str());
BackupID backup_id = 0;
sscanf(file.c_str(), "%u", &backup_id);
if (backup_id == 0 || file != std::to_string(backup_id)) {
// Invalid file name, will be deleted with auto-GC when user
// initiates an append or write operation. (Behave as read-only until
// then.)
ROCKS_LOG_INFO(options_.info_log, "Skipping unrecognized meta file %s",
file.c_str());
continue;
}
assert(backups_.find(backup_id) == backups_.end());
// Insert all the (backup_id, BackupMeta) that will be loaded later
// The loading performed later will check whether there are corrupt backups
// and move the corrupt backups to corrupt_backups_
backups_.insert(std::make_pair(
backup_id, std::unique_ptr<BackupMeta>(new BackupMeta(
GetBackupMetaFile(backup_id, false /* tmp */),
GetBackupMetaFile(backup_id, true /* tmp */),
&backuped_file_infos_, backup_env_, backup_fs_))));
}
latest_backup_id_ = 0;
latest_valid_backup_id_ = 0;
if (options_.destroy_old_data) { // Destroy old data
assert(!read_only_);
ROCKS_LOG_INFO(
options_.info_log,
"Backup Engine started with destroy_old_data == true, deleting all "
"backups");
IOStatus io_s = PurgeOldBackups(0);
if (io_s.ok()) {
io_s = GarbageCollect();
}
if (!io_s.ok()) {
return io_s;
}
} else { // Load data from storage
// abs_path_to_size: maps absolute paths of files in backup directory to
// their corresponding sizes
std::unordered_map<std::string, uint64_t> abs_path_to_size;
// Insert files and their sizes in backup sub-directories (shared and
// shared_checksum) to abs_path_to_size
for (const auto& rel_dir :
{GetSharedFileRel(), GetSharedFileWithChecksumRel()}) {
const auto abs_dir = GetAbsolutePath(rel_dir);
IOStatus io_s =
ReadChildFileCurrentSizes(abs_dir, backup_fs_, &abs_path_to_size);
if (!io_s.ok()) {
// I/O error likely impacting all backups
return io_s;
}
}
// load the backups if any, until valid_backups_to_open of the latest
// non-corrupted backups have been successfully opened.
int valid_backups_to_open = options_.max_valid_backups_to_open;
for (auto backup_iter = backups_.rbegin(); backup_iter != backups_.rend();
++backup_iter) {
assert(latest_backup_id_ == 0 || latest_backup_id_ > backup_iter->first);
if (latest_backup_id_ == 0) {
latest_backup_id_ = backup_iter->first;
}
if (valid_backups_to_open == 0) {
break;
}
// Insert files and their sizes in backup sub-directories
// (private/backup_id) to abs_path_to_size
IOStatus io_s = ReadChildFileCurrentSizes(
GetAbsolutePath(GetPrivateFileRel(backup_iter->first)), backup_fs_,
&abs_path_to_size);
if (io_s.ok()) {
io_s = backup_iter->second->LoadFromFile(
options_.backup_dir, abs_path_to_size,
options_.backup_rate_limiter.get(), options_.info_log,
&reported_ignored_fields_);
}
if (io_s.IsCorruption() || io_s.IsNotSupported()) {
ROCKS_LOG_INFO(options_.info_log, "Backup %u corrupted -- %s",
backup_iter->first, io_s.ToString().c_str());
corrupt_backups_.insert(std::make_pair(
backup_iter->first,
std::make_pair(io_s, std::move(backup_iter->second))));
} else if (!io_s.ok()) {
// Distinguish corruption errors from errors in the backup Env.
// Errors in the backup Env (i.e., this code path) will cause Open() to
// fail, whereas corruption errors would not cause Open() failures.
return io_s;
} else {
ROCKS_LOG_INFO(options_.info_log, "Loading backup %" PRIu32 " OK:\n%s",
backup_iter->first,
backup_iter->second->GetInfoString().c_str());
assert(latest_valid_backup_id_ == 0 ||
latest_valid_backup_id_ > backup_iter->first);
if (latest_valid_backup_id_ == 0) {
latest_valid_backup_id_ = backup_iter->first;
}
--valid_backups_to_open;
}
}
for (const auto& corrupt : corrupt_backups_) {
backups_.erase(backups_.find(corrupt.first));
}
// erase the backups before max_valid_backups_to_open
int num_unopened_backups;
if (options_.max_valid_backups_to_open == 0) {
num_unopened_backups = 0;
} else {
num_unopened_backups =
std::max(0, static_cast<int>(backups_.size()) -
options_.max_valid_backups_to_open);
}
for (int i = 0; i < num_unopened_backups; ++i) {
assert(backups_.begin()->second->Empty());
backups_.erase(backups_.begin());
}
}
ROCKS_LOG_INFO(options_.info_log, "Latest backup is %u", latest_backup_id_);
ROCKS_LOG_INFO(options_.info_log, "Latest valid backup is %u",
latest_valid_backup_id_);
// set up threads perform copies from files_to_copy_or_create_ in the
// background
threads_cpu_priority_ = CpuPriority::kNormal;
threads_.reserve(options_.max_background_operations);
for (int t = 0; t < options_.max_background_operations; t++) {
threads_.emplace_back([this]() {
#if defined(_GNU_SOURCE) && defined(__GLIBC_PREREQ)
#if __GLIBC_PREREQ(2, 12)
pthread_setname_np(pthread_self(), "backup_engine");
#endif
#endif
CpuPriority current_priority = CpuPriority::kNormal;
CopyOrCreateWorkItem work_item;
uint64_t bytes_toward_next_callback = 0;
while (files_to_copy_or_create_.read(work_item)) {
CpuPriority priority = threads_cpu_priority_;
if (current_priority != priority) {
TEST_SYNC_POINT_CALLBACK(
"BackupEngineImpl::Initialize:SetCpuPriority", &priority);
port::SetCpuPriority(0, priority);
current_priority = priority;
}
// `bytes_read` and `bytes_written` stats are enabled based on
// compile-time support and cannot be dynamically toggled. So we do not
// need to worry about `PerfLevel` here, unlike many other
// `IOStatsContext` / `PerfContext` stats.
uint64_t prev_bytes_read = IOSTATS(bytes_read);
uint64_t prev_bytes_written = IOSTATS(bytes_written);
CopyOrCreateResult result;
Temperature temp = work_item.src_temperature;
result.io_status = CopyOrCreateFile(
work_item.src_path, work_item.dst_path, work_item.contents,
work_item.size_limit, work_item.src_env, work_item.dst_env,
work_item.src_env_options, work_item.sync, work_item.rate_limiter,
work_item.progress_callback, &temp, work_item.dst_temperature,
&bytes_toward_next_callback, &result.size, &result.checksum_hex);
RecordTick(work_item.stats, BACKUP_READ_BYTES,
IOSTATS(bytes_read) - prev_bytes_read);
RecordTick(work_item.stats, BACKUP_WRITE_BYTES,
IOSTATS(bytes_written) - prev_bytes_written);
result.db_id = work_item.db_id;
result.db_session_id = work_item.db_session_id;
result.expected_src_temperature = work_item.src_temperature;
result.current_src_temperature = temp;
if (result.io_status.ok() && !work_item.src_checksum_hex.empty()) {
// unknown checksum function name implies no db table file checksum in
// db manifest; work_item.src_checksum_hex not empty means
// backup engine has calculated its crc32c checksum for the table
// file; therefore, we are able to compare the checksums.
if (work_item.src_checksum_func_name ==
kUnknownFileChecksumFuncName ||
work_item.src_checksum_func_name == kDbFileChecksumFuncName) {
if (work_item.src_checksum_hex != result.checksum_hex) {
std::string checksum_info(
"Expected checksum is " + work_item.src_checksum_hex +
" while computed checksum is " + result.checksum_hex);
result.io_status = IOStatus::Corruption(
"Checksum mismatch after copying to " + work_item.dst_path +
": " + checksum_info);
}
} else {
// FIXME(peterd): dead code?
std::string checksum_function_info(
"Existing checksum function is " +
work_item.src_checksum_func_name +
" while provided checksum function is " +
kBackupFileChecksumFuncName);
ROCKS_LOG_INFO(
options_.info_log,
"Unable to verify checksum after copying to %s: %s\n",
work_item.dst_path.c_str(), checksum_function_info.c_str());
}
}
work_item.result.set_value(std::move(result));
}
});
}
ROCKS_LOG_INFO(options_.info_log, "Initialized BackupEngine");
return IOStatus::OK();
}
IOStatus BackupEngineImpl::CreateNewBackupWithMetadata(
const CreateBackupOptions& options, DB* db, const std::string& app_metadata,
BackupID* new_backup_id_ptr) {
assert(initialized_);
assert(!read_only_);
if (app_metadata.size() > kMaxAppMetaSize) {
return IOStatus::InvalidArgument("App metadata too large");
}
bool maybe_exclude_items = bool{options.exclude_files_callback};
if (maybe_exclude_items && options_.schema_version < 2) {
return IOStatus::InvalidArgument(
"exclude_files_callback requires schema_version >= 2");
}
if (options.decrease_background_thread_cpu_priority) {
if (options.background_thread_cpu_priority < threads_cpu_priority_) {
threads_cpu_priority_.store(options.background_thread_cpu_priority);
}
}
BackupID new_backup_id = latest_backup_id_ + 1;
// `bytes_read` and `bytes_written` stats are enabled based on compile-time
// support and cannot be dynamically toggled. So we do not need to worry about
// `PerfLevel` here, unlike many other `IOStatsContext` / `PerfContext` stats.
uint64_t prev_bytes_read = IOSTATS(bytes_read);
uint64_t prev_bytes_written = IOSTATS(bytes_written);
assert(backups_.find(new_backup_id) == backups_.end());
auto private_dir = GetAbsolutePath(GetPrivateFileRel(new_backup_id));
IOStatus io_s = backup_fs_->FileExists(private_dir, io_options_, nullptr);
if (io_s.ok()) {
// maybe last backup failed and left partial state behind, clean it up.
// need to do this before updating backups_ such that a private dir
// named after new_backup_id will be cleaned up.
