rocksdb/db_stress_tool/db_stress_gflags.cc
Changyu Bi cc23b46da1 Support using ZDICT_finalizeDictionary to generate zstd dictionary (#9857)
Summary:
An untrained dictionary is currently simply the concatenation of several samples. The ZSTD API, ZDICT_finalizeDictionary(), can improve such a dictionary's effectiveness at low cost. This PR changes how dictionary is created by calling the ZSTD ZDICT_finalizeDictionary() API instead of creating raw content dictionary (when max_dict_buffer_bytes > 0), and pass in all buffered uncompressed data blocks as samples.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9857

Test Plan:
#### db_bench test for cpu/memory of compression+decompression and space saving on synthetic data:
Set up: change the parameter [here](fb9a167a55/tools/db_bench_tool.cc (L1766)) to 16384 to make synthetic data more compressible.
```
# linked local ZSTD with version 1.5.2
# DEBUG_LEVEL=0 ROCKSDB_NO_FBCODE=1 ROCKSDB_DISABLE_ZSTD=1  EXTRA_CXXFLAGS="-DZSTD_STATIC_LINKING_ONLY -DZSTD -I/data/users/changyubi/install/include/" EXTRA_LDFLAGS="-L/data/users/changyubi/install/lib/ -l:libzstd.a" make -j32 db_bench

dict_bytes=16384
train_bytes=1048576
echo "========== No Dictionary =========="
TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=filluniquerandom,compact -num=10000000 -compression_type=zstd -compression_max_dict_bytes=0 -block_size=4096 -max_background_jobs=24 -memtablerep=vector -allow_concurrent_memtable_write=false -disable_wal=true -max_write_buffer_number=8 >/dev/null 2>&1
TEST_TMPDIR=/dev/shm /usr/bin/time ./db_bench -use_existing_db=true -benchmarks=compact -compression_type=zstd -compression_max_dict_bytes=0 -block_size=4096 2>&1 | grep elapsed
du -hc /dev/shm/dbbench/*sst | grep total

echo "========== Raw Content Dictionary =========="
TEST_TMPDIR=/dev/shm ./db_bench_main -benchmarks=filluniquerandom,compact -num=10000000 -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -block_size=4096 -max_background_jobs=24 -memtablerep=vector -allow_concurrent_memtable_write=false -disable_wal=true -max_write_buffer_number=8 >/dev/null 2>&1
TEST_TMPDIR=/dev/shm /usr/bin/time ./db_bench_main -use_existing_db=true -benchmarks=compact -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -block_size=4096 2>&1 | grep elapsed
du -hc /dev/shm/dbbench/*sst | grep total

echo "========== FinalizeDictionary =========="
TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=filluniquerandom,compact -num=10000000 -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -compression_zstd_max_train_bytes=$train_bytes -compression_use_zstd_dict_trainer=false -block_size=4096 -max_background_jobs=24 -memtablerep=vector -allow_concurrent_memtable_write=false -disable_wal=true -max_write_buffer_number=8 >/dev/null 2>&1
TEST_TMPDIR=/dev/shm /usr/bin/time ./db_bench -use_existing_db=true -benchmarks=compact -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -compression_zstd_max_train_bytes=$train_bytes -compression_use_zstd_dict_trainer=false -block_size=4096 2>&1 | grep elapsed
du -hc /dev/shm/dbbench/*sst | grep total

echo "========== TrainDictionary =========="
TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=filluniquerandom,compact -num=10000000 -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -compression_zstd_max_train_bytes=$train_bytes -block_size=4096 -max_background_jobs=24 -memtablerep=vector -allow_concurrent_memtable_write=false -disable_wal=true -max_write_buffer_number=8 >/dev/null 2>&1
TEST_TMPDIR=/dev/shm /usr/bin/time ./db_bench -use_existing_db=true -benchmarks=compact -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -compression_zstd_max_train_bytes=$train_bytes -block_size=4096 2>&1 | grep elapsed
du -hc /dev/shm/dbbench/*sst | grep total

# Result: TrainDictionary is much better on space saving, but FinalizeDictionary seems to use less memory.
# before compression data size: 1.2GB
dict_bytes=16384
max_dict_buffer_bytes =  1048576
                    space   cpu/memory
No Dictionary       468M    14.93user 1.00system 0:15.92elapsed 100%CPU (0avgtext+0avgdata 23904maxresident)k
Raw Dictionary      251M    15.81user 0.80system 0:16.56elapsed 100%CPU (0avgtext+0avgdata 156808maxresident)k
FinalizeDictionary  236M    11.93user 0.64system 0:12.56elapsed 100%CPU (0avgtext+0avgdata 89548maxresident)k
TrainDictionary     84M     7.29user 0.45system 0:07.75elapsed 100%CPU (0avgtext+0avgdata 97288maxresident)k
```

#### Benchmark on 10 sample SST files for spacing saving and CPU time on compression:
FinalizeDictionary is comparable to TrainDictionary in terms of space saving, and takes less time in compression.
