rocksdb/monitoring/perf_context.cc

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// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
#include <sstream>
#include "monitoring/perf_context_imp.h"
namespace ROCKSDB_NAMESPACE {
#if defined(NPERF_CONTEXT)
// Should not be used because the counters are not thread-safe.
// Put here just to make get_perf_context() simple without ifdef.
PerfContext perf_context;
#else
thread_local PerfContext perf_context;
#endif
PerfContext* get_perf_context() {
return &perf_context;
}
PerfContext::~PerfContext() {
#if !defined(NPERF_CONTEXT) && !defined(OS_SOLARIS)
ClearPerLevelPerfContext();
#endif
}
PerfContext::PerfContext(const PerfContext& other) {
#ifdef NPERF_CONTEXT
(void)other;
#else
user_key_comparison_count = other.user_key_comparison_count;
block_cache_hit_count = other.block_cache_hit_count;
block_read_count = other.block_read_count;
block_read_byte = other.block_read_byte;
block_read_time = other.block_read_time;
block_cache_index_hit_count = other.block_cache_index_hit_count;
index_block_read_count = other.index_block_read_count;
block_cache_filter_hit_count = other.block_cache_filter_hit_count;
filter_block_read_count = other.filter_block_read_count;
compression_dict_block_read_count = other.compression_dict_block_read_count;
secondary_cache_hit_count = other.secondary_cache_hit_count;
block_checksum_time = other.block_checksum_time;
block_decompress_time = other.block_decompress_time;
get_read_bytes = other.get_read_bytes;
multiget_read_bytes = other.multiget_read_bytes;
iter_read_bytes = other.iter_read_bytes;
internal_key_skipped_count = other.internal_key_skipped_count;
internal_delete_skipped_count = other.internal_delete_skipped_count;
internal_recent_skipped_count = other.internal_recent_skipped_count;
internal_merge_count = other.internal_merge_count;
write_wal_time = other.write_wal_time;
get_snapshot_time = other.get_snapshot_time;
get_from_memtable_time = other.get_from_memtable_time;
get_from_memtable_count = other.get_from_memtable_count;
get_post_process_time = other.get_post_process_time;
get_from_output_files_time = other.get_from_output_files_time;
seek_on_memtable_time = other.seek_on_memtable_time;
seek_on_memtable_count = other.seek_on_memtable_count;
next_on_memtable_count = other.next_on_memtable_count;
prev_on_memtable_count = other.prev_on_memtable_count;
seek_child_seek_time = other.seek_child_seek_time;
seek_child_seek_count = other.seek_child_seek_count;
seek_min_heap_time = other.seek_min_heap_time;
seek_internal_seek_time = other.seek_internal_seek_time;
find_next_user_entry_time = other.find_next_user_entry_time;
write_pre_and_post_process_time = other.write_pre_and_post_process_time;
write_memtable_time = other.write_memtable_time;
write_delay_time = other.write_delay_time;
write_thread_wait_nanos = other.write_thread_wait_nanos;
write_scheduling_flushes_compactions_time =
other.write_scheduling_flushes_compactions_time;
db_mutex_lock_nanos = other.db_mutex_lock_nanos;
db_condition_wait_nanos = other.db_condition_wait_nanos;
merge_operator_time_nanos = other.merge_operator_time_nanos;
read_index_block_nanos = other.read_index_block_nanos;
read_filter_block_nanos = other.read_filter_block_nanos;
new_table_block_iter_nanos = other.new_table_block_iter_nanos;
new_table_iterator_nanos = other.new_table_iterator_nanos;
block_seek_nanos = other.block_seek_nanos;
find_table_nanos = other.find_table_nanos;
bloom_memtable_hit_count = other.bloom_memtable_hit_count;
bloom_memtable_miss_count = other.bloom_memtable_miss_count;
bloom_sst_hit_count = other.bloom_sst_hit_count;
bloom_sst_miss_count = other.bloom_sst_miss_count;
key_lock_wait_time = other.key_lock_wait_time;
key_lock_wait_count = other.key_lock_wait_count;
env_new_sequential_file_nanos = other.env_new_sequential_file_nanos;
env_new_random_access_file_nanos = other.env_new_random_access_file_nanos;
env_new_writable_file_nanos = other.env_new_writable_file_nanos;
env_reuse_writable_file_nanos = other.env_reuse_writable_file_nanos;
env_new_random_rw_file_nanos = other.env_new_random_rw_file_nanos;
env_new_directory_nanos = other.env_new_directory_nanos;
env_file_exists_nanos = other.env_file_exists_nanos;
env_get_children_nanos = other.env_get_children_nanos;
env_get_children_file_attributes_nanos =
other.env_get_children_file_attributes_nanos;
env_delete_file_nanos = other.env_delete_file_nanos;
env_create_dir_nanos = other.env_create_dir_nanos;
env_create_dir_if_missing_nanos = other.env_create_dir_if_missing_nanos;
env_delete_dir_nanos = other.env_delete_dir_nanos;
env_get_file_size_nanos = other.env_get_file_size_nanos;
env_get_file_modification_time_nanos =
other.env_get_file_modification_time_nanos;
env_rename_file_nanos = other.env_rename_file_nanos;
env_link_file_nanos = other.env_link_file_nanos;
env_lock_file_nanos = other.env_lock_file_nanos;
env_unlock_file_nanos = other.env_unlock_file_nanos;
env_new_logger_nanos = other.env_new_logger_nanos;
get_cpu_nanos = other.get_cpu_nanos;
iter_next_cpu_nanos = other.iter_next_cpu_nanos;
iter_prev_cpu_nanos = other.iter_prev_cpu_nanos;
iter_seek_cpu_nanos = other.iter_seek_cpu_nanos;
Seek parallelization (#9994) Summary: The RocksDB iterator is a hierarchy of iterators. MergingIterator maintains a heap of LevelIterators, one for each L0 file and for each non-zero level. The Seek() operation naturally lends itself to parallelization, as it involves positioning every LevelIterator on the correct data block in the correct SST file. It lookups a level for a target key, to find the first key that's >= the target key. This typically involves reading one data block that is likely to contain the target key, and scan forward to find the first valid key. The forward scan may read more data blocks. In order to find the right data block, the iterator may read some metadata blocks (required for opening a file and searching the index). This flow can be parallelized. Design: Seek will be called two times under async_io option. First seek will send asynchronous request to prefetch the data blocks at each level and second seek will follow the normal flow and in FilePrefetchBuffer::TryReadFromCacheAsync it will wait for the Poll() to get the results and add the iterator to min_heap. - Status::TryAgain is passed down from FilePrefetchBuffer::PrefetchAsync to block_iter_.Status indicating asynchronous request has been submitted. - If for some reason asynchronous request returns error in submitting the request, it will fallback to sequential reading of blocks in one pass. - If the data already exists in prefetch_buffer, it will return the data without prefetching further and it will be treated as single pass of seek. