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rocksdb/db/db_impl/db_impl_files.cc

667 lines
24 KiB

// 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.
#include "db/db_impl/db_impl.h"
#include <cinttypes>
#include <set>
#include <unordered_set>
#include "db/event_helpers.h"
#include "db/memtable_list.h"
#include "file/file_util.h"
#include "file/sst_file_manager_impl.h"
#include "util/autovector.h"
namespace ROCKSDB_NAMESPACE {
uint64_t DBImpl::MinLogNumberToKeep() {
if (allow_2pc()) {
return versions_->min_log_number_to_keep_2pc();
} else {
return versions_->MinLogNumberWithUnflushedData();
}
}
uint64_t DBImpl::MinObsoleteSstNumberToKeep() {
mutex_.AssertHeld();
if (!pending_outputs_.empty()) {
return *pending_outputs_.begin();
}
return std::numeric_limits<uint64_t>::max();
}
// * Returns the list of live files in 'sst_live'
// If it's doing full scan:
// * Returns the list of all files in the filesystem in
// 'full_scan_candidate_files'.
// Otherwise, gets obsolete files from VersionSet.
// no_full_scan = true -- never do the full scan using GetChildren()
// force = false -- don't force the full scan, except every
// mutable_db_options_.delete_obsolete_files_period_micros
// force = true -- force the full scan
void DBImpl::FindObsoleteFiles(JobContext* job_context, bool force,
bool no_full_scan) {
mutex_.AssertHeld();
// if deletion is disabled, do nothing
if (disable_delete_obsolete_files_ > 0) {
return;
}
bool doing_the_full_scan = false;
// logic for figuring out if we're doing the full scan
if (no_full_scan) {
doing_the_full_scan = false;
} else if (force ||
mutable_db_options_.delete_obsolete_files_period_micros == 0) {
doing_the_full_scan = true;
} else {
const uint64_t now_micros = env_->NowMicros();
if ((delete_obsolete_files_last_run_ +
mutable_db_options_.delete_obsolete_files_period_micros) <
now_micros) {
doing_the_full_scan = true;
delete_obsolete_files_last_run_ = now_micros;
}
}
// don't delete files that might be currently written to from compaction
// threads
// Since job_context->min_pending_output is set, until file scan finishes,
// mutex_ cannot be released. Otherwise, we might see no min_pending_output
// here but later find newer generated unfinalized files while scanning.
if (!pending_outputs_.empty()) {
job_context->min_pending_output = *pending_outputs_.begin();
} else {
// delete all of them
job_context->min_pending_output = std::numeric_limits<uint64_t>::max();
}
// Get obsolete files. This function will also update the list of
// pending files in VersionSet().
versions_->GetObsoleteFiles(&job_context->sst_delete_files,
&job_context->manifest_delete_files,
job_context->min_pending_output);
// Mark the elements in job_context->sst_delete_files as grabbedForPurge
// so that other threads calling FindObsoleteFiles with full_scan=true
// will not add these files to candidate list for purge.
for (const auto& sst_to_del : job_context->sst_delete_files) {
MarkAsGrabbedForPurge(sst_to_del.metadata->fd.GetNumber());
}
// store the current filenum, lognum, etc
job_context->manifest_file_number = versions_->manifest_file_number();
job_context->pending_manifest_file_number =
versions_->pending_manifest_file_number();
job_context->log_number = MinLogNumberToKeep();
job_context->prev_log_number = versions_->prev_log_number();
versions_->AddLiveFiles(&job_context->sst_live);
if (doing_the_full_scan) {
InfoLogPrefix info_log_prefix(!immutable_db_options_.db_log_dir.empty(),
dbname_);
std::set<std::string> paths;
for (size_t path_id = 0; path_id < immutable_db_options_.db_paths.size();
path_id++) {
paths.insert(immutable_db_options_.db_paths[path_id].path);
}
// Note that if cf_paths is not specified in the ColumnFamilyOptions
// of a particular column family, we use db_paths as the cf_paths
// setting. Hence, there can be multiple duplicates of files from db_paths
// in the following code. The duplicate are removed while identifying
// unique files in PurgeObsoleteFiles.
