rocksdb/options/cf_options.h
Sagar Vemuri 04c11b867d Level Compaction with TTL
Summary:
Level Compaction with TTL.

As of today, a file could exist in the LSM tree without going through the compaction process for a really long time if there are no updates to the data in the file's key range. For example, in certain use cases, the keys are not actually "deleted"; instead they are just set to empty values. There might not be any more writes to this "deleted" key range, and if so, such data could remain in the LSM for a really long time resulting in wasted space.

Introducing a TTL could solve this problem. Files (and, in turn, data) older than TTL will be scheduled for compaction when there is no other background work. This will make the data go through the regular compaction process and get rid of old unwanted data.
This also has the (good) side-effect of all the data in the non-bottommost level being newer than ttl, and all data in the bottommost level older than ttl. It could lead to more writes while reducing space.

This functionality can be controlled by the newly introduced column family option -- ttl.

TODO for later:
- Make ttl mutable
- Extend TTL to Universal compaction as well? (TTL is already supported in FIFO)
- Maybe deprecate CompactionOptionsFIFO.ttl in favor of this new ttl option.
Closes https://github.com/facebook/rocksdb/pull/3591

Differential Revision: D7275442

Pulled By: sagar0

fbshipit-source-id: dcba484717341200d419b0953dafcdf9eb2f0267
2018-04-02 22:14:28 -07:00

