rocksdb/db/db_impl.h
Yi Wu 5d4fddfa52 WritePrepared: Fix visible key compacted out by compaction (#4883)
Summary:
With WritePrepared transaction, flush/compaction can contain uncommitted keys, and those keys can get committed during compaction. If a snapshot is taken before the key is committed, it should not see the key. On the other hand, compaction grab the list of snapshots at its beginning, and only consider those snapshots to dedup keys. Consider the case:
```
seq = 1: put "foo" = "bar"
seq = 2: transaction T: delete "foo", prepare
seq = 3: compaction start
seq = 4: take snapshot S
seq = 5: transaction T: commit.
...
seq = N: compaction iterator reached key "foo".
```
When compaction start, the list of snapshot is empty. Compaction doesn't take snapshot S into account. When it reached "foo", transaction T is committed. Compaction may think the value "foo=bar" is not visible by any snapshot (which is wrong), and compact the value out.

The fix is to explicitly take a snapshot before compaction grabbing the list of snapshots. Compaction will then has to keep keys visible to this snapshot.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4883

Differential Revision: D13668775

Pulled By: maysamyabandeh

fbshipit-source-id: 1cab9615f94b7d3e8522cc3d44c3a14c7d4720e4
2019-01-15 21:34:38 -08:00

1695 lines
70 KiB
C++

// 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.
#pragma once
#include <atomic>
#include <deque>
#include <functional>
#include <limits>
#include <list>
#include <map>
#include <set>
#include <string>
#include <utility>
#include <vector>
#include "db/column_family.h"
#include "db/compaction_job.h"
#include "db/dbformat.h"
#include "db/error_handler.h"
#include "db/event_helpers.h"
#include "db/external_sst_file_ingestion_job.h"
#include "db/flush_job.h"
#include "db/flush_scheduler.h"
#include "db/internal_stats.h"
#include "db/log_writer.h"
#include "db/logs_with_prep_tracker.h"
#include "db/pre_release_callback.h"
#include "db/range_del_aggregator.h"
#include "db/read_callback.h"
#include "db/snapshot_checker.h"
#include "db/snapshot_impl.h"
#include "db/version_edit.h"
#include "db/wal_manager.h"
#include "db/write_controller.h"
#include "db/write_thread.h"
#include "memtable_list.h"
#include "monitoring/instrumented_mutex.h"
#include "options/db_options.h"
#include "port/port.h"
#include "rocksdb/db.h"
#include "rocksdb/env.h"
#include "rocksdb/memtablerep.h"
#include "rocksdb/status.h"
#include "rocksdb/trace_reader_writer.h"
#include "rocksdb/transaction_log.h"
#include "rocksdb/write_buffer_manager.h"
#include "table/scoped_arena_iterator.h"
#include "util/autovector.h"
#include "util/event_logger.h"
#include "util/hash.h"
#include "util/repeatable_thread.h"
#include "util/stop_watch.h"
#include "util/thread_local.h"
#include "util/trace_replay.h"
namespace rocksdb {
class Arena;
class ArenaWrappedDBIter;
class MemTable;
class TableCache;
class TaskLimiterToken;
class Version;
class VersionEdit;
class VersionSet;
class WriteCallback;
struct JobContext;
struct ExternalSstFileInfo;
struct MemTableInfo;
class DBImpl : public DB {
public:
DBImpl(const DBOptions& options, const std::string& dbname,
const bool seq_per_batch = false, const bool batch_per_txn = true);
virtual ~DBImpl();
using DB::Resume;
virtual Status Resume() override;
// Implementations of the DB interface
using DB::Put;
virtual Status Put(const WriteOptions& options,
ColumnFamilyHandle* column_family, const Slice& key,
const Slice& value) override;
using DB::Merge;
virtual Status Merge(const WriteOptions& options,
ColumnFamilyHandle* column_family, const Slice& key,
const Slice& value) override;
using DB::Delete;
virtual Status Delete(const WriteOptions& options,
ColumnFamilyHandle* column_family,
const Slice& key) override;
using DB::SingleDelete;
virtual Status SingleDelete(const WriteOptions& options,
ColumnFamilyHandle* column_family,
const Slice& key) override;
using DB::Write;
virtual Status Write(const WriteOptions& options,
WriteBatch* updates) override;
using DB::Get;
virtual Status Get(const ReadOptions& options,
ColumnFamilyHandle* column_family, const Slice& key,
PinnableSlice* value) override;
// Function that Get and KeyMayExist call with no_io true or false
// Note: 'value_found' from KeyMayExist propagates here
Status GetImpl(const ReadOptions& options, ColumnFamilyHandle* column_family,
const Slice& key, PinnableSlice* value,
bool* value_found = nullptr, ReadCallback* callback = nullptr,
bool* is_blob_index = nullptr);
using DB::MultiGet;
virtual std::vector<Status> MultiGet(
const ReadOptions& options,
const std::vector<ColumnFamilyHandle*>& column_family,
const std::vector<Slice>& keys,
std::vector<std::string>* values) override;
virtual Status CreateColumnFamily(const ColumnFamilyOptions& cf_options,
const std::string& column_family,
ColumnFamilyHandle** handle) override;
virtual Status CreateColumnFamilies(
const ColumnFamilyOptions& cf_options,
const std::vector<std::string>& column_family_names,
std::vector<ColumnFamilyHandle*>* handles) override;
virtual Status CreateColumnFamilies(
const std::vector<ColumnFamilyDescriptor>& column_families,
std::vector<ColumnFamilyHandle*>* handles) override;
virtual Status DropColumnFamily(ColumnFamilyHandle* column_family) override;
virtual Status DropColumnFamilies(
const std::vector<ColumnFamilyHandle*>& column_families) override;
// Returns false if key doesn't exist in the database and true if it may.
// If value_found is not passed in as null, then return the value if found in
// memory. On return, if value was found, then value_found will be set to true
// , otherwise false.
using DB::KeyMayExist;
virtual bool KeyMayExist(const ReadOptions& options,
ColumnFamilyHandle* column_family, const Slice& key,
std::string* value,
bool* value_found = nullptr) override;
using DB::NewIterator;
virtual Iterator* NewIterator(const ReadOptions& options,
ColumnFamilyHandle* column_family) override;
virtual Status NewIterators(
const ReadOptions& options,
const std::vector<ColumnFamilyHandle*>& column_families,
std::vector<Iterator*>* iterators) override;
ArenaWrappedDBIter* NewIteratorImpl(const ReadOptions& options,
ColumnFamilyData* cfd,
SequenceNumber snapshot,
ReadCallback* read_callback,
bool allow_blob = false,
bool allow_refresh = true);
virtual const Snapshot* GetSnapshot() override;
virtual void ReleaseSnapshot(const Snapshot* snapshot) override;
using DB::GetProperty;
virtual bool GetProperty(ColumnFamilyHandle* column_family,
const Slice& property, std::string* value) override;
using DB::GetMapProperty;
virtual bool GetMapProperty(
ColumnFamilyHandle* column_family, const Slice& property,
std::map<std::string, std::string>* value) override;
using DB::GetIntProperty;
virtual bool GetIntProperty(ColumnFamilyHandle* column_family,
const Slice& property, uint64_t* value) override;
using DB::GetAggregatedIntProperty;
virtual bool GetAggregatedIntProperty(const Slice& property,
uint64_t* aggregated_value) override;
using DB::GetApproximateSizes;
virtual void GetApproximateSizes(ColumnFamilyHandle* column_family,
const Range* range, int n, uint64_t* sizes,
uint8_t include_flags
= INCLUDE_FILES) override;
using DB::GetApproximateMemTableStats;
virtual void GetApproximateMemTableStats(ColumnFamilyHandle* column_family,
const Range& range,
uint64_t* const count,
uint64_t* const size) override;
using DB::CompactRange;
virtual Status CompactRange(const CompactRangeOptions& options,
ColumnFamilyHandle* column_family,
const Slice* begin, const Slice* end) override;
using DB::CompactFiles;
virtual Status CompactFiles(
const CompactionOptions& compact_options,
ColumnFamilyHandle* column_family,
const std::vector<std::string>& input_file_names, const int output_level,
const int output_path_id = -1,
std::vector<std::string>* const output_file_names = nullptr,
CompactionJobInfo* compaction_job_info = nullptr) override;
virtual Status PauseBackgroundWork() override;
virtual Status ContinueBackgroundWork() override;
virtual Status EnableAutoCompaction(
const std::vector<ColumnFamilyHandle*>& column_family_handles) override;
using DB::SetOptions;
Status SetOptions(
ColumnFamilyHandle* column_family,
const std::unordered_map<std::string, std::string>& options_map) override;
virtual Status SetDBOptions(
const std::unordered_map<std::string, std::string>& options_map) override;
using DB::NumberLevels;
virtual int NumberLevels(ColumnFamilyHandle* column_family) override;
using DB::MaxMemCompactionLevel;
virtual int MaxMemCompactionLevel(ColumnFamilyHandle* column_family) override;
using DB::Level0StopWriteTrigger;
virtual int Level0StopWriteTrigger(
ColumnFamilyHandle* column_family) override;
virtual const std::string& GetName() const override;
virtual Env* GetEnv() const override;
using DB::GetOptions;
virtual Options GetOptions(ColumnFamilyHandle* column_family) const override;
using DB::GetDBOptions;
virtual DBOptions GetDBOptions() const override;
using DB::Flush;
virtual Status Flush(const FlushOptions& options,
ColumnFamilyHandle* column_family) override;
virtual Status Flush(
const FlushOptions& options,
const std::vector<ColumnFamilyHandle*>& column_families) override;
virtual Status FlushWAL(bool sync) override;
bool TEST_WALBufferIsEmpty();
virtual Status SyncWAL() override;
virtual SequenceNumber GetLatestSequenceNumber() const override;
virtual SequenceNumber GetLastPublishedSequence() const {
if (last_seq_same_as_publish_seq_) {
return versions_->LastSequence();
} else {
return versions_->LastPublishedSequence();
}
}
// REQUIRES: joined the main write queue if two_write_queues is disabled, and
// the second write queue otherwise.