for (auto cfd : *versions_->GetColumnFamilySet()) {
for (size_t path_id = 0; path_id < cfd->ioptions()->cf_paths.size();
path_id++) {
auto& path = cfd->ioptions()->cf_paths[path_id].path;
if (paths.find(path) == paths.end()) {
paths.insert(path);
}
}
}
for (auto& path : paths) {
// set of all files in the directory. We'll exclude files that are still
// alive in the subsequent processings.
std::vector<std::string> files;
env_->GetChildren(path, &files); // Ignore errors
for (const std::string& file : files) {
uint64_t number;
FileType type;
// 1. If we cannot parse the file name, we skip;
// 2. If the file with file_number equals number has already been
// grabbed for purge by another compaction job, or it has already been
// schedule for purge, we also skip it if we
// are doing full scan in order to avoid double deletion of the same
// file under race conditions. See
// https://github.com/facebook/rocksdb/issues/3573
if (!ParseFileName(file, &number, info_log_prefix.prefix, &type) ||
!ShouldPurge(number)) {
continue;
}
// TODO(icanadi) clean up this mess to avoid having one-off "/" prefixes
job_context->full_scan_candidate_files.emplace_back("/" + file, path);
}
}
// Add log files in wal_dir
if (immutable_db_options_.wal_dir != dbname_) {
std::vector<std::string> log_files;
env_->GetChildren(immutable_db_options_.wal_dir,
&log_files); // Ignore errors
for (const std::string& log_file : log_files) {
job_context->full_scan_candidate_files.emplace_back(
log_file, immutable_db_options_.wal_dir);
}
}
// Add info log files in db_log_dir
if (!immutable_db_options_.db_log_dir.empty() &&
immutable_db_options_.db_log_dir != dbname_) {
std::vector<std::string> info_log_files;
// Ignore errors
env_->GetChildren(immutable_db_options_.db_log_dir, &info_log_files);
for (std::string& log_file : info_log_files) {
job_context->full_scan_candidate_files.emplace_back(
log_file, immutable_db_options_.db_log_dir);
}
}
}
// logs_ is empty when called during recovery, in which case there can't yet
// be any tracked obsolete logs
if (!alive_log_files_.empty() && !logs_.empty()) {
uint64_t min_log_number = job_context->log_number;
size_t num_alive_log_files = alive_log_files_.size();
// find newly obsoleted log files
while (alive_log_files_.begin()->number < min_log_number) {
auto& earliest = *alive_log_files_.begin();
if (immutable_db_options_.recycle_log_file_num >
log_recycle_files_.size()) {
ROCKS_LOG_INFO(immutable_db_options_.info_log,
"adding log %" PRIu64 " to recycle list\n",
earliest.number);
log_recycle_files_.push_back(earliest.number);
} else {
job_context->log_delete_files.push_back(earliest.number);
}
if (job_context->size_log_to_delete == 0) {
job_context->prev_total_log_size = total_log_size_;
job_context->num_alive_log_files = num_alive_log_files;
}
job_context->size_log_to_delete += earliest.size;
total_log_size_ -= earliest.size;
if (two_write_queues_) {
log_write_mutex_.Lock();
}
alive_log_files_.pop_front();
if (two_write_queues_) {
log_write_mutex_.Unlock();
}
// Current log should always stay alive since it can't have
// number < MinLogNumber().
assert(alive_log_files_.size());
}
while (!logs_.empty() && logs_.front().number < min_log_number) {
auto& log = logs_.front();
if (log.getting_synced) {
log_sync_cv_.Wait();
// logs_ could have changed while we were waiting.
continue;
}
logs_to_free_.push_back(log.ReleaseWriter());
{
InstrumentedMutexLock wl(&log_write_mutex_);
logs_.pop_front();
}
}
// Current log cannot be obsolete.
