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rocksdb/utilities/blob_db/blob_db_impl.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).
#ifndef ROCKSDB_LITE
#include "utilities/blob_db/blob_db_impl.h"
#include <algorithm>
#include <cinttypes>
#include <iomanip>
#include <memory>
#include "db/db_impl.h"
#include "db/write_batch_internal.h"
#include "monitoring/instrumented_mutex.h"
#include "monitoring/statistics.h"
#include "rocksdb/convenience.h"
#include "rocksdb/env.h"
#include "rocksdb/iterator.h"
#include "rocksdb/utilities/stackable_db.h"
#include "rocksdb/utilities/transaction.h"
#include "table/block.h"
#include "table/block_based_table_builder.h"
#include "table/block_builder.h"
#include "table/meta_blocks.h"
#include "util/cast_util.h"
#include "util/crc32c.h"
#include "util/file_reader_writer.h"
#include "util/filename.h"
#include "util/logging.h"
#include "util/mutexlock.h"
#include "util/random.h"
#include "util/stop_watch.h"
#include "util/sync_point.h"
#include "util/timer_queue.h"
#include "utilities/blob_db/blob_compaction_filter.h"
#include "utilities/blob_db/blob_db_iterator.h"
#include "utilities/blob_db/blob_db_listener.h"
#include "utilities/blob_db/blob_index.h"
namespace {
int kBlockBasedTableVersionFormat = 2;
} // end namespace
namespace rocksdb {
namespace blob_db {
WalFilter::WalProcessingOption BlobReconcileWalFilter::LogRecordFound(
unsigned long long /*log_number*/, const std::string& /*log_file_name*/,
const WriteBatch& /*batch*/, WriteBatch* /*new_batch*/,
bool* /*batch_changed*/) {
return WalFilter::WalProcessingOption::kContinueProcessing;
}
bool blobf_compare_ttl::operator()(const std::shared_ptr<BlobFile>& lhs,
const std::shared_ptr<BlobFile>& rhs) const {
assert(lhs->HasTTL() && rhs->HasTTL());
if (lhs->expiration_range_.first < rhs->expiration_range_.first) {
return true;
}
if (lhs->expiration_range_.first > rhs->expiration_range_.first) {
return false;
}
return lhs->BlobFileNumber() < rhs->BlobFileNumber();
}
BlobDBImpl::BlobDBImpl(const std::string& dbname,
const BlobDBOptions& blob_db_options,
const DBOptions& db_options,
const ColumnFamilyOptions& cf_options)
: BlobDB(),
dbname_(dbname),
db_impl_(nullptr),
env_(db_options.env),
ttl_extractor_(blob_db_options.ttl_extractor.get()),
bdb_options_(blob_db_options),
db_options_(db_options),
cf_options_(cf_options),
env_options_(db_options),
statistics_(db_options_.statistics.get()),
next_file_number_(1),
epoch_of_(0),
closed_(true),
open_file_count_(0),
total_blob_size_(0),
live_sst_size_(0),
fifo_eviction_seq_(0),
evict_expiration_up_to_(0),
debug_level_(0) {
blob_dir_ = (bdb_options_.path_relative)
? dbname + "/" + bdb_options_.blob_dir
: bdb_options_.blob_dir;
env_options_.bytes_per_sync = blob_db_options.bytes_per_sync;
}
BlobDBImpl::~BlobDBImpl() {
// CancelAllBackgroundWork(db_, true);
Status s __attribute__((__unused__)) = Close();
assert(s.ok());
}
Status BlobDBImpl::Close() {
if (closed_) {
return Status::OK();
}
closed_ = true;
// Close base DB before BlobDBImpl destructs to stop event listener and
// compaction filter call.
Status s = db_->Close();
// delete db_ anyway even if close failed.
delete db_;
// Reset pointers to avoid StackableDB delete the pointer again.
db_ = nullptr;
db_impl_ = nullptr;
if (!s.ok()) {
return s;
}
s = SyncBlobFiles();
return s;
}
BlobDBOptions BlobDBImpl::GetBlobDBOptions() const { return bdb_options_; }
Status BlobDBImpl::Open(std::vector<ColumnFamilyHandle*>* handles) {
assert(handles != nullptr);
assert(db_ == nullptr);
if (blob_dir_.empty()) {
return Status::NotSupported("No blob directory in options");
}
if (cf_options_.compaction_filter != nullptr ||
cf_options_.compaction_filter_factory != nullptr) {
return Status::NotSupported("Blob DB doesn't support compaction filter.");
}
Status s;
// Create info log.
if (db_options_.info_log == nullptr) {
s = CreateLoggerFromOptions(dbname_, db_options_, &db_options_.info_log);
if (!s.ok()) {
return s;
}
}
ROCKS_LOG_INFO(db_options_.info_log, "Opening BlobDB...");
// Open blob directory.
s = env_->CreateDirIfMissing(blob_dir_);
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to create blob_dir %s, status: %s",
blob_dir_.c_str(), s.ToString().c_str());
}
s = env_->NewDirectory(blob_dir_, &dir_ent_);
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to open blob_dir %s, status: %s", blob_dir_.c_str(),
s.ToString().c_str());
return s;
}
// Open blob files.
s = OpenAllBlobFiles();
if (!s.ok()) {
return s;
}
// Update options
db_options_.listeners.push_back(std::make_shared<BlobDBListener>(this));
cf_options_.compaction_filter_factory.reset(
new BlobIndexCompactionFilterFactory(this, env_, statistics_));
// Open base db.
ColumnFamilyDescriptor cf_descriptor(kDefaultColumnFamilyName, cf_options_);
s = DB::Open(db_options_, dbname_, {cf_descriptor}, handles, &db_);
if (!s.ok()) {
return s;
}
db_impl_ = static_cast_with_check<DBImpl, DB>(db_->GetRootDB());
UpdateLiveSSTSize();
// Start background jobs.
if (!bdb_options_.disable_background_tasks) {
StartBackgroundTasks();
}
ROCKS_LOG_INFO(db_options_.info_log, "BlobDB pointer %p", this);
bdb_options_.Dump(db_options_.info_log.get());
closed_ = false;
return s;
}
void BlobDBImpl::StartBackgroundTasks() {
// store a call to a member function and object
tqueue_.add(
kReclaimOpenFilesPeriodMillisecs,
std::bind(&BlobDBImpl::ReclaimOpenFiles, this, std::placeholders::_1));
tqueue_.add(static_cast<int64_t>(
bdb_options_.garbage_collection_interval_secs * 1000),
std::bind(&BlobDBImpl::RunGC, this, std::placeholders::_1));
tqueue_.add(
kDeleteObsoleteFilesPeriodMillisecs,
std::bind(&BlobDBImpl::DeleteObsoleteFiles, this, std::placeholders::_1));
tqueue_.add(kSanityCheckPeriodMillisecs,
std::bind(&BlobDBImpl::SanityCheck, this, std::placeholders::_1));
tqueue_.add(
kCheckSeqFilesPeriodMillisecs,
std::bind(&BlobDBImpl::CheckSeqFiles, this, std::placeholders::_1));
}
Status BlobDBImpl::GetAllBlobFiles(std::set<uint64_t>* file_numbers) {
assert(file_numbers != nullptr);
std::vector<std::string> all_files;
Status s = env_->GetChildren(blob_dir_, &all_files);
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to get list of blob files, status: %s",
s.ToString().c_str());
return s;
}
for (const auto& file_name : all_files) {
uint64_t file_number;
FileType type;
bool success = ParseFileName(file_name, &file_number, &type);
if (success && type == kBlobFile) {
file_numbers->insert(file_number);
} else {
ROCKS_LOG_WARN(db_options_.info_log,
"Skipping file in blob directory: %s", file_name.c_str());
}
}
return s;
}
Status BlobDBImpl::OpenAllBlobFiles() {
std::set<uint64_t> file_numbers;
Status s = GetAllBlobFiles(&file_numbers);
if (!s.ok()) {
return s;
}
if (!file_numbers.empty()) {
next_file_number_.store(*file_numbers.rbegin() + 1);
}
std::string blob_file_list;
std::string obsolete_file_list;
for (auto& file_number : file_numbers) {
std::shared_ptr<BlobFile> blob_file = std::make_shared<BlobFile>(
this, blob_dir_, file_number, db_options_.info_log.get());
blob_file->MarkImmutable();
// Read file header and footer
Status read_metadata_status = blob_file->ReadMetadata(env_, env_options_);
if (read_metadata_status.IsCorruption()) {
// Remove incomplete file.