```
dict_bytes=16384
train_bytes=1048576

for sst_file in `ls ../temp/myrock-sst/`
do
  echo "********** $sst_file **********"
  echo "========== No Dictionary =========="
  ./sst_dump --file="../temp/myrock-sst/$sst_file" --command=recompress --compression_level_from=6 --compression_level_to=6 --compression_types=kZSTD

  echo "========== Raw Content Dictionary =========="
  ./sst_dump --file="../temp/myrock-sst/$sst_file" --command=recompress --compression_level_from=6 --compression_level_to=6 --compression_types=kZSTD --compression_max_dict_bytes=$dict_bytes

  echo "========== FinalizeDictionary =========="
  ./sst_dump --file="../temp/myrock-sst/$sst_file" --command=recompress --compression_level_from=6 --compression_level_to=6 --compression_types=kZSTD --compression_max_dict_bytes=$dict_bytes --compression_zstd_max_train_bytes=$train_bytes --compression_use_zstd_finalize_dict

  echo "========== TrainDictionary =========="
  ./sst_dump --file="../temp/myrock-sst/$sst_file" --command=recompress --compression_level_from=6 --compression_level_to=6 --compression_types=kZSTD --compression_max_dict_bytes=$dict_bytes --compression_zstd_max_train_bytes=$train_bytes
done

                         010240.sst (Size/Time) 011029.sst              013184.sst              021552.sst              185054.sst              185137.sst              191666.sst              7560381.sst             7604174.sst             7635312.sst
No Dictionary           28165569 / 2614419      32899411 / 2976832      32977848 / 3055542      31966329 / 2004590      33614351 / 1755877      33429029 / 1717042      33611933 / 1776936      33634045 / 2771417      33789721 / 2205414      33592194 / 388254
Raw Content Dictionary  28019950 / 2697961      33748665 / 3572422      33896373 / 3534701      26418431 / 2259658      28560825 / 1839168      28455030 / 1846039      28494319 / 1861349      32391599 / 3095649      33772142 / 2407843      33592230 / 474523
FinalizeDictionary      27896012 / 2650029      33763886 / 3719427      33904283 / 3552793      26008225 / 2198033      28111872 / 1869530      28014374 / 1789771      28047706 / 1848300      32296254 / 3204027      33698698 / 2381468      33592344 / 517433
TrainDictionary         28046089 / 2740037      33706480 / 3679019      33885741 / 3629351      25087123 / 2204558      27194353 / 1970207      27234229 / 1896811      27166710 / 1903119      32011041 / 3322315      32730692 / 2406146      33608631 / 570593
```

#### Decompression/Read test:
With FinalizeDictionary/TrainDictionary, some data structure used for decompression are in stored in dictionary, so they are expected to be faster in terms of decompression/reads.
```
dict_bytes=16384
train_bytes=1048576
echo "No Dictionary"
TEST_TMPDIR=/dev/shm/ ./db_bench -benchmarks=filluniquerandom,compact -compression_type=zstd -compression_max_dict_bytes=0 > /dev/null 2>&1
TEST_TMPDIR=/dev/shm/ ./db_bench -use_existing_db=true -benchmarks=readrandom -cache_size=0 -compression_type=zstd -compression_max_dict_bytes=0 2>&1 | grep MB/s

echo "Raw Dictionary"
TEST_TMPDIR=/dev/shm/ ./db_bench -benchmarks=filluniquerandom,compact -compression_type=zstd -compression_max_dict_bytes=$dict_bytes > /dev/null 2>&1
TEST_TMPDIR=/dev/shm/ ./db_bench -use_existing_db=true -benchmarks=readrandom -cache_size=0 -compression_type=zstd  -compression_max_dict_bytes=$dict_bytes 2>&1 | grep MB/s

echo "FinalizeDict"
TEST_TMPDIR=/dev/shm/ ./db_bench -benchmarks=filluniquerandom,compact -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -compression_zstd_max_train_bytes=$train_bytes -compression_use_zstd_dict_trainer=false  > /dev/null 2>&1
TEST_TMPDIR=/dev/shm/ ./db_bench -use_existing_db=true -benchmarks=readrandom -cache_size=0 -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -compression_zstd_max_train_bytes=$train_bytes -compression_use_zstd_dict_trainer=false 2>&1 | grep MB/s

echo "Train Dictionary"
TEST_TMPDIR=/dev/shm/ ./db_bench -benchmarks=filluniquerandom,compact -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -compression_zstd_max_train_bytes=$train_bytes > /dev/null 2>&1
TEST_TMPDIR=/dev/shm/ ./db_bench -use_existing_db=true -benchmarks=readrandom -cache_size=0 -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -compression_zstd_max_train_bytes=$train_bytes 2>&1 | grep MB/s

No Dictionary
readrandom   :      12.183 micros/op 82082 ops/sec 12.183 seconds 1000000 operations;    9.1 MB/s (1000000 of 1000000 found)
Raw Dictionary
readrandom   :      12.314 micros/op 81205 ops/sec 12.314 seconds 1000000 operations;    9.0 MB/s (1000000 of 1000000 found)
FinalizeDict
readrandom   :       9.787 micros/op 102180 ops/sec 9.787 seconds 1000000 operations;   11.3 MB/s (1000000 of 1000000 found)
Train Dictionary
readrandom   :       9.698 micros/op 103108 ops/sec 9.699 seconds 1000000 operations;   11.4 MB/s (1000000 of 1000000 found)
```

Reviewed By: ajkr

Differential Revision: D35720026

Pulled By: cbi42

fbshipit-source-id: 24d230fdff0fd28a1bb650658798f00dfcfb2a1f
2022-05-20 12:09:09 -07:00

969 lines
41 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.
#ifdef GFLAGS
#include "db_stress_tool/db_stress_common.h"
static bool ValidateUint32Range(const char* flagname, uint64_t value) {
if (value > std::numeric_limits<uint32_t>::max()) {
fprintf(stderr, "Invalid value for --%s: %lu, overflow\n", flagname,
(unsigned long)value);
return false;
}
return true;
}
DEFINE_uint64(seed, 2341234,
"Seed for PRNG. When --nooverwritepercent is "
"nonzero and --expected_values_dir is nonempty, this value "
"must be fixed across invocations.");
static const bool FLAGS_seed_dummy __attribute__((__unused__)) =
RegisterFlagValidator(&FLAGS_seed, &ValidateUint32Range);
DEFINE_bool(read_only, false, "True if open DB in read-only mode during tests");
DEFINE_int64(max_key, 1 * KB * KB,
"Max number of key/values to place in database");
DEFINE_int32(max_key_len, 3, "Maximum length of a key in 8-byte units");
DEFINE_string(key_len_percent_dist, "",
"Percentages of keys of various lengths. For example, 1,30,69 "
"means 1% of keys are 8 bytes, 30% are 16 bytes, and 69% are "
"24 bytes. If not specified, it will be evenly distributed");
DEFINE_int32(key_window_scale_factor, 10,
"This value will be multiplied by 100 to come up with a window "
"size for varying the key length");
DEFINE_int32(column_families, 10, "Number of column families");
DEFINE_double(
hot_key_alpha, 0,