assert(!logs_.empty());
}
// We're just cleaning up for DB::Write().
assert(job_context->logs_to_free.empty());
job_context->logs_to_free = logs_to_free_;
job_context->log_recycle_files.assign(log_recycle_files_.begin(),
log_recycle_files_.end());
if (job_context->HaveSomethingToDelete()) {
++pending_purge_obsolete_files_;
}
logs_to_free_.clear();
}
namespace {
bool CompareCandidateFile(const JobContext::CandidateFileInfo& first,
const JobContext::CandidateFileInfo& second) {
if (first.file_name > second.file_name) {
return true;
} else if (first.file_name < second.file_name) {
return false;
} else {
return (first.file_path > second.file_path);
}
}
}; // namespace
// Delete obsolete files and log status and information of file deletion
void DBImpl::DeleteObsoleteFileImpl(int job_id, const std::string& fname,
const std::string& path_to_sync,
FileType type, uint64_t number) {
Status file_deletion_status;
if (type == kTableFile || type == kLogFile) {
file_deletion_status =
DeleteDBFile(&immutable_db_options_, fname, path_to_sync,
/*force_bg=*/false, /*force_fg=*/!wal_in_db_path_);
} else {
file_deletion_status = env_->DeleteFile(fname);
}
TEST_SYNC_POINT_CALLBACK("DBImpl::DeleteObsoleteFileImpl:AfterDeletion",
&file_deletion_status);
if (file_deletion_status.ok()) {
ROCKS_LOG_DEBUG(immutable_db_options_.info_log,
"[JOB %d] Delete %s type=%d #%" PRIu64 " -- %s\n", job_id,
fname.c_str(), type, number,
file_deletion_status.ToString().c_str());
} else if (env_->FileExists(fname).IsNotFound()) {
ROCKS_LOG_INFO(
immutable_db_options_.info_log,
"[JOB %d] Tried to delete a non-existing file %s type=%d #%" PRIu64
" -- %s\n",
job_id, fname.c_str(), type, number,
file_deletion_status.ToString().c_str());
} else {
ROCKS_LOG_ERROR(immutable_db_options_.info_log,
"[JOB %d] Failed to delete %s type=%d #%" PRIu64 " -- %s\n",
job_id, fname.c_str(), type, number,
file_deletion_status.ToString().c_str());
}
if (type == kTableFile) {
EventHelpers::LogAndNotifyTableFileDeletion(
&event_logger_, job_id, number, fname, file_deletion_status, GetName(),
immutable_db_options_.listeners);
}
}
// Diffs the files listed in filenames and those that do not
// belong to live files are possibly removed. Also, removes all the
// files in sst_delete_files and log_delete_files.
// It is not necessary to hold the mutex when invoking this method.
void DBImpl::PurgeObsoleteFiles(JobContext& state, bool schedule_only) {
TEST_SYNC_POINT("DBImpl::PurgeObsoleteFiles:Begin");
// we'd better have sth to delete
assert(state.HaveSomethingToDelete());
// FindObsoleteFiles() should've populated this so nonzero
assert(state.manifest_file_number != 0);
// Now, convert live list to an unordered map, WITHOUT mutex held;
// set is slow.
std::unordered_map<uint64_t, const FileDescriptor*> sst_live_map;
for (const FileDescriptor& fd : state.sst_live) {
sst_live_map[fd.GetNumber()] = &fd;
}
std::unordered_set<uint64_t> log_recycle_files_set(
state.log_recycle_files.begin(), state.log_recycle_files.end());
auto candidate_files = state.full_scan_candidate_files;
candidate_files.reserve(
candidate_files.size() + state.sst_delete_files.size() +
state.log_delete_files.size() + state.manifest_delete_files.size());
// We may ignore the dbname when generating the file names.