// (If an incomplete new backup is followed by an incomplete delete
// of the latest full backup, then there could be more than one next
// id with a private dir, the last thing to be deleted in delete
// backup, but all will be cleaned up with a GarbageCollect.)
io_s = GarbageCollect();
} else if (io_s.IsNotFound()) {
// normal case, the new backup's private dir doesn't exist yet
io_s = IOStatus::OK();
}
auto ret = backups_.insert(std::make_pair(
new_backup_id, std::unique_ptr<BackupMeta>(new BackupMeta(
GetBackupMetaFile(new_backup_id, false /* tmp */),
GetBackupMetaFile(new_backup_id, true /* tmp */),
&backuped_file_infos_, backup_env_, backup_fs_))));
assert(ret.second == true);
auto& new_backup = ret.first->second;
new_backup->RecordTimestamp();
new_backup->SetAppMetadata(app_metadata);
auto start_backup = backup_env_->NowMicros();
ROCKS_LOG_INFO(options_.info_log,
"Started the backup process -- creating backup %u",
new_backup_id);
if (options_.share_table_files && !options_.share_files_with_checksum) {
ROCKS_LOG_WARN(options_.info_log,
"BackupEngineOptions::share_files_with_checksum=false is "
"DEPRECATED and could lead to data loss.");
}
if (io_s.ok()) {
io_s = backup_fs_->CreateDir(private_dir, io_options_, nullptr);
}
// A set into which we will insert the dst_paths that are calculated for live
// files and live WAL files.
// This is used to check whether a live files shares a dst_path with another
// live file.
std::unordered_set<std::string> live_dst_paths;
std::deque<BackupWorkItemPair> excludable_items;
std::deque<BackupAfterCopyOrCreateWorkItem> backup_items_to_finish;
// Add a CopyOrCreateWorkItem to the channel for each live file
Status disabled = db->DisableFileDeletions();
DBOptions db_options = db->GetDBOptions();
Statistics* stats = db_options.statistics.get();
if (io_s.ok()) {
CheckpointImpl checkpoint(db);
uint64_t sequence_number = 0;
FileChecksumGenFactory* db_checksum_factory =
db_options.file_checksum_gen_factory.get();
const std::string kFileChecksumGenFactoryName =
"FileChecksumGenCrc32cFactory";
bool compare_checksum =
db_checksum_factory != nullptr &&
db_checksum_factory->Name() == kFileChecksumGenFactoryName
? true
: false;
EnvOptions src_raw_env_options(db_options);
RateLimiter* rate_limiter = options_.backup_rate_limiter.get();
io_s = status_to_io_status(checkpoint.CreateCustomCheckpoint(
[&](const std::string& /*src_dirname*/, const std::string& /*fname*/,
FileType) {
// custom checkpoint will switch to calling copy_file_cb after it sees
// NotSupported returned from link_file_cb.
return IOStatus::NotSupported();
} /* link_file_cb */,
[&](const std::string& src_dirname, const std::string& fname,
uint64_t size_limit_bytes, FileType type,
const std::string& checksum_func_name,
const std::string& checksum_val,
const Temperature src_temperature) {
if (type == kWalFile && !options_.backup_log_files) {
return IOStatus::OK();
}
Log(options_.info_log, "add file for backup %s", fname.c_str());
uint64_t size_bytes = 0;
IOStatus io_st;
if (type == kTableFile || type == kBlobFile) {
io_st = db_fs_->GetFileSize(src_dirname + "/" + fname, io_options_,
&size_bytes, nullptr);
if (!io_st.ok()) {
Log(options_.info_log, "GetFileSize is failed: %s",
io_st.ToString().c_str());
return io_st;
}
}
EnvOptions src_env_options;
switch (type) {
case kWalFile:
src_env_options =
db_env_->OptimizeForLogRead(src_raw_env_options);
break;
case kTableFile:
src_env_options = db_env_->OptimizeForCompactionTableRead(
src_raw_env_options, ImmutableDBOptions(db_options));
break;
case kDescriptorFile:
src_env_options =
db_env_->OptimizeForManifestRead(src_raw_env_options);
break;
case kBlobFile:
src_env_options = db_env_->OptimizeForBlobFileRead(
src_raw_env_options, ImmutableDBOptions(db_options));
break;
default:
// Other backed up files (like options file) are not read by live
// DB, so don't need to worry about avoiding mixing buffered and
// direct I/O. Just use plain defaults.
src_env_options = src_raw_env_options;
break;
}
io_st = AddBackupFileWorkItem(
live_dst_paths, backup_items_to_finish,
maybe_exclude_items ? &excludable_items : nullptr, new_backup_id,
options_.share_table_files &&
(type == kTableFile || type == kBlobFile),
src_dirname, fname, src_env_options, rate_limiter, type,
size_bytes, db_options.statistics.get(), size_limit_bytes,
options_.share_files_with_checksum &&
(type == kTableFile || type == kBlobFile),
options.progress_callback, "" /* contents */, checksum_func_name,
checksum_val, src_temperature);
return io_st;
} /* copy_file_cb */,
[&](const std::string& fname, const std::string& contents,
FileType type) {
Log(options_.info_log, "add file for backup %s", fname.c_str());
return AddBackupFileWorkItem(
live_dst_paths, backup_items_to_finish,
maybe_exclude_items ? &excludable_items : nullptr, new_backup_id,
false /* shared */, "" /* src_dir */, fname,
EnvOptions() /* src_env_options */, rate_limiter, type,
contents.size(), db_options.statistics.get(), 0 /* size_limit */,
false /* shared_checksum */, options.progress_callback, contents);
} /* create_file_cb */,
&sequence_number,
options.flush_before_backup ? 0 : std::numeric_limits<uint64_t>::max(),
compare_checksum));
if (io_s.ok()) {
new_backup->SetSequenceNumber(sequence_number);
}
}
ROCKS_LOG_INFO(options_.info_log, "add files for backup done.");
if (io_s.ok() && maybe_exclude_items) {
assert(options.exclude_files_callback);
size_t count = excludable_items.size();
std::vector<MaybeExcludeBackupFile> maybe_exclude_files;
maybe_exclude_files.reserve(count);
for (auto& e : excludable_items) {
maybe_exclude_files.emplace_back(
BackupExcludedFileInfo(e.second.dst_relative));
}
if (count > 0) {
try {
options.exclude_files_callback(
&maybe_exclude_files.front(),
/*end pointer*/ &maybe_exclude_files.back() + 1);
} catch (const std::exception& exn) {
io_s = IOStatus::Aborted("Exception in exclude_files_callback: " +
std::string(exn.what()));
} catch (...) {
io_s = IOStatus::Aborted("Unknown exception in exclude_files_callback");
}
}
if (io_s.ok()) {
for (size_t i = 0; i < count; ++i) {
auto& e = excludable_items[i];
if (maybe_exclude_files[i].exclude_decision) {
new_backup.get()->AddExcludedFile(e.second.dst_relative);
} else {
files_to_copy_or_create_.write(std::move(e.first));
backup_items_to_finish.push_back(std::move(e.second));
}
}
}
excludable_items.clear();
} else {
assert(!options.exclude_files_callback);
assert(excludable_items.empty());
}
ROCKS_LOG_INFO(options_.info_log,
"dispatch files for backup done, wait for finish.");
IOStatus item_io_status;
for (auto& item : backup_items_to_finish) {
item.result.wait();
auto result = item.result.get();
item_io_status = result.io_status;
Temperature temp = result.expected_src_temperature;
if (result.current_src_temperature != Temperature::kUnknown &&
(temp == Temperature::kUnknown ||
options_.current_temperatures_override_manifest)) {
temp = result.current_src_temperature;
}
if (item_io_status.ok() && item.shared && item.needed_to_copy) {
item_io_status = item.backup_env->GetFileSystem()->RenameFile(
item.dst_path_tmp, item.dst_path, io_options_, nullptr);
}
if (item_io_status.ok()) {
item_io_status = new_backup.get()->AddFile(std::make_shared<FileInfo>(
item.dst_relative, result.size, result.checksum_hex, result.db_id,
result.db_session_id, temp));
}
if (!item_io_status.ok()) {
io_s = item_io_status;
}
}
// we copied all the files, enable file deletions
if (disabled.ok()) { // If we successfully disabled file deletions
db->EnableFileDeletions(false).PermitUncheckedError();
}
auto backup_time = backup_env_->NowMicros() - start_backup;
if (io_s.ok()) {
// persist the backup metadata on the disk
io_s = new_backup->StoreToFile(options_.sync, options_.schema_version,
schema_test_options_.get());
}
if (io_s.ok() && options_.sync) {
std::unique_ptr<FSDirectory> backup_private_directory;
backup_fs_
->NewDirectory(GetAbsolutePath(GetPrivateFileRel(new_backup_id, false)),
io_options_, &backup_private_directory, nullptr)
.PermitUncheckedError();
if (backup_private_directory != nullptr) {
io_s = backup_private_directory->FsyncWithDirOptions(io_options_, nullptr,
DirFsyncOptions());
}
if (io_s.ok() && private_directory_ != nullptr) {
io_s = private_directory_->FsyncWithDirOptions(io_options_, nullptr,
DirFsyncOptions());
}
if (io_s.ok() && meta_directory_ != nullptr) {
io_s = meta_directory_->FsyncWithDirOptions(io_options_, nullptr,
DirFsyncOptions());
}
if (io_s.ok() && shared_directory_ != nullptr) {
io_s = shared_directory_->FsyncWithDirOptions(io_options_, nullptr,
DirFsyncOptions());
}
if (io_s.ok() && backup_directory_ != nullptr) {
io_s = backup_directory_->FsyncWithDirOptions(io_options_, nullptr,
DirFsyncOptions());
}
}
if (io_s.ok()) {
backup_statistics_.IncrementNumberSuccessBackup();
// here we know that we succeeded and installed the new backup
latest_backup_id_ = new_backup_id;
latest_valid_backup_id_ = new_backup_id;
if (new_backup_id_ptr) {
*new_backup_id_ptr = new_backup_id;
}
ROCKS_LOG_INFO(options_.info_log, "Backup DONE. All is good");
// backup_speed is in byte/second
double backup_speed = new_backup->GetSize() / (1.048576 * backup_time);
ROCKS_LOG_INFO(options_.info_log, "Backup number of files: %u",
new_backup->GetNumberFiles());
char human_size[16];
AppendHumanBytes(new_backup->GetSize(), human_size, sizeof(human_size));
ROCKS_LOG_INFO(options_.info_log, "Backup size: %s", human_size);
ROCKS_LOG_INFO(options_.info_log, "Backup time: %" PRIu64 " microseconds",
backup_time);
ROCKS_LOG_INFO(options_.info_log, "Backup speed: %.3f MB/s", backup_speed);
ROCKS_LOG_INFO(options_.info_log, "Backup Statistics %s",
backup_statistics_.ToString().c_str());
} else {
backup_statistics_.IncrementNumberFailBackup();
// clean all the files we might have created
ROCKS_LOG_INFO(options_.info_log, "Backup failed -- %s",
io_s.ToString().c_str());
ROCKS_LOG_INFO(options_.info_log, "Backup Statistics %s\n",
backup_statistics_.ToString().c_str());
// delete files that we might have already written
might_need_garbage_collect_ = true;
DeleteBackup(new_backup_id).PermitUncheckedError();
}
RecordTick(stats, BACKUP_READ_BYTES, IOSTATS(bytes_read) - prev_bytes_read);
RecordTick(stats, BACKUP_WRITE_BYTES,
IOSTATS(bytes_written) - prev_bytes_written);
return io_s;
}
IOStatus BackupEngineImpl::PurgeOldBackups(uint32_t num_backups_to_keep) {
assert(initialized_);
assert(!read_only_);
// Best effort deletion even with errors
IOStatus overall_status = IOStatus::OK();
ROCKS_LOG_INFO(options_.info_log, "Purging old backups, keeping %u",
num_backups_to_keep);
std::vector<BackupID> to_delete;
auto itr = backups_.begin();
while ((backups_.size() - to_delete.size()) > num_backups_to_keep) {
to_delete.push_back(itr->first);
itr++;
}
for (auto backup_id : to_delete) {
// Do not GC until end
IOStatus io_s = DeleteBackupNoGC(backup_id);
if (!io_s.ok()) {
overall_status = io_s;
}
}
// Clean up after any incomplete backup deletion, potentially from
// earlier session.