virtual void SetLastPublishedSequence(SequenceNumber seq);
// Returns LastSequence in last_seq_same_as_publish_seq_
// mode and LastAllocatedSequence otherwise. This is useful when visiblility
// depends also on data written to the WAL but not to the memtable.
SequenceNumber TEST_GetLastVisibleSequence() const;
virtual bool SetPreserveDeletesSequenceNumber(SequenceNumber seqnum) override;
#ifndef ROCKSDB_LITE
using DB::ResetStats;
virtual Status ResetStats() override;
virtual Status DisableFileDeletions() override;
virtual Status EnableFileDeletions(bool force) override;
virtual int IsFileDeletionsEnabled() const;
// All the returned filenames start with "/"
virtual Status GetLiveFiles(std::vector<std::string>&,
uint64_t* manifest_file_size,
bool flush_memtable = true) override;
virtual Status GetSortedWalFiles(VectorLogPtr& files) override;
virtual Status GetUpdatesSince(
SequenceNumber seq_number, std::unique_ptr<TransactionLogIterator>* iter,
const TransactionLogIterator::ReadOptions& read_options =
TransactionLogIterator::ReadOptions()) override;
virtual Status DeleteFile(std::string name) override;
Status DeleteFilesInRanges(ColumnFamilyHandle* column_family,
const RangePtr* ranges, size_t n,
bool include_end = true);
virtual void GetLiveFilesMetaData(
std::vector<LiveFileMetaData>* metadata) override;
// Obtains the meta data of the specified column family of the DB.
// Status::NotFound() will be returned if the current DB does not have
// any column family match the specified name.
// TODO(yhchiang): output parameter is placed in the end in this codebase.
virtual void GetColumnFamilyMetaData(
ColumnFamilyHandle* column_family,
ColumnFamilyMetaData* metadata) override;
Status SuggestCompactRange(ColumnFamilyHandle* column_family,
const Slice* begin, const Slice* end) override;
Status PromoteL0(ColumnFamilyHandle* column_family,
int target_level) override;
// Similar to Write() but will call the callback once on the single write
// thread to determine whether it is safe to perform the write.
virtual Status WriteWithCallback(const WriteOptions& write_options,
WriteBatch* my_batch,
WriteCallback* callback);
// Returns the sequence number that is guaranteed to be smaller than or equal
// to the sequence number of any key that could be inserted into the current
// memtables. It can then be assumed that any write with a larger(or equal)
// sequence number will be present in this memtable or a later memtable.
//
// If the earliest sequence number could not be determined,
// kMaxSequenceNumber will be returned.
//
// If include_history=true, will also search Memtables in MemTableList
// History.
SequenceNumber GetEarliestMemTableSequenceNumber(SuperVersion* sv,
bool include_history);
// For a given key, check to see if there are any records for this key
// in the memtables, including memtable history. If cache_only is false,
// SST files will also be checked.
//
// If a key is found, *found_record_for_key will be set to true and
// *seq will be set to the stored sequence number for the latest
// operation on this key or kMaxSequenceNumber if unknown.
// If no key is found, *found_record_for_key will be set to false.
//
// Note: If cache_only=false, it is possible for *seq to be set to 0 if
// the sequence number has been cleared from the record. If the caller is
// holding an active db snapshot, we know the missing sequence must be less
// than the snapshot's sequence number (sequence numbers are only cleared
// when there are no earlier active snapshots).
//
// If NotFound is returned and found_record_for_key is set to false, then no
// record for this key was found. If the caller is holding an active db
// snapshot, we know that no key could have existing after this snapshot
// (since we do not compact keys that have an earlier snapshot).
//
// Returns OK or NotFound on success,
// other status on unexpected error.
// TODO(andrewkr): this API need to be aware of range deletion operations
Status GetLatestSequenceForKey(SuperVersion* sv, const Slice& key,
bool cache_only, SequenceNumber* seq,
bool* found_record_for_key,
bool* is_blob_index = nullptr);
using DB::IngestExternalFile;
virtual Status IngestExternalFile(
ColumnFamilyHandle* column_family,
const std::vector<std::string>& external_files,
const IngestExternalFileOptions& ingestion_options) override;
virtual Status VerifyChecksum() override;
using DB::StartTrace;
virtual Status StartTrace(
const TraceOptions& options,
std::unique_ptr<TraceWriter>&& trace_writer) override;
using DB::EndTrace;
virtual Status EndTrace() override;
Status TraceIteratorSeek(const uint32_t& cf_id, const Slice& key);
Status TraceIteratorSeekForPrev(const uint32_t& cf_id, const Slice& key);
#endif // ROCKSDB_LITE
// Similar to GetSnapshot(), but also lets the db know that this snapshot
// will be used for transaction write-conflict checking. The DB can then
// make sure not to compact any keys that would prevent a write-conflict from
// being detected.
const Snapshot* GetSnapshotForWriteConflictBoundary();
// checks if all live files exist on file system and that their file sizes
// match to our in-memory records
virtual Status CheckConsistency();
virtual Status GetDbIdentity(std::string& identity) const override;
Status RunManualCompaction(ColumnFamilyData* cfd, int input_level,
int output_level, uint32_t output_path_id,
uint32_t max_subcompactions,
const Slice* begin, const Slice* end,
bool exclusive,
bool disallow_trivial_move = false);
// Return an internal iterator over the current state of the database.
// The keys of this iterator are internal keys (see format.h).
// The returned iterator should be deleted when no longer needed.
InternalIterator* NewInternalIterator(
Arena* arena, RangeDelAggregator* range_del_agg, SequenceNumber sequence,
ColumnFamilyHandle* column_family = nullptr);
LogsWithPrepTracker* logs_with_prep_tracker() {
return &logs_with_prep_tracker_;
}
#ifndef NDEBUG
// Extra methods (for testing) that are not in the public DB interface
// Implemented in db_impl_debug.cc
// Compact any files in the named level that overlap [*begin, *end]
Status TEST_CompactRange(int level, const Slice* begin, const Slice* end,
ColumnFamilyHandle* column_family = nullptr,
bool disallow_trivial_move = false);
void TEST_SwitchWAL();
bool TEST_UnableToReleaseOldestLog() { return unable_to_release_oldest_log_; }
bool TEST_IsLogGettingFlushed() {
return alive_log_files_.begin()->getting_flushed;
}
Status TEST_SwitchMemtable(ColumnFamilyData* cfd = nullptr);
// Force current memtable contents to be flushed.