for (auto& file : state.sst_delete_files) {
candidate_files.emplace_back(
MakeTableFileName(file.metadata->fd.GetNumber()), file.path);
if (file.metadata->table_reader_handle) {
table_cache_->Release(file.metadata->table_reader_handle);
}
file.DeleteMetadata();
}
for (auto file_num : state.log_delete_files) {
if (file_num > 0) {
candidate_files.emplace_back(LogFileName(file_num),
immutable_db_options_.wal_dir);
}
}
for (const auto& filename : state.manifest_delete_files) {
candidate_files.emplace_back(filename, dbname_);
}
// dedup state.candidate_files so we don't try to delete the same
// file twice
std::sort(candidate_files.begin(), candidate_files.end(),
CompareCandidateFile);
candidate_files.erase(
std::unique(candidate_files.begin(), candidate_files.end()),
candidate_files.end());
if (state.prev_total_log_size > 0) {
ROCKS_LOG_INFO(immutable_db_options_.info_log,
"[JOB %d] Try to delete WAL files size %" PRIu64
", prev total WAL file size %" PRIu64
", number of live WAL files %" ROCKSDB_PRIszt ".\n",
state.job_id, state.size_log_to_delete,
state.prev_total_log_size, state.num_alive_log_files);
}
std::vector<std::string> old_info_log_files;
InfoLogPrefix info_log_prefix(!immutable_db_options_.db_log_dir.empty(),
dbname_);
// File numbers of most recent two OPTIONS file in candidate_files (found in
// previos FindObsoleteFiles(full_scan=true))
// At this point, there must not be any duplicate file numbers in
// candidate_files.
uint64_t optsfile_num1 = std::numeric_limits<uint64_t>::min();
uint64_t optsfile_num2 = std::numeric_limits<uint64_t>::min();
for (const auto& candidate_file : candidate_files) {
const std::string& fname = candidate_file.file_name;
uint64_t number;
FileType type;
if (!ParseFileName(fname, &number, info_log_prefix.prefix, &type) ||
type != kOptionsFile) {
continue;
}
if (number > optsfile_num1) {
optsfile_num2 = optsfile_num1;
optsfile_num1 = number;
} else if (number > optsfile_num2) {
optsfile_num2 = number;
}
}
// Close WALs before trying to delete them.
for (const auto w : state.logs_to_free) {
// TODO: maybe check the return value of Close.
w->Close();
}
bool own_files = OwnTablesAndLogs();
std::unordered_set<uint64_t> files_to_del;
for (const auto& candidate_file : candidate_files) {
const std::string& to_delete = candidate_file.file_name;
uint64_t number;
FileType type;
// Ignore file if we cannot recognize it.
if (!ParseFileName(to_delete, &number, info_log_prefix.prefix, &type)) {
continue;
}
bool keep = true;
switch (type) {
case kLogFile:
keep = ((number >= state.log_number) ||
(number == state.prev_log_number) ||
(log_recycle_files_set.find(number) !=
log_recycle_files_set.end()));
break;
case kDescriptorFile:
// Keep my manifest file, and any newer incarnations'
// (can happen during manifest roll)
keep = (number >= state.manifest_file_number);
break;
case kTableFile:
// If the second condition is not there, this makes
// DontDeletePendingOutputs fail
keep = (sst_live_map.find(number) != sst_live_map.end()) ||
number >= state.min_pending_output;
if (!keep) {
files_to_del.insert(number);
}
break;
case kTempFile:
// Any temp files that are currently being written to must
// be recorded in pending_outputs_, which is inserted into "live".
// Also, SetCurrentFile creates a temp file when writing out new
// manifest, which is equal to state.pending_manifest_file_number. We
// should not delete that file
//
// TODO(yhchiang): carefully modify the third condition to safely
// remove the temp options files.