if (might_need_garbage_collect_) {
IOStatus io_s = GarbageCollect();
if (!io_s.ok() && overall_status.ok()) {
overall_status = io_s;
}
}
return overall_status;
}
IOStatus BackupEngineImpl::DeleteBackup(BackupID backup_id) {
IOStatus s1 = DeleteBackupNoGC(backup_id);
IOStatus s2 = IOStatus::OK();
// Clean up after any incomplete backup deletion, potentially from
// earlier session.
if (might_need_garbage_collect_) {
s2 = GarbageCollect();
}
if (!s1.ok()) {
// Any failure in the primary objective trumps any failure in the
// secondary objective.
s2.PermitUncheckedError();
return s1;
} else {
return s2;
}
}
// Does not auto-GarbageCollect nor lock
IOStatus BackupEngineImpl::DeleteBackupNoGC(BackupID backup_id) {
assert(initialized_);
assert(!read_only_);
ROCKS_LOG_INFO(options_.info_log, "Deleting backup %u", backup_id);
auto backup = backups_.find(backup_id);
if (backup != backups_.end()) {
IOStatus io_s = backup->second->Delete();
if (!io_s.ok()) {
return io_s;
}
backups_.erase(backup);
if (backups_.empty()) {
latest_valid_backup_id_ = 0;
} else {
latest_valid_backup_id_ = backups_.rbegin()->first;
}
} else {
auto corrupt = corrupt_backups_.find(backup_id);
if (corrupt == corrupt_backups_.end()) {
return IOStatus::NotFound("Backup not found");
}
IOStatus io_s = corrupt->second.second->Delete();
if (!io_s.ok()) {
return io_s;
}
corrupt->second.first.PermitUncheckedError();
corrupt_backups_.erase(corrupt);
}
// After removing meta file, best effort deletion even with errors.
// (Don't delete other files if we can't delete the meta file right
// now.)
std::vector<std::string> to_delete;
for (auto& itr : backuped_file_infos_) {
if (itr.second->refs == 0) {
IOStatus io_s = backup_fs_->DeleteFile(GetAbsolutePath(itr.first),
io_options_, nullptr);
ROCKS_LOG_INFO(options_.info_log, "Deleting %s -- %s", itr.first.c_str(),
io_s.ToString().c_str());
to_delete.push_back(itr.first);
if (!io_s.ok()) {
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
}
for (auto& td : to_delete) {
backuped_file_infos_.erase(td);
}
// take care of private dirs -- GarbageCollect() will take care of them
// if they are not empty
std::string private_dir = GetPrivateFileRel(backup_id);
IOStatus io_s =
backup_fs_->DeleteDir(GetAbsolutePath(private_dir), io_options_, nullptr);
ROCKS_LOG_INFO(options_.info_log, "Deleting private dir %s -- %s",
private_dir.c_str(), io_s.ToString().c_str());
if (!io_s.ok()) {
// Full gc or trying again later might work
might_need_garbage_collect_ = true;
}
return IOStatus::OK();
}
void BackupEngineImpl::SetBackupInfoFromBackupMeta(
BackupID id, const BackupMeta& meta, BackupInfo* backup_info,
bool include_file_details) const {
*backup_info = BackupInfo(id, meta.GetTimestamp(), meta.GetSize(),
meta.GetNumberFiles(), meta.GetAppMetadata());
std::string dir =
options_.backup_dir + "/" + kPrivateDirSlash + std::to_string(id);
if (include_file_details) {
auto& file_details = backup_info->file_details;
file_details.reserve(meta.GetFiles().size());
for (auto& file_ptr : meta.GetFiles()) {
BackupFileInfo& finfo = file_details.emplace_back();
finfo.relative_filename = file_ptr->filename;
finfo.size = file_ptr->size;
finfo.directory = dir;
uint64_t number;
FileType type;
bool ok = ParseFileName(file_ptr->filename, &number, &type);
if (ok) {
finfo.file_number = number;
finfo.file_type = type;
}
// TODO: temperature, file_checksum, file_checksum_func_name
// finfo.temperature = file_ptr->temp;
}
backup_info->excluded_files = meta.GetExcludedFiles();
backup_info->name_for_open = GetAbsolutePath(GetPrivateFileRel(id));
backup_info->name_for_open.pop_back(); // remove trailing '/'
backup_info->env_for_open = meta.GetEnvForOpen();
}
}
Status BackupEngineImpl::GetBackupInfo(BackupID backup_id,
BackupInfo* backup_info,
bool include_file_details) const {
assert(initialized_);
if (backup_id == kLatestBackupIDMarker) {
// Note: Read latest_valid_backup_id_ inside of lock
backup_id = latest_valid_backup_id_;
}
auto corrupt_itr = corrupt_backups_.find(backup_id);
if (corrupt_itr != corrupt_backups_.end()) {
return Status::Corruption(corrupt_itr->second.first.ToString());
}
auto backup_itr = backups_.find(backup_id);
if (backup_itr == backups_.end()) {
return Status::NotFound("Backup not found");
}
auto& backup = backup_itr->second;
if (backup->Empty()) {
return Status::NotFound("Backup not found");
}
SetBackupInfoFromBackupMeta(backup_id, *backup, backup_info,
include_file_details);
return Status::OK();
}
void BackupEngineImpl::GetBackupInfo(std::vector<BackupInfo>* backup_info,
bool include_file_details) const {
assert(initialized_);
backup_info->resize(backups_.size());
size_t i = 0;
for (auto& backup : backups_) {
const BackupMeta& meta = *backup.second;
if (!meta.Empty()) {
SetBackupInfoFromBackupMeta(backup.first, meta, &backup_info->at(i++),
include_file_details);
}
}
}
void BackupEngineImpl::GetCorruptedBackups(
std::vector<BackupID>* corrupt_backup_ids) const {
assert(initialized_);
corrupt_backup_ids->reserve(corrupt_backups_.size());
for (auto& backup : corrupt_backups_) {
corrupt_backup_ids->push_back(backup.first);
}
}
IOStatus BackupEngineImpl::RestoreDBFromBackup(
const RestoreOptions& options, BackupID backup_id,
const std::string& db_dir, const std::string& wal_dir,
const std::list<const BackupEngineImpl*>& locked_restore_from_dirs) const {
assert(initialized_);
if (backup_id == kLatestBackupIDMarker) {
// Note: Read latest_valid_backup_id_ inside of lock
backup_id = latest_valid_backup_id_;
}
auto corrupt_itr = corrupt_backups_.find(backup_id);
if (corrupt_itr != corrupt_backups_.end()) {
return corrupt_itr->second.first;
}
auto backup_itr = backups_.find(backup_id);
if (backup_itr == backups_.end()) {
return IOStatus::NotFound("Backup not found");
}
auto& backup = backup_itr->second;
if (backup->Empty()) {
return IOStatus::NotFound("Backup not found");
}
ROCKS_LOG_INFO(options_.info_log, "Restoring backup id %u\n", backup_id);
ROCKS_LOG_INFO(options_.info_log, "keep_log_files: %d\n",
static_cast<int>(options.keep_log_files));
// just in case. Ignore errors
db_fs_->CreateDirIfMissing(db_dir, io_options_, nullptr)
.PermitUncheckedError();
db_fs_->CreateDirIfMissing(wal_dir, io_options_, nullptr)
.PermitUncheckedError();
if (options.keep_log_files) {
// delete files in db_dir, but keep all the log files
DeleteChildren(db_dir, 1 << kWalFile);
// move all the files from archive dir to wal_dir
std::string archive_dir = ArchivalDirectory(wal_dir);
std::vector<std::string> archive_files;
db_fs_->GetChildren(archive_dir, io_options_, &archive_files, nullptr)
.PermitUncheckedError(); // ignore errors
for (const auto& f : archive_files) {
uint64_t number;
FileType type;
bool ok = ParseFileName(f, &number, &type);
if (ok && type == kWalFile) {
ROCKS_LOG_INFO(options_.info_log,
"Moving log file from archive/ to wal_dir: %s",
f.c_str());
IOStatus io_s = db_fs_->RenameFile(
archive_dir + "/" + f, wal_dir + "/" + f, io_options_, nullptr);
if (!io_s.ok()) {
// if we can't move log file from archive_dir to wal_dir,
// we should fail, since it might mean data loss
return io_s;
}
}
}
} else {
DeleteChildren(wal_dir);
DeleteChildren(ArchivalDirectory(wal_dir));
DeleteChildren(db_dir);
}
// Files to restore, and from where (taking into account excluded files)
std::vector<std::pair<const BackupEngineImpl*, const FileInfo*>>
restore_file_infos;
restore_file_infos.reserve(backup->GetFiles().size() +
backup->GetExcludedFiles().size());
for (const auto& ef : backup->GetExcludedFiles()) {
const std::string& file = ef.relative_file;
bool found = false;
for (auto be : locked_restore_from_dirs) {
auto it = be->backuped_file_infos_.find(file);
if (it != backuped_file_infos_.end()) {
restore_file_infos.emplace_back(be, &*it->second);
found = true;
break;
}
}
if (!found) {
return IOStatus::InvalidArgument(
"Excluded file " + file + " not found in other backups nor in " +
std::to_string(locked_restore_from_dirs.size() - 1) +
" alternate backup directories");
}
}
// Non-excluded files
for (const auto& file_info_shared : backup->GetFiles()) {
restore_file_infos.emplace_back(this, &*file_info_shared);
}
IOStatus io_s;
std::vector<RestoreAfterCopyOrCreateWorkItem> restore_items_to_finish;
std::string temporary_current_file;
std::string final_current_file;
std::unique_ptr<FSDirectory> db_dir_for_fsync;
std::unique_ptr<FSDirectory> wal_dir_for_fsync;
for (const auto& engine_and_file_info : restore_file_infos) {
const FileInfo* file_info = engine_and_file_info.second;
const std::string& file = file_info->filename;
std::string absolute_file =
engine_and_file_info.first->GetAbsolutePath(file);
Env* src_env = engine_and_file_info.first->backup_env_;
// 1. get DB filename
std::string dst = file_info->GetDbFileName();
// 2. find the filetype
uint64_t number;
FileType type;
bool ok = ParseFileName(dst, &number, &type);
if (!ok) {
return IOStatus::Corruption("Backup corrupted: Fail to parse filename " +
dst);
}
// 3. Construct the final path
// kWalFile lives in wal_dir and all the rest live in db_dir
if (type == kWalFile) {
dst = wal_dir + "/" + dst;
if (options_.sync && !wal_dir_for_fsync) {
io_s = db_fs_->NewDirectory(wal_dir, io_options_, &wal_dir_for_fsync,
nullptr);
if (!io_s.ok()) {
return io_s;
}
}
} else {
dst = db_dir + "/" + dst;
if (options_.sync && !db_dir_for_fsync) {
io_s = db_fs_->NewDirectory(db_dir, io_options_, &db_dir_for_fsync,
nullptr);
if (!io_s.ok()) {
return io_s;
}
}
}
// For atomicity, initially restore CURRENT file to a temporary name.
