rocksdb/db/compaction
Levi Tamasi 320d9a8e8a Use a sorted vector instead of a map to store blob file metadata (#9526)
Summary:
The patch replaces `std::map` with a sorted `std::vector` for
`VersionStorageInfo::blob_files_` and preallocates the space
for the `vector` before saving the `BlobFileMetaData` into the
new `VersionStorageInfo` in `VersionBuilder::Rep::SaveBlobFilesTo`.
These changes reduce the time the DB mutex is held while
saving new `Version`s, and using a sorted `vector` also makes
lookups faster thanks to better memory locality.

In addition, the patch introduces helper methods
`VersionStorageInfo::GetBlobFileMetaData` and
`VersionStorageInfo::GetBlobFileMetaDataLB` that can be used by
clients to perform lookups in the `vector`, and does some general
cleanup in the parts of code where blob file metadata are used.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9526

Test Plan:
Ran `make check` and the crash test script for a while.

Performance was tested using a load-optimized benchmark (`fillseq` with vector memtable, no WAL) and small file sizes so that a significant number of files are produced:

```
numactl --interleave=all ./db_bench --benchmarks=fillseq --allow_concurrent_memtable_write=false --level0_file_num_compaction_trigger=4 --level0_slowdown_writes_trigger=20 --level0_stop_writes_trigger=30 --max_background_jobs=8 --max_write_buffer_number=8 --db=/data/ltamasi-dbbench --wal_dir=/data/ltamasi-dbbench --num=800000000 --num_levels=8 --key_size=20 --value_size=400 --block_size=8192 --cache_size=51539607552 --cache_numshardbits=6 --compression_max_dict_bytes=0 --compression_ratio=0.5 --compression_type=lz4 --bytes_per_sync=8388608 --cache_index_and_filter_blocks=1 --cache_high_pri_pool_ratio=0.5 --benchmark_write_rate_limit=0 --write_buffer_size=16777216 --target_file_size_base=16777216 --max_bytes_for_level_base=67108864 --verify_checksum=1 --delete_obsolete_files_period_micros=62914560 --max_bytes_for_level_multiplier=8 --statistics=0 --stats_per_interval=1 --stats_interval_seconds=20 --histogram=1 --memtablerep=skip_list --bloom_bits=10 --open_files=-1 --subcompactions=1 --compaction_style=0 --min_level_to_compress=3 --level_compaction_dynamic_level_bytes=true --pin_l0_filter_and_index_blocks_in_cache=1 --soft_pending_compaction_bytes_limit=167503724544 --hard_pending_compaction_bytes_limit=335007449088 --min_level_to_compress=0 --use_existing_db=0 --sync=0 --threads=1 --memtablerep=vector --allow_concurrent_memtable_write=false --disable_wal=1 --enable_blob_files=1 --blob_file_size=16777216 --min_blob_size=0 --blob_compression_type=lz4 --enable_blob_garbage_collection=1 --seed=<some value>
```

Final statistics before the patch:

```
Cumulative writes: 0 writes, 700M keys, 0 commit groups, 0.0 writes per commit group, ingest: 284.62 GB, 121.27 MB/s
Interval writes: 0 writes, 334K keys, 0 commit groups, 0.0 writes per commit group, ingest: 139.28 MB, 72.46 MB/s
```

With the patch:

```
Cumulative writes: 0 writes, 760M keys, 0 commit groups, 0.0 writes per commit group, ingest: 308.66 GB, 131.52 MB/s
Interval writes: 0 writes, 445K keys, 0 commit groups, 0.0 writes per commit group, ingest: 185.35 MB, 93.15 MB/s
```

Total time to complete the benchmark is 2611 seconds with the patch, down from 2986 secs.

Reviewed By: riversand963

Differential Revision: D34082728

Pulled By: ltamasi

fbshipit-source-id: fc598abf676dce436734d06bb9d2d99a26a004fc
2022-02-09 12:36:43 -08:00
..
clipping_iterator.h Add a clipping internal iterator (#8327) 2021-06-09 15:41:16 -07:00
clipping_iterator_test.cc Cleanup multiple implementations of VectorIterator (#8901) 2021-10-06 07:48:31 -07:00
compaction.cc Try to start TTL earlier with kMinOverlappingRatio is used (#8749) 2021-11-01 14:36:31 -07:00
compaction.h Try to start TTL earlier with kMinOverlappingRatio is used (#8749) 2021-11-01 14:36:31 -07:00
compaction_iteration_stats.h Support readahead during compaction for blob files (#9187) 2021-11-19 17:53:47 -08:00
compaction_iterator.cc Use a sorted vector instead of a map to store blob file metadata (#9526) 2022-02-09 12:36:43 -08:00
compaction_iterator.h Remove iter_start_seqnum and preserve_deletes (#9430) 2022-01-28 13:28:38 -08:00
compaction_iterator_test.cc Use the comparator from the sst file table properties in sst_dump_tool (#9491) 2022-02-08 12:15:35 -08:00
compaction_job.cc Use a sorted vector instead of a map to store blob file metadata (#9526) 2022-02-09 12:36:43 -08:00
compaction_job.h Cleanup includes in dbformat.h (#8930) 2021-09-29 04:04:40 -07:00
compaction_job_stats_test.cc Make MemTableRepFactory into a Customizable class (#8419) 2021-09-08 07:46:44 -07:00
compaction_job_test.cc Use the comparator from the sst file table properties in sst_dump_tool (#9491) 2022-02-08 12:15:35 -08:00
compaction_picker.cc Ignore non-overlapping levels when determinig grandparent files (#9051) 2021-10-19 12:48:18 -07:00
compaction_picker.h Make ImmutableOptions struct that inherits from ImmutableCFOptions and ImmutableDBOptions (#8262) 2021-05-05 14:00:17 -07:00
compaction_picker_fifo.cc Cleanup includes in dbformat.h (#8930) 2021-09-29 04:04:40 -07:00
compaction_picker_fifo.h Move old files to warm tier in FIFO compactions (#8310) 2021-08-09 12:51:14 -07:00
compaction_picker_level.cc Make it possible to force the garbage collection of the oldest blob files (#8994) 2021-10-11 18:03:01 -07:00
compaction_picker_level.h Make ImmutableOptions struct that inherits from ImmutableCFOptions and ImmutableDBOptions (#8262) 2021-05-05 14:00:17 -07:00
compaction_picker_test.cc Clean up VersionStorageInfo a bit (#9494) 2022-02-04 08:19:20 -08:00
compaction_picker_universal.cc Fix num files in single compaction for universal compaction (#9168) 2021-11-30 15:11:21 -08:00
compaction_picker_universal.h Make ImmutableOptions struct that inherits from ImmutableCFOptions and ImmutableDBOptions (#8262) 2021-05-05 14:00:17 -07:00
compaction_service_test.cc Enable a few unit tests to use custom Env objects (#9087) 2021-11-08 11:05:59 -08:00
file_pri.h Try to start TTL earlier with kMinOverlappingRatio is used (#8749) 2021-11-01 14:36:31 -07:00
sst_partitioner.cc Restore Regex support for ObjectLibrary::Register, rename new APIs to allow old one to be deprecated in the future (#9362) 2022-01-11 06:33:48 -08:00