ObsoleteBlobFile(blob_file, 0 /*obsolete_seq*/, false /*update_size*/);
if (!obsolete_file_list.empty()) {
obsolete_file_list.append(", ");
}
obsolete_file_list.append(ToString(file_number));
continue;
} else if (!read_metadata_status.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Unable to read metadata of blob file % " PRIu64
", status: '%s'",
file_number, read_metadata_status.ToString().c_str());
return read_metadata_status;
}
total_blob_size_ += blob_file->GetFileSize();
blob_files_[file_number] = blob_file;
if (!blob_file_list.empty()) {
blob_file_list.append(", ");
}
blob_file_list.append(ToString(file_number));
}
ROCKS_LOG_INFO(db_options_.info_log,
"Found %" ROCKSDB_PRIszt " blob files: %s", blob_files_.size(),
blob_file_list.c_str());
ROCKS_LOG_INFO(db_options_.info_log,
"Found %" ROCKSDB_PRIszt
" incomplete or corrupted blob files: %s",
obsolete_files_.size(), obsolete_file_list.c_str());
return s;
}
void BlobDBImpl::CloseRandomAccessLocked(
const std::shared_ptr<BlobFile>& bfile) {
bfile->CloseRandomAccessLocked();
open_file_count_--;
}
std::shared_ptr<RandomAccessFileReader> BlobDBImpl::GetOrOpenRandomAccessReader(
const std::shared_ptr<BlobFile>& bfile, Env* env,
const EnvOptions& env_options) {
bool fresh_open = false;
auto rar = bfile->GetOrOpenRandomAccessReader(env, env_options, &fresh_open);
if (fresh_open) open_file_count_++;
return rar;
}
std::shared_ptr<BlobFile> BlobDBImpl::NewBlobFile(const std::string& reason) {
uint64_t file_num = next_file_number_++;
auto bfile = std::make_shared<BlobFile>(this, blob_dir_, file_num,
db_options_.info_log.get());
ROCKS_LOG_DEBUG(db_options_.info_log, "New blob file created: %s reason='%s'",
bfile->PathName().c_str(), reason.c_str());
LogFlush(db_options_.info_log);
return bfile;
}
Status BlobDBImpl::CreateWriterLocked(const std::shared_ptr<BlobFile>& bfile) {
std::string fpath(bfile->PathName());
std::unique_ptr<WritableFile> wfile;
Status s = env_->ReopenWritableFile(fpath, &wfile, env_options_);
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to open blob file for write: %s status: '%s'"
" exists: '%s'",
fpath.c_str(), s.ToString().c_str(),
env_->FileExists(fpath).ToString().c_str());
return s;
}
std::unique_ptr<WritableFileWriter> fwriter;
fwriter.reset(new WritableFileWriter(std::move(wfile), env_options_));
uint64_t boffset = bfile->GetFileSize();
if (debug_level_ >= 2 && boffset) {
ROCKS_LOG_DEBUG(db_options_.info_log, "Open blob file: %s with offset: %d",
fpath.c_str(), boffset);
}
Writer::ElemType et = Writer::kEtNone;
if (bfile->file_size_ == BlobLogHeader::kSize) {
et = Writer::kEtFileHdr;
} else if (bfile->file_size_ > BlobLogHeader::kSize) {
et = Writer::kEtRecord;
} else if (bfile->file_size_) {
ROCKS_LOG_WARN(db_options_.info_log,
"Open blob file: %s with wrong size: %d", fpath.c_str(),
boffset);
return Status::Corruption("Invalid blob file size");
}
bfile->log_writer_ = std::make_shared<Writer>(
std::move(fwriter), env_, statistics_, bfile->file_number_,
bdb_options_.bytes_per_sync, db_options_.use_fsync, boffset);
bfile->log_writer_->last_elem_type_ = et;
return s;
}
std::shared_ptr<BlobFile> BlobDBImpl::FindBlobFileLocked(
uint64_t expiration) const {
if (open_ttl_files_.empty()) {
return nullptr;
}
std::shared_ptr<BlobFile> tmp = std::make_shared<BlobFile>();
tmp->SetHasTTL(true);
tmp->expiration_range_ = std::make_pair(expiration, 0);
tmp->file_number_ = std::numeric_limits<uint64_t>::max();
auto citr = open_ttl_files_.equal_range(tmp);
if (citr.first == open_ttl_files_.end()) {
assert(citr.second == open_ttl_files_.end());
std::shared_ptr<BlobFile> check = *(open_ttl_files_.rbegin());
return (check->expiration_range_.second <= expiration) ? nullptr : check;
}
if (citr.first != citr.second) {
return *(citr.first);
}
auto finditr = citr.second;
if (finditr != open_ttl_files_.begin()) {
--finditr;
}
bool b2 = (*finditr)->expiration_range_.second <= expiration;
bool b1 = (*finditr)->expiration_range_.first > expiration;
return (b1 || b2) ? nullptr : (*finditr);
}
std::shared_ptr<Writer> BlobDBImpl::CheckOrCreateWriterLocked(
const std::shared_ptr<BlobFile>& bfile) {
std::shared_ptr<Writer> writer = bfile->GetWriter();
if (writer) return writer;
Status s = CreateWriterLocked(bfile);
if (!s.ok()) return nullptr;
writer = bfile->GetWriter();
return writer;
}
std::shared_ptr<BlobFile> BlobDBImpl::SelectBlobFile() {
{
ReadLock rl(&mutex_);
if (open_non_ttl_file_ != nullptr) {
return open_non_ttl_file_;
}
}
// CHECK again
WriteLock wl(&mutex_);
if (open_non_ttl_file_ != nullptr) {
return open_non_ttl_file_;
}
std::shared_ptr<BlobFile> bfile = NewBlobFile("SelectBlobFile");
assert(bfile);
// file not visible, hence no lock
std::shared_ptr<Writer> writer = CheckOrCreateWriterLocked(bfile);
if (!writer) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to get writer from blob file: %s",
bfile->PathName().c_str());
return nullptr;
}
bfile->file_size_ = BlobLogHeader::kSize;
bfile->header_.compression = bdb_options_.compression;
bfile->header_.has_ttl = false;
bfile->header_.column_family_id =
reinterpret_cast<ColumnFamilyHandleImpl*>(DefaultColumnFamily())->GetID();
bfile->header_valid_ = true;
bfile->SetColumnFamilyId(bfile->header_.column_family_id);
bfile->SetHasTTL(false);
bfile->SetCompression(bdb_options_.compression);
Status s = writer->WriteHeader(bfile->header_);
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to write header to new blob file: %s"
" status: '%s'",
bfile->PathName().c_str(), s.ToString().c_str());
return nullptr;
}
blob_files_.insert(std::make_pair(bfile->BlobFileNumber(), bfile));
open_non_ttl_file_ = bfile;
total_blob_size_ += BlobLogHeader::kSize;
return bfile;
}
std::shared_ptr<BlobFile> BlobDBImpl::SelectBlobFileTTL(uint64_t expiration) {
assert(expiration != kNoExpiration);
uint64_t epoch_read = 0;
std::shared_ptr<BlobFile> bfile;
{
ReadLock rl(&mutex_);
bfile = FindBlobFileLocked(expiration);
epoch_read = epoch_of_.load();
}
if (bfile) {
assert(!bfile->Immutable());
return bfile;
}
uint64_t exp_low =
(expiration / bdb_options_.ttl_range_secs) * bdb_options_.ttl_range_secs;
uint64_t exp_high = exp_low + bdb_options_.ttl_range_secs;
ExpirationRange expiration_range = std::make_pair(exp_low, exp_high);
bfile = NewBlobFile("SelectBlobFileTTL");
assert(bfile);
ROCKS_LOG_INFO(db_options_.info_log, "New blob file TTL range: %s %d %d",
bfile->PathName().c_str(), exp_low, exp_high);
LogFlush(db_options_.info_log);
// we don't need to take lock as no other thread is seeing bfile yet
std::shared_ptr<Writer> writer = CheckOrCreateWriterLocked(bfile);
if (!writer) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to get writer from blob file with TTL: %s",
bfile->PathName().c_str());
return nullptr;
}
bfile->header_.expiration_range = expiration_range;
bfile->header_.compression = bdb_options_.compression;
bfile->header_.has_ttl = true;
bfile->header_.column_family_id =
reinterpret_cast<ColumnFamilyHandleImpl*>(DefaultColumnFamily())->GetID();
;
bfile->header_valid_ = true;
bfile->SetColumnFamilyId(bfile->header_.column_family_id);
bfile->SetHasTTL(true);
bfile->SetCompression(bdb_options_.compression);
bfile->file_size_ = BlobLogHeader::kSize;
// set the first value of the range, since that is
// concrete at this time. also necessary to add to open_ttl_files_
bfile->expiration_range_ = expiration_range;
WriteLock wl(&mutex_);
// in case the epoch has shifted in the interim, then check
// check condition again - should be rare.