// This is useful even without options_.sync e.g. in case the restore
// process is interrupted.
if (type == kCurrentFile) {
final_current_file = dst;
dst = temporary_current_file = dst + ".tmp";
}
ROCKS_LOG_INFO(options_.info_log, "Restoring %s to %s\n", file.c_str(),
dst.c_str());
CopyOrCreateWorkItem copy_or_create_work_item(
absolute_file, dst, Temperature::kUnknown /* src_temp */,
file_info->temp, "" /* contents */, src_env, db_env_,
EnvOptions() /* src_env_options */, options_.sync,
options_.restore_rate_limiter.get(), file_info->size,
nullptr /* stats */);
RestoreAfterCopyOrCreateWorkItem after_copy_or_create_work_item(
copy_or_create_work_item.result.get_future(), file, dst,
file_info->checksum_hex);
files_to_copy_or_create_.write(std::move(copy_or_create_work_item));
restore_items_to_finish.push_back(
std::move(after_copy_or_create_work_item));
}
IOStatus item_io_status;
for (auto& item : restore_items_to_finish) {
item.result.wait();
auto result = item.result.get();
item_io_status = result.io_status;
// Note: It is possible that both of the following bad-status cases occur
// during copying. But, we only return one status.
if (!item_io_status.ok()) {
io_s = item_io_status;
break;
} else if (!item.checksum_hex.empty() &&
item.checksum_hex != result.checksum_hex) {
io_s = IOStatus::Corruption(
"While restoring " + item.from_file + " -> " + item.to_file +
": expected checksum is " + item.checksum_hex +
" while computed checksum is " + result.checksum_hex);
break;
}
}
// When enabled, the first FsyncWithDirOptions is to ensure all files are
// fully persisted before renaming CURRENT.tmp
if (io_s.ok() && db_dir_for_fsync) {
ROCKS_LOG_INFO(options_.info_log, "Restore: fsync\n");
io_s = db_dir_for_fsync->FsyncWithDirOptions(io_options_, nullptr,
DirFsyncOptions());
}
if (io_s.ok() && wal_dir_for_fsync) {
io_s = wal_dir_for_fsync->FsyncWithDirOptions(io_options_, nullptr,
DirFsyncOptions());
}
if (io_s.ok() && !temporary_current_file.empty()) {
ROCKS_LOG_INFO(options_.info_log, "Restore: atomic rename CURRENT.tmp\n");
assert(!final_current_file.empty());
io_s = db_fs_->RenameFile(temporary_current_file, final_current_file,
io_options_, nullptr);
}
if (io_s.ok() && db_dir_for_fsync && !temporary_current_file.empty()) {
// Second FsyncWithDirOptions is to ensure the final atomic rename of DB
// restore is fully persisted even if power goes out right after restore
// operation returns success
assert(db_dir_for_fsync);
io_s = db_dir_for_fsync->FsyncWithDirOptions(
io_options_, nullptr, DirFsyncOptions(final_current_file));
}
ROCKS_LOG_INFO(options_.info_log, "Restoring done -- %s\n",
io_s.ToString().c_str());
return io_s;
}
IOStatus BackupEngineImpl::VerifyBackup(BackupID backup_id,
bool verify_with_checksum) const {
assert(initialized_);
// Check if backup_id is corrupted, or valid and registered
auto corrupt_itr = corrupt_backups_.find(backup_id);
if (corrupt_itr != corrupt_backups_.end()) {
return corrupt_itr->second.first;
}
auto backup_itr = backups_.find(backup_id);
if (backup_itr == backups_.end()) {
return IOStatus::NotFound();
}
auto& backup = backup_itr->second;
if (backup->Empty()) {
return IOStatus::NotFound();
}
ROCKS_LOG_INFO(options_.info_log, "Verifying backup id %u\n", backup_id);
// Find all existing backup files belong to backup_id
std::unordered_map<std::string, uint64_t> curr_abs_path_to_size;
for (const auto& rel_dir : {GetPrivateFileRel(backup_id), GetSharedFileRel(),
GetSharedFileWithChecksumRel()}) {
const auto abs_dir = GetAbsolutePath(rel_dir);
// Shared directories allowed to be missing in some cases. Expected but
// missing files will be reported a few lines down.
ReadChildFileCurrentSizes(abs_dir, backup_fs_, &curr_abs_path_to_size)
.PermitUncheckedError();
}
// For all files registered in backup
for (const auto& file_info : backup->GetFiles()) {
const auto abs_path = GetAbsolutePath(file_info->filename);
// check existence of the file
if (curr_abs_path_to_size.find(abs_path) == curr_abs_path_to_size.end()) {
return IOStatus::NotFound("File missing: " + abs_path);
}
// verify file size
if (file_info->size != curr_abs_path_to_size[abs_path]) {
std::string size_info("Expected file size is " +
std::to_string(file_info->size) +
" while found file size is " +
std::to_string(curr_abs_path_to_size[abs_path]));
return IOStatus::Corruption("File corrupted: File size mismatch for " +
abs_path + ": " + size_info);
}
if (verify_with_checksum && !file_info->checksum_hex.empty()) {
// verify file checksum
std::string checksum_hex;
ROCKS_LOG_INFO(options_.info_log, "Verifying %s checksum...\n",
abs_path.c_str());
IOStatus io_s = ReadFileAndComputeChecksum(
abs_path, backup_fs_, EnvOptions(), 0 /* size_limit */, &checksum_hex,
Temperature::kUnknown);
if (!io_s.ok()) {
return io_s;
} else if (file_info->checksum_hex != checksum_hex) {
std::string checksum_info(
"Expected checksum is " + file_info->checksum_hex +
" while computed checksum is " + checksum_hex);
return IOStatus::Corruption("File corrupted: Checksum mismatch for " +
abs_path + ": " + checksum_info);
}
}
}
return IOStatus::OK();
}
IOStatus BackupEngineImpl::CopyOrCreateFile(
const std::string& src, const std::string& dst, const std::string& contents,
uint64_t size_limit, Env* src_env, Env* dst_env,
const EnvOptions& src_env_options, bool sync, RateLimiter* rate_limiter,
std::function<void()> progress_callback, Temperature* src_temperature,
Temperature dst_temperature, uint64_t* bytes_toward_next_callback,
uint64_t* size, std::string* checksum_hex) {
assert(src.empty() != contents.empty());
IOStatus io_s;
std::unique_ptr<FSWritableFile> dst_file;
std::unique_ptr<FSSequentialFile> src_file;
FileOptions dst_file_options;
dst_file_options.use_mmap_writes = false;
dst_file_options.temperature = dst_temperature;
// TODO:(gzh) maybe use direct reads/writes here if possible
if (size != nullptr) {
*size = 0;
}
uint32_t checksum_value = 0;
// Check if size limit is set. if not, set it to very big number
if (size_limit == 0) {
size_limit = std::numeric_limits<uint64_t>::max();
}
io_s = dst_env->GetFileSystem()->NewWritableFile(dst, dst_file_options,
&dst_file, nullptr);
if (io_s.ok() && !src.empty()) {
auto src_file_options = FileOptions(src_env_options);
src_file_options.temperature = *src_temperature;
io_s = src_env->GetFileSystem()->NewSequentialFile(src, src_file_options,
&src_file, nullptr);
}
if (io_s.IsPathNotFound() && *src_temperature != Temperature::kUnknown) {
// Retry without temperature hint in case the FileSystem is strict with
// non-kUnknown temperature option
io_s = src_env->GetFileSystem()->NewSequentialFile(
src, FileOptions(src_env_options), &src_file, nullptr);
}
if (!io_s.ok()) {
return io_s;
}
size_t buf_size =
rate_limiter ? static_cast<size_t>(rate_limiter->GetSingleBurstBytes())
: kDefaultCopyFileBufferSize;
std::unique_ptr<WritableFileWriter> dest_writer(
new WritableFileWriter(std::move(dst_file), dst, dst_file_options));
std::unique_ptr<SequentialFileReader> src_reader;
std::unique_ptr<char[]> buf;
if (!src.empty()) {
// Return back current temperature in FileSystem
*src_temperature = src_file->GetTemperature();
src_reader.reset(new SequentialFileReader(
std::move(src_file), src, nullptr /* io_tracer */, {}, rate_limiter));
buf.reset(new char[buf_size]);
}
Slice data;
do {
if (stop_backup_.load(std::memory_order_acquire)) {
return status_to_io_status(Status::Incomplete("Backup stopped"));
}
if (!src.empty()) {
size_t buffer_to_read =
(buf_size < size_limit) ? buf_size : static_cast<size_t>(size_limit);
io_s = src_reader->Read(buffer_to_read, &data, buf.get(),
Env::IO_LOW /* rate_limiter_priority */);
*bytes_toward_next_callback += data.size();
} else {
data = contents;
}
size_limit -= data.size();
TEST_SYNC_POINT_CALLBACK(
"BackupEngineImpl::CopyOrCreateFile:CorruptionDuringBackup",
(src.length() > 4 && src.rfind(".sst") == src.length() - 4) ? &data
: nullptr);
if (!io_s.ok()) {
return io_s;
}
if (size != nullptr) {
*size += data.size();
}
if (checksum_hex != nullptr) {
checksum_value = crc32c::Extend(checksum_value, data.data(), data.size());
}
io_s = dest_writer->Append(data);
if (rate_limiter != nullptr) {
if (!src.empty()) {
rate_limiter->Request(data.size(), Env::IO_LOW, nullptr /* stats */,
RateLimiter::OpType::kWrite);
} else {
LoopRateLimitRequestHelper(data.size(), rate_limiter, Env::IO_LOW,
nullptr /* stats */,