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9994 Test Plan: - **Run Regressions.** ``` ./db_bench -db=/tmp/prefix_scan_prefetch_main -benchmarks="fillseq" -key_size=32 -value_size=512 -num=5000000 -use_direct_io_for_flush_and_compaction=true -target_file_size_base=16777216 ``` i) Previous release 7.0 run for normal prefetching with async_io disabled: ``` ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 Initializing RocksDB Options from the specified file Initializing RocksDB Options from command-line flags RocksDB: version 7.0 Date: Thu Mar 17 13:11:34 2022 CPU: 24 * Intel Core Processor (Broadwell) CPUCache: 16384 KB Keys: 32 bytes each (+ 0 bytes user-defined timestamp) Values: 512 bytes each (256 bytes after compression) Entries: 5000000 Prefix: 0 bytes Keys per prefix: 0 RawSize: 2594.0 MB (estimated) FileSize: 1373.3 MB (estimated) Write rate: 0 bytes/second Read rate: 0 ops/second Compression: Snappy Compression sampling rate: 0 Memtablerep: SkipListFactory Perf Level: 1 ------------------------------------------------ DB path: [/tmp/prefix_scan_prefetch_main] seekrandom : 483618.390 micros/op 2 ops/sec; 338.9 MB/s (249 of 249 found) ``` ii) normal prefetching after changes with async_io disable: ``` ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 Set seed to 1652922591315307 because --seed was 0 Initializing RocksDB Options from the specified file Initializing RocksDB Options from command-line flags RocksDB: version 7.3 Date: Wed May 18 18:09:51 2022 CPU: 32 * Intel Xeon Processor (Skylake) CPUCache: 16384 KB Keys: 32 bytes each (+ 0 bytes user-defined timestamp) Values: 512 bytes each (256 bytes after compression) Entries: 5000000 Prefix: 0 bytes Keys per prefix: 0 RawSize: 2594.0 MB (estimated) FileSize: 1373.3 MB (estimated) Write rate: 0 bytes/second Read rate: 0 ops/second Compression: Snappy Compression sampling rate: 0 Memtablerep: SkipListFactory Perf Level: 1 ------------------------------------------------ DB path: [/tmp/prefix_scan_prefetch_main] seekrandom : 483080.466 micros/op 2 ops/sec 120.287 seconds 249 operations; 340.8 MB/s (249 of 249 found) ``` iii) db_bench with async_io enabled completed succesfully ``` ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 -async_io=1 -adaptive_readahead=1 Set seed to 1652924062021732 because --seed was 0 Initializing RocksDB Options from the specified file Initializing RocksDB Options from command-line flags RocksDB: version 7.3 Date: Wed May 18 18:34:22 2022 CPU: 32 * Intel Xeon Processor (Skylake) CPUCache: 16384 KB Keys: 32 bytes each (+ 0 bytes user-defined timestamp) Values: 512 bytes each (256 bytes after compression) Entries: 5000000 Prefix: 0 bytes Keys per prefix: 0 RawSize: 2594.0 MB (estimated) FileSize: 1373.3 MB (estimated) Write rate: 0 bytes/second Read rate: 0 ops/second Compression: Snappy Compression sampling rate: 0 Memtablerep: SkipListFactory Perf Level: 1 ------------------------------------------------ DB path: [/tmp/prefix_scan_prefetch_main] seekrandom : 553913.576 micros/op 1 ops/sec 120.199 seconds 217 operations; 293.6 MB/s (217 of 217 found) ``` - db_stress with async_io disabled completed succesfully ``` export CRASH_TEST_EXT_ARGS=" --async_io=0" make crash_test -j ``` I**n Progress**: db_stress with async_io is failing and working on debugging/fixing it. Reviewed By: anand1976 Differential Revision: D36459323 Pulled By: akankshamahajan15 fbshipit-source-id: abb1cd944abe712bae3986ae5b16704b3338917c
2022-05-21 01:09:33 +02:00
number_async_seek = other.number_async_seek;
if (per_level_perf_context_enabled && level_to_perf_context != nullptr) {
ClearPerLevelPerfContext();
}
if (other.level_to_perf_context != nullptr) {
level_to_perf_context = new std::map<uint32_t, PerfContextByLevel>();
*level_to_perf_context = *other.level_to_perf_context;
}
per_level_perf_context_enabled = other.per_level_perf_context_enabled;
#endif
}
PerfContext::PerfContext(PerfContext&& other) noexcept {
#ifdef NPERF_CONTEXT
(void)other;
#else
user_key_comparison_count = other.user_key_comparison_count;
block_cache_hit_count = other.block_cache_hit_count;
block_read_count = other.block_read_count;
block_read_byte = other.block_read_byte;
block_read_time = other.block_read_time;
block_cache_index_hit_count = other.block_cache_index_hit_count;
index_block_read_count = other.index_block_read_count;
block_cache_filter_hit_count = other.block_cache_filter_hit_count;
filter_block_read_count = other.filter_block_read_count;
compression_dict_block_read_count = other.compression_dict_block_read_count;
secondary_cache_hit_count = other.secondary_cache_hit_count;
block_checksum_time = other.block_checksum_time;
block_decompress_time = other.block_decompress_time;
get_read_bytes = other.get_read_bytes;
multiget_read_bytes = other.multiget_read_bytes;
iter_read_bytes = other.iter_read_bytes;
internal_key_skipped_count = other.internal_key_skipped_count;
internal_delete_skipped_count = other.internal_delete_skipped_count;
internal_recent_skipped_count = other.internal_recent_skipped_count;
internal_merge_count = other.internal_merge_count;
write_wal_time = other.write_wal_time;
get_snapshot_time = other.get_snapshot_time;
get_from_memtable_time = other.get_from_memtable_time;
get_from_memtable_count = other.get_from_memtable_count;
get_post_process_time = other.get_post_process_time;
get_from_output_files_time = other.get_from_output_files_time;
seek_on_memtable_time = other.seek_on_memtable_time;