if (epoch_of_.load() != epoch_read) {
auto bfile2 = FindBlobFileLocked(expiration);
if (bfile2) return bfile2;
}
Status s = writer->WriteHeader(bfile->header_);
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to write header to new blob file: %s"
" status: '%s'",
bfile->PathName().c_str(), s.ToString().c_str());
return nullptr;
}
blob_files_.insert(std::make_pair(bfile->BlobFileNumber(), bfile));
open_ttl_files_.insert(bfile);
total_blob_size_ += BlobLogHeader::kSize;
epoch_of_++;
return bfile;
}
class BlobDBImpl::BlobInserter : public WriteBatch::Handler {
private:
const WriteOptions& options_;
BlobDBImpl* blob_db_impl_;
uint32_t default_cf_id_;
WriteBatch batch_;
public:
BlobInserter(const WriteOptions& options, BlobDBImpl* blob_db_impl,
uint32_t default_cf_id)
: options_(options),
blob_db_impl_(blob_db_impl),
default_cf_id_(default_cf_id) {}
WriteBatch* batch() { return &batch_; }
virtual Status PutCF(uint32_t column_family_id, const Slice& key,
const Slice& value) override {
if (column_family_id != default_cf_id_) {
return Status::NotSupported(
"Blob DB doesn't support non-default column family.");
}
std::string new_value;
Slice value_slice;
uint64_t expiration =
blob_db_impl_->ExtractExpiration(key, value, &value_slice, &new_value);
Status s = blob_db_impl_->PutBlobValue(options_, key, value_slice,
expiration, &batch_);
return s;
}
virtual Status DeleteCF(uint32_t column_family_id,
const Slice& key) override {
if (column_family_id != default_cf_id_) {
return Status::NotSupported(
"Blob DB doesn't support non-default column family.");
}
Status s = WriteBatchInternal::Delete(&batch_, column_family_id, key);
return s;
}
virtual Status DeleteRange(uint32_t column_family_id, const Slice& begin_key,
const Slice& end_key) {
if (column_family_id != default_cf_id_) {
return Status::NotSupported(
"Blob DB doesn't support non-default column family.");
}
Status s = WriteBatchInternal::DeleteRange(&batch_, column_family_id,
begin_key, end_key);
return s;
}
virtual Status SingleDeleteCF(uint32_t /*column_family_id*/,
const Slice& /*key*/) override {
return Status::NotSupported("Not supported operation in blob db.");
}
virtual Status MergeCF(uint32_t /*column_family_id*/, const Slice& /*key*/,
const Slice& /*value*/) override {
return Status::NotSupported("Not supported operation in blob db.");
}
virtual void LogData(const Slice& blob) override { batch_.PutLogData(blob); }
};
Status BlobDBImpl::Write(const WriteOptions& options, WriteBatch* updates) {
StopWatch write_sw(env_, statistics_, BLOB_DB_WRITE_MICROS);
RecordTick(statistics_, BLOB_DB_NUM_WRITE);
uint32_t default_cf_id =
reinterpret_cast<ColumnFamilyHandleImpl*>(DefaultColumnFamily())->GetID();
Status s;
BlobInserter blob_inserter(options, this, default_cf_id);
{
// Release write_mutex_ before DB write to avoid race condition with
// flush begin listener, which also require write_mutex_ to sync
// blob files.
MutexLock l(&write_mutex_);
s = updates->Iterate(&blob_inserter);
}
if (!s.ok()) {
return s;
}
return db_->Write(options, blob_inserter.batch());
}
Status BlobDBImpl::GetLiveFiles(std::vector<std::string>& ret,
uint64_t* manifest_file_size,
bool flush_memtable) {
// Hold a lock in the beginning to avoid updates to base DB during the call
ReadLock rl(&mutex_);
Status s = db_->GetLiveFiles(ret, manifest_file_size, flush_memtable);
if (!s.ok()) {
return s;
}
ret.reserve(ret.size() + blob_files_.size());
for (auto bfile_pair : blob_files_) {
auto blob_file = bfile_pair.second;
ret.emplace_back(blob_file->PathName());
}
return Status::OK();
}
void BlobDBImpl::GetLiveFilesMetaData(std::vector<LiveFileMetaData>* metadata) {
// Hold a lock in the beginning to avoid updates to base DB during the call
ReadLock rl(&mutex_);
db_->GetLiveFilesMetaData(metadata);
for (auto bfile_pair : blob_files_) {
auto blob_file = bfile_pair.second;
LiveFileMetaData filemetadata;
filemetadata.size = blob_file->GetFileSize();
filemetadata.name = blob_file->PathName();
auto cfh =
reinterpret_cast<ColumnFamilyHandleImpl*>(DefaultColumnFamily());
filemetadata.column_family_name = cfh->GetName();
metadata->emplace_back(filemetadata);
}
}
Status BlobDBImpl::Put(const WriteOptions& options, const Slice& key,
const Slice& value) {
std::string new_value;
Slice value_slice;
uint64_t expiration = ExtractExpiration(key, value, &value_slice, &new_value);
return PutUntil(options, key, value_slice, expiration);
}
Status BlobDBImpl::PutWithTTL(const WriteOptions& options,
const Slice& key, const Slice& value,
uint64_t ttl) {
uint64_t now = EpochNow();
uint64_t expiration = kNoExpiration - now > ttl ? now + ttl : kNoExpiration;
return PutUntil(options, key, value, expiration);
}
Status BlobDBImpl::PutUntil(const WriteOptions& options, const Slice& key,
const Slice& value, uint64_t expiration) {
StopWatch write_sw(env_, statistics_, BLOB_DB_WRITE_MICROS);
RecordTick(statistics_, BLOB_DB_NUM_PUT);
TEST_SYNC_POINT("BlobDBImpl::PutUntil:Start");
Status s;
WriteBatch batch;
{
// Release write_mutex_ before DB write to avoid race condition with
// flush begin listener, which also require write_mutex_ to sync
// blob files.
MutexLock l(&write_mutex_);
s = PutBlobValue(options, key, value, expiration, &batch);
}
if (s.ok()) {
s = db_->Write(options, &batch);
}
TEST_SYNC_POINT("BlobDBImpl::PutUntil:Finish");
return s;
}
Status BlobDBImpl::PutBlobValue(const WriteOptions& /*options*/,
const Slice& key, const Slice& value,
uint64_t expiration, WriteBatch* batch) {
write_mutex_.AssertHeld();
Status s;
std::string index_entry;
uint32_t column_family_id =
reinterpret_cast<ColumnFamilyHandleImpl*>(DefaultColumnFamily())->GetID();
if (value.size() < bdb_options_.min_blob_size) {
if (expiration == kNoExpiration) {
// Put as normal value
s = batch->Put(key, value);
RecordTick(statistics_, BLOB_DB_WRITE_INLINED);
} else {
// Inlined with TTL
BlobIndex::EncodeInlinedTTL(&index_entry, expiration, value);
s = WriteBatchInternal::PutBlobIndex(batch, column_family_id, key,
index_entry);
RecordTick(statistics_, BLOB_DB_WRITE_INLINED_TTL);
}
} else {
std::string compression_output;
Slice value_compressed = GetCompressedSlice(value, &compression_output);
std::string headerbuf;
Writer::ConstructBlobHeader(&headerbuf, key, value_compressed, expiration);
// Check DB size limit before selecting blob file to
// Since CheckSizeAndEvictBlobFiles() can close blob files, it needs to be
// done before calling SelectBlobFile().