Status TEST_FlushMemTable(bool wait = true, bool allow_write_stall = false,
ColumnFamilyHandle* cfh = nullptr);
// Wait for memtable compaction
Status TEST_WaitForFlushMemTable(ColumnFamilyHandle* column_family = nullptr);
// Wait for any compaction
// We add a bool parameter to wait for unscheduledCompactions_ == 0, but this
// is only for the special test of CancelledCompactions
Status TEST_WaitForCompact(bool waitUnscheduled = false);
// Return the maximum overlapping data (in bytes) at next level for any
// file at a level >= 1.
int64_t TEST_MaxNextLevelOverlappingBytes(ColumnFamilyHandle* column_family =
nullptr);
// Return the current manifest file no.
uint64_t TEST_Current_Manifest_FileNo();
// Returns the number that'll be assigned to the next file that's created.
uint64_t TEST_Current_Next_FileNo();
// get total level0 file size. Only for testing.
uint64_t TEST_GetLevel0TotalSize();
void TEST_GetFilesMetaData(ColumnFamilyHandle* column_family,
std::vector<std::vector<FileMetaData>>* metadata);
void TEST_LockMutex();
void TEST_UnlockMutex();
// REQUIRES: mutex locked
void* TEST_BeginWrite();
// REQUIRES: mutex locked
// pass the pointer that you got from TEST_BeginWrite()
void TEST_EndWrite(void* w);
uint64_t TEST_MaxTotalInMemoryState() const {
return max_total_in_memory_state_;
}
size_t TEST_LogsToFreeSize();
uint64_t TEST_LogfileNumber();
uint64_t TEST_total_log_size() const { return total_log_size_; }
// Returns column family name to ImmutableCFOptions map.
Status TEST_GetAllImmutableCFOptions(
std::unordered_map<std::string, const ImmutableCFOptions*>* iopts_map);
// Return the lastest MutableCFOptions of a column family
Status TEST_GetLatestMutableCFOptions(ColumnFamilyHandle* column_family,
MutableCFOptions* mutable_cf_options);
Cache* TEST_table_cache() { return table_cache_.get(); }
WriteController& TEST_write_controler() { return write_controller_; }
uint64_t TEST_FindMinLogContainingOutstandingPrep();
uint64_t TEST_FindMinPrepLogReferencedByMemTable();
size_t TEST_PreparedSectionCompletedSize();
size_t TEST_LogsWithPrepSize();
int TEST_BGCompactionsAllowed() const;
int TEST_BGFlushesAllowed() const;
size_t TEST_GetWalPreallocateBlockSize(uint64_t write_buffer_size) const;
void TEST_WaitForTimedTaskRun(std::function<void()> callback) const;
#endif // NDEBUG
struct BGJobLimits {
int max_flushes;
int max_compactions;
};
// Returns maximum background flushes and compactions allowed to be scheduled
BGJobLimits GetBGJobLimits() const;
// Need a static version that can be called during SanitizeOptions().
static BGJobLimits GetBGJobLimits(int max_background_flushes,
int max_background_compactions,
int max_background_jobs,
bool parallelize_compactions);
// move logs pending closing from job_context to the DB queue and
// schedule a purge
void ScheduleBgLogWriterClose(JobContext* job_context);
uint64_t MinLogNumberToKeep();
// Returns the lower bound file number for SSTs that won't be deleted, even if
// they're obsolete. This lower bound is used internally to prevent newly
// created flush/compaction output files from being deleted before they're
// installed. This technique avoids the need for tracking the exact numbers of
// files pending creation, although it prevents more files than necessary from
// being deleted.
uint64_t MinObsoleteSstNumberToKeep();
// Returns the list of live files in 'live' and the list
// of all files in the filesystem in 'candidate_files'.
// If force == false and the last call was less than
// db_options_.delete_obsolete_files_period_micros microseconds ago,
// it will not fill up the job_context
void FindObsoleteFiles(JobContext* job_context, bool force,
bool no_full_scan = false);
// 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.
// If FindObsoleteFiles() was run, we need to also run
// PurgeObsoleteFiles(), even if disable_delete_obsolete_files_ is true
void PurgeObsoleteFiles(JobContext& background_contet,
bool schedule_only = false);
void SchedulePurge();
ColumnFamilyHandle* DefaultColumnFamily() const override;
const SnapshotList& snapshots() const { return snapshots_; }
const ImmutableDBOptions& immutable_db_options() const {
return immutable_db_options_;
}
void CancelAllBackgroundWork(bool wait);
// Find Super version and reference it. Based on options, it might return
// the thread local cached one.
// Call ReturnAndCleanupSuperVersion() when it is no longer needed.
SuperVersion* GetAndRefSuperVersion(ColumnFamilyData* cfd);
// Similar to the previous function but looks up based on a column family id.
// nullptr will be returned if this column family no longer exists.
// REQUIRED: this function should only be called on the write thread or if the
// mutex is held.
SuperVersion* GetAndRefSuperVersion(uint32_t column_family_id);
// Un-reference the super version and clean it up if it is the last reference.
void CleanupSuperVersion(SuperVersion* sv);
// Un-reference the super version and return it to thread local cache if
// needed. If it is the last reference of the super version. Clean it up
// after un-referencing it.
void ReturnAndCleanupSuperVersion(ColumnFamilyData* cfd, SuperVersion* sv);
// Similar to the previous function but looks up based on a column family id.
// nullptr will be returned if this column family no longer exists.
// REQUIRED: this function should only be called on the write thread.
void ReturnAndCleanupSuperVersion(uint32_t colun_family_id, SuperVersion* sv);
// REQUIRED: this function should only be called on the write thread or if the
// mutex is held. Return value only valid until next call to this function or
// mutex is released.
ColumnFamilyHandle* GetColumnFamilyHandle(uint32_t column_family_id);
// Same as above, should called without mutex held and not on write thread.
std::unique_ptr<ColumnFamilyHandle> GetColumnFamilyHandleUnlocked(
uint32_t column_family_id);
// Returns the number of currently running flushes.
// REQUIREMENT: mutex_ must be held when calling this function.
int num_running_flushes() {
mutex_.AssertHeld();
return num_running_flushes_;
}
// Returns the number of currently running compactions.
// REQUIREMENT: mutex_ must be held when calling this function.
int num_running_compactions() {
mutex_.AssertHeld();
return num_running_compactions_;
}
const WriteController& write_controller() { return write_controller_; }
InternalIterator* NewInternalIterator(
const ReadOptions&, ColumnFamilyData* cfd, SuperVersion* super_version,
Arena* arena, RangeDelAggregator* range_del_agg, SequenceNumber sequence);
// hollow transactions shell used for recovery.
// these will then be passed to TransactionDB so that
// locks can be reacquired before writing can resume.
struct RecoveredTransaction {
std::string name_;
bool unprepared_;
struct BatchInfo {
uint64_t log_number_;
// TODO(lth): For unprepared, the memory usage here can be big for
// unprepared transactions. This is only useful for rollbacks, and we
// can in theory just keep keyset for that.
WriteBatch* batch_;
// Number of sub-batches. A new sub-batch is created if txn attempts to
// insert a duplicate key,seq to memtable. This is currently used in
// WritePreparedTxn/WriteUnpreparedTxn.
size_t batch_cnt_;
};
// This maps the seq of the first key in the batch to BatchInfo, which
// contains WriteBatch and other information relevant to the batch.