"Use Zipfian distribution to generate the key "
"distribution. If it is not specified, write path will use random "
"distribution to generate the keys. The parameter is [0, double_max]). "
"However, the larger alpha is, the more shewed will be. If alpha is "
"larger than 2, it is likely that only 1 key will be accessed. The "
"Recommended value is [0.8-1.5]. The distribution is also related to "
"max_key and total iterations of generating the hot key. ");
DEFINE_string(
options_file, "",
"The path to a RocksDB options file. If specified, then db_stress will "
"run with the RocksDB options in the default column family of the "
"specified options file. Note that, when an options file is provided, "
"db_stress will ignore the flag values for all options that may be passed "
"via options file.");
DEFINE_int64(
active_width, 0,
"Number of keys in active span of the key-range at any given time. The "
"span begins with its left endpoint at key 0, gradually moves rightwards, "
"and ends with its right endpoint at max_key. If set to 0, active_width "
"will be sanitized to be equal to max_key.");
// TODO(noetzli) Add support for single deletes
DEFINE_bool(test_batches_snapshots, false,
"If set, the test uses MultiGet(), MultiPut() and MultiDelete()"
" which read/write/delete multiple keys in a batch. In this mode,"
" we do not verify db content by comparing the content with the "
"pre-allocated array. Instead, we do partial verification inside"
" MultiGet() by checking various values in a batch. Benefit of"
" this mode:\n"
"\t(a) No need to acquire mutexes during writes (less cache "
"flushes in multi-core leading to speed up)\n"
"\t(b) No long validation at the end (more speed up)\n"
"\t(c) Test snapshot and atomicity of batch writes");
DEFINE_bool(atomic_flush, false,
"If set, enables atomic flush in the options.\n");
DEFINE_bool(test_cf_consistency, false,
"If set, runs the stress test dedicated to verifying writes to "
"multiple column families are consistent. Setting this implies "
"`atomic_flush=true` is set true if `disable_wal=false`.\n");
DEFINE_bool(test_multi_ops_txns, false,
"If set, runs stress test dedicated to verifying multi-ops "
"transactions on a simple relational table with primary and "
"secondary index.");
DEFINE_int32(threads, 32, "Number of concurrent threads to run.");
DEFINE_int32(ttl, -1,
"Opens the db with this ttl value if this is not -1. "
"Carefully specify a large value such that verifications on "
"deleted values don't fail");
DEFINE_int32(value_size_mult, 8,
"Size of value will be this number times rand_int(1,3) bytes");
DEFINE_int32(compaction_readahead_size, 0, "Compaction readahead size");
DEFINE_bool(enable_pipelined_write, false, "Pipeline WAL/memtable writes");
DEFINE_bool(verify_before_write, false, "Verify before write");
DEFINE_bool(histogram, false, "Print histogram of operation timings");
DEFINE_bool(destroy_db_initially, true,
"Destroys the database dir before start if this is true");
DEFINE_bool(verbose, false, "Verbose");
DEFINE_bool(progress_reports, true,
"If true, db_stress will report number of finished operations");
DEFINE_uint64(db_write_buffer_size,
ROCKSDB_NAMESPACE::Options().db_write_buffer_size,
"Number of bytes to buffer in all memtables before compacting");
DEFINE_int32(
write_buffer_size,
static_cast<int32_t>(ROCKSDB_NAMESPACE::Options().write_buffer_size),
"Number of bytes to buffer in memtable before compacting");
DEFINE_int32(max_write_buffer_number,
ROCKSDB_NAMESPACE::Options().max_write_buffer_number,
"The number of in-memory memtables. "
"Each memtable is of size FLAGS_write_buffer_size.");
DEFINE_int32(min_write_buffer_number_to_merge,
ROCKSDB_NAMESPACE::Options().min_write_buffer_number_to_merge,
"The minimum number of write buffers that will be merged together "
"before writing to storage. This is cheap because it is an "
"in-memory merge. If this feature is not enabled, then all these "
"write buffers are flushed to L0 as separate files and this "
"increases read amplification because a get request has to check "
"in all of these files. Also, an in-memory merge may result in "
"writing less data to storage if there are duplicate records in"
" each of these individual write buffers.");
DEFINE_int32(max_write_buffer_number_to_maintain,
ROCKSDB_NAMESPACE::Options().max_write_buffer_number_to_maintain,
"The total maximum number of write buffers to maintain in memory "
"including copies of buffers that have already been flushed. "
"Unlike max_write_buffer_number, this parameter does not affect "
"flushing. This controls the minimum amount of write history "
"that will be available in memory for conflict checking when "
"Transactions are used. If this value is too low, some "
"transactions may fail at commit time due to not being able to "
"determine whether there were any write conflicts. Setting this "
"value to 0 will cause write buffers to be freed immediately "
"after they are flushed. If this value is set to -1, "
"'max_write_buffer_number' will be used.");
DEFINE_int64(max_write_buffer_size_to_maintain,
ROCKSDB_NAMESPACE::Options().max_write_buffer_size_to_maintain,
"The total maximum size of write buffers to maintain in memory "
"including copies of buffers that have already been flushed. "
"Unlike max_write_buffer_number, this parameter does not affect "
"flushing. This controls the minimum amount of write history "
"that will be available in memory for conflict checking when "
"Transactions are used. If this value is too low, some "
"transactions may fail at commit time due to not being able to "
"determine whether there were any write conflicts. Setting this "
"value to 0 will cause write buffers to be freed immediately "
"after they are flushed. If this value is set to -1, "
"'max_write_buffer_number' will be used.");
DEFINE_double(memtable_prefix_bloom_size_ratio,
ROCKSDB_NAMESPACE::Options().memtable_prefix_bloom_size_ratio,
"creates prefix blooms for memtables, each with size "
"`write_buffer_size * memtable_prefix_bloom_size_ratio`.");
DEFINE_bool(memtable_whole_key_filtering,
ROCKSDB_NAMESPACE::Options().memtable_whole_key_filtering,
"Enable whole key filtering in memtables.");
DEFINE_int32(open_files, ROCKSDB_NAMESPACE::Options().max_open_files,
"Maximum number of files to keep open at the same time "
"(use default if == 0)");
DEFINE_int64(compressed_cache_size, 0,
"Number of bytes to use as a cache of compressed data."
