db0435772f
Summary: After introducing adaptive_readahead, the original flow got broken. Readahead size was set to 0 because of which rocksdb wasn't be able to do automatic prefetching which it enables after seeing sequential reads. This PR fixes it. ---------------------------------------------------------------------------------------------------- Before this patch: b_bench -use_existing_db=true -db=/tmp/prefix_scan -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 6.27 Date: Tue Nov 30 11:56:50 2021 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 WARNING: Assertions are enabled; benchmarks unnecessarily slow ------------------------------------------------ DB path: [/tmp/prefix_scan] seekrandom : 5356367.174 micros/op 0 ops/sec; 29.4 MB/s (23 of 23 found) ---------------------------------------------------------------------------------------------------- After the patch: ./db_bench -use_existing_db=true -db=/tmp/prefix_scan -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 6.27 Date: Tue Nov 30 14:38:33 2021 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 WARNING: Assertions are enabled; benchmarks unnecessarily slow ------------------------------------------------ DB path: [/tmp/prefix_scan] seekrandom : 456504.277 micros/op 2 ops/sec; 359.8 MB/s (264 of 264 found) Pull Request resolved: https://github.com/facebook/rocksdb/pull/9234 Test Plan: Ran ./db_bench -db=/data/mysql/rocksdb/prefix_scan -benchmarks="fillseq" -key_size=32 -value_size=512 -num=5000000 -use_d irect_io_for_flush_and_compaction=true -target_file_size_base=16777216 and then ./db_bench -use_existing_db=true -db=/data/mysql/rocksdb/prefix_scan -benchmarks="seekrandom" -key_size=32 -value_siz e=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 and compared the results. Reviewed By: anand1976 Differential Revision: D32743965 Pulled By: akankshamahajan15 fbshipit-source-id: b950fba68c91963b7deb5c20acdf471bc60251f5 |
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.. | ||
binary_search_index_reader.cc | ||
binary_search_index_reader.h | ||
block_based_filter_block_test.cc | ||
block_based_filter_block.cc | ||
block_based_filter_block.h | ||
block_based_table_builder.cc | ||
block_based_table_builder.h | ||
block_based_table_factory.cc | ||
block_based_table_factory.h | ||
block_based_table_iterator.cc | ||
block_based_table_iterator.h | ||
block_based_table_reader_impl.h | ||
block_based_table_reader_test.cc | ||
block_based_table_reader.cc | ||
block_based_table_reader.h | ||
block_builder.cc | ||
block_builder.h | ||
block_like_traits.h | ||
block_prefetcher.cc | ||
block_prefetcher.h | ||
block_prefix_index.cc | ||
block_prefix_index.h | ||
block_test.cc | ||
block_type.h | ||
block.cc | ||
block.h | ||
cachable_entry.h | ||
data_block_footer.cc | ||
data_block_footer.h | ||
data_block_hash_index_test.cc | ||
data_block_hash_index.cc | ||
data_block_hash_index.h | ||
filter_block_reader_common.cc | ||
filter_block_reader_common.h | ||
filter_block.h | ||
filter_policy_internal.h | ||
filter_policy.cc | ||
flush_block_policy.cc | ||
flush_block_policy.h | ||
full_filter_block_test.cc | ||
full_filter_block.cc | ||
full_filter_block.h | ||
hash_index_reader.cc | ||
hash_index_reader.h | ||
index_builder.cc | ||
index_builder.h | ||
index_reader_common.cc | ||
index_reader_common.h | ||
mock_block_based_table.h | ||
parsed_full_filter_block.cc | ||
parsed_full_filter_block.h | ||
partitioned_filter_block_test.cc | ||
partitioned_filter_block.cc | ||
partitioned_filter_block.h | ||
partitioned_index_iterator.cc | ||
partitioned_index_iterator.h | ||
partitioned_index_reader.cc | ||
partitioned_index_reader.h | ||
reader_common.cc | ||
reader_common.h | ||
uncompression_dict_reader.cc | ||
uncompression_dict_reader.h |