//
// For WriteUnprepared, batches_ can have size greater than 1, but for
// other write policies, it must be of size 1.
std::map<SequenceNumber, BatchInfo> batches_;
explicit RecoveredTransaction(const uint64_t log, const std::string& name,
WriteBatch* batch, SequenceNumber seq,
size_t batch_cnt, bool unprepared)
: name_(name), unprepared_(unprepared) {
batches_[seq] = {log, batch, batch_cnt};
}
~RecoveredTransaction() {
for (auto& it : batches_) {
delete it.second.batch_;
}
}
void AddBatch(SequenceNumber seq, uint64_t log_number, WriteBatch* batch,
size_t batch_cnt, bool unprepared) {
assert(batches_.count(seq) == 0);
batches_[seq] = {log_number, batch, batch_cnt};
// Prior state must be unprepared, since the prepare batch must be the
// last batch.
assert(unprepared_);
unprepared_ = unprepared;
}
};
bool allow_2pc() const { return immutable_db_options_.allow_2pc; }
std::unordered_map<std::string, RecoveredTransaction*>
recovered_transactions() {
return recovered_transactions_;
}
RecoveredTransaction* GetRecoveredTransaction(const std::string& name) {
auto it = recovered_transactions_.find(name);
if (it == recovered_transactions_.end()) {
return nullptr;
} else {
return it->second;
}
}
void InsertRecoveredTransaction(const uint64_t log, const std::string& name,
WriteBatch* batch, SequenceNumber seq,
size_t batch_cnt, bool unprepared_batch) {
// For WriteUnpreparedTxn, InsertRecoveredTransaction is called multiple
// times for every unprepared batch encountered during recovery.
//
// If the transaction is prepared, then the last call to
// InsertRecoveredTransaction will have unprepared_batch = false.
auto rtxn = recovered_transactions_.find(name);
if (rtxn == recovered_transactions_.end()) {
recovered_transactions_[name] = new RecoveredTransaction(
log, name, batch, seq, batch_cnt, unprepared_batch);
} else {
rtxn->second->AddBatch(seq, log, batch, batch_cnt, unprepared_batch);
}
logs_with_prep_tracker_.MarkLogAsContainingPrepSection(log);
}
void DeleteRecoveredTransaction(const std::string& name) {
auto it = recovered_transactions_.find(name);
assert(it != recovered_transactions_.end());
auto* trx = it->second;
recovered_transactions_.erase(it);
for (const auto& info : trx->batches_) {
logs_with_prep_tracker_.MarkLogAsHavingPrepSectionFlushed(
info.second.log_number_);
}
delete trx;
}
void DeleteAllRecoveredTransactions() {
for (auto it = recovered_transactions_.begin();
it != recovered_transactions_.end(); it++) {
delete it->second;
}
recovered_transactions_.clear();
}
void AddToLogsToFreeQueue(log::Writer* log_writer) {
logs_to_free_queue_.push_back(log_writer);
}
void SetSnapshotChecker(SnapshotChecker* snapshot_checker);
// Fill JobContext with snapshot information needed by flush and compaction.
void GetSnapshotContext(JobContext* job_context,
std::vector<SequenceNumber>* snapshot_seqs,
SequenceNumber* earliest_write_conflict_snapshot,
SnapshotChecker** snapshot_checker);
// Not thread-safe.
void SetRecoverableStatePreReleaseCallback(PreReleaseCallback* callback);
InstrumentedMutex* mutex() { return &mutex_; }
Status NewDB();
// This is to be used only by internal rocksdb classes.
static Status Open(const DBOptions& db_options, const std::string& name,
const std::vector<ColumnFamilyDescriptor>& column_families,
std::vector<ColumnFamilyHandle*>* handles, DB** dbptr,
const bool seq_per_batch, const bool batch_per_txn);
virtual Status Close() override;
static Status CreateAndNewDirectory(Env* env, const std::string& dirname,
std::unique_ptr<Directory>* directory);
protected:
Env* const env_;
const std::string dbname_;
std::unique_ptr<VersionSet> versions_;
// Flag to check whether we allocated and own the info log file
bool own_info_log_;
const DBOptions initial_db_options_;
const ImmutableDBOptions immutable_db_options_;
MutableDBOptions mutable_db_options_;
Statistics* stats_;
std::unordered_map<std::string, RecoveredTransaction*>
recovered_transactions_;
std::unique_ptr<Tracer> tracer_;
InstrumentedMutex trace_mutex_;
// Except in DB::Open(), WriteOptionsFile can only be called when:
// Persist options to options file.
// If need_mutex_lock = false, the method will lock DB mutex.
// If need_enter_write_thread = false, the method will enter write thread.
Status WriteOptionsFile(bool need_mutex_lock, bool need_enter_write_thread);
// The following two functions can only be called when:
// 1. WriteThread::Writer::EnterUnbatched() is used.
// 2. db_mutex is NOT held
Status RenameTempFileToOptionsFile(const std::string& file_name);
Status DeleteObsoleteOptionsFiles();
void NotifyOnFlushBegin(ColumnFamilyData* cfd, FileMetaData* file_meta,
const MutableCFOptions& mutable_cf_options,
int job_id, TableProperties prop);
void NotifyOnFlushCompleted(ColumnFamilyData* cfd, FileMetaData* file_meta,
const MutableCFOptions& mutable_cf_options,
int job_id, TableProperties prop);
void NotifyOnCompactionBegin(ColumnFamilyData* cfd,
Compaction *c, const Status &st,
const CompactionJobStats& job_stats,
int job_id);
void NotifyOnCompactionCompleted(ColumnFamilyData* cfd,
Compaction *c, const Status &st,
const CompactionJobStats& job_stats,
int job_id);
void NotifyOnMemTableSealed(ColumnFamilyData* cfd,
const MemTableInfo& mem_table_info);
#ifndef ROCKSDB_LITE
void NotifyOnExternalFileIngested(
ColumnFamilyData* cfd, const ExternalSstFileIngestionJob& ingestion_job);
#endif // !ROCKSDB_LITE
void NewThreadStatusCfInfo(ColumnFamilyData* cfd) const;
void EraseThreadStatusCfInfo(ColumnFamilyData* cfd) const;
void EraseThreadStatusDbInfo() const;
// If disable_memtable is set the application logic must guarantee that the
// batch will still be skipped from memtable during the recovery. An excption
// to this is seq_per_batch_ mode, in which since each batch already takes one
// seq, it is ok for the batch to write to memtable during recovery as long as
// it only takes one sequence number: i.e., no duplicate keys.
// In WriteCommitted it is guarnateed since disable_memtable is used for
// prepare batch which will be written to memtable later during the commit,
// and in WritePrepared it is guaranteed since it will be used only for WAL
// markers which will never be written to memtable. If the commit marker is
// accompanied with CommitTimeWriteBatch that is not written to memtable as
// long as it has no duplicate keys, it does not violate the one-seq-per-batch
// policy.
// batch_cnt is expected to be non-zero in seq_per_batch mode and
// indicates the number of sub-patches. A sub-patch is a subset of the write
// batch that does not have duplicate keys.
Status WriteImpl(const WriteOptions& options, WriteBatch* updates,
WriteCallback* callback = nullptr,
uint64_t* log_used = nullptr, uint64_t log_ref = 0,
bool disable_memtable = false, uint64_t* seq_used = nullptr,
size_t batch_cnt = 0,
PreReleaseCallback* pre_release_callback = nullptr);
Status PipelinedWriteImpl(const WriteOptions& options, WriteBatch* updates,
WriteCallback* callback = nullptr,
uint64_t* log_used = nullptr, uint64_t log_ref = 0,
bool disable_memtable = false,
uint64_t* seq_used = nullptr);
// batch_cnt is expected to be non-zero in seq_per_batch mode and indicates
// the number of sub-patches. A sub-patch is a subset of the write batch that
// does not have duplicate keys.
Status WriteImplWALOnly(const WriteOptions& options, WriteBatch* updates,
WriteCallback* callback = nullptr,
uint64_t* log_used = nullptr, uint64_t log_ref = 0,
uint64_t* seq_used = nullptr, size_t batch_cnt = 0,
PreReleaseCallback* pre_release_callback = nullptr);
// write cached_recoverable_state_ to memtable if it is not empty
// The writer must be the leader in write_thread_ and holding mutex_
Status WriteRecoverableState();
// Actual implementation of Close()
Status CloseImpl();
private:
friend class DB;
friend class ErrorHandler;
friend class InternalStats;
friend class PessimisticTransaction;
friend class TransactionBaseImpl;
friend class WriteCommittedTxn;
friend class WritePreparedTxn;
friend class WritePreparedTxnDB;
friend class WriteBatchWithIndex;
friend class WriteUnpreparedTxnDB;
friend class WriteUnpreparedTxn;
#ifndef ROCKSDB_LITE
friend class ForwardIterator;
#endif
friend struct SuperVersion;
friend class CompactedDBImpl;
friend class DBTest_ConcurrentFlushWAL_Test;
friend class DBTest_MixedSlowdownOptionsStop_Test;
#ifndef NDEBUG
friend class DBTest2_ReadCallbackTest_Test;
friend class WriteCallbackTest_WriteWithCallbackTest_Test;
friend class XFTransactionWriteHandler;
friend class DBBlobIndexTest;
friend class WriteUnpreparedTransactionTest_RecoveryTest_Test;
#endif
struct CompactionState;
struct WriteContext {
SuperVersionContext superversion_context;
autovector<MemTable*> memtables_to_free_;
explicit WriteContext(bool create_superversion = false)
: superversion_context(create_superversion) {}
~WriteContext() {
superversion_context.Clean();
for (auto& m : memtables_to_free_) {
delete m;
}
}
};
struct PrepickedCompaction;
struct PurgeFileInfo;
// Recover the descriptor from persistent storage. May do a significant
// amount of work to recover recently logged updates. Any changes to
// be made to the descriptor are added to *edit.