s = CheckSizeAndEvictBlobFiles(headerbuf.size() + key.size() +
value_compressed.size());
if (!s.ok()) {
return s;
}
std::shared_ptr<BlobFile> bfile = (expiration != kNoExpiration)
? SelectBlobFileTTL(expiration)
: SelectBlobFile();
assert(bfile != nullptr);
assert(bfile->compression() == bdb_options_.compression);
s = AppendBlob(bfile, headerbuf, key, value_compressed, expiration,
&index_entry);
if (expiration == kNoExpiration) {
RecordTick(statistics_, BLOB_DB_WRITE_BLOB);
} else {
RecordTick(statistics_, BLOB_DB_WRITE_BLOB_TTL);
}
if (s.ok()) {
if (expiration != kNoExpiration) {
bfile->ExtendExpirationRange(expiration);
}
s = CloseBlobFileIfNeeded(bfile);
if (s.ok()) {
s = WriteBatchInternal::PutBlobIndex(batch, column_family_id, key,
index_entry);
}
} else {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to append blob to FILE: %s: KEY: %s VALSZ: %d"
" status: '%s' blob_file: '%s'",
bfile->PathName().c_str(), key.ToString().c_str(),
value.size(), s.ToString().c_str(),
bfile->DumpState().c_str());
}
}
RecordTick(statistics_, BLOB_DB_NUM_KEYS_WRITTEN);
RecordTick(statistics_, BLOB_DB_BYTES_WRITTEN, key.size() + value.size());
MeasureTime(statistics_, BLOB_DB_KEY_SIZE, key.size());
MeasureTime(statistics_, BLOB_DB_VALUE_SIZE, value.size());
return s;
}
Slice BlobDBImpl::GetCompressedSlice(const Slice& raw,
std::string* compression_output) const {
if (bdb_options_.compression == kNoCompression) {
return raw;
}
StopWatch compression_sw(env_, statistics_, BLOB_DB_COMPRESSION_MICROS);
CompressionType ct = bdb_options_.compression;
CompressionContext compression_ctx(ct);
CompressBlock(raw, compression_ctx, &ct, kBlockBasedTableVersionFormat,
compression_output);
return *compression_output;
}
uint64_t BlobDBImpl::ExtractExpiration(const Slice& key, const Slice& value,
Slice* value_slice,
std::string* new_value) {
uint64_t expiration = kNoExpiration;
bool has_expiration = false;
bool value_changed = false;
if (ttl_extractor_ != nullptr) {
has_expiration = ttl_extractor_->ExtractExpiration(
key, value, EpochNow(), &expiration, new_value, &value_changed);
}
*value_slice = value_changed ? Slice(*new_value) : value;
return has_expiration ? expiration : kNoExpiration;
}
void BlobDBImpl::GetCompactionContext(BlobCompactionContext* context) {
ReadLock l(&mutex_);
context->next_file_number = next_file_number_.load();
context->current_blob_files.clear();
for (auto& p : blob_files_) {
context->current_blob_files.insert(p.first);
}
context->fifo_eviction_seq = fifo_eviction_seq_;
context->evict_expiration_up_to = evict_expiration_up_to_;
}
void BlobDBImpl::UpdateLiveSSTSize() {
uint64_t live_sst_size = 0;
bool ok = GetIntProperty(DB::Properties::kLiveSstFilesSize, &live_sst_size);
if (ok) {
live_sst_size_.store(live_sst_size);
ROCKS_LOG_INFO(db_options_.info_log,
"Updated total SST file size: %" PRIu64 " bytes.",
live_sst_size);
} else {
ROCKS_LOG_ERROR(
db_options_.info_log,
"Failed to update total SST file size after flush or compaction.");
}
{
// Trigger FIFO eviction if needed.
MutexLock l(&write_mutex_);
Status s = CheckSizeAndEvictBlobFiles(0, true /*force*/);
if (s.IsNoSpace()) {
ROCKS_LOG_WARN(db_options_.info_log,
"DB grow out-of-space after SST size updated. Current live"
" SST size: %" PRIu64
" , current blob files size: %" PRIu64 ".",
live_sst_size_.load(), total_blob_size_.load());
}
}
}
Status BlobDBImpl::CheckSizeAndEvictBlobFiles(uint64_t blob_size,
bool force_evict) {
write_mutex_.AssertHeld();
uint64_t live_sst_size = live_sst_size_.load();
if (bdb_options_.max_db_size == 0 ||
live_sst_size + total_blob_size_.load() + blob_size <=
bdb_options_.max_db_size) {
return Status::OK();
}
if (bdb_options_.is_fifo == false ||
(!force_evict && live_sst_size + blob_size > bdb_options_.max_db_size)) {
// FIFO eviction is disabled, or no space to insert new blob even we evict
// all blob files.
return Status::NoSpace(
"Write failed, as writing it would exceed max_db_size limit.");
}
std::vector<std::shared_ptr<BlobFile>> candidate_files;
CopyBlobFiles(&candidate_files,
[&](const std::shared_ptr<BlobFile>& blob_file) {
// Only evict TTL files
return blob_file->HasTTL();
});
std::sort(candidate_files.begin(), candidate_files.end(),
blobf_compare_ttl());
std::reverse(candidate_files.begin(), candidate_files.end());
fifo_eviction_seq_ = GetLatestSequenceNumber();
WriteLock l(&mutex_);
while (!candidate_files.empty() &&
live_sst_size + total_blob_size_.load() + blob_size >
bdb_options_.max_db_size) {
std::shared_ptr<BlobFile> blob_file = candidate_files.back();
candidate_files.pop_back();
WriteLock file_lock(&blob_file->mutex_);
if (blob_file->Obsolete()) {
// File already obsoleted by someone else.
continue;
}
// FIFO eviction can evict open blob files.
if (!blob_file->Immutable()) {
Status s = CloseBlobFile(blob_file, false /*need_lock*/);
if (!s.ok()) {
return s;
}
}
assert(blob_file->Immutable());
auto expiration_range = blob_file->GetExpirationRange();
ROCKS_LOG_INFO(db_options_.info_log,
"Evict oldest blob file since DB out of space. Current "
"live SST file size: %" PRIu64 ", total blob size: %" PRIu64
", max db size: %" PRIu64 ", evicted blob file #%" PRIu64
" with expiration range (%" PRIu64 ", %" PRIu64 ").",
live_sst_size, total_blob_size_.load(),
bdb_options_.max_db_size, blob_file->BlobFileNumber(),
expiration_range.first, expiration_range.second);
ObsoleteBlobFile(blob_file, fifo_eviction_seq_, true /*update_size*/);
evict_expiration_up_to_ = expiration_range.first;
RecordTick(statistics_, BLOB_DB_FIFO_NUM_FILES_EVICTED);
RecordTick(statistics_, BLOB_DB_FIFO_NUM_KEYS_EVICTED,
blob_file->BlobCount());
RecordTick(statistics_, BLOB_DB_FIFO_BYTES_EVICTED,
blob_file->GetFileSize());
TEST_SYNC_POINT("BlobDBImpl::EvictOldestBlobFile:Evicted");
}
if (live_sst_size + total_blob_size_.load() + blob_size >
bdb_options_.max_db_size) {
return Status::NoSpace(
"Write failed, as writing it would exceed max_db_size limit.");
}
return Status::OK();
}
Status BlobDBImpl::AppendBlob(const std::shared_ptr<BlobFile>& bfile,
const std::string& headerbuf, const Slice& key,
const Slice& value, uint64_t expiration,
std::string* index_entry) {
Status s;
uint64_t blob_offset = 0;
uint64_t key_offset = 0;
{
WriteLock lockbfile_w(&bfile->mutex_);
std::shared_ptr<Writer> writer = CheckOrCreateWriterLocked(bfile);
if (!writer) {
return Status::IOError("Failed to create blob writer");
}
// write the blob to the blob log.
s = writer->EmitPhysicalRecord(headerbuf, key, value, &key_offset,
&blob_offset);
}
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Invalid status in AppendBlob: %s status: '%s'",
bfile->PathName().c_str(), s.ToString().c_str());
return s;
}
// increment blob count
bfile->blob_count_++;
uint64_t size_put = headerbuf.size() + key.size() + value.size();
bfile->file_size_ += size_put;
total_blob_size_ += size_put;
if (expiration == kNoExpiration) {
BlobIndex::EncodeBlob(index_entry, bfile->BlobFileNumber(), blob_offset,
value.size(), bdb_options_.compression);
} else {
BlobIndex::EncodeBlobTTL(index_entry, expiration, bfile->BlobFileNumber(),
blob_offset, value.size(),
bdb_options_.compression);
}
return s;
}
std::vector<Status> BlobDBImpl::MultiGet(
const ReadOptions& read_options,
const std::vector<Slice>& keys, std::vector<std::string>* values) {
StopWatch multiget_sw(env_, statistics_, BLOB_DB_MULTIGET_MICROS);
RecordTick(statistics_, BLOB_DB_NUM_MULTIGET);
// Get a snapshot to avoid blob file get deleted between we
// fetch and index entry and reading from the file.