seek_on_memtable_count = other.seek_on_memtable_count;
next_on_memtable_count = other.next_on_memtable_count;
prev_on_memtable_count = other.prev_on_memtable_count;
seek_child_seek_time = other.seek_child_seek_time;
seek_child_seek_count = other.seek_child_seek_count;
seek_min_heap_time = other.seek_min_heap_time;
seek_internal_seek_time = other.seek_internal_seek_time;
find_next_user_entry_time = other.find_next_user_entry_time;
write_pre_and_post_process_time = other.write_pre_and_post_process_time;
write_memtable_time = other.write_memtable_time;
write_delay_time = other.write_delay_time;
write_thread_wait_nanos = other.write_thread_wait_nanos;
write_scheduling_flushes_compactions_time =
other.write_scheduling_flushes_compactions_time;
db_mutex_lock_nanos = other.db_mutex_lock_nanos;
db_condition_wait_nanos = other.db_condition_wait_nanos;
merge_operator_time_nanos = other.merge_operator_time_nanos;
read_index_block_nanos = other.read_index_block_nanos;
read_filter_block_nanos = other.read_filter_block_nanos;
new_table_block_iter_nanos = other.new_table_block_iter_nanos;
new_table_iterator_nanos = other.new_table_iterator_nanos;
block_seek_nanos = other.block_seek_nanos;
find_table_nanos = other.find_table_nanos;
bloom_memtable_hit_count = other.bloom_memtable_hit_count;
bloom_memtable_miss_count = other.bloom_memtable_miss_count;
bloom_sst_hit_count = other.bloom_sst_hit_count;
bloom_sst_miss_count = other.bloom_sst_miss_count;
key_lock_wait_time = other.key_lock_wait_time;
key_lock_wait_count = other.key_lock_wait_count;
env_new_sequential_file_nanos = other.env_new_sequential_file_nanos;
env_new_random_access_file_nanos = other.env_new_random_access_file_nanos;
env_new_writable_file_nanos = other.env_new_writable_file_nanos;
env_reuse_writable_file_nanos = other.env_reuse_writable_file_nanos;
env_new_random_rw_file_nanos = other.env_new_random_rw_file_nanos;
env_new_directory_nanos = other.env_new_directory_nanos;
env_file_exists_nanos = other.env_file_exists_nanos;
env_get_children_nanos = other.env_get_children_nanos;
env_get_children_file_attributes_nanos =
other.env_get_children_file_attributes_nanos;
env_delete_file_nanos = other.env_delete_file_nanos;
env_create_dir_nanos = other.env_create_dir_nanos;
env_create_dir_if_missing_nanos = other.env_create_dir_if_missing_nanos;
env_delete_dir_nanos = other.env_delete_dir_nanos;
env_get_file_size_nanos = other.env_get_file_size_nanos;
env_get_file_modification_time_nanos =
other.env_get_file_modification_time_nanos;
env_rename_file_nanos = other.env_rename_file_nanos;
env_link_file_nanos = other.env_link_file_nanos;
env_lock_file_nanos = other.env_lock_file_nanos;
env_unlock_file_nanos = other.env_unlock_file_nanos;
env_new_logger_nanos = other.env_new_logger_nanos;
get_cpu_nanos = other.get_cpu_nanos;
iter_next_cpu_nanos = other.iter_next_cpu_nanos;
iter_prev_cpu_nanos = other.iter_prev_cpu_nanos;
iter_seek_cpu_nanos = other.iter_seek_cpu_nanos;
Seek parallelization (#9994) Summary: The RocksDB iterator is a hierarchy of iterators. MergingIterator maintains a heap of LevelIterators, one for each L0 file and for each non-zero level. The Seek() operation naturally lends itself to parallelization, as it involves positioning every LevelIterator on the correct data block in the correct SST file. It lookups a level for a target key, to find the first key that's >= the target key. This typically involves reading one data block that is likely to contain the target key, and scan forward to find the first valid key. The forward scan may read more data blocks. In order to find the right data block, the iterator may read some metadata blocks (required for opening a file and searching the index). This flow can be parallelized. Design: Seek will be called two times under async_io option. First seek will send asynchronous request to prefetch the data blocks at each level and second seek will follow the normal flow and in FilePrefetchBuffer::TryReadFromCacheAsync it will wait for the Poll() to get the results and add the iterator to min_heap. - Status::TryAgain is passed down from FilePrefetchBuffer::PrefetchAsync to block_iter_.Status indicating asynchronous request has been submitted. - If for some reason asynchronous request returns error in submitting the request, it will fallback to sequential reading of blocks in one pass. - If the data already exists in prefetch_buffer, it will return the data without prefetching further and it will be treated as single pass of seek. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9994 Test Plan: - **Run Regressions.** ``` ./db_bench -db=/tmp/prefix_scan_prefetch_main -benchmarks="fillseq" -key_size=32 -value_size=512 -num=5000000 -use_direct_io_for_flush_and_compaction=true -target_file_size_base=16777216 ``` i) Previous release 7.0 run for normal prefetching with async_io disabled: ``` ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 Initializing RocksDB Options from the specified file Initializing RocksDB Options from command-line flags RocksDB: version 7.0 Date: Thu Mar 17 13:11:34 2022 CPU: 24 * Intel Core Processor (Broadwell) CPUCache: 16384 KB Keys: 32 bytes each (+ 0 bytes user-defined timestamp) Values: 512 bytes each (256 bytes after compression) Entries: 5000000 Prefix: 0 bytes Keys per prefix: 0 RawSize: 2594.0 MB (estimated) FileSize: 1373.3 MB (estimated) Write rate: 0 bytes/second Read rate: 0 ops/second Compression: Snappy Compression sampling rate: 0 Memtablerep: SkipListFactory Perf Level: 1 ------------------------------------------------ DB path: [/tmp/prefix_scan_prefetch_main] seekrandom : 483618.390 micros/op 2 ops/sec; 338.9 MB/s (249 of 249 found) ``` ii) normal prefetching after changes with async_io disable: ``` ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 Set seed to 1652922591315307 because --seed was 0 Initializing RocksDB Options from the specified file Initializing RocksDB Options from command-line flags RocksDB: version 7.3 Date: Wed May 18 18:09:51 2022 CPU: 32 * Intel Xeon Processor (Skylake) CPUCache: 16384 KB