Status Recover(const std::vector<ColumnFamilyDescriptor>& column_families,
bool read_only = false, bool error_if_log_file_exist = false,
bool error_if_data_exists_in_logs = false);
Status ResumeImpl();
void MaybeIgnoreError(Status* s) const;
const Status CreateArchivalDirectory();
Status CreateColumnFamilyImpl(const ColumnFamilyOptions& cf_options,
const std::string& cf_name,
ColumnFamilyHandle** handle);
Status DropColumnFamilyImpl(ColumnFamilyHandle* column_family);
// Delete any unneeded files and stale in-memory entries.
void DeleteObsoleteFiles();
// Delete obsolete files and log status and information of file deletion
void DeleteObsoleteFileImpl(int job_id, const std::string& fname,
const std::string& path_to_sync, FileType type,
uint64_t number);
// Background process needs to call
// auto x = CaptureCurrentFileNumberInPendingOutputs()
// auto file_num = versions_->NewFileNumber();
// <do something>
// ReleaseFileNumberFromPendingOutputs(x)
// This will protect any file with number `file_num` or greater from being
// deleted while <do something> is running.
// -----------
// This function will capture current file number and append it to
// pending_outputs_. This will prevent any background process to delete any
// file created after this point.
std::list<uint64_t>::iterator CaptureCurrentFileNumberInPendingOutputs();
// This function should be called with the result of
// CaptureCurrentFileNumberInPendingOutputs(). It then marks that any file
// created between the calls CaptureCurrentFileNumberInPendingOutputs() and
// ReleaseFileNumberFromPendingOutputs() can now be deleted (if it's not live
// and blocked by any other pending_outputs_ calls)
void ReleaseFileNumberFromPendingOutputs(std::list<uint64_t>::iterator v);
Status SyncClosedLogs(JobContext* job_context);
// Flush the in-memory write buffer to storage. Switches to a new
// log-file/memtable and writes a new descriptor iff successful. Then
// installs a new super version for the column family.
Status FlushMemTableToOutputFile(ColumnFamilyData* cfd,
const MutableCFOptions& mutable_cf_options,
bool* madeProgress, JobContext* job_context,
SuperVersionContext* superversion_context,
LogBuffer* log_buffer);
// Argument required by background flush thread.
struct BGFlushArg {
BGFlushArg()
: cfd_(nullptr), max_memtable_id_(0), superversion_context_(nullptr) {}
BGFlushArg(ColumnFamilyData* cfd, uint64_t max_memtable_id,
SuperVersionContext* superversion_context)
: cfd_(cfd),
max_memtable_id_(max_memtable_id),
superversion_context_(superversion_context) {}
// Column family to flush.
ColumnFamilyData* cfd_;
// Maximum ID of memtable to flush. In this column family, memtables with
// IDs smaller than this value must be flushed before this flush completes.
uint64_t max_memtable_id_;
// Pointer to a SuperVersionContext object. After flush completes, RocksDB
// installs a new superversion for the column family. This operation
// requires a SuperVersionContext object (currently embedded in JobContext).
SuperVersionContext* superversion_context_;
};
// Flush the memtables of (multiple) column families to multiple files on
// persistent storage.
Status FlushMemTablesToOutputFiles(
const autovector<BGFlushArg>& bg_flush_args, bool* made_progress,
JobContext* job_context, LogBuffer* log_buffer);
Status AtomicFlushMemTablesToOutputFiles(
const autovector<BGFlushArg>& bg_flush_args, bool* made_progress,
JobContext* job_context, LogBuffer* log_buffer);
// REQUIRES: log_numbers are sorted in ascending order
Status RecoverLogFiles(const std::vector<uint64_t>& log_numbers,
SequenceNumber* next_sequence, bool read_only);
// The following two methods are used to flush a memtable to
// storage. The first one is used at database RecoveryTime (when the
// database is opened) and is heavyweight because it holds the mutex
// for the entire period. The second method WriteLevel0Table supports
// concurrent flush memtables to storage.
Status WriteLevel0TableForRecovery(int job_id, ColumnFamilyData* cfd,
MemTable* mem, VersionEdit* edit);
// Restore alive_log_files_ and total_log_size_ after recovery.
// It needs to run only when there's no flush during recovery
// (e.g. avoid_flush_during_recovery=true). May also trigger flush
// in case total_log_size > max_total_wal_size.
Status RestoreAliveLogFiles(const std::vector<uint64_t>& log_numbers);
// num_bytes: for slowdown case, delay time is calculated based on
// `num_bytes` going through.
Status DelayWrite(uint64_t num_bytes, const WriteOptions& write_options);
Status ThrottleLowPriWritesIfNeeded(const WriteOptions& write_options,
WriteBatch* my_batch);
Status ScheduleFlushes(WriteContext* context);
Status SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context);
void SelectColumnFamiliesForAtomicFlush(autovector<ColumnFamilyData*>* cfds);
// Force current memtable contents to be flushed.
Status FlushMemTable(ColumnFamilyData* cfd, const FlushOptions& options,
FlushReason flush_reason, bool writes_stopped = false);
Status AtomicFlushMemTables(
const autovector<ColumnFamilyData*>& column_family_datas,
const FlushOptions& options, FlushReason flush_reason,
bool writes_stopped = false);
// Wait until flushing this column family won't stall writes
Status WaitUntilFlushWouldNotStallWrites(ColumnFamilyData* cfd,
bool* flush_needed);
// Wait for memtable flushed.
// If flush_memtable_id is non-null, wait until the memtable with the ID
// gets flush. Otherwise, wait until the column family don't have any
// memtable pending flush.
// resuming_from_bg_err indicates whether the caller is attempting to resume
// from background error.
Status WaitForFlushMemTable(ColumnFamilyData* cfd,
const uint64_t* flush_memtable_id = nullptr,
bool resuming_from_bg_err = false) {
return WaitForFlushMemTables({cfd}, {flush_memtable_id},
resuming_from_bg_err);
}
// Wait for memtables to be flushed for multiple column families.
Status WaitForFlushMemTables(
const autovector<ColumnFamilyData*>& cfds,
const autovector<const uint64_t*>& flush_memtable_ids,
bool resuming_from_bg_err);
// REQUIRES: mutex locked and in write thread.
void AssignAtomicFlushSeq(const autovector<ColumnFamilyData*>& cfds);
// REQUIRES: mutex locked
Status SwitchWAL(WriteContext* write_context);
// REQUIRES: mutex locked
Status HandleWriteBufferFull(WriteContext* write_context);
// REQUIRES: mutex locked
Status PreprocessWrite(const WriteOptions& write_options, bool* need_log_sync,
WriteContext* write_context);
WriteBatch* MergeBatch(const WriteThread::WriteGroup& write_group,
WriteBatch* tmp_batch, size_t* write_with_wal,
WriteBatch** to_be_cached_state);
Status WriteToWAL(const WriteBatch& merged_batch, log::Writer* log_writer,
uint64_t* log_used, uint64_t* log_size);
Status WriteToWAL(const WriteThread::WriteGroup& write_group,
log::Writer* log_writer, uint64_t* log_used,
bool need_log_sync, bool need_log_dir_sync,
SequenceNumber sequence);
Status ConcurrentWriteToWAL(const WriteThread::WriteGroup& write_group,
uint64_t* log_used, SequenceNumber* last_sequence,
size_t seq_inc);
// Used by WriteImpl to update bg_error_ if paranoid check is enabled.
void WriteStatusCheck(const Status& status);
// Used by WriteImpl to update bg_error_ in case of memtable insert error.
void MemTableInsertStatusCheck(const Status& memtable_insert_status);
#ifndef ROCKSDB_LITE
Status CompactFilesImpl(const CompactionOptions& compact_options,
ColumnFamilyData* cfd, Version* version,
const std::vector<std::string>& input_file_names,
std::vector<std::string>* const output_file_names,
const int output_level, int output_path_id,
JobContext* job_context, LogBuffer* log_buffer,
CompactionJobInfo* compaction_job_info);
// Wait for current IngestExternalFile() calls to finish.