ReadOptions ro(read_options);
bool snapshot_created = SetSnapshotIfNeeded(&ro);
std::vector<Status> statuses;
statuses.reserve(keys.size());
values->clear();
values->reserve(keys.size());
PinnableSlice value;
for (size_t i = 0; i < keys.size(); i++) {
statuses.push_back(Get(ro, DefaultColumnFamily(), keys[i], &value));
values->push_back(value.ToString());
value.Reset();
}
if (snapshot_created) {
db_->ReleaseSnapshot(ro.snapshot);
}
return statuses;
}
bool BlobDBImpl::SetSnapshotIfNeeded(ReadOptions* read_options) {
assert(read_options != nullptr);
if (read_options->snapshot != nullptr) {
return false;
}
read_options->snapshot = db_->GetSnapshot();
return true;
}
Status BlobDBImpl::GetBlobValue(const Slice& key, const Slice& index_entry,
PinnableSlice* value) {
assert(value != nullptr);
BlobIndex blob_index;
Status s = blob_index.DecodeFrom(index_entry);
if (!s.ok()) {
return s;
}
if (blob_index.HasTTL() && blob_index.expiration() <= EpochNow()) {
return Status::NotFound("Key expired");
}
if (blob_index.IsInlined()) {
// TODO(yiwu): If index_entry is a PinnableSlice, we can also pin the same
// memory buffer to avoid extra copy.
value->PinSelf(blob_index.value());
return Status::OK();
}
if (blob_index.size() == 0) {
value->PinSelf("");
return Status::OK();
}
// offset has to have certain min, as we will read CRC
// later from the Blob Header, which needs to be also a
// valid offset.
if (blob_index.offset() <
(BlobLogHeader::kSize + BlobLogRecord::kHeaderSize + key.size())) {
if (debug_level_ >= 2) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Invalid blob index file_number: %" PRIu64
" blob_offset: %" PRIu64 " blob_size: %" PRIu64
" key: %s",
blob_index.file_number(), blob_index.offset(),
blob_index.size(), key.data());
}
return Status::NotFound("Invalid blob offset");
}
std::shared_ptr<BlobFile> bfile;
{
ReadLock rl(&mutex_);
auto hitr = blob_files_.find(blob_index.file_number());
// file was deleted
if (hitr == blob_files_.end()) {
return Status::NotFound("Blob Not Found as blob file missing");
}
bfile = hitr->second;
}
if (blob_index.size() == 0 && value != nullptr) {
value->PinSelf("");
return Status::OK();
}
// takes locks when called
std::shared_ptr<RandomAccessFileReader> reader =
GetOrOpenRandomAccessReader(bfile, env_, env_options_);
assert(blob_index.offset() > key.size() + sizeof(uint32_t));
uint64_t record_offset = blob_index.offset() - key.size() - sizeof(uint32_t);
uint64_t record_size = sizeof(uint32_t) + key.size() + blob_index.size();
// Allocate the buffer. This is safe in C++11
std::string buffer_str(record_size, static_cast<char>(0));
char* buffer = &buffer_str[0];
// A partial blob record contain checksum, key and value.
Slice blob_record;
{
StopWatch read_sw(env_, statistics_, BLOB_DB_BLOB_FILE_READ_MICROS);
s = reader->Read(record_offset, record_size, &blob_record, buffer);
RecordTick(statistics_, BLOB_DB_BLOB_FILE_BYTES_READ, blob_record.size());
}
if (!s.ok()) {
ROCKS_LOG_DEBUG(db_options_.info_log,
"Failed to read blob from blob file %" PRIu64
", blob_offset: %" PRIu64 ", blob_size: %" PRIu64
", key_size: " PRIu64 ", read " PRIu64
" bytes, status: '%s'",
bfile->BlobFileNumber(), blob_index.offset(),
blob_index.size(), key.size(), s.ToString().c_str());
return s;
}
if (blob_record.size() != record_size) {
ROCKS_LOG_DEBUG(db_options_.info_log,
"Failed to read blob from blob file %" PRIu64
", blob_offset: %" PRIu64 ", blob_size: %" PRIu64
", key_size: " PRIu64 ", read " PRIu64
" bytes, status: '%s'",
bfile->BlobFileNumber(), blob_index.offset(),
blob_index.size(), key.size(), s.ToString().c_str());
return Status::Corruption("Failed to retrieve blob from blob index.");
}
Slice crc_slice(blob_record.data(), sizeof(uint32_t));
Slice blob_value(blob_record.data() + sizeof(uint32_t) + key.size(),
blob_index.size());
uint32_t crc_exp;
if (!GetFixed32(&crc_slice, &crc_exp)) {
ROCKS_LOG_DEBUG(db_options_.info_log,
"Unable to decode CRC from blob file %" PRIu64
", blob_offset: %" PRIu64 ", blob_size: %" PRIu64
", key size: %" PRIu64 ", status: '%s'",
bfile->BlobFileNumber(), blob_index.offset(),
blob_index.size(), key.size(), s.ToString().c_str());
return Status::Corruption("Unable to decode checksum.");
}
uint32_t crc = crc32c::Value(blob_record.data() + sizeof(uint32_t),
blob_record.size() - sizeof(uint32_t));
crc = crc32c::Mask(crc); // Adjust for storage
if (crc != crc_exp) {
if (debug_level_ >= 2) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Blob crc mismatch file: %s blob_offset: %" PRIu64
" blob_size: %" PRIu64 " key: %s status: '%s'",
bfile->PathName().c_str(), blob_index.offset(),
blob_index.size(), key.data(), s.ToString().c_str());
}
return Status::Corruption("Corruption. Blob CRC mismatch");
}
if (bfile->compression() == kNoCompression) {
value->PinSelf(blob_value);
} else {
BlockContents contents;
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(DefaultColumnFamily());
{
StopWatch decompression_sw(env_, statistics_,
BLOB_DB_DECOMPRESSION_MICROS);
UncompressionContext uncompression_ctx(bfile->compression());
s = UncompressBlockContentsForCompressionType(
uncompression_ctx,
blob_value.data(), blob_value.size(), &contents,
kBlockBasedTableVersionFormat,
*(cfh->cfd()->ioptions()));
}
value->PinSelf(contents.data);
}
return s;
}
Status BlobDBImpl::Get(const ReadOptions& read_options,
ColumnFamilyHandle* column_family, const Slice& key,
PinnableSlice* value) {
StopWatch get_sw(env_, statistics_, BLOB_DB_GET_MICROS);
RecordTick(statistics_, BLOB_DB_NUM_GET);
return GetImpl(read_options, column_family, key, value);
}
Status BlobDBImpl::GetImpl(const ReadOptions& read_options,
ColumnFamilyHandle* column_family, const Slice& key,
PinnableSlice* value) {
if (column_family != DefaultColumnFamily()) {
return Status::NotSupported(
"Blob DB doesn't support non-default column family.");
}
// Get a snapshot to avoid blob file get deleted between we
// fetch and index entry and reading from the file.
// TODO(yiwu): For Get() retry if file not found would be a simpler strategy.