RateLimiter::OpType::kWrite);
}
}
while (*bytes_toward_next_callback >=
options_.callback_trigger_interval_size) {
*bytes_toward_next_callback -= options_.callback_trigger_interval_size;
if (progress_callback) {
std::lock_guard<std::mutex> lock(byte_report_mutex_);
try {
progress_callback();
} catch (const std::exception& exn) {
io_s = IOStatus::Aborted("Exception in progress_callback: " +
std::string(exn.what()));
break;
} catch (...) {
io_s = IOStatus::Aborted("Unknown exception in progress_callback");
break;
}
}
}
} while (io_s.ok() && contents.empty() && data.size() > 0 && size_limit > 0);
// Convert uint32_t checksum to hex checksum
if (checksum_hex != nullptr) {
checksum_hex->assign(ChecksumInt32ToHex(checksum_value));
}
if (io_s.ok() && sync) {
io_s = dest_writer->Sync(false);
}
if (io_s.ok()) {
io_s = dest_writer->Close();
}
return io_s;
}
// fname will always start with "/"
IOStatus BackupEngineImpl::AddBackupFileWorkItem(
std::unordered_set<std::string>& live_dst_paths,
std::deque<BackupAfterCopyOrCreateWorkItem>& backup_items_to_finish,
std::deque<BackupWorkItemPair>* excludable_items, BackupID backup_id,
bool shared, const std::string& src_dir, const std::string& fname,
const EnvOptions& src_env_options, RateLimiter* rate_limiter,
FileType file_type, uint64_t size_bytes, Statistics* stats,
uint64_t size_limit, bool shared_checksum,
std::function<void()> progress_callback, const std::string& contents,
const std::string& src_checksum_func_name,
const std::string& src_checksum_str, const Temperature src_temperature) {
assert(contents.empty() != src_dir.empty());
std::string src_path = src_dir + "/" + fname;
std::string dst_relative;
std::string dst_relative_tmp;
std::string db_id;
std::string db_session_id;
// crc32c checksum in hex. empty == unavailable / unknown
std::string checksum_hex;
// Whenever a default checksum function name is passed in, we will compares
// the corresponding checksum values after copying. Note that only table and
// blob files may have a known checksum function name passed in.
//
// If no default checksum function name is passed in and db session id is not
// available, we will calculate the checksum *before* copying in two cases
// (we always calcuate checksums when copying or creating for any file types):
// a) share_files_with_checksum is true and file type is table;
// b) share_table_files is true and the file exists already.
//
// Step 0: Check if default checksum function name is passed in
if (kDbFileChecksumFuncName == src_checksum_func_name) {
if (src_checksum_str == kUnknownFileChecksum) {
return status_to_io_status(
Status::Aborted("Unknown checksum value for " + fname));
}
checksum_hex = ChecksumStrToHex(src_checksum_str);
}
// Step 1: Prepare the relative path to destination
if (shared && shared_checksum) {
if (GetNamingNoFlags() != BackupEngineOptions::kLegacyCrc32cAndFileSize &&
file_type != kBlobFile) {
// Prepare db_session_id to add to the file name
// Ignore the returned status
// In the failed cases, db_id and db_session_id will be empty
GetFileDbIdentities(db_env_, src_env_options, src_path, src_temperature,
rate_limiter, &db_id, &db_session_id)
.PermitUncheckedError();
}
// Calculate checksum if checksum and db session id are not available.
// If db session id is available, we will not calculate the checksum
// since the session id should suffice to avoid file name collision in
// the shared_checksum directory.
if (checksum_hex.empty() && db_session_id.empty()) {
IOStatus io_s = ReadFileAndComputeChecksum(
src_path, db_fs_, src_env_options, size_limit, &checksum_hex,
src_temperature);
if (!io_s.ok()) {
return io_s;
}
}
if (size_bytes == std::numeric_limits<uint64_t>::max()) {
return IOStatus::NotFound("File missing: " + src_path);
}
// dst_relative depends on the following conditions:
// 1) the naming scheme is kUseDbSessionId,
// 2) db_session_id is not empty,
// 3) checksum is available in the DB manifest.
// If 1,2,3) are satisfied, then dst_relative will be of the form:
// shared_checksum/<file_number>_<checksum>_<db_session_id>.sst
// If 1,2) are satisfied, then dst_relative will be of the form:
// shared_checksum/<file_number>_<db_session_id>.sst
// Otherwise, dst_relative is of the form
// shared_checksum/<file_number>_<checksum>_<size>.sst
//
// For blob files, db_session_id is not supported with the blob file format.
// It uses original/legacy naming scheme.
// dst_relative will be of the form:
// shared_checksum/<file_number>_<checksum>_<size>.blob
dst_relative = GetSharedFileWithChecksum(fname, checksum_hex, size_bytes,
db_session_id);
dst_relative_tmp = GetSharedFileWithChecksumRel(dst_relative, true);
dst_relative = GetSharedFileWithChecksumRel(dst_relative, false);
} else if (shared) {
dst_relative_tmp = GetSharedFileRel(fname, true);
dst_relative = GetSharedFileRel(fname, false);
} else {
dst_relative = GetPrivateFileRel(backup_id, false, fname);
}
// We copy into `temp_dest_path` and, once finished, rename it to
// `final_dest_path`. This allows files to atomically appear at
// `final_dest_path`. We can copy directly to the final path when atomicity
// is unnecessary, like for files in private backup directories.
const std::string* copy_dest_path;
std::string temp_dest_path;
std::string final_dest_path = GetAbsolutePath(dst_relative);
if (!dst_relative_tmp.empty()) {
temp_dest_path = GetAbsolutePath(dst_relative_tmp);
copy_dest_path = &temp_dest_path;
} else {
copy_dest_path = &final_dest_path;
}
// Step 2: Determine whether to copy or not
// if it's shared, we also need to check if it exists -- if it does, no need
// to copy it again.
bool need_to_copy = true;
// true if final_dest_path is the same path as another live file
const bool same_path =
live_dst_paths.find(final_dest_path) != live_dst_paths.end();
bool file_exists = false;
if (shared && !same_path) {
// Should be in shared directory but not a live path, check existence in
// shared directory
IOStatus exist =
backup_fs_->FileExists(final_dest_path, io_options_, nullptr);
if (exist.ok()) {
file_exists = true;
} else if (exist.IsNotFound()) {
file_exists = false;
} else {
return exist;
}
}
if (!contents.empty()) {
need_to_copy = false;
} else if (shared && (same_path || file_exists)) {
need_to_copy = false;
auto find_result = backuped_file_infos_.find(dst_relative);
if (find_result == backuped_file_infos_.end() && !same_path) {
// file exists but not referenced
ROCKS_LOG_INFO(
options_.info_log,
"%s already present, but not referenced by any backup. We will "
"overwrite the file.",
fname.c_str());
need_to_copy = true;
// Defer any failure reporting to when we try to write the file
backup_fs_->DeleteFile(final_dest_path, io_options_, nullptr)
.PermitUncheckedError();
} else {
// file exists and referenced
if (checksum_hex.empty()) {
// same_path should not happen for a standard DB, so OK to
// read file contents to check for checksum mismatch between
// two files from same DB getting same name.
// For compatibility with future meta file that might not have
// crc32c checksum available, consider it might be empty, but
// we don't currently generate meta file without crc32c checksum.
// Therefore we have to read & compute it if we don't have it.
if (!same_path && !find_result->second->checksum_hex.empty()) {
assert(find_result != backuped_file_infos_.end());
// Note: to save I/O on incremental backups, we copy prior known
// checksum of the file instead of reading entire file contents
// to recompute it.
checksum_hex = find_result->second->checksum_hex;
// Regarding corruption detection, consider:
// (a) the DB file is corrupt (since previous backup) and the backup
// file is OK: we failed to detect, but the backup is safe. DB can
// be repaired/restored once its corruption is detected.
// (b) the backup file is corrupt (since previous backup) and the
// db file is OK: we failed to detect, but the backup is corrupt.
// CreateNewBackup should support fast incremental backups and
// there's no way to support that without reading all the files.
// We might add an option for extra checks on incremental backup,
// but until then, use VerifyBackups to check existing backup data.
// (c) file name collision with legitimately different content.
// This is almost inconceivable with a well-generated DB session
// ID, but even in that case, we double check the file sizes in
// BackupMeta::AddFile.