" 0 means use default settings.");
DEFINE_int32(
compressed_cache_numshardbits, -1,
"Number of shards for the compressed block cache is 2 ** "
"compressed_cache_numshardbits. Negative value means default settings. "
"This is applied only if compressed_cache_size is greater than 0.");
DEFINE_int32(compaction_style, ROCKSDB_NAMESPACE::Options().compaction_style,
"");
DEFINE_int32(num_levels, ROCKSDB_NAMESPACE::Options().num_levels,
"Number of levels in the DB");
DEFINE_int32(level0_file_num_compaction_trigger,
ROCKSDB_NAMESPACE::Options().level0_file_num_compaction_trigger,
"Level0 compaction start trigger");
DEFINE_int32(level0_slowdown_writes_trigger,
ROCKSDB_NAMESPACE::Options().level0_slowdown_writes_trigger,
"Number of files in level-0 that will slow down writes");
DEFINE_int32(level0_stop_writes_trigger,
ROCKSDB_NAMESPACE::Options().level0_stop_writes_trigger,
"Number of files in level-0 that will trigger put stop.");
DEFINE_int32(block_size,
static_cast<int32_t>(
ROCKSDB_NAMESPACE::BlockBasedTableOptions().block_size),
"Number of bytes in a block.");
DEFINE_int32(format_version,
static_cast<int32_t>(
ROCKSDB_NAMESPACE::BlockBasedTableOptions().format_version),
"Format version of SST files.");
DEFINE_int32(
index_block_restart_interval,
ROCKSDB_NAMESPACE::BlockBasedTableOptions().index_block_restart_interval,
"Number of keys between restart points "
"for delta encoding of keys in index block.");
DEFINE_bool(disable_auto_compactions,
ROCKSDB_NAMESPACE::Options().disable_auto_compactions,
"If true, RocksDB internally will not trigger compactions.");
DEFINE_int32(max_background_compactions,
ROCKSDB_NAMESPACE::Options().max_background_compactions,
"The maximum number of concurrent background compactions "
"that can occur in parallel.");
DEFINE_int32(num_bottom_pri_threads, 0,
"The number of threads in the bottom-priority thread pool (used "
"by universal compaction only).");
DEFINE_int32(compaction_thread_pool_adjust_interval, 0,
"The interval (in milliseconds) to adjust compaction thread pool "
"size. Don't change it periodically if the value is 0.");
DEFINE_int32(compaction_thread_pool_variations, 2,
"Range of background thread pool size variations when adjusted "
"periodically.");
DEFINE_int32(max_background_flushes,
ROCKSDB_NAMESPACE::Options().max_background_flushes,
"The maximum number of concurrent background flushes "
"that can occur in parallel.");
DEFINE_int32(universal_size_ratio, 0,
"The ratio of file sizes that trigger"
" compaction in universal style");
DEFINE_int32(universal_min_merge_width, 0,
"The minimum number of files to "
"compact in universal style compaction");
DEFINE_int32(universal_max_merge_width, 0,
"The max number of files to compact"
" in universal style compaction");
DEFINE_int32(universal_max_size_amplification_percent, 0,
"The max size amplification for universal style compaction");
DEFINE_int32(clear_column_family_one_in, 1000000,
"With a chance of 1/N, delete a column family and then recreate "
"it again. If N == 0, never drop/create column families. "
"When test_batches_snapshots is true, this flag has no effect");
DEFINE_int32(get_live_files_one_in, 1000000,
"With a chance of 1/N, call GetLiveFiles to verify if it returns "
"correctly. If N == 0, do not call the interface.");
DEFINE_int32(
get_sorted_wal_files_one_in, 1000000,
"With a chance of 1/N, call GetSortedWalFiles to verify if it returns "
"correctly. (Note that this API may legitimately return an error.) If N == "
"0, do not call the interface.");
DEFINE_int32(
get_current_wal_file_one_in, 1000000,
"With a chance of 1/N, call GetCurrentWalFile to verify if it returns "
"correctly. (Note that this API may legitimately return an error.) If N == "
"0, do not call the interface.");
DEFINE_int32(set_options_one_in, 0,
"With a chance of 1/N, change some random options");
DEFINE_int32(set_in_place_one_in, 0,
"With a chance of 1/N, toggle in place support option");
DEFINE_int64(cache_size, 2LL * KB * KB * KB,
"Number of bytes to use as a cache of uncompressed data.");
DEFINE_int32(cache_numshardbits, 6,
"Number of shards for the block cache"
" is 2 ** cache_numshardbits. Negative means use default settings."
" This is applied only if FLAGS_cache_size is non-negative.");
DEFINE_bool(cache_index_and_filter_blocks, false,
"True if indexes/filters should be cached in block cache.");
DEFINE_bool(charge_compression_dictionary_building_buffer, false,
"Setting for "
"CacheEntryRoleOptions::charged of"
"CacheEntryRole::kCompressionDictionaryBuildingBuffer");
DEFINE_bool(charge_filter_construction, false,
"Setting for "
"CacheEntryRoleOptions::charged of"
"CacheEntryRole::kFilterConstruction");
DEFINE_bool(charge_table_reader, false,
"Setting for "
"CacheEntryRoleOptions::charged of"
"CacheEntryRole::kBlockBasedTableReader");
DEFINE_int32(
top_level_index_pinning,
static_cast<int32_t>(ROCKSDB_NAMESPACE::PinningTier::kFallback),
"Type of pinning for top-level indexes into metadata partitions (see "
"`enum PinningTier` in table.h)");
DEFINE_int32(
partition_pinning,
static_cast<int32_t>(ROCKSDB_NAMESPACE::PinningTier::kFallback),
"Type of pinning for metadata partitions (see `enum PinningTier` in "
"table.h)");
DEFINE_int32(
unpartitioned_pinning,
static_cast<int32_t>(ROCKSDB_NAMESPACE::PinningTier::kFallback),