Keys: 32 bytes each (+ 0 bytes user-defined timestamp) Values: 512 bytes each (256 bytes after compression) Entries: 5000000 Prefix: 0 bytes Keys per prefix: 0 RawSize: 2594.0 MB (estimated) FileSize: 1373.3 MB (estimated) Write rate: 0 bytes/second Read rate: 0 ops/second Compression: Snappy Compression sampling rate: 0 Memtablerep: SkipListFactory Perf Level: 1 ------------------------------------------------ DB path: [/tmp/prefix_scan_prefetch_main] seekrandom : 483080.466 micros/op 2 ops/sec 120.287 seconds 249 operations; 340.8 MB/s (249 of 249 found) ``` iii) db_bench with async_io enabled completed succesfully ``` ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 -async_io=1 -adaptive_readahead=1 Set seed to 1652924062021732 because --seed was 0 Initializing RocksDB Options from the specified file Initializing RocksDB Options from command-line flags RocksDB: version 7.3 Date: Wed May 18 18:34:22 2022 CPU: 32 * Intel Xeon Processor (Skylake) CPUCache: 16384 KB Keys: 32 bytes each (+ 0 bytes user-defined timestamp) Values: 512 bytes each (256 bytes after compression) Entries: 5000000 Prefix: 0 bytes Keys per prefix: 0 RawSize: 2594.0 MB (estimated) FileSize: 1373.3 MB (estimated) Write rate: 0 bytes/second Read rate: 0 ops/second Compression: Snappy Compression sampling rate: 0 Memtablerep: SkipListFactory Perf Level: 1 ------------------------------------------------ DB path: [/tmp/prefix_scan_prefetch_main] seekrandom : 553913.576 micros/op 1 ops/sec 120.199 seconds 217 operations; 293.6 MB/s (217 of 217 found) ``` - db_stress with async_io disabled completed succesfully ``` export CRASH_TEST_EXT_ARGS=" --async_io=0" make crash_test -j ``` I**n Progress**: db_stress with async_io is failing and working on debugging/fixing it. Reviewed By: anand1976 Differential Revision: D36459323 Pulled By: akankshamahajan15 fbshipit-source-id: abb1cd944abe712bae3986ae5b16704b3338917c
2022-05-21 01:09:33 +02:00
number_async_seek = other.number_async_seek;
if (per_level_perf_context_enabled && level_to_perf_context != nullptr) {
ClearPerLevelPerfContext();
}
if (other.level_to_perf_context != nullptr) {
level_to_perf_context = other.level_to_perf_context;
other.level_to_perf_context = nullptr;
}
per_level_perf_context_enabled = other.per_level_perf_context_enabled;
#endif
}
// TODO(Zhongyi): reduce code duplication between copy constructor and
// assignment operator
PerfContext& PerfContext::operator=(const PerfContext& other) {
#ifdef NPERF_CONTEXT
(void)other;
#else
user_key_comparison_count = other.user_key_comparison_count;
block_cache_hit_count = other.block_cache_hit_count;
block_read_count = other.block_read_count;
block_read_byte = other.block_read_byte;
block_read_time = other.block_read_time;
block_cache_index_hit_count = other.block_cache_index_hit_count;
index_block_read_count = other.index_block_read_count;
block_cache_filter_hit_count = other.block_cache_filter_hit_count;
filter_block_read_count = other.filter_block_read_count;
compression_dict_block_read_count = other.compression_dict_block_read_count;
secondary_cache_hit_count = other.secondary_cache_hit_count;
block_checksum_time = other.block_checksum_time;
block_decompress_time = other.block_decompress_time;
get_read_bytes = other.get_read_bytes;
multiget_read_bytes = other.multiget_read_bytes;
iter_read_bytes = other.iter_read_bytes;
internal_key_skipped_count = other.internal_key_skipped_count;
internal_delete_skipped_count = other.internal_delete_skipped_count;
internal_recent_skipped_count = other.internal_recent_skipped_count;
internal_merge_count = other.internal_merge_count;
write_wal_time = other.write_wal_time;
get_snapshot_time = other.get_snapshot_time;
get_from_memtable_time = other.get_from_memtable_time;
get_from_memtable_count = other.get_from_memtable_count;
get_post_process_time = other.get_post_process_time;
get_from_output_files_time = other.get_from_output_files_time;
seek_on_memtable_time = other.seek_on_memtable_time;
seek_on_memtable_count = other.seek_on_memtable_count;
next_on_memtable_count = other.next_on_memtable_count;
prev_on_memtable_count = other.prev_on_memtable_count;
seek_child_seek_time = other.seek_child_seek_time;
seek_child_seek_count = other.seek_child_seek_count;
seek_min_heap_time = other.seek_min_heap_time;
seek_internal_seek_time = other.seek_internal_seek_time;
find_next_user_entry_time = other.find_next_user_entry_time;
write_pre_and_post_process_time = other.write_pre_and_post_process_time;
write_memtable_time = other.write_memtable_time;
write_delay_time = other.write_delay_time;
write_thread_wait_nanos = other.write_thread_wait_nanos;
write_scheduling_flushes_compactions_time =
other.write_scheduling_flushes_compactions_time;
db_mutex_lock_nanos = other.db_mutex_lock_nanos;
db_condition_wait_nanos = other.db_condition_wait_nanos;
merge_operator_time_nanos = other.merge_operator_time_nanos;
read_index_block_nanos = other.read_index_block_nanos;
read_filter_block_nanos = other.read_filter_block_nanos;
new_table_block_iter_nanos = other.new_table_block_iter_nanos;
new_table_iterator_nanos = other.new_table_iterator_nanos;
block_seek_nanos = other.block_seek_nanos;
find_table_nanos = other.find_table_nanos;
bloom_memtable_hit_count = other.bloom_memtable_hit_count;
bloom_memtable_miss_count = other.bloom_memtable_miss_count;
bloom_sst_hit_count = other.bloom_sst_hit_count;
bloom_sst_miss_count = other.bloom_sst_miss_count;
key_lock_wait_time = other.key_lock_wait_time;
key_lock_wait_count = other.key_lock_wait_count;
env_new_sequential_file_nanos = other.env_new_sequential_file_nanos;
env_new_random_access_file_nanos = other.env_new_random_access_file_nanos;
env_new_writable_file_nanos = other.env_new_writable_file_nanos;
env_reuse_writable_file_nanos = other.env_reuse_writable_file_nanos;
env_new_random_rw_file_nanos = other.env_new_random_rw_file_nanos;
env_new_directory_nanos = other.env_new_directory_nanos;
env_file_exists_nanos = other.env_file_exists_nanos;
env_get_children_nanos = other.env_get_children_nanos;
env_get_children_file_attributes_nanos =