// REQUIRES: mutex_ held
void WaitForIngestFile();
#else
// IngestExternalFile is not supported in ROCKSDB_LITE so this function
// will be no-op
void WaitForIngestFile() {}
#endif // ROCKSDB_LITE
ColumnFamilyData* GetColumnFamilyDataByName(const std::string& cf_name);
void MaybeScheduleFlushOrCompaction();
// A flush request specifies the column families to flush as well as the
// largest memtable id to persist for each column family. Once all the
// memtables whose IDs are smaller than or equal to this per-column-family
// specified value, this flush request is considered to have completed its
// work of flushing this column family. After completing the work for all
// column families in this request, this flush is considered complete.
typedef std::vector<std::pair<ColumnFamilyData*, uint64_t>> FlushRequest;
void GenerateFlushRequest(const autovector<ColumnFamilyData*>& cfds,
FlushRequest* req);
void SchedulePendingFlush(const FlushRequest& req, FlushReason flush_reason);
void SchedulePendingCompaction(ColumnFamilyData* cfd);
void SchedulePendingPurge(std::string fname, std::string dir_to_sync,
FileType type, uint64_t number, int job_id);
static void BGWorkCompaction(void* arg);
// Runs a pre-chosen universal compaction involving bottom level in a
// separate, bottom-pri thread pool.
static void BGWorkBottomCompaction(void* arg);
static void BGWorkFlush(void* db);
static void BGWorkPurge(void* arg);
static void UnscheduleCallback(void* arg);
void BackgroundCallCompaction(PrepickedCompaction* prepicked_compaction,
Env::Priority bg_thread_pri);
void BackgroundCallFlush();
void BackgroundCallPurge();
Status BackgroundCompaction(bool* madeProgress, JobContext* job_context,
LogBuffer* log_buffer,
PrepickedCompaction* prepicked_compaction);
Status BackgroundFlush(bool* madeProgress, JobContext* job_context,
LogBuffer* log_buffer, FlushReason* reason);
bool EnoughRoomForCompaction(ColumnFamilyData* cfd,
const std::vector<CompactionInputFiles>& inputs,
bool* sfm_bookkeeping, LogBuffer* log_buffer);
// Request compaction tasks token from compaction thread limiter.
// It always succeeds if force = true or limiter is disable.
bool RequestCompactionToken(ColumnFamilyData* cfd, bool force,
std::unique_ptr<TaskLimiterToken>* token,
LogBuffer* log_buffer);
// Schedule background tasks
void StartTimedTasks();
void PrintStatistics();
// dump rocksdb.stats to LOG
void DumpStats();
// Return the minimum empty level that could hold the total data in the
// input level. Return the input level, if such level could not be found.
int FindMinimumEmptyLevelFitting(ColumnFamilyData* cfd,
const MutableCFOptions& mutable_cf_options, int level);
// Move the files in the input level to the target level.
// If target_level < 0, automatically calculate the minimum level that could
// hold the data set.
Status ReFitLevel(ColumnFamilyData* cfd, int level, int target_level = -1);
// helper functions for adding and removing from flush & compaction queues
void AddToCompactionQueue(ColumnFamilyData* cfd);
ColumnFamilyData* PopFirstFromCompactionQueue();
FlushRequest PopFirstFromFlushQueue();
// Pick the first unthrottled compaction with task token from queue.
ColumnFamilyData* PickCompactionFromQueue(
std::unique_ptr<TaskLimiterToken>* token, LogBuffer* log_buffer);
// helper function to call after some of the logs_ were synced
void MarkLogsSynced(uint64_t up_to, bool synced_dir, const Status& status);
SnapshotImpl* GetSnapshotImpl(bool is_write_conflict_boundary,
bool lock = true);
uint64_t GetMaxTotalWalSize() const;
Directory* GetDataDir(ColumnFamilyData* cfd, size_t path_id) const;
Status CloseHelper();
void WaitForBackgroundWork();
// table_cache_ provides its own synchronization
std::shared_ptr<Cache> table_cache_;
// Lock over the persistent DB state. Non-nullptr iff successfully acquired.
FileLock* db_lock_;
// In addition to mutex_, log_write_mutex_ protected writes to logs_ and
// logfile_number_. With two_write_queues it also protects alive_log_files_,
// and log_empty_. Refer to the definition of each variable below for more
// details.
InstrumentedMutex log_write_mutex_;
// State below is protected by mutex_
// With two_write_queues enabled, some of the variables that accessed during
// WriteToWAL need different synchronization: log_empty_, alive_log_files_,
// logs_, logfile_number_. Refer to the definition of each variable below for
// more description.
mutable InstrumentedMutex mutex_;
std::atomic<bool> shutting_down_;
// This condition variable is signaled on these conditions:
// * whenever bg_compaction_scheduled_ goes down to 0
// * if AnyManualCompaction, whenever a compaction finishes, even if it hasn't
// made any progress
// * whenever a compaction made any progress
// * whenever bg_flush_scheduled_ or bg_purge_scheduled_ value decreases
// (i.e. whenever a flush is done, even if it didn't make any progress)
// * whenever there is an error in background purge, flush or compaction
// * whenever num_running_ingest_file_ goes to 0.
// * whenever pending_purge_obsolete_files_ goes to 0.
// * whenever disable_delete_obsolete_files_ goes to 0.
// * whenever SetOptions successfully updates options.
// * whenever a column family is dropped.
InstrumentedCondVar bg_cv_;
// Writes are protected by locking both mutex_ and log_write_mutex_, and reads
// must be under either mutex_ or log_write_mutex_. Since after ::Open,
// logfile_number_ is currently updated only in write_thread_, it can be read
// from the same write_thread_ without any locks.
uint64_t logfile_number_;
std::deque<uint64_t>
log_recycle_files_; // a list of log files that we can recycle
bool log_dir_synced_;
// Without two_write_queues, read and writes to log_empty_ are protected by
// mutex_. Since it is currently updated/read only in write_thread_, it can be
// accessed from the same write_thread_ without any locks. With
// two_write_queues writes, where it can be updated in different threads,
// read and writes are protected by log_write_mutex_ instead. This is to avoid
// expesnive mutex_ lock during WAL write, which update log_empty_.
bool log_empty_;
ColumnFamilyHandleImpl* default_cf_handle_;
InternalStats* default_cf_internal_stats_;
std::unique_ptr<ColumnFamilyMemTablesImpl> column_family_memtables_;
struct LogFileNumberSize {
explicit LogFileNumberSize(uint64_t _number)
: number(_number) {}
void AddSize(uint64_t new_size) { size += new_size; }
uint64_t number;
uint64_t size = 0;
bool getting_flushed = false;
};
struct LogWriterNumber {
// pass ownership of _writer
LogWriterNumber(uint64_t _number, log::Writer* _writer)
: number(_number), writer(_writer) {}
log::Writer* ReleaseWriter() {
auto* w = writer;
writer = nullptr;
return w;
}
Status ClearWriter() {
Status s = writer->WriteBuffer();
delete writer;
writer = nullptr;
return s;
}
uint64_t number;
// Visual Studio doesn't support deque's member to be noncopyable because
// of a std::unique_ptr as a member.
log::Writer* writer; // own
// true for some prefix of logs_
bool getting_synced = false;
};
// Without two_write_queues, read and writes to alive_log_files_ are
// protected by mutex_. However since back() is never popped, and push_back()
// is done only from write_thread_, the same thread can access the item
// reffered by back() without mutex_. With two_write_queues_, writes
// are protected by locking both mutex_ and log_write_mutex_, and reads must
// be under either mutex_ or log_write_mutex_.
std::deque<LogFileNumberSize> alive_log_files_;
// Log files that aren't fully synced, and the current log file.