ReadOptions ro(read_options);
bool snapshot_created = SetSnapshotIfNeeded(&ro);
Status s;
bool is_blob_index = false;
s = db_impl_->GetImpl(ro, column_family, key, value,
nullptr /*value_found*/, nullptr /*read_callback*/,
&is_blob_index);
TEST_SYNC_POINT("BlobDBImpl::Get:AfterIndexEntryGet:1");
TEST_SYNC_POINT("BlobDBImpl::Get:AfterIndexEntryGet:2");
if (s.ok() && is_blob_index) {
std::string index_entry = value->ToString();
value->Reset();
s = GetBlobValue(key, index_entry, value);
}
if (snapshot_created) {
db_->ReleaseSnapshot(ro.snapshot);
}
RecordTick(statistics_, BLOB_DB_NUM_KEYS_READ);
RecordTick(statistics_, BLOB_DB_BYTES_READ, value->size());
return s;
}
std::pair<bool, int64_t> BlobDBImpl::SanityCheck(bool aborted) {
if (aborted) return std::make_pair(false, -1);
ROCKS_LOG_INFO(db_options_.info_log, "Starting Sanity Check");
ROCKS_LOG_INFO(db_options_.info_log, "Number of files %" PRIu64,
blob_files_.size());
ROCKS_LOG_INFO(db_options_.info_log, "Number of open files %" PRIu64,
open_ttl_files_.size());
for (auto bfile : open_ttl_files_) {
assert(!bfile->Immutable());
}
uint64_t epoch_now = EpochNow();
for (auto bfile_pair : blob_files_) {
auto bfile = bfile_pair.second;
ROCKS_LOG_INFO(
db_options_.info_log, "Blob File %s %" PRIu64 " %" PRIu64 " %" PRIu64,
bfile->PathName().c_str(), bfile->GetFileSize(), bfile->BlobCount(),
(bfile->expiration_range_.second - epoch_now));
}
// reschedule
return std::make_pair(true, -1);
}
Status BlobDBImpl::CloseBlobFile(std::shared_ptr<BlobFile> bfile,
bool need_lock) {
assert(bfile != nullptr);
write_mutex_.AssertHeld();
Status s;
ROCKS_LOG_INFO(db_options_.info_log,
"Closing blob file %" PRIu64 ". Path: %s",
bfile->BlobFileNumber(), bfile->PathName().c_str());
{
std::unique_ptr<WriteLock> lock;
if (need_lock) {
lock.reset(new WriteLock(&mutex_));
}
if (bfile->HasTTL()) {
size_t erased __attribute__((__unused__));
erased = open_ttl_files_.erase(bfile);
} else if (bfile == open_non_ttl_file_) {
open_non_ttl_file_ = nullptr;
}
}
if (!bfile->closed_.load()) {
std::unique_ptr<WriteLock> file_lock;
if (need_lock) {
file_lock.reset(new WriteLock(&bfile->mutex_));
}
s = bfile->WriteFooterAndCloseLocked();
}
if (s.ok()) {
total_blob_size_ += BlobLogFooter::kSize;
} else {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to close blob file %" PRIu64 "with error: %s",
bfile->BlobFileNumber(), s.ToString().c_str());
}
return s;
}
Status BlobDBImpl::CloseBlobFileIfNeeded(std::shared_ptr<BlobFile>& bfile) {
// atomic read
if (bfile->GetFileSize() < bdb_options_.blob_file_size) {
return Status::OK();
}
return CloseBlobFile(bfile);
}
void BlobDBImpl::ObsoleteBlobFile(std::shared_ptr<BlobFile> blob_file,
SequenceNumber obsolete_seq,
bool update_size) {
// Should hold write lock of mutex_ or during DB open.
blob_file->MarkObsolete(obsolete_seq);
obsolete_files_.push_back(blob_file);
assert(total_blob_size_.load() >= blob_file->GetFileSize());
if (update_size) {
total_blob_size_ -= blob_file->GetFileSize();
}
}
bool BlobDBImpl::VisibleToActiveSnapshot(
const std::shared_ptr<BlobFile>& bfile) {
assert(bfile->Obsolete());
// We check whether the oldest snapshot is no less than the last sequence
// by the time the blob file become obsolete. If so, the blob file is not
// visible to all existing snapshots.
//
// If we keep track of the earliest sequence of the keys in the blob file,
// we could instead check if there's a snapshot falls in range
// [earliest_sequence, obsolete_sequence). But doing so will make the
// implementation more complicated.
SequenceNumber obsolete_sequence = bfile->GetObsoleteSequence();
SequenceNumber oldest_snapshot = 0;
{
// Need to lock DBImpl mutex before access snapshot list.
InstrumentedMutexLock l(db_impl_->mutex());
auto snapshots = db_impl_->snapshots();
if (!snapshots.empty()) {
oldest_snapshot = snapshots.oldest()->GetSequenceNumber();
}
}
return oldest_snapshot < obsolete_sequence;
}
std::pair<bool, int64_t> BlobDBImpl::CheckSeqFiles(bool aborted) {
if (aborted) return std::make_pair(false, -1);
std::vector<std::shared_ptr<BlobFile>> process_files;
{
uint64_t epoch_now = EpochNow();
ReadLock rl(&mutex_);
for (auto bfile : open_ttl_files_) {
{
ReadLock lockbfile_r(&bfile->mutex_);
if (bfile->expiration_range_.second > epoch_now) {
continue;
}
process_files.push_back(bfile);
}
}
}
MutexLock l(&write_mutex_);
for (auto bfile : process_files) {
CloseBlobFile(bfile);
}
return std::make_pair(true, -1);
}
Status BlobDBImpl::SyncBlobFiles() {
MutexLock l(&write_mutex_);
std::vector<std::shared_ptr<BlobFile>> process_files;
{
ReadLock rl(&mutex_);
for (auto fitr : open_ttl_files_) {
process_files.push_back(fitr);
}
if (open_non_ttl_file_ != nullptr) {
process_files.push_back(open_non_ttl_file_);
}
}
Status s;
for (auto& blob_file : process_files) {
s = blob_file->Fsync();
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to sync blob file %" PRIu64 ", status: %s",
blob_file->BlobFileNumber(), s.ToString().c_str());
return s;
}
}
s = dir_ent_->Fsync();
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failed to sync blob directory, status: %s",
s.ToString().c_str());
}
return s;
}
std::pair<bool, int64_t> BlobDBImpl::ReclaimOpenFiles(bool aborted) {
if (aborted) return std::make_pair(false, -1);
if (open_file_count_.load() < kOpenFilesTrigger) {
return std::make_pair(true, -1);
}
// in the future, we should sort by last_access_
// instead of closing every file
ReadLock rl(&mutex_);
for (auto const& ent : blob_files_) {
auto bfile = ent.second;
if (bfile->last_access_.load() == -1) continue;
WriteLock lockbfile_w(&bfile->mutex_);
CloseRandomAccessLocked(bfile);
}
return std::make_pair(true, -1);
}
// Write callback for garbage collection to check if key has been updated
// since last read. Similar to how OptimisticTransaction works. See inline
// comment in GCFileAndUpdateLSM().
class BlobDBImpl::GarbageCollectionWriteCallback : public WriteCallback {
public:
GarbageCollectionWriteCallback(ColumnFamilyData* cfd, const Slice& key,
SequenceNumber upper_bound)
: cfd_(cfd), key_(key), upper_bound_(upper_bound) {}
virtual Status Callback(DB* db) override {
auto* db_impl = reinterpret_cast<DBImpl*>(db);
auto* sv = db_impl->GetAndRefSuperVersion(cfd_);
SequenceNumber latest_seq = 0;
bool found_record_for_key = false;
bool is_blob_index = false;
Status s = db_impl->GetLatestSequenceForKey(
sv, key_, false /*cache_only*/, &latest_seq, &found_record_for_key,
&is_blob_index);
db_impl->ReturnAndCleanupSuperVersion(cfd_, sv);
if (!s.ok() && !s.IsNotFound()) {
// Error.
assert(!s.IsBusy());
return s;
}
if (s.IsNotFound()) {
assert(!found_record_for_key);
return Status::Busy("Key deleted");
}
assert(found_record_for_key);
assert(is_blob_index);
if (latest_seq > upper_bound_) {
return Status::Busy("Key overwritten");
}
return s;
}
virtual bool AllowWriteBatching() override { return false; }
private:
ColumnFamilyData* cfd_;
// Key to check
Slice key_;
// Upper bound of sequence number to proceed.