keep = (sst_live_map.find(number) != sst_live_map.end()) ||
(number == state.pending_manifest_file_number) ||
(to_delete.find(kOptionsFileNamePrefix) != std::string::npos);
break;
case kInfoLogFile:
keep = true;
if (number != 0) {
old_info_log_files.push_back(to_delete);
}
break;
case kOptionsFile:
keep = (number >= optsfile_num2);
TEST_SYNC_POINT_CALLBACK(
"DBImpl::PurgeObsoleteFiles:CheckOptionsFiles:1",
reinterpret_cast<void*>(&number));
TEST_SYNC_POINT_CALLBACK(
"DBImpl::PurgeObsoleteFiles:CheckOptionsFiles:2",
reinterpret_cast<void*>(&keep));
break;
case kCurrentFile:
case kDBLockFile:
case kIdentityFile:
case kMetaDatabase:
case kBlobFile:
keep = true;
break;
}
if (keep) {
continue;
}
std::string fname;
std::string dir_to_sync;
if (type == kTableFile) {
// evict from cache
TableCache::Evict(table_cache_.get(), number);
fname = MakeTableFileName(candidate_file.file_path, number);
dir_to_sync = candidate_file.file_path;
} else {
dir_to_sync =
(type == kLogFile) ? immutable_db_options_.wal_dir : dbname_;
fname = dir_to_sync +
((!dir_to_sync.empty() && dir_to_sync.back() == '/') ||
(!to_delete.empty() && to_delete.front() == '/')
? ""
: "/") +
to_delete;
}
#ifndef ROCKSDB_LITE
if (type == kLogFile && (immutable_db_options_.wal_ttl_seconds > 0 ||
immutable_db_options_.wal_size_limit_mb > 0)) {
wal_manager_.ArchiveWALFile(fname, number);
continue;
}
#endif // !ROCKSDB_LITE
// If I do not own these files, e.g. secondary instance with max_open_files
// = -1, then no need to delete or schedule delete these files since they
// will be removed by their owner, e.g. the primary instance.
if (!own_files) {
continue;
}
Status file_deletion_status;
if (schedule_only) {
InstrumentedMutexLock guard_lock(&mutex_);
SchedulePendingPurge(fname, dir_to_sync, type, number, state.job_id);
} else {
DeleteObsoleteFileImpl(state.job_id, fname, dir_to_sync, type, number);
}
}
{
// After purging obsolete files, remove them from files_grabbed_for_purge_.
InstrumentedMutexLock guard_lock(&mutex_);
autovector<uint64_t> to_be_removed;
for (auto fn : files_grabbed_for_purge_) {
if (files_to_del.count(fn) != 0) {
to_be_removed.emplace_back(fn);
}
}
for (auto fn : to_be_removed) {
files_grabbed_for_purge_.erase(fn);
}
}
// Delete old info log files.
size_t old_info_log_file_count = old_info_log_files.size();
if (old_info_log_file_count != 0 &&
old_info_log_file_count >= immutable_db_options_.keep_log_file_num) {
std::sort(old_info_log_files.begin(), old_info_log_files.end());
size_t end =
old_info_log_file_count - immutable_db_options_.keep_log_file_num;
for (unsigned int i = 0; i <= end; i++) {
std::string& to_delete = old_info_log_files.at(i);
std::string full_path_to_delete =
(immutable_db_options_.db_log_dir.empty()
? dbname_
: immutable_db_options_.db_log_dir) +
"/" + to_delete;
ROCKS_LOG_INFO(immutable_db_options_.info_log,
"[JOB %d] Delete info log file %s\n", state.job_id,
full_path_to_delete.c_str());
Status s = env_->DeleteFile(full_path_to_delete);
if (!s.ok()) {
if (env_->FileExists(full_path_to_delete).IsNotFound()) {
ROCKS_LOG_INFO(
immutable_db_options_.info_log,
"[JOB %d] Tried to delete non-existing info log file %s FAILED "
"-- %s\n",
state.job_id, to_delete.c_str(), s.ToString().c_str());
} else {
ROCKS_LOG_ERROR(immutable_db_options_.info_log,
"[JOB %d] Delete info log file %s FAILED -- %s\n",
state.job_id, to_delete.c_str(),
s.ToString().c_str());
}
}
}
}
#ifndef ROCKSDB_LITE
wal_manager_.PurgeObsoleteWALFiles();