other.env_get_children_file_attributes_nanos;
env_delete_file_nanos = other.env_delete_file_nanos;
env_create_dir_nanos = other.env_create_dir_nanos;
env_create_dir_if_missing_nanos = other.env_create_dir_if_missing_nanos;
env_delete_dir_nanos = other.env_delete_dir_nanos;
env_get_file_size_nanos = other.env_get_file_size_nanos;
env_get_file_modification_time_nanos =
other.env_get_file_modification_time_nanos;
env_rename_file_nanos = other.env_rename_file_nanos;
env_link_file_nanos = other.env_link_file_nanos;
env_lock_file_nanos = other.env_lock_file_nanos;
env_unlock_file_nanos = other.env_unlock_file_nanos;
env_new_logger_nanos = other.env_new_logger_nanos;
get_cpu_nanos = other.get_cpu_nanos;
iter_next_cpu_nanos = other.iter_next_cpu_nanos;
iter_prev_cpu_nanos = other.iter_prev_cpu_nanos;
iter_seek_cpu_nanos = other.iter_seek_cpu_nanos;
Seek parallelization (#9994) Summary: The RocksDB iterator is a hierarchy of iterators. MergingIterator maintains a heap of LevelIterators, one for each L0 file and for each non-zero level. The Seek() operation naturally lends itself to parallelization, as it involves positioning every LevelIterator on the correct data block in the correct SST file. It lookups a level for a target key, to find the first key that's >= the target key. This typically involves reading one data block that is likely to contain the target key, and scan forward to find the first valid key. The forward scan may read more data blocks. In order to find the right data block, the iterator may read some metadata blocks (required for opening a file and searching the index). This flow can be parallelized. Design: Seek will be called two times under async_io option. First seek will send asynchronous request to prefetch the data blocks at each level and second seek will follow the normal flow and in FilePrefetchBuffer::TryReadFromCacheAsync it will wait for the Poll() to get the results and add the iterator to min_heap. - Status::TryAgain is passed down from FilePrefetchBuffer::PrefetchAsync to block_iter_.Status indicating asynchronous request has been submitted. - If for some reason asynchronous request returns error in submitting the request, it will fallback to sequential reading of blocks in one pass. - If the data already exists in prefetch_buffer, it will return the data without prefetching further and it will be treated as single pass of seek. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9994 Test Plan: - **Run Regressions.** ``` ./db_bench -db=/tmp/prefix_scan_prefetch_main -benchmarks="fillseq" -key_size=32 -value_size=512 -num=5000000 -use_direct_io_for_flush_and_compaction=true -target_file_size_base=16777216 ``` i) Previous release 7.0 run for normal prefetching with async_io disabled: ``` ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 Initializing RocksDB Options from the specified file Initializing RocksDB Options from command-line flags RocksDB: version 7.0 Date: Thu Mar 17 13:11:34 2022 CPU: 24 * Intel Core Processor (Broadwell) CPUCache: 16384 KB Keys: 32 bytes each (+ 0 bytes user-defined timestamp) Values: 512 bytes each (256 bytes after compression) Entries: 5000000 Prefix: 0 bytes Keys per prefix: 0 RawSize: 2594.0 MB (estimated) FileSize: 1373.3 MB (estimated) Write rate: 0 bytes/second Read rate: 0 ops/second Compression: Snappy Compression sampling rate: 0 Memtablerep: SkipListFactory Perf Level: 1 ------------------------------------------------ DB path: [/tmp/prefix_scan_prefetch_main] seekrandom : 483618.390 micros/op 2 ops/sec; 338.9 MB/s (249 of 249 found) ``` ii) normal prefetching after changes with async_io disable: ``` ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 Set seed to 1652922591315307 because --seed was 0 Initializing RocksDB Options from the specified file Initializing RocksDB Options from command-line flags RocksDB: version 7.3 Date: Wed May 18 18:09:51 2022 CPU: 32 * Intel Xeon Processor (Skylake) CPUCache: 16384 KB Keys: 32 bytes each (+ 0 bytes user-defined timestamp) Values: 512 bytes each (256 bytes after compression) Entries: 5000000 Prefix: 0 bytes Keys per prefix: 0 RawSize: 2594.0 MB (estimated) FileSize: 1373.3 MB (estimated) Write rate: 0 bytes/second Read rate: 0 ops/second Compression: Snappy Compression sampling rate: 0 Memtablerep: SkipListFactory Perf Level: 1 ------------------------------------------------ DB path: [/tmp/prefix_scan_prefetch_main] seekrandom : 483080.466 micros/op 2 ops/sec 120.287 seconds 249 operations; 340.8 MB/s (249 of 249 found) ``` iii) db_bench with async_io enabled completed succesfully ``` ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 -async_io=1 -adaptive_readahead=1 Set seed to 1652924062021732 because --seed was 0 Initializing RocksDB Options from the specified file Initializing RocksDB Options from command-line flags RocksDB: version 7.3 Date: Wed May 18 18:34:22 2022 CPU: 32 * Intel Xeon Processor (Skylake) CPUCache: 16384 KB Keys: 32 bytes each (+ 0 bytes user-defined timestamp) Values: 512 bytes each (256 bytes after compression) Entries: 5000000 Prefix: 0 bytes Keys per prefix: 0 RawSize: 2594.0 MB (estimated) FileSize: 1373.3 MB (estimated) Write rate: 0 bytes/second Read rate: 0 ops/second Compression: Snappy Compression sampling rate: 0 Memtablerep: SkipListFactory Perf Level: 1 ------------------------------------------------ DB path: [/tmp/prefix_scan_prefetch_main] seekrandom : 553913.576 micros/op 1 ops/sec 120.199 seconds 217 operations; 293.6 MB/s (217 of 217 found) ``` - db_stress with async_io disabled completed succesfully ``` export CRASH_TEST_EXT_ARGS=" --async_io=0" make crash_test -j ``` I**n Progress**: db_stress with async_io is failing and working on debugging/fixing it. Reviewed By: anand1976 Differential Revision: D36459323 Pulled By: akankshamahajan15 fbshipit-source-id: abb1cd944abe712bae3986ae5b16704b3338917c
2022-05-21 01:09:33 +02:00
number_async_seek = other.number_async_seek;
if (per_level_perf_context_enabled && level_to_perf_context != nullptr) {
ClearPerLevelPerfContext();
}
if (other.level_to_perf_context != nullptr) {