// Synchronization:
// - push_back() is done from write_thread_ with locked mutex_ and
// log_write_mutex_
// - pop_front() is done from any thread with locked mutex_ and
// log_write_mutex_
// - reads are done with either locked mutex_ or log_write_mutex_
// - back() and items with getting_synced=true are not popped,
// - The same thread that sets getting_synced=true will reset it.
// - it follows that the object referred by back() can be safely read from
// the write_thread_ without using mutex
// - it follows that the items with getting_synced=true can be safely read
// from the same thread that has set getting_synced=true
std::deque<LogWriterNumber> logs_;
// Signaled when getting_synced becomes false for some of the logs_.
InstrumentedCondVar log_sync_cv_;
// This is the app-level state that is written to the WAL but will be used
// only during recovery. Using this feature enables not writing the state to
// memtable on normal writes and hence improving the throughput. Each new
// write of the state will replace the previous state entirely even if the
// keys in the two consecuitive states do not overlap.
// It is protected by log_write_mutex_ when two_write_queues_ is enabled.
// Otherwise only the heaad of write_thread_ can access it.
WriteBatch cached_recoverable_state_;
std::atomic<bool> cached_recoverable_state_empty_ = {true};
std::atomic<uint64_t> total_log_size_;
// only used for dynamically adjusting max_total_wal_size. it is a sum of
// [write_buffer_size * max_write_buffer_number] over all column families
uint64_t max_total_in_memory_state_;
// If true, we have only one (default) column family. We use this to optimize
// some code-paths
bool single_column_family_mode_;
// If this is non-empty, we need to delete these log files in background
// threads. Protected by db mutex.
autovector<log::Writer*> logs_to_free_;
bool is_snapshot_supported_;
// Class to maintain directories for all database paths other than main one.
class Directories {
public:
Status SetDirectories(Env* env, const std::string& dbname,
const std::string& wal_dir,
const std::vector<DbPath>& data_paths);
Directory* GetDataDir(size_t path_id) const;
Directory* GetWalDir() {
if (wal_dir_) {
return wal_dir_.get();
}
return db_dir_.get();
}
Directory* GetDbDir() { return db_dir_.get(); }
private:
std::unique_ptr<Directory> db_dir_;
std::vector<std::unique_ptr<Directory>> data_dirs_;
std::unique_ptr<Directory> wal_dir_;
};
Directories directories_;
WriteBufferManager* write_buffer_manager_;
WriteThread write_thread_;
WriteBatch tmp_batch_;
// The write thread when the writers have no memtable write. This will be used
// in 2PC to batch the prepares separately from the serial commit.
WriteThread nonmem_write_thread_;
WriteController write_controller_;
std::unique_ptr<RateLimiter> low_pri_write_rate_limiter_;
// Size of the last batch group. In slowdown mode, next write needs to
// sleep if it uses up the quota.
// Note: This is to protect memtable and compaction. If the batch only writes
// to the WAL its size need not to be included in this.
uint64_t last_batch_group_size_;
FlushScheduler flush_scheduler_;
SnapshotList snapshots_;
// For each background job, pending_outputs_ keeps the current file number at
// the time that background job started.
// FindObsoleteFiles()/PurgeObsoleteFiles() never deletes any file that has
// number bigger than any of the file number in pending_outputs_. Since file
// numbers grow monotonically, this also means that pending_outputs_ is always
// sorted. After a background job is done executing, its file number is
// deleted from pending_outputs_, which allows PurgeObsoleteFiles() to clean
// it up.
// State is protected with db mutex.
std::list<uint64_t> pending_outputs_;
// PurgeFileInfo is a structure to hold information of files to be deleted in
// purge_queue_
struct PurgeFileInfo {
std::string fname;
std::string dir_to_sync;
FileType type;
uint64_t number;
int job_id;
PurgeFileInfo(std::string fn, std::string d, FileType t, uint64_t num,
int jid)
: fname(fn), dir_to_sync(d), type(t), number(num), job_id(jid) {}
};
// flush_queue_ and compaction_queue_ hold column families that we need to
// flush and compact, respectively.
// A column family is inserted into flush_queue_ when it satisfies condition
// cfd->imm()->IsFlushPending()
// A column family is inserted into compaction_queue_ when it satisfied
// condition cfd->NeedsCompaction()
// Column families in this list are all Ref()-erenced
// TODO(icanadi) Provide some kind of ReferencedColumnFamily class that will
// do RAII on ColumnFamilyData
// Column families are in this queue when they need to be flushed or
// compacted. Consumers of these queues are flush and compaction threads. When
// column family is put on this queue, we increase unscheduled_flushes_ and
// unscheduled_compactions_. When these variables are bigger than zero, that
// means we need to schedule background threads for flush and compaction.
// Once the background threads are scheduled, we decrease unscheduled_flushes_
// and unscheduled_compactions_. That way we keep track of number of
// compaction and flush threads we need to schedule. This scheduling is done
// in MaybeScheduleFlushOrCompaction()
// invariant(column family present in flush_queue_ <==>
// ColumnFamilyData::pending_flush_ == true)
std::deque<FlushRequest> flush_queue_;
// invariant(column family present in compaction_queue_ <==>
// ColumnFamilyData::pending_compaction_ == true)
std::deque<ColumnFamilyData*> compaction_queue_;
// A queue to store filenames of the files to be purged
std::deque<PurgeFileInfo> purge_queue_;
// A vector to store the file numbers that have been assigned to certain
// JobContext. Current implementation tracks ssts only.
std::vector<uint64_t> files_grabbed_for_purge_;
// A queue to store log writers to close
std::deque<log::Writer*> logs_to_free_queue_;
int unscheduled_flushes_;
int unscheduled_compactions_;
// count how many background compactions are running or have been scheduled in
// the BOTTOM pool
int bg_bottom_compaction_scheduled_;
// count how many background compactions are running or have been scheduled
int bg_compaction_scheduled_;
// stores the number of compactions are currently running
int num_running_compactions_;
// number of background memtable flush jobs, submitted to the HIGH pool
int bg_flush_scheduled_;
// stores the number of flushes are currently running
int num_running_flushes_;
// number of background obsolete file purge jobs, submitted to the HIGH pool
int bg_purge_scheduled_;
// Information for a manual compaction
struct ManualCompactionState {
ColumnFamilyData* cfd;
int input_level;
int output_level;
uint32_t output_path_id;
Status status;
bool done;
bool in_progress; // compaction request being processed?
bool incomplete; // only part of requested range compacted
bool exclusive; // current behavior of only one manual
bool disallow_trivial_move; // Force actual compaction to run
const InternalKey* begin; // nullptr means beginning of key range
const InternalKey* end; // nullptr means end of key range
InternalKey* manual_end; // how far we are compacting
InternalKey tmp_storage; // Used to keep track of compaction progress
InternalKey tmp_storage1; // Used to keep track of compaction progress
};
struct PrepickedCompaction {
// background compaction takes ownership of `compaction`.
Compaction* compaction;
// caller retains ownership of `manual_compaction_state` as it is reused
// across background compactions.
ManualCompactionState* manual_compaction_state; // nullptr if non-manual
// task limiter token is requested during compaction picking.
std::unique_ptr<TaskLimiterToken> task_token;
};
std::deque<ManualCompactionState*> manual_compaction_dequeue_;
struct CompactionArg {
// caller retains ownership of `db`.
DBImpl* db;
// background compaction takes ownership of `prepicked_compaction`.
PrepickedCompaction* prepicked_compaction;
};
// shall we disable deletion of obsolete files
// if 0 the deletion is enabled.
// if non-zero, files will not be getting deleted
// This enables two different threads to call
// EnableFileDeletions() and DisableFileDeletions()
// without any synchronization
int disable_delete_obsolete_files_;
// Number of times FindObsoleteFiles has found deletable files and the
// corresponding call to PurgeObsoleteFiles has not yet finished.
int pending_purge_obsolete_files_;
// last time when DeleteObsoleteFiles with full scan was executed. Originaly
// initialized with startup time.
uint64_t delete_obsolete_files_last_run_;
// last time stats were dumped to LOG
std::atomic<uint64_t> last_stats_dump_time_microsec_;
// Each flush or compaction gets its own job id. this counter makes sure
// they're unique
std::atomic<int> next_job_id_;
// A flag indicating whether the current rocksdb database has any
// data that is not yet persisted into either WAL or SST file.