"Type of pinning for unpartitioned metadata blocks (see `enum PinningTier` "
"in table.h)");
DEFINE_bool(use_clock_cache, false,
"Replace default LRU block cache with clock cache.");
DEFINE_uint64(subcompactions, 1,
"Maximum number of subcompactions to divide L0-L1 compactions "
"into.");
DEFINE_uint64(periodic_compaction_seconds, 1000,
"Files older than this value will be picked up for compaction.");
DEFINE_uint64(compaction_ttl, 1000,
"Files older than TTL will be compacted to the next level.");
DEFINE_bool(allow_concurrent_memtable_write, false,
"Allow multi-writers to update mem tables in parallel.");
DEFINE_double(experimental_mempurge_threshold, 0.0,
"Maximum estimated useful payload that triggers a "
"mempurge process to collect memtable garbage bytes.");
DEFINE_bool(enable_write_thread_adaptive_yield, true,
"Use a yielding spin loop for brief writer thread waits.");
#ifndef ROCKSDB_LITE
// Options for StackableDB-based BlobDB
DEFINE_bool(use_blob_db, false, "[Stacked BlobDB] Use BlobDB.");
DEFINE_uint64(
blob_db_min_blob_size,
ROCKSDB_NAMESPACE::blob_db::BlobDBOptions().min_blob_size,
"[Stacked BlobDB] Smallest blob to store in a file. Blobs "
"smaller than this will be inlined with the key in the LSM tree.");
DEFINE_uint64(
blob_db_bytes_per_sync,
ROCKSDB_NAMESPACE::blob_db::BlobDBOptions().bytes_per_sync,
"[Stacked BlobDB] Sync blob files once per every N bytes written.");
DEFINE_uint64(blob_db_file_size,
ROCKSDB_NAMESPACE::blob_db::BlobDBOptions().blob_file_size,
"[Stacked BlobDB] Target size of each blob file.");
DEFINE_bool(
blob_db_enable_gc,
ROCKSDB_NAMESPACE::blob_db::BlobDBOptions().enable_garbage_collection,
"[Stacked BlobDB] Enable BlobDB garbage collection.");
DEFINE_double(
blob_db_gc_cutoff,
ROCKSDB_NAMESPACE::blob_db::BlobDBOptions().garbage_collection_cutoff,
"[Stacked BlobDB] Cutoff ratio for BlobDB garbage collection.");
#endif // !ROCKSDB_LITE
// Options for integrated BlobDB
DEFINE_bool(allow_setting_blob_options_dynamically, false,
"[Integrated BlobDB] Allow setting blob options dynamically.");
DEFINE_bool(
enable_blob_files,
ROCKSDB_NAMESPACE::AdvancedColumnFamilyOptions().enable_blob_files,
"[Integrated BlobDB] Enable writing large values to separate blob files.");
DEFINE_uint64(min_blob_size,
ROCKSDB_NAMESPACE::AdvancedColumnFamilyOptions().min_blob_size,
"[Integrated BlobDB] The size of the smallest value to be stored "
"separately in a blob file.");
DEFINE_uint64(blob_file_size,
ROCKSDB_NAMESPACE::AdvancedColumnFamilyOptions().blob_file_size,
"[Integrated BlobDB] The size limit for blob files.");
DEFINE_string(blob_compression_type, "none",
"[Integrated BlobDB] The compression algorithm to use for large "
"values stored in blob files.");
DEFINE_bool(enable_blob_garbage_collection,
ROCKSDB_NAMESPACE::AdvancedColumnFamilyOptions()
.enable_blob_garbage_collection,
"[Integrated BlobDB] Enable blob garbage collection.");
DEFINE_double(blob_garbage_collection_age_cutoff,
ROCKSDB_NAMESPACE::AdvancedColumnFamilyOptions()
.blob_garbage_collection_age_cutoff,
"[Integrated BlobDB] The cutoff in terms of blob file age for "
"garbage collection.");
DEFINE_double(blob_garbage_collection_force_threshold,
ROCKSDB_NAMESPACE::AdvancedColumnFamilyOptions()
.blob_garbage_collection_force_threshold,
"[Integrated BlobDB] The threshold for the ratio of garbage in "
"the oldest blob files for forcing garbage collection.");
DEFINE_uint64(blob_compaction_readahead_size,
ROCKSDB_NAMESPACE::AdvancedColumnFamilyOptions()
.blob_compaction_readahead_size,
"[Integrated BlobDB] Compaction readahead for blob files.");
static const bool FLAGS_subcompactions_dummy __attribute__((__unused__)) =
RegisterFlagValidator(&FLAGS_subcompactions, &ValidateUint32Range);
static bool ValidateInt32Positive(const char* flagname, int32_t value) {
if (value < 0) {
fprintf(stderr, "Invalid value for --%s: %d, must be >=0\n", flagname,
value);
return false;
}
return true;
}
DEFINE_int32(reopen, 10, "Number of times database reopens");
static const bool FLAGS_reopen_dummy __attribute__((__unused__)) =
RegisterFlagValidator(&FLAGS_reopen, &ValidateInt32Positive);
DEFINE_double(bloom_bits, 10,
"Bloom filter bits per key. "
"Negative means use default settings.");
DEFINE_bool(use_block_based_filter, false,
"use block based filter"
"instead of full filter for block based table");
DEFINE_int32(
ribbon_starting_level, 999,
"Use Bloom filter on levels below specified and Ribbon beginning on level "
"specified. Flush is considered level -1. 999 or more -> always Bloom. 0 "
"-> Ribbon except Bloom for flush. -1 -> always Ribbon.");
DEFINE_bool(partition_filters, false,
"use partitioned filters "
"for block-based table");
DEFINE_bool(
optimize_filters_for_memory,
ROCKSDB_NAMESPACE::BlockBasedTableOptions().optimize_filters_for_memory,
"Minimize memory footprint of filters");
DEFINE_bool(
detect_filter_construct_corruption,
ROCKSDB_NAMESPACE::BlockBasedTableOptions()
.detect_filter_construct_corruption,
"Detect corruption during new Bloom Filter and Ribbon Filter construction");
DEFINE_int32(
index_type,
static_cast<int32_t>(
ROCKSDB_NAMESPACE::BlockBasedTableOptions::kBinarySearch),
"Type of block-based table index (see `enum IndexType` in table.h)");
DEFINE_string(db, "", "Use the db with the following name.");
DEFINE_string(secondaries_base, "",