} else {
IOStatus io_s = ReadFileAndComputeChecksum(
src_path, db_fs_, src_env_options, size_limit, &checksum_hex,
src_temperature);
if (!io_s.ok()) {
return io_s;
}
}
}
if (!db_session_id.empty()) {
ROCKS_LOG_INFO(options_.info_log,
"%s already present, with checksum %s, size %" PRIu64
" and DB session identity %s",
fname.c_str(), checksum_hex.c_str(), size_bytes,
db_session_id.c_str());
} else {
ROCKS_LOG_INFO(options_.info_log,
"%s already present, with checksum %s and size %" PRIu64,
fname.c_str(), checksum_hex.c_str(), size_bytes);
}
}
}
live_dst_paths.insert(final_dest_path);
// Step 3: Add work item
if (!contents.empty() || need_to_copy) {
CopyOrCreateWorkItem copy_or_create_work_item(
src_dir.empty() ? "" : src_path, *copy_dest_path, src_temperature,
Temperature::kUnknown /*dst_temp*/, contents, db_env_, backup_env_,
src_env_options, options_.sync, rate_limiter, size_limit, stats,
progress_callback, src_checksum_func_name, checksum_hex, db_id,
db_session_id);
BackupAfterCopyOrCreateWorkItem after_copy_or_create_work_item(
copy_or_create_work_item.result.get_future(), shared, need_to_copy,
backup_env_, temp_dest_path, final_dest_path, dst_relative);
if (excludable_items != nullptr && shared && shared_checksum &&
need_to_copy) {
ROCKS_LOG_INFO(options_.info_log, "Copying (if not excluded) %s to %s",
fname.c_str(), copy_dest_path->c_str());
excludable_items->emplace_back(std::move(copy_or_create_work_item),
std::move(after_copy_or_create_work_item));
} else {
// For files known not excluded, can start copying even before finishing
// the checkpoint
ROCKS_LOG_INFO(options_.info_log, "Copying %s to %s", fname.c_str(),
copy_dest_path->c_str());
files_to_copy_or_create_.write(std::move(copy_or_create_work_item));
backup_items_to_finish.push_back(
std::move(after_copy_or_create_work_item));
}
} else {
std::promise<CopyOrCreateResult> promise_result;
BackupAfterCopyOrCreateWorkItem after_copy_or_create_work_item(
promise_result.get_future(), shared, need_to_copy, backup_env_,
temp_dest_path, final_dest_path, dst_relative);
backup_items_to_finish.push_back(std::move(after_copy_or_create_work_item));
CopyOrCreateResult result;
result.io_status = IOStatus::OK();
result.size = size_bytes;
result.checksum_hex = std::move(checksum_hex);
result.db_id = std::move(db_id);
result.db_session_id = std::move(db_session_id);
promise_result.set_value(std::move(result));
}
return IOStatus::OK();
}
IOStatus BackupEngineImpl::ReadFileAndComputeChecksum(
const std::string& src, const std::shared_ptr<FileSystem>& src_fs,
const EnvOptions& src_env_options, uint64_t size_limit,
std::string* checksum_hex, const Temperature src_temperature) const {
if (checksum_hex == nullptr) {
return status_to_io_status(Status::Aborted("Checksum pointer is null"));
}
uint32_t checksum_value = 0;
if (size_limit == 0) {
size_limit = std::numeric_limits<uint64_t>::max();
}
std::unique_ptr<SequentialFileReader> src_reader;
auto file_options = FileOptions(src_env_options);
file_options.temperature = src_temperature;
RateLimiter* rate_limiter = options_.backup_rate_limiter.get();
IOStatus io_s = SequentialFileReader::Create(
src_fs, src, file_options, &src_reader, nullptr /* dbg */, rate_limiter);
if (io_s.IsPathNotFound() && src_temperature != Temperature::kUnknown) {
// Retry without temperature hint in case the FileSystem is strict with
// non-kUnknown temperature option
file_options.temperature = Temperature::kUnknown;
io_s = SequentialFileReader::Create(src_fs, src, file_options, &src_reader,
nullptr /* dbg */, rate_limiter);
}
if (!io_s.ok()) {
return io_s;
}
size_t buf_size = kDefaultCopyFileBufferSize;
std::unique_ptr<char[]> buf(new char[buf_size]);
Slice data;
do {
if (stop_backup_.load(std::memory_order_acquire)) {
return status_to_io_status(Status::Incomplete("Backup stopped"));
}
size_t buffer_to_read =
(buf_size < size_limit) ? buf_size : static_cast<size_t>(size_limit);
io_s = src_reader->Read(buffer_to_read, &data, buf.get(),
Env::IO_LOW /* rate_limiter_priority */);
if (!io_s.ok()) {
return io_s;
}
size_limit -= data.size();
checksum_value = crc32c::Extend(checksum_value, data.data(), data.size());
} while (data.size() > 0 && size_limit > 0);
checksum_hex->assign(ChecksumInt32ToHex(checksum_value));
return io_s;
}
Status BackupEngineImpl::GetFileDbIdentities(
Env* src_env, const EnvOptions& src_env_options,
const std::string& file_path, Temperature file_temp,
RateLimiter* rate_limiter, std::string* db_id, std::string* db_session_id) {
assert(db_id != nullptr || db_session_id != nullptr);
Options options;
options.env = src_env;
SstFileDumper sst_reader(options, file_path, file_temp,
2 * 1024 * 1024
/* readahead_size */,
false /* verify_checksum */, false /* output_hex */,
false /* decode_blob_index */, src_env_options,
true /* silent */);
const TableProperties* table_properties = nullptr;
std::shared_ptr<const TableProperties> tp;
Status s = sst_reader.getStatus();
if (s.ok()) {
// Try to get table properties from the table reader of sst_reader
if (!sst_reader.ReadTableProperties(&tp).ok()) {
// Try to use table properites from the initialization of sst_reader
table_properties = sst_reader.GetInitTableProperties();
} else {
table_properties = tp.get();
if (table_properties != nullptr && rate_limiter != nullptr) {
// sizeof(*table_properties) is a sufficent but far-from-exact
// approximation of read bytes due to metaindex block, std::string
// properties and varint compression
LoopRateLimitRequestHelper(sizeof(*table_properties), rate_limiter,
Env::IO_LOW, nullptr /* stats */,
RateLimiter::OpType::kRead);
}
}
} else {
ROCKS_LOG_INFO(options_.info_log, "Failed to read %s: %s",
file_path.c_str(), s.ToString().c_str());
return s;
}
if (table_properties != nullptr) {
if (db_id != nullptr) {
db_id->assign(table_properties->db_id);
}
if (db_session_id != nullptr) {
db_session_id->assign(table_properties->db_session_id);
if (db_session_id->empty()) {
s = Status::NotFound("DB session identity not found in " + file_path);
ROCKS_LOG_INFO(options_.info_log, "%s", s.ToString().c_str());
return s;
}
}
return Status::OK();
} else {
s = Status::Corruption("Table properties missing in " + file_path);
ROCKS_LOG_INFO(options_.info_log, "%s", s.ToString().c_str());
return s;
}
}
void BackupEngineImpl::LoopRateLimitRequestHelper(
const size_t total_bytes_to_request, RateLimiter* rate_limiter,
const Env::IOPriority pri, Statistics* stats,
const RateLimiter::OpType op_type) {
assert(rate_limiter != nullptr);
size_t remaining_bytes = total_bytes_to_request;
size_t request_bytes = 0;
while (remaining_bytes > 0) {
request_bytes =
std::min(static_cast<size_t>(rate_limiter->GetSingleBurstBytes()),
remaining_bytes);
rate_limiter->Request(request_bytes, pri, stats, op_type);
remaining_bytes -= request_bytes;
}
}
void BackupEngineImpl::DeleteChildren(const std::string& dir,
uint32_t file_type_filter) const {
std::vector<std::string> children;
db_fs_->GetChildren(dir, io_options_, &children, nullptr)
.PermitUncheckedError(); // ignore errors
for (const auto& f : children) {
uint64_t number;
FileType type;
bool ok = ParseFileName(f, &number, &type);
if (ok && (file_type_filter & (1 << type))) {
// don't delete this file
continue;
}
db_fs_->DeleteFile(dir + "/" + f, io_options_, nullptr)
.PermitUncheckedError(); // ignore errors
}
}
IOStatus BackupEngineImpl::ReadChildFileCurrentSizes(
const std::string& dir, const std::shared_ptr<FileSystem>& fs,
std::unordered_map<std::string, uint64_t>* result) const {
assert(result != nullptr);
std::vector<Env::FileAttributes> files_attrs;
IOStatus io_status = fs->FileExists(dir, io_options_, nullptr);
if (io_status.ok()) {
io_status =
fs->GetChildrenFileAttributes(dir, io_options_, &files_attrs, nullptr);
} else if (io_status.IsNotFound()) {
// Insert no entries can be considered success
io_status = IOStatus::OK();
}
const bool slash_needed = dir.empty() || dir.back() != '/';
for (const auto& file_attrs : files_attrs) {
result->emplace(dir + (slash_needed ? "/" : "") + file_attrs.name,
file_attrs.size_bytes);
}
return io_status;
}
IOStatus BackupEngineImpl::GarbageCollect() {
assert(!read_only_);
// We will make a best effort to remove all garbage even in the presence
// of inconsistencies or I/O failures that inhibit finding garbage.