244 lines
7.8 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).
#pragma once
#include <string>
#include <vector>
#include "db/dbformat.h"
#include "options/db_options.h"
#include "rocksdb/options.h"
#include "util/compression.h"
namespace rocksdb {
// ImmutableCFOptions is a data struct used by RocksDB internal. It contains a
// subset of Options that should not be changed during the entire lifetime
// of DB. Raw pointers defined in this struct do not have ownership to the data
// they point to. Options contains shared_ptr to these data.
struct ImmutableCFOptions {
ImmutableCFOptions();
explicit ImmutableCFOptions(const Options& options);
ImmutableCFOptions(const ImmutableDBOptions& db_options,
const ColumnFamilyOptions& cf_options);
CompactionStyle compaction_style;
CompactionPri compaction_pri;
const SliceTransform* prefix_extractor;
const Comparator* user_comparator;
InternalKeyComparator internal_comparator;
MergeOperator* merge_operator;
const CompactionFilter* compaction_filter;
CompactionFilterFactory* compaction_filter_factory;
int min_write_buffer_number_to_merge;
int max_write_buffer_number_to_maintain;
bool inplace_update_support;
UpdateStatus (*inplace_callback)(char* existing_value,
uint32_t* existing_value_size,
Slice delta_value,
std::string* merged_value);
Logger* info_log;
Statistics* statistics;
RateLimiter* rate_limiter;
InfoLogLevel info_log_level;
Env* env;
// Allow the OS to mmap file for reading sst tables. Default: false
bool allow_mmap_reads;
// Allow the OS to mmap file for writing. Default: false
bool allow_mmap_writes;
std::vector<DbPath> db_paths;
MemTableRepFactory* memtable_factory;
TableFactory* table_factory;
Options::TablePropertiesCollectorFactories
table_properties_collector_factories;
bool advise_random_on_open;
// This options is required by PlainTableReader. May need to move it
// to PlainTableOptions just like bloom_bits_per_key
uint32_t bloom_locality;
bool purge_redundant_kvs_while_flush;
bool use_fsync;
std::vector<CompressionType> compression_per_level;
CompressionType bottommost_compression;
CompressionOptions compression_opts;
bool level_compaction_dynamic_level_bytes;
Options::AccessHint access_hint_on_compaction_start;
bool new_table_reader_for_compaction_inputs;
int num_levels;
bool optimize_filters_for_hits;
bool force_consistency_checks;
bool allow_ingest_behind;
bool preserve_deletes;
// A vector of EventListeners which call-back functions will be called
// when specific RocksDB event happens.
std::vector<std::shared_ptr<EventListener>> listeners;
std::shared_ptr<Cache> row_cache;
uint32_t max_subcompactions;
const SliceTransform* memtable_insert_with_hint_prefix_extractor;
uint64_t ttl;
};
struct MutableCFOptions {
explicit MutableCFOptions(const ColumnFamilyOptions& options)
: write_buffer_size(options.write_buffer_size),
max_write_buffer_number(options.max_write_buffer_number),
arena_block_size(options.arena_block_size),
memtable_prefix_bloom_size_ratio(
options.memtable_prefix_bloom_size_ratio),
memtable_huge_page_size(options.memtable_huge_page_size),
max_successive_merges(options.max_successive_merges),
inplace_update_num_locks(options.inplace_update_num_locks),
disable_auto_compactions(options.disable_auto_compactions),
soft_pending_compaction_bytes_limit(
options.soft_pending_compaction_bytes_limit),
hard_pending_compaction_bytes_limit(
options.hard_pending_compaction_bytes_limit),
level0_file_num_compaction_trigger(
options.level0_file_num_compaction_trigger),
level0_slowdown_writes_trigger(options.level0_slowdown_writes_trigger),
level0_stop_writes_trigger(options.level0_stop_writes_trigger),
max_compaction_bytes(options.max_compaction_bytes),
target_file_size_base(options.target_file_size_base),
target_file_size_multiplier(options.target_file_size_multiplier),
max_bytes_for_level_base(options.max_bytes_for_level_base),
max_bytes_for_level_multiplier(options.max_bytes_for_level_multiplier),
max_bytes_for_level_multiplier_additional(
options.max_bytes_for_level_multiplier_additional),
compaction_options_fifo(options.compaction_options_fifo),
compaction_options_universal(options.compaction_options_universal),
max_sequential_skip_in_iterations(
options.max_sequential_skip_in_iterations),
paranoid_file_checks(options.paranoid_file_checks),
report_bg_io_stats(options.report_bg_io_stats),
compression(options.compression) {
RefreshDerivedOptions(options.num_levels, options.compaction_style);
}
MutableCFOptions()
: write_buffer_size(0),
max_write_buffer_number(0),
arena_block_size(0),
memtable_prefix_bloom_size_ratio(0),
memtable_huge_page_size(0),
max_successive_merges(0),
inplace_update_num_locks(0),
disable_auto_compactions(false),
soft_pending_compaction_bytes_limit(0),
hard_pending_compaction_bytes_limit(0),
level0_file_num_compaction_trigger(0),
level0_slowdown_writes_trigger(0),
level0_stop_writes_trigger(0),
max_compaction_bytes(0),
target_file_size_base(0),
target_file_size_multiplier(0),
max_bytes_for_level_base(0),
max_bytes_for_level_multiplier(0),
compaction_options_fifo(),
max_sequential_skip_in_iterations(0),
paranoid_file_checks(false),
report_bg_io_stats(false),
compression(Snappy_Supported() ? kSnappyCompression : kNoCompression) {}
// Must be called after any change to MutableCFOptions
void RefreshDerivedOptions(int num_levels, CompactionStyle compaction_style);
void RefreshDerivedOptions(const ImmutableCFOptions& ioptions) {
RefreshDerivedOptions(ioptions.num_levels, ioptions.compaction_style);
}
// Get the max file size in a given level.
uint64_t MaxFileSizeForLevel(int level) const;
int MaxBytesMultiplerAdditional(int level) const {
if (level >=
static_cast<int>(max_bytes_for_level_multiplier_additional.size())) {
return 1;
}
return max_bytes_for_level_multiplier_additional[level];
}
void Dump(Logger* log) const;
// Memtable related options
size_t write_buffer_size;
int max_write_buffer_number;
size_t arena_block_size;
double memtable_prefix_bloom_size_ratio;
size_t memtable_huge_page_size;
size_t max_successive_merges;
size_t inplace_update_num_locks;
// Compaction related options
bool disable_auto_compactions;
uint64_t soft_pending_compaction_bytes_limit;
uint64_t hard_pending_compaction_bytes_limit;
int level0_file_num_compaction_trigger;
int level0_slowdown_writes_trigger;
int level0_stop_writes_trigger;
uint64_t max_compaction_bytes;
uint64_t target_file_size_base;
int target_file_size_multiplier;
uint64_t max_bytes_for_level_base;
double max_bytes_for_level_multiplier;
std::vector<int> max_bytes_for_level_multiplier_additional;
CompactionOptionsFIFO compaction_options_fifo;
CompactionOptionsUniversal compaction_options_universal;
// Misc options
uint64_t max_sequential_skip_in_iterations;
bool paranoid_file_checks;
bool report_bg_io_stats;
CompressionType compression;
// Derived options
// Per-level target file size.
std::vector<uint64_t> max_file_size;
};
uint64_t MultiplyCheckOverflow(uint64_t op1, double op2);
} // namespace rocksdb