SequenceNumber upper_bound_;
};
// iterate over the blobs sequentially and check if the blob sequence number
// is the latest. If it is the latest, preserve it, otherwise delete it
// if it is TTL based, and the TTL has expired, then
// we can blow the entity if the key is still the latest or the Key is not
// found
// WHAT HAPPENS IF THE KEY HAS BEEN OVERRIDEN. Then we can drop the blob
// without doing anything if the earliest snapshot is not
// referring to that sequence number, i.e. it is later than the sequence number
// of the new key
//
// if it is not TTL based, then we can blow the key if the key has been
// DELETED in the LSM
Status BlobDBImpl::GCFileAndUpdateLSM(const std::shared_ptr<BlobFile>& bfptr,
GCStats* gc_stats) {
StopWatch gc_sw(env_, statistics_, BLOB_DB_GC_MICROS);
uint64_t now = EpochNow();
std::shared_ptr<Reader> reader =
bfptr->OpenSequentialReader(env_, db_options_, env_options_);
if (!reader) {
ROCKS_LOG_ERROR(db_options_.info_log,
"File sequential reader could not be opened",
bfptr->PathName().c_str());
return Status::IOError("failed to create sequential reader");
}
BlobLogHeader header;
Status s = reader->ReadHeader(&header);
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Failure to read header for blob-file %s",
bfptr->PathName().c_str());
return s;
}
auto* cfh =
db_impl_->GetColumnFamilyHandleUnlocked(bfptr->column_family_id());
auto* cfd = reinterpret_cast<ColumnFamilyHandleImpl*>(cfh)->cfd();
auto column_family_id = cfd->GetID();
bool has_ttl = header.has_ttl;
// this reads the key but skips the blob
Reader::ReadLevel shallow = Reader::kReadHeaderKey;
bool file_expired = has_ttl && now >= bfptr->GetExpirationRange().second;
if (!file_expired) {
// read the blob because you have to write it back to new file
shallow = Reader::kReadHeaderKeyBlob;
}
BlobLogRecord record;
std::shared_ptr<BlobFile> newfile;
std::shared_ptr<Writer> new_writer;
uint64_t blob_offset = 0;
while (true) {
assert(s.ok());
// Read the next blob record.
Status read_record_status =
reader->ReadRecord(&record, shallow, &blob_offset);
// Exit if we reach the end of blob file.
// TODO(yiwu): properly handle ReadRecord error.
if (!read_record_status.ok()) {
break;
}
gc_stats->blob_count++;
// Similar to OptimisticTransaction, we obtain latest_seq from
// base DB, which is guaranteed to be no smaller than the sequence of
// current key. We use a WriteCallback on write to check the key sequence
// on write. If the key sequence is larger than latest_seq, we know
// a new versions is inserted and the old blob can be disgard.
//
// We cannot use OptimisticTransaction because we need to pass
// is_blob_index flag to GetImpl.
SequenceNumber latest_seq = GetLatestSequenceNumber();
bool is_blob_index = false;
PinnableSlice index_entry;
Status get_status = db_impl_->GetImpl(
ReadOptions(), cfh, record.key, &index_entry, nullptr /*value_found*/,
nullptr /*read_callback*/, &is_blob_index);
TEST_SYNC_POINT("BlobDBImpl::GCFileAndUpdateLSM:AfterGetFromBaseDB");
if (!get_status.ok() && !get_status.IsNotFound()) {
// error
s = get_status;
ROCKS_LOG_ERROR(db_options_.info_log,
"Error while getting index entry: %s",
s.ToString().c_str());
break;
}
if (get_status.IsNotFound() || !is_blob_index) {
// Either the key is deleted or updated with a newer version whish is
// inlined in LSM.
gc_stats->num_keys_overwritten++;
gc_stats->bytes_overwritten += record.record_size();
continue;
}
BlobIndex blob_index;
s = blob_index.DecodeFrom(index_entry);
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"Error while decoding index entry: %s",
s.ToString().c_str());
break;
}
if (blob_index.IsInlined() ||
blob_index.file_number() != bfptr->BlobFileNumber() ||
blob_index.offset() != blob_offset) {
// Key has been overwritten. Drop the blob record.
gc_stats->num_keys_overwritten++;
gc_stats->bytes_overwritten += record.record_size();
continue;
}
GarbageCollectionWriteCallback callback(cfd, record.key, latest_seq);
// If key has expired, remove it from base DB.
// TODO(yiwu): Blob indexes will be remove by BlobIndexCompactionFilter.
// We can just drop the blob record.
if (file_expired || (has_ttl && now >= record.expiration)) {
gc_stats->num_keys_expired++;
gc_stats->bytes_expired += record.record_size();
TEST_SYNC_POINT("BlobDBImpl::GCFileAndUpdateLSM:BeforeDelete");
WriteBatch delete_batch;
Status delete_status = delete_batch.Delete(record.key);
if (delete_status.ok()) {
delete_status = db_impl_->WriteWithCallback(WriteOptions(),
&delete_batch, &callback);
}
if (!delete_status.ok() && !delete_status.IsBusy()) {
// We hit an error.
s = delete_status;
ROCKS_LOG_ERROR(db_options_.info_log,
"Error while deleting expired key: %s",
s.ToString().c_str());
break;
}
// Continue to next blob record or retry.
continue;
}
// Relocate the blob record to new file.
if (!newfile) {
// new file
std::string reason("GC of ");
reason += bfptr->PathName();
newfile = NewBlobFile(reason);
new_writer = CheckOrCreateWriterLocked(newfile);
// Can't use header beyond this point
newfile->header_ = std::move(header);
newfile->header_valid_ = true;
newfile->file_size_ = BlobLogHeader::kSize;
newfile->SetColumnFamilyId(bfptr->column_family_id());
newfile->SetHasTTL(bfptr->HasTTL());
newfile->SetCompression(bfptr->compression());
newfile->expiration_range_ = bfptr->expiration_range_;
s = new_writer->WriteHeader(newfile->header_);
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"File: %s - header writing failed",
newfile->PathName().c_str());
break;
}
// We don't add the file to open_ttl_files_ or open_non_ttl_files_, to
// avoid user writes writing to the file, and avoid CheckSeqFiles close
// the file by mistake.
WriteLock wl(&mutex_);
blob_files_.insert(std::make_pair(newfile->BlobFileNumber(), newfile));
}
std::string new_index_entry;
uint64_t new_blob_offset = 0;
uint64_t new_key_offset = 0;
// write the blob to the blob log.
s = new_writer->AddRecord(record.key, record.value, record.expiration,
&new_key_offset, &new_blob_offset);
BlobIndex::EncodeBlob(&new_index_entry, newfile->BlobFileNumber(),
new_blob_offset, record.value.size(),
bdb_options_.compression);
newfile->blob_count_++;
newfile->file_size_ +=
BlobLogRecord::kHeaderSize + record.key.size() + record.value.size();
TEST_SYNC_POINT("BlobDBImpl::GCFileAndUpdateLSM:BeforeRelocate");
WriteBatch rewrite_batch;
Status rewrite_status = WriteBatchInternal::PutBlobIndex(
&rewrite_batch, column_family_id, record.key, new_index_entry);
if (rewrite_status.ok()) {
rewrite_status = db_impl_->WriteWithCallback(WriteOptions(),
&rewrite_batch, &callback);
}
if (rewrite_status.ok()) {
gc_stats->num_keys_relocated++;
gc_stats->bytes_relocated += record.record_size();
} else if (rewrite_status.IsBusy()) {
// The key is overwritten in the meanwhile. Drop the blob record.
gc_stats->num_keys_overwritten++;
gc_stats->bytes_overwritten += record.record_size();
} else {
// We hit an error.