"Use this path as the base path for secondary instances.");
DEFINE_bool(test_secondary, false, "Test secondary instance.");
DEFINE_string(
expected_values_dir, "",
"Dir where files containing info about the latest/historical values will "
"be stored. If provided and non-empty, the DB state will be verified "
"against values from these files after recovery. --max_key and "
"--column_family must be kept the same across invocations of this program "
"that use the same --expected_values_dir. Currently historical values are "
"only tracked when --sync_fault_injection is set. See --seed and "
"--nooverwritepercent for further requirements.");
DEFINE_bool(verify_checksum, false,
"Verify checksum for every block read from storage");
DEFINE_bool(mmap_read, ROCKSDB_NAMESPACE::Options().allow_mmap_reads,
"Allow reads to occur via mmap-ing files");
DEFINE_bool(mmap_write, ROCKSDB_NAMESPACE::Options().allow_mmap_writes,
"Allow writes to occur via mmap-ing files");
DEFINE_bool(use_direct_reads, ROCKSDB_NAMESPACE::Options().use_direct_reads,
"Use O_DIRECT for reading data");
DEFINE_bool(use_direct_io_for_flush_and_compaction,
ROCKSDB_NAMESPACE::Options().use_direct_io_for_flush_and_compaction,
"Use O_DIRECT for writing data");
DEFINE_bool(mock_direct_io, false,
"Mock direct IO by not using O_DIRECT for direct IO read");
DEFINE_bool(statistics, false, "Create database statistics");
DEFINE_bool(sync, false, "Sync all writes to disk");
DEFINE_bool(use_fsync, false, "If true, issue fsync instead of fdatasync");
DEFINE_uint64(bytes_per_sync, ROCKSDB_NAMESPACE::Options().bytes_per_sync,
"If nonzero, sync SST file data incrementally after every "
"`bytes_per_sync` bytes are written");
DEFINE_uint64(wal_bytes_per_sync,
ROCKSDB_NAMESPACE::Options().wal_bytes_per_sync,
"If nonzero, sync WAL file data incrementally after every "
"`bytes_per_sync` bytes are written");
DEFINE_int32(kill_random_test, 0,
"If non-zero, kill at various points in source code with "
"probability 1/this");
static const bool FLAGS_kill_random_test_dummy __attribute__((__unused__)) =
RegisterFlagValidator(&FLAGS_kill_random_test, &ValidateInt32Positive);
DEFINE_string(kill_exclude_prefixes, "",
"If non-empty, kill points with prefix in the list given will be"
" skipped. Items are comma-separated.");
extern std::vector<std::string> rocksdb_kill_exclude_prefixes;
DEFINE_bool(disable_wal, false, "If true, do not write WAL for write.");
DEFINE_uint64(recycle_log_file_num,
ROCKSDB_NAMESPACE::Options().recycle_log_file_num,
"Number of old WAL files to keep around for later recycling");
DEFINE_int64(target_file_size_base,
ROCKSDB_NAMESPACE::Options().target_file_size_base,
"Target level-1 file size for compaction");
DEFINE_int32(target_file_size_multiplier, 1,
"A multiplier to compute target level-N file size (N >= 2)");
DEFINE_uint64(max_bytes_for_level_base,
ROCKSDB_NAMESPACE::Options().max_bytes_for_level_base,
"Max bytes for level-1");
DEFINE_double(max_bytes_for_level_multiplier, 2,
"A multiplier to compute max bytes for level-N (N >= 2)");
DEFINE_int32(range_deletion_width, 10,
"The width of the range deletion intervals.");
DEFINE_uint64(rate_limiter_bytes_per_sec, 0, "Set options.rate_limiter value.");
DEFINE_bool(rate_limit_bg_reads, false,
"Use options.rate_limiter on compaction reads");
DEFINE_bool(rate_limit_user_ops, false,
"When true use Env::IO_USER priority level to charge internal rate "
"limiter for reads associated with user operations.");
DEFINE_bool(rate_limit_auto_wal_flush, false,
"When true use Env::IO_USER priority level to charge internal rate "
"limiter for automatic WAL flush (`Options::manual_wal_flush` == "
"false) after the user "
"write operation.");
DEFINE_uint64(sst_file_manager_bytes_per_sec, 0,
"Set `Options::sst_file_manager` to delete at this rate. By "
"default the deletion rate is unbounded.");
DEFINE_uint64(sst_file_manager_bytes_per_truncate, 0,
"Set `Options::sst_file_manager` to delete in chunks of this "
"many bytes. By default whole files will be deleted.");
DEFINE_bool(use_txn, false,
"Use TransactionDB. Currently the default write policy is "
"TxnDBWritePolicy::WRITE_PREPARED");
DEFINE_uint64(txn_write_policy, 0,
"The transaction write policy. Default is "
"TxnDBWritePolicy::WRITE_COMMITTED. Note that this should not be "
"changed accross crashes.");
DEFINE_bool(unordered_write, false,
"Turn on the unordered_write feature. This options is currently "
"tested only in combination with use_txn=true and "
"txn_write_policy=TxnDBWritePolicy::WRITE_PREPARED.");
DEFINE_int32(backup_one_in, 0,
"If non-zero, then CreateNewBackup() will be called once for "
"every N operations on average. 0 indicates CreateNewBackup() "
"is disabled.");
DEFINE_uint64(backup_max_size, 100 * 1024 * 1024,
"If non-zero, skip checking backup/restore when DB size in "
"bytes exceeds this setting.");
DEFINE_int32(checkpoint_one_in, 0,
"If non-zero, then CreateCheckpoint() will be called once for "
"every N operations on average. 0 indicates CreateCheckpoint() "
"is disabled.");
DEFINE_int32(ingest_external_file_one_in, 0,
"If non-zero, then IngestExternalFile() will be called once for "
"every N operations on average. 0 indicates IngestExternalFile() "
"is disabled.");
DEFINE_int32(ingest_external_file_width, 1000,
"The width of the ingested external files.");