IOStatus overall_status = IOStatus::OK();
// If all goes well, we don't need another auto-GC this session
might_need_garbage_collect_ = false;
ROCKS_LOG_INFO(options_.info_log, "Starting garbage collection");
// delete obsolete shared files
for (bool with_checksum : {false, true}) {
std::vector<std::string> shared_children;
{
std::string shared_path;
if (with_checksum) {
shared_path = GetAbsolutePath(GetSharedFileWithChecksumRel());
} else {
shared_path = GetAbsolutePath(GetSharedFileRel());
}
IOStatus io_s = backup_fs_->FileExists(shared_path, io_options_, nullptr);
if (io_s.ok()) {
io_s = backup_fs_->GetChildren(shared_path, io_options_,
&shared_children, nullptr);
} else if (io_s.IsNotFound()) {
io_s = IOStatus::OK();
}
if (!io_s.ok()) {
overall_status = io_s;
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
for (auto& child : shared_children) {
std::string rel_fname;
if (with_checksum) {
rel_fname = GetSharedFileWithChecksumRel(child);
} else {
rel_fname = GetSharedFileRel(child);
}
auto child_itr = backuped_file_infos_.find(rel_fname);
// if it's not refcounted, delete it
if (child_itr == backuped_file_infos_.end() ||
child_itr->second->refs == 0) {
// this might be a directory, but DeleteFile will just fail in that
// case, so we're good
IOStatus io_s = backup_fs_->DeleteFile(GetAbsolutePath(rel_fname),
io_options_, nullptr);
ROCKS_LOG_INFO(options_.info_log, "Deleting %s -- %s",
rel_fname.c_str(), io_s.ToString().c_str());
backuped_file_infos_.erase(rel_fname);
if (!io_s.ok()) {
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
}
}
// delete obsolete private files
std::vector<std::string> private_children;
{
IOStatus io_s =
backup_fs_->GetChildren(GetAbsolutePath(kPrivateDirName), io_options_,
&private_children, nullptr);
if (!io_s.ok()) {
overall_status = io_s;
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
for (auto& child : private_children) {
BackupID backup_id = 0;
bool tmp_dir = child.find(".tmp") != std::string::npos;
sscanf(child.c_str(), "%u", &backup_id);
if (!tmp_dir && // if it's tmp_dir, delete it
(backup_id == 0 || backups_.find(backup_id) != backups_.end())) {
// it's either not a number or it's still alive. continue
continue;
}
// here we have to delete the dir and all its children
std::string full_private_path =
GetAbsolutePath(GetPrivateFileRel(backup_id));
std::vector<std::string> subchildren;
if (backup_fs_
->GetChildren(full_private_path, io_options_, &subchildren, nullptr)
.ok()) {
for (auto& subchild : subchildren) {
IOStatus io_s = backup_fs_->DeleteFile(full_private_path + subchild,
io_options_, nullptr);
ROCKS_LOG_INFO(options_.info_log, "Deleting %s -- %s",
(full_private_path + subchild).c_str(),
io_s.ToString().c_str());
if (!io_s.ok()) {
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
}
// finally delete the private dir
IOStatus io_s =
backup_fs_->DeleteDir(full_private_path, io_options_, nullptr);
ROCKS_LOG_INFO(options_.info_log, "Deleting dir %s -- %s",
full_private_path.c_str(), io_s.ToString().c_str());
if (!io_s.ok()) {
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
assert(overall_status.ok() || might_need_garbage_collect_);
return overall_status;
}
// ------- BackupMeta class --------
IOStatus BackupEngineImpl::BackupMeta::AddFile(
std::shared_ptr<FileInfo> file_info) {
auto itr = file_infos_->find(file_info->filename);
if (itr == file_infos_->end()) {
auto ret = file_infos_->insert({file_info->filename, file_info});
if (ret.second) {
itr = ret.first;
itr->second->refs = 1;
} else {
// if this happens, something is seriously wrong
return IOStatus::Corruption("In memory metadata insertion error");
}
} else {
// Compare sizes, because we scanned that off the filesystem on both
// ends. This is like a check in VerifyBackup.
if (itr->second->size != file_info->size) {
std::string msg = "Size mismatch for existing backup file: ";
msg.append(file_info->filename);
msg.append(" Size in backup is " + std::to_string(itr->second->size) +
" while size in DB is " + std::to_string(file_info->size));
msg.append(
" If this DB file checks as not corrupt, try deleting old"
" backups or backing up to a different backup directory.");
return IOStatus::Corruption(msg);
}
if (file_info->checksum_hex.empty()) {
// No checksum available to check
} else if (itr->second->checksum_hex.empty()) {
// Remember checksum if newly acquired
itr->second->checksum_hex = file_info->checksum_hex;
} else if (itr->second->checksum_hex != file_info->checksum_hex) {
// Note: to save I/O, these will be equal trivially on already backed
// up files that don't have the checksum in their name. And it should
// never fail for files that do have checksum in their name.
// Should never reach here, but produce an appropriate corruption
// message in case we do in a release build.
assert(false);
std::string msg = "Checksum mismatch for existing backup file: ";
msg.append(file_info->filename);
msg.append(" Expected checksum is " + itr->second->checksum_hex +
" while computed checksum is " + file_info->checksum_hex);
msg.append(
" If this DB file checks as not corrupt, try deleting old"
" backups or backing up to a different backup directory.");
return IOStatus::Corruption(msg);
}
++itr->second->refs; // increase refcount if already present
}
size_ += file_info->size;
files_.push_back(itr->second);
return IOStatus::OK();
}
IOStatus BackupEngineImpl::BackupMeta::Delete(bool delete_meta) {
IOStatus io_s;
for (const auto& file : files_) {
--file->refs; // decrease refcount
}
files_.clear();
// delete meta file
if (delete_meta) {
io_s = fs_->FileExists(meta_filename_, iooptions_, nullptr);
if (io_s.ok()) {
io_s = fs_->DeleteFile(meta_filename_, iooptions_, nullptr);
} else if (io_s.IsNotFound()) {
io_s = IOStatus::OK(); // nothing to delete
}
}
timestamp_ = 0;
return io_s;
}
// Constants for backup meta file schema (see LoadFromFile)
const std::string kSchemaVersionPrefix{"schema_version "};
const std::string kFooterMarker{"// FOOTER"};
const std::string kAppMetaDataFieldName{"metadata"};
// WART: The checksums are crc32c but named "crc32"
const std::string kFileCrc32cFieldName{"crc32"};
const std::string kFileSizeFieldName{"size"};
const std::string kTemperatureFieldName{"temp"};
const std::string kExcludedFieldName{"ni::excluded"};
// Marks a (future) field that should cause failure if not recognized.
// Other fields are assumed to be ignorable. For example, in the future
// we might add
// ni::file_name_escape uri_percent
// to indicate all file names have had spaces and special characters
// escaped using a URI percent encoding.
const std::string kNonIgnorableFieldPrefix{"ni::"};
// Each backup meta file is of the format (schema version 1):
//----------------------------------------------------------
// <timestamp>
// <seq number>
// metadata <metadata> (optional)
// <number of files>
// <file1> crc32 <crc32c_as_unsigned_decimal>
// <file2> crc32 <crc32c_as_unsigned_decimal>
// ...
//----------------------------------------------------------
//
// For schema version 2.x:
//----------------------------------------------------------
// schema_version <ver>
// <timestamp>
// <seq number>
// [<field name> <field data>]
// ...
// <number of files>
// <file1>( <field name> <field data no spaces>)*
// <file2>( <field name> <field data no spaces>)*
// ...
// [// FOOTER]
// [<field name> <field data>]
// ...
//----------------------------------------------------------
// where
// <ver> ::= [0-9]+([.][0-9]+)
// <field name> ::= [A-Za-z_][A-Za-z_0-9.]+
// <field data> is anything but newline
// <field data no spaces> is anything but space and newline
// Although "// FOOTER" wouldn't strictly be required as a delimiter
// given the number of files is included, it is there for parsing
// sanity in case of corruption. It is only required if followed
// by footer fields, such as a checksum of the meta file (so far).
// Unrecognized fields are ignored, to support schema evolution on
// non-critical features with forward compatibility. Update schema
// major version for breaking changes. Schema minor versions are indicated
// only for diagnostic/debugging purposes.
//
// Fields in schema version 2.0:
// * Top-level meta fields:
// * Only "metadata" as in schema version 1
// * File meta fields:
// * "crc32" - a crc32c checksum as in schema version 1
// * "size" - the size of the file (new)
// * Footer meta fields:
// * None yet (future use for meta file checksum anticipated)
//
IOStatus BackupEngineImpl::BackupMeta::LoadFromFile(
const std::string& backup_dir,
const std::unordered_map<std::string, uint64_t>& abs_path_to_size,
RateLimiter* rate_limiter, Logger* info_log,
std::unordered_set<std::string>* reported_ignored_fields) {
assert(reported_ignored_fields);
assert(Empty());
std::unique_ptr<LineFileReader> backup_meta_reader;
{
IOStatus io_s = LineFileReader::Create(fs_, meta_filename_, FileOptions(),
&backup_meta_reader,
nullptr /* dbg */, rate_limiter);
if (!io_s.ok()) {
return io_s;
}
}
// If we don't read an explicit schema_version, that implies version 1,
// which is what we call the original backup meta schema.
int schema_major_version = 1;
// Failures handled at the end
std::string line;
if (backup_meta_reader->ReadLine(&line,
Env::IO_LOW /* rate_limiter_priority */)) {
if (StartsWith(line, kSchemaVersionPrefix)) {
std::string ver = line.substr(kSchemaVersionPrefix.size());
if (ver == "2" || StartsWith(ver, "2.")) {
schema_major_version = 2;
} else {
return IOStatus::NotSupported(
"Unsupported/unrecognized schema version: " + ver);
}
line.clear();
} else if (line.empty()) {
return IOStatus::Corruption("Unexpected empty line");
}
}
if (!line.empty()) {
timestamp_ = std::strtoull(line.c_str(), nullptr, /*base*/ 10);
} else if (backup_meta_reader->ReadLine(
&line, Env::IO_LOW /* rate_limiter_priority */)) {
timestamp_ = std::strtoull(line.c_str(), nullptr, /*base*/ 10);
}
if (backup_meta_reader->ReadLine(&line,
Env::IO_LOW /* rate_limiter_priority */)) {
sequence_number_ = std::strtoull(line.c_str(), nullptr, /*base*/ 10);
}
uint32_t num_files = UINT32_MAX;
while (backup_meta_reader->ReadLine(
&line, Env::IO_LOW /* rate_limiter_priority */)) {
if (line.empty()) {
return IOStatus::Corruption("Unexpected empty line");
}
// Number -> number of files -> exit loop reading optional meta fields
if (line[0] >= '0' && line[0] <= '9') {
num_files = static_cast<uint32_t>(strtoul(line.c_str(), nullptr, 10));
break;
}
// else, must be a meta field assignment
auto space_pos = line.find_first_of(' ');
if (space_pos == std::string::npos) {
return IOStatus::Corruption("Expected number of files or meta field");
}
std::string field_name = line.substr(0, space_pos);
std::string field_data = line.substr(space_pos + 1);
if (field_name == kAppMetaDataFieldName) {
// app metadata present
bool decode_success = Slice(field_data).DecodeHex(&app_metadata_);
if (!decode_success) {
return IOStatus::Corruption(
"Failed to decode stored hex encoded app metadata");
}
} else if (schema_major_version < 2) {
return IOStatus::Corruption("Expected number of files or \"" +
kAppMetaDataFieldName + "\" field");
} else if (StartsWith(field_name, kNonIgnorableFieldPrefix)) {
return IOStatus::NotSupported("Unrecognized non-ignorable meta field " +
field_name + " (from future version?)");
} else {
// Warn the first time we see any particular unrecognized meta field
if (reported_ignored_fields->insert("meta:" + field_name).second) {
ROCKS_LOG_WARN(info_log, "Ignoring unrecognized backup meta field %s",
field_name.c_str());
}
}
}
std::vector<std::shared_ptr<FileInfo>> files;
bool footer_present = false;
while (backup_meta_reader->ReadLine(
&line, Env::IO_LOW /* rate_limiter_priority */)) {
std::vector<std::string> components = StringSplit(line, ' ');
if (components.size() < 1) {
return IOStatus::Corruption("Empty line instead of file entry.");
}
if (schema_major_version >= 2 && components.size() == 2 &&
line == kFooterMarker) {
footer_present = true;
break;
}
const std::string& filename = components[0];
if (schema_major_version >= 2) {
if (components.size() % 2 != 1) {
return IOStatus::Corruption(
"Bad number of line components for file entry.");
}
} else {
// Check restricted original schema
if (components.size() < 3) {
return IOStatus::Corruption("File checksum is missing for " + filename +
" in " + meta_filename_);
}
if (components[1] != kFileCrc32cFieldName) {
return IOStatus::Corruption("Unknown checksum type for " + filename +
" in " + meta_filename_);
}
if (components.size() > 3) {
return IOStatus::Corruption("Extra data for entry " + filename +
" in " + meta_filename_);
}
}
std::optional<uint64_t> expected_size{};
std::string checksum_hex;
Temperature temp = Temperature::kUnknown;
bool excluded = false;
for (unsigned i = 1; i < components.size(); i += 2) {
const std::string& field_name = components[i];
const std::string& field_data = components[i + 1];
if (field_name == kFileCrc32cFieldName) {
uint32_t checksum_value =
static_cast<uint32_t>(strtoul(field_data.c_str(), nullptr, 10));
if (field_data != std::to_string(checksum_value)) {
return IOStatus::Corruption("Invalid checksum value for " + filename +
" in " + meta_filename_);
}
checksum_hex = ChecksumInt32ToHex(checksum_value);
} else if (field_name == kFileSizeFieldName) {
expected_size = std::strtoull(field_data.c_str(), nullptr, /*base*/ 10);
} else if (field_name == kTemperatureFieldName) {
auto iter = temperature_string_map.find(field_data);
if (iter != temperature_string_map.end()) {
temp = iter->second;
} else {
// Could report corruption, but in case of new temperatures added
// in future, letting those map to kUnknown which should generally
// be safe.
