Summary:
[Compaction::IsTrivialMove](a2b9be42b6/db/compaction/compaction.cc (L318)) checks whether allow_trivial_move is set, and if so it returns the value of is_trivial_move_. The allow_trivial_move option is there for universal compaction. So when this is set and leveled compaction is enabled, then useful code that follows this block never gets a chance to run.
A check that [compaction_style == kCompactionStyleUniversal](320d9a8e8a/db/db_impl/db_impl_compaction_flush.cc (L1030)) should be added to avoid doing the wrong thing for leveled.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9586
Test Plan:
To reproduce this:
First edit db/compaction/compaction.cc with
```
diff --git a/db/compaction/compaction.cc b/db/compaction/compaction.cc
index 7ae50b91e..52dd489b1 100644
--- a/db/compaction/compaction.cc
+++ b/db/compaction/compaction.cc
@@ -319,6 +319,8 @@ bool Compaction::IsTrivialMove() const {
// input files are non overlapping
if ((mutable_cf_options_.compaction_options_universal.allow_trivial_move) &&
(output_level_ != 0)) {
+ printf("IsTrivialMove:: return %d because universal allow_trivial_move\n", (int) is_trivial_move_);
+ // abort();
return is_trivial_move_;
}
```
And then run
```
./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/m/rx --wal_dir=/data/m/rx --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 --seed=1641328309 --universal_allow_trivial_move=1
```
Example output with the debug code added
```
IsTrivialMove:: return 0 because universal allow_trivial_move
IsTrivialMove:: return 0 because universal allow_trivial_move
```
After this PR, the bug is fixed.
Reviewed By: ajkr
Differential Revision: D34350451
Pulled By: gitbw95
fbshipit-source-id: 3232005cc47c40a7e75d316cfc7960beb5bdff3a
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 especially suitable for storing multiple terabytes of data in a
single database.
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.
RocksDB is dual-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). You may select, at your option, one of the above-listed licenses.