level_to_perf_context = new std::map<uint32_t, PerfContextByLevel>();
*level_to_perf_context = *other.level_to_perf_context;
}
per_level_perf_context_enabled = other.per_level_perf_context_enabled;
#endif
return *this;
}
void PerfContext::Reset() {
#ifndef NPERF_CONTEXT
user_key_comparison_count = 0;
block_cache_hit_count = 0;
block_read_count = 0;
block_read_byte = 0;
block_read_time = 0;
block_cache_index_hit_count = 0;
index_block_read_count = 0;
block_cache_filter_hit_count = 0;
filter_block_read_count = 0;
compression_dict_block_read_count = 0;
secondary_cache_hit_count = 0;
block_checksum_time = 0;
block_decompress_time = 0;
get_read_bytes = 0;
multiget_read_bytes = 0;
iter_read_bytes = 0;
internal_key_skipped_count = 0;
internal_delete_skipped_count = 0;
internal_recent_skipped_count = 0;
internal_merge_count = 0;
write_wal_time = 0;
get_snapshot_time = 0;
get_from_memtable_time = 0;
get_from_memtable_count = 0;
get_post_process_time = 0;
get_from_output_files_time = 0;
seek_on_memtable_time = 0;
seek_on_memtable_count = 0;
next_on_memtable_count = 0;
prev_on_memtable_count = 0;
seek_child_seek_time = 0;
seek_child_seek_count = 0;
seek_min_heap_time = 0;
seek_internal_seek_time = 0;
find_next_user_entry_time = 0;
write_pre_and_post_process_time = 0;
write_memtable_time = 0;
write_delay_time = 0;
write_thread_wait_nanos = 0;
write_scheduling_flushes_compactions_time = 0;
db_mutex_lock_nanos = 0;
db_condition_wait_nanos = 0;
merge_operator_time_nanos = 0;
read_index_block_nanos = 0;
read_filter_block_nanos = 0;
new_table_block_iter_nanos = 0;
new_table_iterator_nanos = 0;
block_seek_nanos = 0;
find_table_nanos = 0;
bloom_memtable_hit_count = 0;
bloom_memtable_miss_count = 0;
bloom_sst_hit_count = 0;
bloom_sst_miss_count = 0;
key_lock_wait_time = 0;
key_lock_wait_count = 0;
env_new_sequential_file_nanos = 0;
env_new_random_access_file_nanos = 0;
env_new_writable_file_nanos = 0;
env_reuse_writable_file_nanos = 0;
env_new_random_rw_file_nanos = 0;
env_new_directory_nanos = 0;
env_file_exists_nanos = 0;
env_get_children_nanos = 0;
env_get_children_file_attributes_nanos = 0;
env_delete_file_nanos = 0;
env_create_dir_nanos = 0;
env_create_dir_if_missing_nanos = 0;
env_delete_dir_nanos = 0;
env_get_file_size_nanos = 0;
env_get_file_modification_time_nanos = 0;
env_rename_file_nanos = 0;
env_link_file_nanos = 0;
env_lock_file_nanos = 0;
env_unlock_file_nanos = 0;
env_new_logger_nanos = 0;
get_cpu_nanos = 0;
iter_next_cpu_nanos = 0;
iter_prev_cpu_nanos = 0;
iter_seek_cpu_nanos = 0;
Seek parallelization (#9994) Summary: The RocksDB iterator is a hierarchy of iterators. MergingIterator maintains a heap of LevelIterators, one for each L0 file and for each non-zero level. The Seek() operation naturally lends itself to parallelization, as it involves positioning every LevelIterator on the correct data block in the correct SST file. It lookups a level for a target key, to find the first key that's >= the target key. This typically involves reading one data block that is likely to contain the target key, and scan forward to find the first valid key. The forward scan may read more data blocks. In order to find the right data block, the iterator may read some metadata blocks (required for opening a file and searching the index). This flow can be parallelized. Design: Seek will be called two times under async_io option. First seek will send asynchronous request to prefetch the data blocks at each level and second seek will follow the normal flow and in FilePrefetchBuffer::TryReadFromCacheAsync it will wait for the Poll() to get the results and add the iterator to min_heap. - Status::TryAgain is passed down from FilePrefetchBuffer::PrefetchAsync to block_iter_.Status indicating asynchronous request has been submitted. - If for some reason asynchronous request returns error in submitting the request, it will fallback to sequential reading of blocks in one pass. - If the data already exists in prefetch_buffer, it will return the data without prefetching further and it will be treated as single pass of seek. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9994 Test Plan: - **Run Regressions.** ``` ./db_bench -db=/tmp/prefix_scan_prefetch_main -benchmarks="fillseq" -key_size=32 -value_size=512 -num=5000000 -use_direct_io_for_flush_and_compaction=true -target_file_size_base=16777216 ``` i) Previous release 7.0 run for normal prefetching with async_io disabled: ``` ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 Initializing RocksDB Options from the specified file Initializing RocksDB Options from command-line flags RocksDB: version 7.0 Date: Thu Mar 17 13:11:34 2022 CPU: 24 * Intel Core Processor (Broadwell) CPUCache: 16384 KB Keys: 32 bytes each (+ 0 bytes user-defined timestamp) Values: 512 bytes each (256 bytes after compression) Entries: 5000000 Prefix: 0 bytes Keys per prefix: 0 RawSize: 2594.0 MB (estimated) FileSize: 1373.3 MB (estimated) Write rate: 0 bytes/second Read rate: 0 ops/second Compression: Snappy Compression sampling rate: 0 Memtablerep: SkipListFactory Perf Level: 1 ------------------------------------------------ DB path: [/tmp/prefix_scan_prefetch_main] seekrandom : 483618.390 micros/op 2 ops/sec; 338.9 MB/s (249 of 249 found) ``` ii) normal prefetching after changes with async_io disable: ``` ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 Set seed to 1652922591315307 because --seed was 0 Initializing RocksDB Options from the specified file Initializing RocksDB Options from command-line flags RocksDB: version 7.3 Date: Wed May 18 18:09:51 2022 CPU: 32 * Intel Xeon Processor (Skylake) CPUCache: 16384 KB Keys: 32 bytes each (+ 0 bytes user-defined timestamp) Values: 512 bytes each (256 bytes after compression) Entries: 5000000 Prefix: 0 bytes Keys per prefix: 0 RawSize: 2594.0 MB (estimated) FileSize: 1373.3 MB (estimated) Write rate: 0 bytes/second Read rate: 0 ops/second Compression: Snappy Compression sampling rate: 0 Memtablerep: SkipListFactory Perf Level: 1 ------------------------------------------------ DB path: [/tmp/prefix_scan_prefetch_main] seekrandom : 483080.466 micros/op 2 ops/sec 120.287 seconds 249 operations; 340.8 MB/s (249 of 249 found) ``` iii) db_bench with async_io enabled completed succesfully ``` ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 -async_io=1 -adaptive_readahead=1 Set seed to 1652924062021732 because --seed was 0 Initializing RocksDB Options from the specified file Initializing RocksDB Options from command-line flags RocksDB: version 7.3 Date: Wed May 18 18:34:22 2022 CPU: 32 * Intel Xeon Processor (Skylake) CPUCache: 16384 KB Keys: 32 bytes each (+ 0 bytes user-defined timestamp) Values: 512 bytes each (256 bytes after compression) Entries: 5000000 Prefix: 0 bytes Keys per prefix: 0 RawSize: 2594.0 MB (estimated) FileSize: 1373.3 MB (estimated) Write rate: 0 bytes/second Read rate: 0 ops/second Compression: Snappy Compression sampling rate: 0 Memtablerep: SkipListFactory Perf Level: 1 ------------------------------------------------ DB path: [/tmp/prefix_scan_prefetch_main] seekrandom : 553913.576 micros/op 1 ops/sec 120.199 seconds 217 operations; 293.6 MB/s (217 of 217 found) ``` - db_stress with async_io disabled completed succesfully ``` export CRASH_TEST_EXT_ARGS=" --async_io=0" make crash_test -j ``` I**n Progress**: db_stress with async_io is failing and working on debugging/fixing it. Reviewed By: anand1976 Differential Revision: D36459323 Pulled By: akankshamahajan15 fbshipit-source-id: abb1cd944abe712bae3986ae5b16704b3338917c
2022-05-21 01:09:33 +02:00
number_async_seek = 0;
if (per_level_perf_context_enabled && level_to_perf_context) {
for (auto& kv : *level_to_perf_context) {
kv.second.Reset();
}
}
#endif
}
#define PERF_CONTEXT_OUTPUT(counter) \
if (!exclude_zero_counters || (counter > 0)) { \
ss << #counter << " = " << counter << ", "; \
}
#define PERF_CONTEXT_BY_LEVEL_OUTPUT_ONE_COUNTER(counter) \
if (per_level_perf_context_enabled && \
level_to_perf_context) { \
ss << #counter << " = "; \
for (auto& kv : *level_to_perf_context) { \
if (!exclude_zero_counters || (kv.second.counter > 0)) { \
ss << kv.second.counter << "@level" << kv.first << ", "; \
} \
} \
}
void PerfContextByLevel::Reset() {
#ifndef NPERF_CONTEXT
bloom_filter_useful = 0;
bloom_filter_full_positive = 0;
bloom_filter_full_true_positive = 0;
block_cache_hit_count = 0;
block_cache_miss_count = 0;
#endif
}
std::string PerfContext::ToString(bool exclude_zero_counters) const {
#ifdef NPERF_CONTEXT
(void)exclude_zero_counters;
return "";
#else
std::ostringstream ss;
PERF_CONTEXT_OUTPUT(user_key_comparison_count);
PERF_CONTEXT_OUTPUT(block_cache_hit_count);
PERF_CONTEXT_OUTPUT(block_read_count);
PERF_CONTEXT_OUTPUT(block_read_byte);
PERF_CONTEXT_OUTPUT(block_read_time);
PERF_CONTEXT_OUTPUT(block_cache_index_hit_count);
PERF_CONTEXT_OUTPUT(index_block_read_count);
PERF_CONTEXT_OUTPUT(block_cache_filter_hit_count);
PERF_CONTEXT_OUTPUT(filter_block_read_count);
PERF_CONTEXT_OUTPUT(compression_dict_block_read_count);
PERF_CONTEXT_OUTPUT(secondary_cache_hit_count);
PERF_CONTEXT_OUTPUT(block_checksum_time);
PERF_CONTEXT_OUTPUT(block_decompress_time);
PERF_CONTEXT_OUTPUT(get_read_bytes);
PERF_CONTEXT_OUTPUT(multiget_read_bytes);
PERF_CONTEXT_OUTPUT(iter_read_bytes);
PERF_CONTEXT_OUTPUT(internal_key_skipped_count);
PERF_CONTEXT_OUTPUT(internal_delete_skipped_count);
PERF_CONTEXT_OUTPUT(internal_recent_skipped_count);
PERF_CONTEXT_OUTPUT(internal_merge_count);
PERF_CONTEXT_OUTPUT(write_wal_time);
PERF_CONTEXT_OUTPUT(get_snapshot_time);
PERF_CONTEXT_OUTPUT(get_from_memtable_time);
PERF_CONTEXT_OUTPUT(get_from_memtable_count);
PERF_CONTEXT_OUTPUT(get_post_process_time);
PERF_CONTEXT_OUTPUT(get_from_output_files_time);
PERF_CONTEXT_OUTPUT(seek_on_memtable_time);
PERF_CONTEXT_OUTPUT(seek_on_memtable_count);
PERF_CONTEXT_OUTPUT(next_on_memtable_count);
PERF_CONTEXT_OUTPUT(prev_on_memtable_count);
PERF_CONTEXT_OUTPUT(seek_child_seek_time);
PERF_CONTEXT_OUTPUT(seek_child_seek_count);
PERF_CONTEXT_OUTPUT(seek_min_heap_time);
PERF_CONTEXT_OUTPUT(seek_internal_seek_time);
PERF_CONTEXT_OUTPUT(find_next_user_entry_time);
PERF_CONTEXT_OUTPUT(write_pre_and_post_process_time);
PERF_CONTEXT_OUTPUT(write_memtable_time);
PERF_CONTEXT_OUTPUT(write_thread_wait_nanos);
PERF_CONTEXT_OUTPUT(write_scheduling_flushes_compactions_time);
PERF_CONTEXT_OUTPUT(db_mutex_lock_nanos);
PERF_CONTEXT_OUTPUT(db_condition_wait_nanos);
PERF_CONTEXT_OUTPUT(merge_operator_time_nanos);
PERF_CONTEXT_OUTPUT(write_delay_time);
PERF_CONTEXT_OUTPUT(read_index_block_nanos);
PERF_CONTEXT_OUTPUT(read_filter_block_nanos);
PERF_CONTEXT_OUTPUT(new_table_block_iter_nanos);
PERF_CONTEXT_OUTPUT(new_table_iterator_nanos);
PERF_CONTEXT_OUTPUT(block_seek_nanos);
PERF_CONTEXT_OUTPUT(find_table_nanos);
PERF_CONTEXT_OUTPUT(bloom_memtable_hit_count);
PERF_CONTEXT_OUTPUT(bloom_memtable_miss_count);
PERF_CONTEXT_OUTPUT(bloom_sst_hit_count);
PERF_CONTEXT_OUTPUT(bloom_sst_miss_count);
PERF_CONTEXT_OUTPUT(key_lock_wait_time);
PERF_CONTEXT_OUTPUT(key_lock_wait_count);
PERF_CONTEXT_OUTPUT(env_new_sequential_file_nanos);
PERF_CONTEXT_OUTPUT(env_new_random_access_file_nanos);
PERF_CONTEXT_OUTPUT(env_new_writable_file_nanos);
PERF_CONTEXT_OUTPUT(env_reuse_writable_file_nanos);
PERF_CONTEXT_OUTPUT(env_new_random_rw_file_nanos);
PERF_CONTEXT_OUTPUT(env_new_directory_nanos);
PERF_CONTEXT_OUTPUT(env_file_exists_nanos);
PERF_CONTEXT_OUTPUT(env_get_children_nanos);
PERF_CONTEXT_OUTPUT(env_get_children_file_attributes_nanos);
PERF_CONTEXT_OUTPUT(env_delete_file_nanos);
PERF_CONTEXT_OUTPUT(env_create_dir_nanos);
PERF_CONTEXT_OUTPUT(env_create_dir_if_missing_nanos);
PERF_CONTEXT_OUTPUT(env_delete_dir_nanos);
PERF_CONTEXT_OUTPUT(env_get_file_size_nanos);
PERF_CONTEXT_OUTPUT(env_get_file_modification_time_nanos);
PERF_CONTEXT_OUTPUT(env_rename_file_nanos);
PERF_CONTEXT_OUTPUT(env_link_file_nanos);
PERF_CONTEXT_OUTPUT(env_lock_file_nanos);
PERF_CONTEXT_OUTPUT(env_unlock_file_nanos);
PERF_CONTEXT_OUTPUT(env_new_logger_nanos);
PERF_CONTEXT_OUTPUT(get_cpu_nanos);
PERF_CONTEXT_OUTPUT(iter_next_cpu_nanos);
PERF_CONTEXT_OUTPUT(iter_prev_cpu_nanos);
PERF_CONTEXT_OUTPUT(iter_seek_cpu_nanos);