// Used when disableWAL is true.
std::atomic<bool> has_unpersisted_data_;
// if an attempt was made to flush all column families that
// the oldest log depends on but uncommitted data in the oldest
// log prevents the log from being released.
// We must attempt to free the dependent memtables again
// at a later time after the transaction in the oldest
// log is fully commited.
bool unable_to_release_oldest_log_;
static const int KEEP_LOG_FILE_NUM = 1000;
// MSVC version 1800 still does not have constexpr for ::max()
static const uint64_t kNoTimeOut = port::kMaxUint64;
std::string db_absolute_path_;
// The options to access storage files
const EnvOptions env_options_;
// Additonal options for compaction and flush
EnvOptions env_options_for_compaction_;
// Number of running IngestExternalFile() calls.
// REQUIRES: mutex held
int num_running_ingest_file_;
#ifndef ROCKSDB_LITE
WalManager wal_manager_;
#endif // ROCKSDB_LITE
// Unified interface for logging events
EventLogger event_logger_;
// A value of > 0 temporarily disables scheduling of background work
int bg_work_paused_;
// A value of > 0 temporarily disables scheduling of background compaction
int bg_compaction_paused_;
// Guard against multiple concurrent refitting
bool refitting_level_;
// Indicate DB was opened successfully
bool opened_successfully_;
LogsWithPrepTracker logs_with_prep_tracker_;
// Callback for compaction to check if a key is visible to a snapshot.
// REQUIRES: mutex held
std::unique_ptr<SnapshotChecker> snapshot_checker_;
// Callback for when the cached_recoverable_state_ is written to memtable
// Only to be set during initialization
std::unique_ptr<PreReleaseCallback> recoverable_state_pre_release_callback_;
// handle for scheduling jobs at fixed intervals
// REQUIRES: mutex locked
std::unique_ptr<rocksdb::RepeatableThread> thread_dump_stats_;
// No copying allowed
DBImpl(const DBImpl&);
void operator=(const DBImpl&);
// Background threads call this function, which is just a wrapper around
// the InstallSuperVersion() function. Background threads carry
// sv_context which can have new_superversion already
// allocated.
// All ColumnFamily state changes go through this function. Here we analyze
// the new state and we schedule background work if we detect that the new
// state needs flush or compaction.
void InstallSuperVersionAndScheduleWork(
ColumnFamilyData* cfd, SuperVersionContext* sv_context,
const MutableCFOptions& mutable_cf_options);
#ifndef ROCKSDB_LITE
using DB::GetPropertiesOfAllTables;
virtual Status GetPropertiesOfAllTables(ColumnFamilyHandle* column_family,
TablePropertiesCollection* props)
override;
virtual Status GetPropertiesOfTablesInRange(
ColumnFamilyHandle* column_family, const Range* range, std::size_t n,
TablePropertiesCollection* props) override;
#endif // ROCKSDB_LITE
bool GetIntPropertyInternal(ColumnFamilyData* cfd,
const DBPropertyInfo& property_info,
bool is_locked, uint64_t* value);
bool GetPropertyHandleOptionsStatistics(std::string* value);
bool HasPendingManualCompaction();
bool HasExclusiveManualCompaction();
void AddManualCompaction(ManualCompactionState* m);
void RemoveManualCompaction(ManualCompactionState* m);
bool ShouldntRunManualCompaction(ManualCompactionState* m);
bool HaveManualCompaction(ColumnFamilyData* cfd);
bool MCOverlap(ManualCompactionState* m, ManualCompactionState* m1);
#ifndef ROCKSDB_LITE
void BuildCompactionJobInfo(const ColumnFamilyData* cfd, Compaction* c,
const Status& st,
const CompactionJobStats& compaction_job_stats,
const int job_id, const Version* current,
CompactionJobInfo* compaction_job_info) const;
#endif
bool ShouldPurge(uint64_t file_number) const;
void MarkAsGrabbedForPurge(uint64_t file_number);
size_t GetWalPreallocateBlockSize(uint64_t write_buffer_size) const;
Env::WriteLifeTimeHint CalculateWALWriteHint() {
return Env::WLTH_SHORT;
}
// When set, we use a separate queue for writes that dont write to memtable.
// In 2PC these are the writes at Prepare phase.
const bool two_write_queues_;
const bool manual_wal_flush_;
// Increase the sequence number after writing each batch, whether memtable is
// disabled for that or not. Otherwise the sequence number is increased after
// writing each key into memtable. This implies that when disable_memtable is
// set, the seq is not increased at all.
//
// Default: false
const bool seq_per_batch_;
// This determines during recovery whether we expect one writebatch per
// recovered transaction, or potentially multiple writebatches per
// transaction. For WriteUnprepared, this is set to false, since multiple
// batches can exist per transaction.
//
// Default: true
const bool batch_per_txn_;
// LastSequence also indicates last published sequence visibile to the
// readers. Otherwise LastPublishedSequence should be used.
const bool last_seq_same_as_publish_seq_;
// It indicates that a customized gc algorithm must be used for
// flush/compaction and if it is not provided vis SnapshotChecker, we should
// disable gc to be safe.
const bool use_custom_gc_;
// Flag to indicate that the DB instance shutdown has been initiated. This
// different from shutting_down_ atomic in that it is set at the beginning
// of shutdown sequence, specifically in order to prevent any background
// error recovery from going on in parallel. The latter, shutting_down_,
// is set a little later during the shutdown after scheduling memtable
// flushes
std::atomic<bool> shutdown_initiated_;
// Flag to indicate whether sst_file_manager object was allocated in
// DB::Open() or passed to us
bool own_sfm_;
// Clients must periodically call SetPreserveDeletesSequenceNumber()
// to advance this seqnum. Default value is 0 which means ALL deletes are
// preserved. Note that this has no effect if DBOptions.preserve_deletes
// is set to false.
std::atomic<SequenceNumber> preserve_deletes_seqnum_;
const bool preserve_deletes_;
// Flag to check whether Close() has been called on this DB
bool closed_;
ErrorHandler error_handler_;
// Conditional variable to coordinate installation of atomic flush results.
// With atomic flush, each bg thread installs the result of flushing multiple
// column families, and different threads can flush different column
// families. It's difficult to rely on one thread to perform batch
// installation for all threads. This is different from the non-atomic flush
// case.
// atomic_flush_install_cv_ makes sure that threads install atomic flush
// results sequentially. Flush results of memtables with lower IDs get
// installed to MANIFEST first.
InstrumentedCondVar atomic_flush_install_cv_;
};
extern Options SanitizeOptions(const std::string& db,
const Options& src);
extern DBOptions SanitizeOptions(const std::string& db, const DBOptions& src);
extern CompressionType GetCompressionFlush(
const ImmutableCFOptions& ioptions,
const MutableCFOptions& mutable_cf_options);
// Return the earliest log file to keep after the memtable flush is
// finalized.
// `cfd_to_flush` is the column family whose memtable (specified in
// `memtables_to_flush`) will be flushed and thus will not depend on any WAL
// file.
// The function is only applicable to 2pc mode.
extern uint64_t PrecomputeMinLogNumberToKeep(
VersionSet* vset, const ColumnFamilyData& cfd_to_flush,
autovector<VersionEdit*> edit_list,
const autovector<MemTable*>& memtables_to_flush,
LogsWithPrepTracker* prep_tracker);
// `cfd_to_flush` is the column family whose memtable will be flushed and thus
// will not depend on any WAL file. nullptr means no memtable is being flushed.
// The function is only applicable to 2pc mode.
extern uint64_t FindMinPrepLogReferencedByMemTable(
VersionSet* vset, const ColumnFamilyData* cfd_to_flush,
const autovector<MemTable*>& memtables_to_flush);
// Fix user-supplied options to be reasonable
template <class T, class V>
static void ClipToRange(T* ptr, V minvalue, V maxvalue) {
if (static_cast<V>(*ptr) > maxvalue) *ptr = maxvalue;
if (static_cast<V>(*ptr) < minvalue) *ptr = minvalue;
}
} // namespace rocksdb