temp = Temperature::kUnknown;
}
} else if (field_name == kExcludedFieldName) {
if (field_data == "true") {
excluded = true;
} else if (field_data == "false") {
excluded = false;
} else {
return IOStatus::NotSupported("Unrecognized value \"" + field_data +
"\" for field " + field_name);
}
} else if (StartsWith(field_name, kNonIgnorableFieldPrefix)) {
return IOStatus::NotSupported("Unrecognized non-ignorable file field " +
field_name + " (from future version?)");
} else {
// Warn the first time we see any particular unrecognized file field
if (reported_ignored_fields->insert("file:" + field_name).second) {
ROCKS_LOG_WARN(info_log, "Ignoring unrecognized backup file field %s",
field_name.c_str());
}
}
}
if (excluded) {
excluded_files_.emplace_back(filename);
} else {
// Verify file exists, with expected size
std::string abs_path = backup_dir + "/" + filename;
auto e = abs_path_to_size.find(abs_path);
if (e == abs_path_to_size.end()) {
return IOStatus::Corruption(
"Pathname in meta file not found on disk: " + abs_path);
}
uint64_t actual_size = e->second;
if (expected_size.has_value() && *expected_size != actual_size) {
return IOStatus::Corruption("For file " + filename + " expected size " +
std::to_string(*expected_size) +
" but found size" +
std::to_string(actual_size));
}
// NOTE: FileInfo will be coalesced for sharing later (AddFile below)
files.emplace_back(
std::make_shared<FileInfo>(filename, actual_size, checksum_hex,
/*id*/ "", /*sid*/ "", temp));
}
}
if (footer_present) {
assert(schema_major_version >= 2);
while (backup_meta_reader->ReadLine(
&line, Env::IO_LOW /* rate_limiter_priority */)) {
if (line.empty()) {
return IOStatus::Corruption("Unexpected empty line");
}
auto space_pos = line.find_first_of(' ');
if (space_pos == std::string::npos) {
return IOStatus::Corruption("Expected footer field");
}
std::string field_name = line.substr(0, space_pos);
std::string field_data = line.substr(space_pos + 1);
if (StartsWith(field_name, kNonIgnorableFieldPrefix)) {
return IOStatus::NotSupported("Unrecognized non-ignorable field " +
field_name + " (from future version?)");
} else if (reported_ignored_fields->insert("footer:" + field_name)
.second) {
// Warn the first time we see any particular unrecognized footer field
ROCKS_LOG_WARN(info_log,
"Ignoring unrecognized backup meta footer field %s",
field_name.c_str());
}
}
}
{
IOStatus io_s = backup_meta_reader->GetStatus();
if (!io_s.ok()) {
return io_s;
}
}
if (num_files != files.size()) {
return IOStatus::Corruption(
"Inconsistent number of files or missing/incomplete header in " +
meta_filename_);
}
files_.reserve(files.size());
for (const auto& file_info : files) {
IOStatus io_s = AddFile(file_info);
if (!io_s.ok()) {
return io_s;
}
}
return IOStatus::OK();
}
const std::vector<std::string> minor_version_strings{
"", // invalid major version 0
"", // implicit major version 1
"2.1",
};
IOStatus BackupEngineImpl::BackupMeta::StoreToFile(
bool sync, int schema_version,
const TEST_BackupMetaSchemaOptions* schema_test_options) {
if (schema_version < 1) {
return IOStatus::InvalidArgument(
"BackupEngineOptions::schema_version must be >= 1");
}
if (schema_version > static_cast<int>(minor_version_strings.size() - 1)) {
return IOStatus::NotSupported(
"Only BackupEngineOptions::schema_version <= " +
std::to_string(minor_version_strings.size() - 1) + " is supported");
}
std::string ver = minor_version_strings[schema_version];
// Need schema_version >= 2 for TEST_BackupMetaSchemaOptions
assert(schema_version >= 2 || schema_test_options == nullptr);
IOStatus io_s;
std::unique_ptr<FSWritableFile> backup_meta_file;
FileOptions file_options;
file_options.use_mmap_writes = false;
file_options.use_direct_writes = false;
io_s = fs_->NewWritableFile(meta_tmp_filename_, file_options,
&backup_meta_file, nullptr);
if (!io_s.ok()) {
return io_s;
}
std::ostringstream buf;
if (schema_test_options) {
// override for testing
ver = schema_test_options->version;
}
if (!ver.empty()) {
assert(schema_version >= 2);
buf << kSchemaVersionPrefix << ver << "\n";
}
buf << static_cast<unsigned long long>(timestamp_) << "\n";
buf << sequence_number_ << "\n";
if (!app_metadata_.empty()) {
std::string hex_encoded_metadata =
Slice(app_metadata_).ToString(/* hex */ true);
buf << kAppMetaDataFieldName << " " << hex_encoded_metadata << "\n";
}
if (schema_test_options) {
for (auto& e : schema_test_options->meta_fields) {
buf << e.first << " " << e.second << "\n";
}
}
buf << files_.size() << "\n";
for (const auto& file : files_) {
buf << file->filename;
if (schema_test_options == nullptr ||
schema_test_options->crc32c_checksums) {
// use crc32c for now, switch to something else if needed
buf << " " << kFileCrc32cFieldName << " "
<< ChecksumHexToInt32(file->checksum_hex);
}
if (schema_version >= 2 && file->temp != Temperature::kUnknown) {
buf << " " << kTemperatureFieldName << " "
<< temperature_to_string[file->temp];
}
if (schema_test_options && schema_test_options->file_sizes) {
buf << " " << kFileSizeFieldName << " " << std::to_string(file->size);
}
if (schema_test_options) {
for (auto& e : schema_test_options->file_fields) {
buf << " " << e.first << " " << e.second;
}
}
buf << "\n";
}
for (const auto& file : excluded_files_) {
assert(schema_version >= 2);
buf << file.relative_file << " " << kExcludedFieldName << " true\n";
}
if (schema_test_options && !schema_test_options->footer_fields.empty()) {
buf << kFooterMarker << "\n";
for (auto& e : schema_test_options->footer_fields) {
buf << e.first << " " << e.second << "\n";
}
}
io_s = backup_meta_file->Append(Slice(buf.str()), iooptions_, nullptr);
IOSTATS_ADD(bytes_written, buf.str().size());
if (io_s.ok() && sync) {
io_s = backup_meta_file->Sync(iooptions_, nullptr);
}
if (io_s.ok()) {
io_s = backup_meta_file->Close(iooptions_, nullptr);
}
if (io_s.ok()) {
io_s = fs_->RenameFile(meta_tmp_filename_, meta_filename_, iooptions_,
nullptr);
}
return io_s;
}
} // namespace
IOStatus BackupEngineReadOnly::Open(const BackupEngineOptions& options,
Env* env,
BackupEngineReadOnly** backup_engine_ptr) {
if (options.destroy_old_data) {
return IOStatus::InvalidArgument(
"Can't destroy old data with ReadOnly BackupEngine");
}
std::unique_ptr<BackupEngineImplThreadSafe> backup_engine(
new BackupEngineImplThreadSafe(options, env, true /*read_only*/));
auto s = backup_engine->Initialize();
if (!s.ok()) {
*backup_engine_ptr = nullptr;
return s;
}
*backup_engine_ptr = backup_engine.release();
return IOStatus::OK();
}
void TEST_SetBackupMetaSchemaOptions(
BackupEngine* engine, const TEST_BackupMetaSchemaOptions& options) {
BackupEngineImplThreadSafe* impl =
static_cast_with_check<BackupEngineImplThreadSafe>(engine);
impl->TEST_SetBackupMetaSchemaOptions(options);
}
void TEST_SetDefaultRateLimitersClock(
BackupEngine* engine,
const std::shared_ptr<SystemClock>& backup_rate_limiter_clock,
const std::shared_ptr<SystemClock>& restore_rate_limiter_clock) {
BackupEngineImplThreadSafe* impl =
static_cast_with_check<BackupEngineImplThreadSafe>(engine);
impl->TEST_SetDefaultRateLimitersClock(backup_rate_limiter_clock,
restore_rate_limiter_clock);
}
} // namespace ROCKSDB_NAMESPACE
#endif // ROCKSDB_LITE