#endif // ROCKSDB_LITE
LogFlush(immutable_db_options_.info_log);
InstrumentedMutexLock l(&mutex_);
--pending_purge_obsolete_files_;
assert(pending_purge_obsolete_files_ >= 0);
if (pending_purge_obsolete_files_ == 0) {
bg_cv_.SignalAll();
}
TEST_SYNC_POINT("DBImpl::PurgeObsoleteFiles:End");
}
void DBImpl::DeleteObsoleteFiles() {
mutex_.AssertHeld();
JobContext job_context(next_job_id_.fetch_add(1));
FindObsoleteFiles(&job_context, true);
mutex_.Unlock();
if (job_context.HaveSomethingToDelete()) {
PurgeObsoleteFiles(job_context);
}
job_context.Clean();
mutex_.Lock();
}
uint64_t FindMinPrepLogReferencedByMemTable(
VersionSet* vset, const ColumnFamilyData* cfd_to_flush,
const autovector<MemTable*>& memtables_to_flush) {
uint64_t min_log = 0;
// we must look through the memtables for two phase transactions
// that have been committed but not yet flushed
for (auto loop_cfd : *vset->GetColumnFamilySet()) {
if (loop_cfd->IsDropped() || loop_cfd == cfd_to_flush) {
continue;
}
auto log = loop_cfd->imm()->PrecomputeMinLogContainingPrepSection(
memtables_to_flush);
if (log > 0 && (min_log == 0 || log < min_log)) {
min_log = log;
}
log = loop_cfd->mem()->GetMinLogContainingPrepSection();
if (log > 0 && (min_log == 0 || log < min_log)) {
min_log = log;
}
}
return min_log;
}
uint64_t PrecomputeMinLogNumberToKeep(
VersionSet* vset, const ColumnFamilyData& cfd_to_flush,
autovector<VersionEdit*> edit_list,
const autovector<MemTable*>& memtables_to_flush,
LogsWithPrepTracker* prep_tracker) {
assert(vset != nullptr);
assert(prep_tracker != nullptr);
// Calculate updated min_log_number_to_keep
// Since the function should only be called in 2pc mode, log number in
// the version edit should be sufficient.
// Precompute the min log number containing unflushed data for the column
// family being flushed (`cfd_to_flush`).
uint64_t cf_min_log_number_to_keep = 0;
for (auto& e : edit_list) {
if (e->HasLogNumber()) {
cf_min_log_number_to_keep =
std::max(cf_min_log_number_to_keep, e->GetLogNumber());
}
}
if (cf_min_log_number_to_keep == 0) {
// No version edit contains information on log number. The log number
// for this column family should stay the same as it is.
cf_min_log_number_to_keep = cfd_to_flush.GetLogNumber();
}
// Get min log number containing unflushed data for other column families.
uint64_t min_log_number_to_keep =
vset->PreComputeMinLogNumberWithUnflushedData(&cfd_to_flush);
if (cf_min_log_number_to_keep != 0) {
min_log_number_to_keep =
std::min(cf_min_log_number_to_keep, min_log_number_to_keep);
}
// if are 2pc we must consider logs containing prepared
// sections of outstanding transactions.
//
// We must check min logs with outstanding prep before we check
// logs references by memtables because a log referenced by the
// first data structure could transition to the second under us.
//
// TODO: iterating over all column families under db mutex.
// should find more optimal solution
auto min_log_in_prep_heap =
prep_tracker->FindMinLogContainingOutstandingPrep();
if (min_log_in_prep_heap != 0 &&
min_log_in_prep_heap < min_log_number_to_keep) {
min_log_number_to_keep = min_log_in_prep_heap;
}
uint64_t min_log_refed_by_mem = FindMinPrepLogReferencedByMemTable(
vset, &cfd_to_flush, memtables_to_flush);
if (min_log_refed_by_mem != 0 &&
min_log_refed_by_mem < min_log_number_to_keep) {
min_log_number_to_keep = min_log_refed_by_mem;
}
return min_log_number_to_keep;
}
} // namespace ROCKSDB_NAMESPACE