Seek parallelization (#9994) Summary: The RocksDB iterator is a hierarchy of iterators. MergingIterator maintains a heap of LevelIterators, one for each L0 file and for each non-zero level. The Seek() operation naturally lends itself to parallelization, as it involves positioning every LevelIterator on the correct data block in the correct SST file. It lookups a level for a target key, to find the first key that's >= the target key. This typically involves reading one data block that is likely to contain the target key, and scan forward to find the first valid key. The forward scan may read more data blocks. In order to find the right data block, the iterator may read some metadata blocks (required for opening a file and searching the index). This flow can be parallelized. Design: Seek will be called two times under async_io option. First seek will send asynchronous request to prefetch the data blocks at each level and second seek will follow the normal flow and in FilePrefetchBuffer::TryReadFromCacheAsync it will wait for the Poll() to get the results and add the iterator to min_heap. - Status::TryAgain is passed down from FilePrefetchBuffer::PrefetchAsync to block_iter_.Status indicating asynchronous request has been submitted. - If for some reason asynchronous request returns error in submitting the request, it will fallback to sequential reading of blocks in one pass. - If the data already exists in prefetch_buffer, it will return the data without prefetching further and it will be treated as single pass of seek. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9994 Test Plan: - **Run Regressions.** ``` ./db_bench -db=/tmp/prefix_scan_prefetch_main -benchmarks="fillseq" -key_size=32 -value_size=512 -num=5000000 -use_direct_io_for_flush_and_compaction=true -target_file_size_base=16777216 ``` i) Previous release 7.0 run for normal prefetching with async_io disabled: ``` ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 Initializing RocksDB Options from the specified file Initializing RocksDB Options from command-line flags RocksDB: version 7.0 Date: Thu Mar 17 13:11:34 2022 CPU: 24 * Intel Core Processor (Broadwell) CPUCache: 16384 KB Keys: 32 bytes each (+ 0 bytes user-defined timestamp) Values: 512 bytes each (256 bytes after compression) Entries: 5000000 Prefix: 0 bytes Keys per prefix: 0 RawSize: 2594.0 MB (estimated) FileSize: 1373.3 MB (estimated) Write rate: 0 bytes/second Read rate: 0 ops/second Compression: Snappy Compression sampling rate: 0 Memtablerep: SkipListFactory Perf Level: 1 ------------------------------------------------ DB path: [/tmp/prefix_scan_prefetch_main] seekrandom : 483618.390 micros/op 2 ops/sec; 338.9 MB/s (249 of 249 found) ``` ii) normal prefetching after changes with async_io disable: ``` ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 Set seed to 1652922591315307 because --seed was 0 Initializing RocksDB Options from the specified file Initializing RocksDB Options from command-line flags RocksDB: version 7.3 Date: Wed May 18 18:09:51 2022 CPU: 32 * Intel Xeon Processor (Skylake) CPUCache: 16384 KB Keys: 32 bytes each (+ 0 bytes user-defined timestamp) Values: 512 bytes each (256 bytes after compression) Entries: 5000000 Prefix: 0 bytes Keys per prefix: 0 RawSize: 2594.0 MB (estimated) FileSize: 1373.3 MB (estimated) Write rate: 0 bytes/second Read rate: 0 ops/second Compression: Snappy Compression sampling rate: 0 Memtablerep: SkipListFactory Perf Level: 1 ------------------------------------------------ DB path: [/tmp/prefix_scan_prefetch_main] seekrandom : 483080.466 micros/op 2 ops/sec 120.287 seconds 249 operations; 340.8 MB/s (249 of 249 found) ``` iii) db_bench with async_io enabled completed succesfully ``` ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 -async_io=1 -adaptive_readahead=1 Set seed to 1652924062021732 because --seed was 0 Initializing RocksDB Options from the specified file Initializing RocksDB Options from command-line flags RocksDB: version 7.3 Date: Wed May 18 18:34:22 2022 CPU: 32 * Intel Xeon Processor (Skylake) CPUCache: 16384 KB Keys: 32 bytes each (+ 0 bytes user-defined timestamp) Values: 512 bytes each (256 bytes after compression) Entries: 5000000 Prefix: 0 bytes Keys per prefix: 0 RawSize: 2594.0 MB (estimated) FileSize: 1373.3 MB (estimated) Write rate: 0 bytes/second Read rate: 0 ops/second Compression: Snappy Compression sampling rate: 0 Memtablerep: SkipListFactory Perf Level: 1 ------------------------------------------------ DB path: [/tmp/prefix_scan_prefetch_main] seekrandom : 553913.576 micros/op 1 ops/sec 120.199 seconds 217 operations; 293.6 MB/s (217 of 217 found) ``` - db_stress with async_io disabled completed succesfully ``` export CRASH_TEST_EXT_ARGS=" --async_io=0" make crash_test -j ``` I**n Progress**: db_stress with async_io is failing and working on debugging/fixing it. Reviewed By: anand1976 Differential Revision: D36459323 Pulled By: akankshamahajan15 fbshipit-source-id: abb1cd944abe712bae3986ae5b16704b3338917c
2022-05-21 01:09:33 +02:00
PERF_CONTEXT_OUTPUT(number_async_seek);
PERF_CONTEXT_BY_LEVEL_OUTPUT_ONE_COUNTER(bloom_filter_useful);
PERF_CONTEXT_BY_LEVEL_OUTPUT_ONE_COUNTER(bloom_filter_full_positive);
PERF_CONTEXT_BY_LEVEL_OUTPUT_ONE_COUNTER(bloom_filter_full_true_positive);
PERF_CONTEXT_BY_LEVEL_OUTPUT_ONE_COUNTER(block_cache_hit_count);
PERF_CONTEXT_BY_LEVEL_OUTPUT_ONE_COUNTER(block_cache_miss_count);
std::string str = ss.str();
str.erase(str.find_last_not_of(", ") + 1);
return str;
#endif
}
void PerfContext::EnablePerLevelPerfContext() {
if (level_to_perf_context == nullptr) {
level_to_perf_context = new std::map<uint32_t, PerfContextByLevel>();
}
per_level_perf_context_enabled = true;
}
void PerfContext::DisablePerLevelPerfContext(){
per_level_perf_context_enabled = false;
}
void PerfContext::ClearPerLevelPerfContext(){
if (level_to_perf_context != nullptr) {
level_to_perf_context->clear();
delete level_to_perf_context;
level_to_perf_context = nullptr;
}
per_level_perf_context_enabled = false;
}
} // namespace ROCKSDB_NAMESPACE