08be1803ee
Summary: See github issue 574: https://github.com/facebook/rocksdb/issues/574 Basically when we're running in DEBUG mode we're calling `usleep(0)` on every mutex lock. I bisected the issue to https://reviews.facebook.net/D36963. Instead of calling sleep(0), this diff just avoids calling SleepForMicroseconds() when delay is not set. Test Plan: bpl=10485760;overlap=10;mcz=2;del=300000000;levels=2;ctrig=10000000; delay=10000000; stop=10000000; wbn=30; mbc=20; mb=1073741824;wbs=268435456; dds=1; sync=0; r=100000; t=1; vs=800; bs=65536; cs=1048576; of=500000; si=1000000; ./db_bench --benchmarks=fillrandom --disable_seek_compaction=1 --mmap_read=0 --statistics=1 --histogram=1 --num=$r --threads=$t --value_size=$vs --block_size=$bs --cache_size=$cs --bloom_bits=10 --cache_numshardbits=4 --open_files=$of --verify_checksum=1 --db=/tmp/rdb10test --sync=$sync --disable_wal=1 --compression_type=snappy --stats_interval=$si --compression_ratio=0.5 --disable_data_sync=$dds --write_buffer_size=$wbs --target_file_size_base=$mb --max_write_buffer_number=$wbn --max_background_compactions=$mbc --level0_file_num_compaction_trigger=$ctrig --level0_slowdown_writes_trigger=$delay --level0_stop_writes_trigger=$stop --num_levels=$levels --delete_obsolete_files_period_micros=$del --min_level_to_compress=$mcz --max_grandparent_overlap_factor=$overlap --stats_per_interval=1 --max_bytes_for_level_base=$bpl --memtablerep=vector --use_existing_db=0 --disable_auto_compactions=1 --source_compaction_factor=10000000 | grep ops Before: fillrandom : 117.525 micros/op 8508 ops/sec; 6.6 MB/s After: fillrandom : 1.283 micros/op 779502 ops/sec; 606.6 MB/s Reviewers: rven, yhchiang, sdong Reviewed By: sdong Subscribers: meyering, dhruba, leveldb Differential Revision: https://reviews.facebook.net/D36963
RocksDB: A Persistent Key-Value Store for Flash and RAM Storage
RocksDB is developed and maintained by Facebook Database Engineering Team. It is built on earlier work on LevelDB by Sanjay Ghemawat (sanjay@google.com) and Jeff Dean (jeff@google.com)
This code is a library that forms the core building block for a fast key value server, especially suited for storing data on flash drives. It has a Log-Structured-Merge-Database (LSM) design with flexible tradeoffs between Write-Amplification-Factor (WAF), Read-Amplification-Factor (RAF) and Space-Amplification-Factor (SAF). It has multi-threaded compactions, making it specially suitable for storing multiple terabytes of data in a single database.
Start with example usage here: https://github.com/facebook/rocksdb/tree/master/examples
See the github wiki for more explanation.
The public interface is in include/. Callers should not include or
rely on the details of any other header files in this package. Those
internal APIs may be changed without warning.
Design discussions are conducted in https://www.facebook.com/groups/rocksdb.dev/