DEFINE_int32(compact_files_one_in, 0,
"If non-zero, then CompactFiles() will be called once for every N "
"operations on average. 0 indicates CompactFiles() is disabled.");
DEFINE_int32(compact_range_one_in, 0,
"If non-zero, then CompactRange() will be called once for every N "
"operations on average. 0 indicates CompactRange() is disabled.");
DEFINE_int32(mark_for_compaction_one_file_in, 0,
"A `TablePropertiesCollectorFactory` will be registered, which "
"creates a `TablePropertiesCollector` with `NeedCompact()` "
"returning true once for every N files on average. 0 or negative "
"mean `NeedCompact()` always returns false.");
DEFINE_int32(flush_one_in, 0,
"If non-zero, then Flush() will be called once for every N ops "
"on average. 0 indicates calls to Flush() are disabled.");
DEFINE_int32(pause_background_one_in, 0,
"If non-zero, then PauseBackgroundWork()+Continue will be called "
"once for every N ops on average. 0 disables.");
DEFINE_int32(compact_range_width, 10000,
"The width of the ranges passed to CompactRange().");
DEFINE_int32(acquire_snapshot_one_in, 0,
"If non-zero, then acquires a snapshot once every N operations on "
"average.");
DEFINE_bool(compare_full_db_state_snapshot, false,
"If set we compare state of entire db (in one of the threads) with"
"each snapshot.");
DEFINE_uint64(snapshot_hold_ops, 0,
"If non-zero, then releases snapshots N operations after they're "
"acquired.");
DEFINE_bool(long_running_snapshots, false,
"If set, hold on some some snapshots for much longer time.");
DEFINE_bool(use_multiget, false,
"If set, use the batched MultiGet API for reads");
static bool ValidateInt32Percent(const char* flagname, int32_t value) {
if (value < 0 || value > 100) {
fprintf(stderr, "Invalid value for --%s: %d, 0<= pct <=100 \n", flagname,
value);
return false;
}
return true;
}
DEFINE_int32(readpercent, 10,
"Ratio of reads to total workload (expressed as a percentage)");
static const bool FLAGS_readpercent_dummy __attribute__((__unused__)) =
RegisterFlagValidator(&FLAGS_readpercent, &ValidateInt32Percent);
DEFINE_int32(prefixpercent, 20,
"Ratio of prefix iterators to total workload (expressed as a"
" percentage)");
static const bool FLAGS_prefixpercent_dummy __attribute__((__unused__)) =
RegisterFlagValidator(&FLAGS_prefixpercent, &ValidateInt32Percent);
DEFINE_int32(writepercent, 45,
"Ratio of writes to total workload (expressed as a percentage)");
static const bool FLAGS_writepercent_dummy __attribute__((__unused__)) =
RegisterFlagValidator(&FLAGS_writepercent, &ValidateInt32Percent);
DEFINE_int32(delpercent, 15,
"Ratio of deletes to total workload (expressed as a percentage)");
static const bool FLAGS_delpercent_dummy __attribute__((__unused__)) =
RegisterFlagValidator(&FLAGS_delpercent, &ValidateInt32Percent);
DEFINE_int32(delrangepercent, 0,
"Ratio of range deletions to total workload (expressed as a "
"percentage). Cannot be used with test_batches_snapshots");
static const bool FLAGS_delrangepercent_dummy __attribute__((__unused__)) =
RegisterFlagValidator(&FLAGS_delrangepercent, &ValidateInt32Percent);
DEFINE_int32(nooverwritepercent, 60,
"Ratio of keys without overwrite to total workload (expressed as "
"a percentage). When --expected_values_dir is nonempty, must "
"keep this value constant across invocations.");
static const bool FLAGS_nooverwritepercent_dummy __attribute__((__unused__)) =
RegisterFlagValidator(&FLAGS_nooverwritepercent, &ValidateInt32Percent);
DEFINE_int32(iterpercent, 10,
"Ratio of iterations to total workload"
" (expressed as a percentage)");
static const bool FLAGS_iterpercent_dummy __attribute__((__unused__)) =
RegisterFlagValidator(&FLAGS_iterpercent, &ValidateInt32Percent);
DEFINE_uint64(num_iterations, 10, "Number of iterations per MultiIterate run");
static const bool FLAGS_num_iterations_dummy __attribute__((__unused__)) =
RegisterFlagValidator(&FLAGS_num_iterations, &ValidateUint32Range);
DEFINE_int32(
customopspercent, 0,
"Ratio of custom operations to total workload (expressed as a percentage)");
DEFINE_string(compression_type, "snappy",
"Algorithm to use to compress the database");
DEFINE_int32(compression_max_dict_bytes, 0,
"Maximum size of dictionary used to prime the compression "
"library.");
DEFINE_int32(compression_zstd_max_train_bytes, 0,
"Maximum size of training data passed to zstd's dictionary "
"trainer.");
DEFINE_int32(compression_parallel_threads, 1,
"Number of threads for parallel compression.");
DEFINE_uint64(compression_max_dict_buffer_bytes, 0,
"Buffering limit for SST file data to sample for dictionary "
"compression.");
DEFINE_bool(
compression_use_zstd_dict_trainer, true,
"Use zstd's trainer to generate dictionary. If the options is false, "
"zstd's finalizeDictionary() API is used to generate dictionary. "
"ZSTD 1.4.5+ is required. If ZSTD 1.4.5+ is not linked with the binary, "
"this flag will have the default value true.");
DEFINE_string(bottommost_compression_type, "disable",
"Algorithm to use to compress bottommost level of the database. "
"\"disable\" means disabling the feature");
DEFINE_string(checksum_type, "kCRC32c", "Algorithm to use to checksum blocks");
DEFINE_string(env_uri, "",
"URI for env lookup. Mutually exclusive with --fs_uri");
DEFINE_string(fs_uri, "",
"URI for registry Filesystem lookup. Mutually exclusive"
" with --env_uri."