s = rewrite_status;
ROCKS_LOG_ERROR(db_options_.info_log, "Error while relocating key: %s",
s.ToString().c_str());
break;
}
} // end of ReadRecord loop
{
WriteLock wl(&mutex_);
ObsoleteBlobFile(bfptr, GetLatestSequenceNumber(), true /*update_size*/);
}
ROCKS_LOG_INFO(
db_options_.info_log,
"%s blob file %" PRIu64 ". Total blob records: %" PRIu64
", expired: %" PRIu64 " keys/%" PRIu64
" bytes, updated or deleted by user: %" PRIu64 " keys/%" PRIu64
" bytes, rewrite to new file: %" PRIu64 " keys/%" PRIu64 " bytes.",
s.ok() ? "Successfully garbage collected" : "Failed to garbage collect",
bfptr->BlobFileNumber(), gc_stats->blob_count, gc_stats->num_keys_expired,
gc_stats->bytes_expired, gc_stats->num_keys_overwritten,
gc_stats->bytes_overwritten, gc_stats->num_keys_relocated,
gc_stats->bytes_relocated);
RecordTick(statistics_, BLOB_DB_GC_NUM_FILES);
RecordTick(statistics_, BLOB_DB_GC_NUM_KEYS_OVERWRITTEN,
gc_stats->num_keys_overwritten);
RecordTick(statistics_, BLOB_DB_GC_NUM_KEYS_EXPIRED,
gc_stats->num_keys_expired);
RecordTick(statistics_, BLOB_DB_GC_BYTES_OVERWRITTEN,
gc_stats->bytes_overwritten);
RecordTick(statistics_, BLOB_DB_GC_BYTES_EXPIRED, gc_stats->bytes_expired);
if (newfile != nullptr) {
{
MutexLock l(&write_mutex_);
CloseBlobFile(newfile);
}
total_blob_size_ += newfile->file_size_;
ROCKS_LOG_INFO(db_options_.info_log, "New blob file %" PRIu64 ".",
newfile->BlobFileNumber());
RecordTick(statistics_, BLOB_DB_GC_NUM_NEW_FILES);
RecordTick(statistics_, BLOB_DB_GC_NUM_KEYS_RELOCATED,
gc_stats->num_keys_relocated);
RecordTick(statistics_, BLOB_DB_GC_BYTES_RELOCATED,
gc_stats->bytes_relocated);
}
if (!s.ok()) {
RecordTick(statistics_, BLOB_DB_GC_FAILURES);
}
return s;
}
std::pair<bool, int64_t> BlobDBImpl::DeleteObsoleteFiles(bool aborted) {
if (aborted) return std::make_pair(false, -1);
{
ReadLock rl(&mutex_);
if (obsolete_files_.empty()) return std::make_pair(true, -1);
}
std::list<std::shared_ptr<BlobFile>> tobsolete;
{
WriteLock wl(&mutex_);
tobsolete.swap(obsolete_files_);
}
bool file_deleted = false;
for (auto iter = tobsolete.begin(); iter != tobsolete.end();) {
auto bfile = *iter;
{
ReadLock lockbfile_r(&bfile->mutex_);
if (VisibleToActiveSnapshot(bfile)) {
ROCKS_LOG_INFO(db_options_.info_log,
"Could not delete file due to snapshot failure %s",
bfile->PathName().c_str());
++iter;
continue;
}
}
ROCKS_LOG_INFO(db_options_.info_log,
"Will delete file due to snapshot success %s",
bfile->PathName().c_str());
blob_files_.erase(bfile->BlobFileNumber());
Status s = env_->DeleteFile(bfile->PathName());
if (!s.ok()) {
ROCKS_LOG_ERROR(db_options_.info_log,
"File failed to be deleted as obsolete %s",
bfile->PathName().c_str());
++iter;
continue;
}
file_deleted = true;
ROCKS_LOG_INFO(db_options_.info_log,
"File deleted as obsolete from blob dir %s",
bfile->PathName().c_str());
iter = tobsolete.erase(iter);
}
// directory change. Fsync
if (file_deleted) {
dir_ent_->Fsync();
}
// put files back into obsolete if for some reason, delete failed
if (!tobsolete.empty()) {
WriteLock wl(&mutex_);
for (auto bfile : tobsolete) {
obsolete_files_.push_front(bfile);
}
}
return std::make_pair(!aborted, -1);
}
void BlobDBImpl::CopyBlobFiles(
std::vector<std::shared_ptr<BlobFile>>* bfiles_copy,
std::function<bool(const std::shared_ptr<BlobFile>&)> predicate) {
ReadLock rl(&mutex_);
for (auto const& p : blob_files_) {
bool pred_value = true;
if (predicate) {
pred_value = predicate(p.second);
}
if (pred_value) {
bfiles_copy->push_back(p.second);
}
}
}
std::pair<bool, int64_t> BlobDBImpl::RunGC(bool aborted) {
if (aborted) {
return std::make_pair(false, -1);
}
// TODO(yiwu): Garbage collection implementation.
// reschedule
return std::make_pair(true, -1);
}
Iterator* BlobDBImpl::NewIterator(const ReadOptions& read_options) {
auto* cfd =
reinterpret_cast<ColumnFamilyHandleImpl*>(DefaultColumnFamily())->cfd();
// Get a snapshot to avoid blob file get deleted between we
// fetch and index entry and reading from the file.
ManagedSnapshot* own_snapshot = nullptr;
const Snapshot* snapshot = read_options.snapshot;
if (snapshot == nullptr) {
own_snapshot = new ManagedSnapshot(db_);
snapshot = own_snapshot->snapshot();
}
auto* iter = db_impl_->NewIteratorImpl(
read_options, cfd, snapshot->GetSequenceNumber(),
nullptr /*read_callback*/, true /*allow_blob*/);
return new BlobDBIterator(own_snapshot, iter, this, env_, statistics_);
}
Status DestroyBlobDB(const std::string& dbname, const Options& options,
const BlobDBOptions& bdb_options) {
const ImmutableDBOptions soptions(SanitizeOptions(dbname, options));
Env* env = soptions.env;
Status status;
std::string blobdir;
blobdir = (bdb_options.path_relative) ? dbname + "/" + bdb_options.blob_dir
: bdb_options.blob_dir;
std::vector<std::string> filenames;
env->GetChildren(blobdir, &filenames);
for (const auto& f : filenames) {
uint64_t number;
FileType type;
if (ParseFileName(f, &number, &type) && type == kBlobFile) {
Status del = env->DeleteFile(blobdir + "/" + f);
if (status.ok() && !del.ok()) {
status = del;
}
}
}
env->DeleteDir(blobdir);
Status destroy = DestroyDB(dbname, options);
if (status.ok() && !destroy.ok()) {
status = destroy;
}
return status;
}
#ifndef NDEBUG
Status BlobDBImpl::TEST_GetBlobValue(const Slice& key, const Slice& index_entry,
PinnableSlice* value) {
return GetBlobValue(key, index_entry, value);
}
std::vector<std::shared_ptr<BlobFile>> BlobDBImpl::TEST_GetBlobFiles() const {
ReadLock l(&mutex_);
std::vector<std::shared_ptr<BlobFile>> blob_files;
for (auto& p : blob_files_) {
blob_files.emplace_back(p.second);
}
return blob_files;
}
std::vector<std::shared_ptr<BlobFile>> BlobDBImpl::TEST_GetObsoleteFiles()
const {
ReadLock l(&mutex_);
std::vector<std::shared_ptr<BlobFile>> obsolete_files;
for (auto& bfile : obsolete_files_) {
obsolete_files.emplace_back(bfile);
}
return obsolete_files;
}
void BlobDBImpl::TEST_DeleteObsoleteFiles() {
DeleteObsoleteFiles(false /*abort*/);
}
Status BlobDBImpl::TEST_CloseBlobFile(std::shared_ptr<BlobFile>& bfile) {
MutexLock l(&write_mutex_);
return CloseBlobFile(bfile);
}
void BlobDBImpl::TEST_ObsoleteBlobFile(std::shared_ptr<BlobFile>& blob_file,
SequenceNumber obsolete_seq,
bool update_size) {
return ObsoleteBlobFile(blob_file, obsolete_seq, update_size);
}
Status BlobDBImpl::TEST_GCFileAndUpdateLSM(std::shared_ptr<BlobFile>& bfile,
GCStats* gc_stats) {
return GCFileAndUpdateLSM(bfile, gc_stats);
}
void BlobDBImpl::TEST_RunGC() { RunGC(false /*abort*/); }
uint64_t BlobDBImpl::TEST_live_sst_size() { return live_sst_size_.load(); }
#endif // !NDEBUG
} // namespace blob_db
} // namespace rocksdb
#endif // ROCKSDB_LITE