" Creates a default environment with the specified filesystem.");
DEFINE_uint64(ops_per_thread, 1200000, "Number of operations per thread.");
static const bool FLAGS_ops_per_thread_dummy __attribute__((__unused__)) =
RegisterFlagValidator(&FLAGS_ops_per_thread, &ValidateUint32Range);
DEFINE_uint64(log2_keys_per_lock, 2, "Log2 of number of keys per lock");
static const bool FLAGS_log2_keys_per_lock_dummy __attribute__((__unused__)) =
RegisterFlagValidator(&FLAGS_log2_keys_per_lock, &ValidateUint32Range);
DEFINE_uint64(max_manifest_file_size, 16384, "Maximum size of a MANIFEST file");
DEFINE_bool(in_place_update, false, "On true, does inplace update in memtable");
DEFINE_int32(secondary_catch_up_one_in, 0,
"If non-zero, the secondaries attemp to catch up with the primary "
"once for every N operations on average. 0 indicates the "
"secondaries do not try to catch up after open.");
DEFINE_string(memtablerep, "skip_list", "");
inline static bool ValidatePrefixSize(const char* flagname, int32_t value) {
if (value < -1 || value > 8) {
fprintf(stderr, "Invalid value for --%s: %d. -1 <= PrefixSize <= 8\n",
flagname, value);
return false;
}
return true;
}
DEFINE_int32(prefix_size, 7,
"Control the prefix size for HashSkipListRep. "
"-1 is disabled.");
static const bool FLAGS_prefix_size_dummy __attribute__((__unused__)) =
RegisterFlagValidator(&FLAGS_prefix_size, &ValidatePrefixSize);
DEFINE_bool(use_merge, false,
"On true, replaces all writes with a Merge "
"that behaves like a Put");
DEFINE_bool(use_full_merge_v1, false,
"On true, use a merge operator that implement the deprecated "
"version of FullMerge");
DEFINE_int32(sync_wal_one_in, 0,
"If non-zero, then SyncWAL() will be called once for every N ops "
"on average. 0 indicates that calls to SyncWAL() are disabled.");
DEFINE_bool(avoid_unnecessary_blocking_io,
ROCKSDB_NAMESPACE::Options().avoid_unnecessary_blocking_io,
"If true, some expensive cleaning up operations will be moved from "
"user reads to high-pri background threads.");
DEFINE_bool(write_dbid_to_manifest,
ROCKSDB_NAMESPACE::Options().write_dbid_to_manifest,
"Write DB_ID to manifest");
DEFINE_bool(avoid_flush_during_recovery,
ROCKSDB_NAMESPACE::Options().avoid_flush_during_recovery,
"Avoid flush during recovery");
DEFINE_uint64(max_write_batch_group_size_bytes,
ROCKSDB_NAMESPACE::Options().max_write_batch_group_size_bytes,
"Max write batch group size");
DEFINE_bool(level_compaction_dynamic_level_bytes,
ROCKSDB_NAMESPACE::Options().level_compaction_dynamic_level_bytes,
"Use dynamic level");
DEFINE_int32(verify_checksum_one_in, 0,
"If non-zero, then DB::VerifyChecksum() will be called to do"
" checksum verification of all the files in the database once for"
" every N ops on average. 0 indicates that calls to"
" VerifyChecksum() are disabled.");
DEFINE_int32(verify_db_one_in, 0,
"If non-zero, call VerifyDb() once for every N ops. 0 indicates "
"that VerifyDb() will not be called in OperateDb(). Note that "
"enabling this can slow down tests.");
DEFINE_int32(continuous_verification_interval, 1000,
"While test is running, verify db every N milliseconds. 0 "
"disables continuous verification.");
DEFINE_int32(approximate_size_one_in, 64,
"If non-zero, DB::GetApproximateSizes() will be called against"
" random key ranges.");
DEFINE_int32(read_fault_one_in, 1000,
"On non-zero, enables fault injection on read");
DEFINE_int32(get_property_one_in, 1000,
"If non-zero, then DB::GetProperty() will be called to get various"
" properties for every N ops on average. 0 indicates that"
" GetProperty() will be not be called.");
DEFINE_bool(sync_fault_injection, false,
"If true, FaultInjectionTestFS will be used for write operations, "
"and unsynced data in DB will lost after crash. In such a case we "
"track DB changes in a trace file (\"*.trace\") in "
"--expected_values_dir for verifying there are no holes in the "
"recovered data.");
DEFINE_bool(best_efforts_recovery, false,
"If true, use best efforts recovery.");
DEFINE_bool(skip_verifydb, false, "If true, skip VerifyDb() calls.");
DEFINE_bool(enable_compaction_filter, false,
"If true, configures a compaction filter that returns a kRemove "
"decision for deleted keys.");
DEFINE_bool(paranoid_file_checks, true,
"After writing every SST file, reopen it and read all the keys "
"and validate checksums");
DEFINE_bool(fail_if_options_file_error, false,
"Fail operations that fail to detect or properly persist options "
"file.");
DEFINE_uint64(batch_protection_bytes_per_key, 0,
"If nonzero, enables integrity protection in `WriteBatch` at the "
"specified number of bytes per key. Currently the only supported "
"nonzero value is eight.");
DEFINE_string(file_checksum_impl, "none",
"Name of an implementation for file_checksum_gen_factory, or "
"\"none\" for null.");
DEFINE_int32(write_fault_one_in, 0,
"On non-zero, enables fault injection on write");
DEFINE_uint64(user_timestamp_size, 0,
"Number of bytes for a user-defined timestamp. Currently, only "
"8-byte is supported");
DEFINE_int32(open_metadata_write_fault_one_in, 0,
"On non-zero, enables fault injection on file metadata write "
"during DB reopen.");
#ifndef ROCKSDB_LITE
DEFINE_string(secondary_cache_uri, "",
"Full URI for creating a customized secondary cache object");
DEFINE_int32(secondary_cache_fault_one_in, 0,
"On non-zero, enables fault injection in secondary cache inserts"
" and lookups");
#endif // ROCKSDB_LITE
DEFINE_int32(open_write_fault_one_in, 0,
"On non-zero, enables fault injection on file writes "
"during DB reopen.");
DEFINE_int32(open_read_fault_one_in, 0,
"On non-zero, enables fault injection on file reads "
"during DB reopen.");
DEFINE_int32(injest_error_severity, 1,
"The severity of the injested IO Error. 1 is soft error (e.g. "
"retryable error), 2 is fatal error, and the default is "
"retryable error.");
DEFINE_int32(prepopulate_block_cache,
static_cast<int32_t>(ROCKSDB_NAMESPACE::BlockBasedTableOptions::
PrepopulateBlockCache::kDisable),
"Options related to cache warming (see `enum "
"PrepopulateBlockCache` in table.h)");
DEFINE_bool(two_write_queues, false,
"Set to true to enable two write queues. Default: false");
#ifndef ROCKSDB_LITE
DEFINE_bool(use_only_the_last_commit_time_batch_for_recovery, false,
"If true, the commit-time write batch will not be immediately "
"inserted into the memtables. Default: false");
DEFINE_uint64(
wp_snapshot_cache_bits, 7ull,
"Number of bits to represent write-prepared transaction db's snapshot "
"cache. Default: 7 (128 entries)");
DEFINE_uint64(wp_commit_cache_bits, 23ull,
"Number of bits to represent write-prepared transaction db's "
"commit cache. Default: 23 (8M entries)");
#endif // !ROCKSDB_LITE
DEFINE_bool(adaptive_readahead, false,
"Carry forward internal auto readahead size from one file to next "
"file at each level during iteration");
DEFINE_bool(
async_io, false,
"Does asynchronous prefetching when internal auto readahead is enabled");
DEFINE_string(wal_compression, "none",
"Algorithm to use for WAL compression. none to disable.");
DEFINE_bool(
verify_sst_unique_id_in_manifest, false,
"Enable DB options `verify_sst_unique_id_in_manifest`, if true, during "
"DB-open try verifying the SST unique id between MANIFEST and SST "
"properties.");
#endif // GFLAGS