rocksdb

Commit Graph

Author	SHA1	Message	Date
Zichen Zhu	8860fc902a	Support subcmpct using reserved resources for round-robin priority (#10341 ) Summary: Earlier implementation of round-robin priority can only pick one file at a time and disallows parallel compactions within the same level. In this PR, round-robin compaction policy will expand towards more input files with respecting some additional constraints, which are summarized as follows: * Constraint 1: We can only pick consecutive files - Constraint 1a: When a file is being compacted (or some input files are being compacted after expanding), we cannot choose it and have to stop choosing more files - Constraint 1b: When we reach the last file (with the largest keys), we cannot choose more files (the next file will be the first one with small keys) * Constraint 2: We should ensure the total compaction bytes (including the overlapped files from the next level) is no more than `mutable_cf_options_.max_compaction_bytes` * Constraint 3: We try our best to pick as many files as possible so that the post-compaction level size can be just less than `MaxBytesForLevel(start_level_)` * Constraint 4: If trivial move is allowed, we reuse the logic of `TryNonL0TrivialMove()` instead of expanding files with Constraint 3 More details can be found in `LevelCompactionBuilder::SetupOtherFilesWithRoundRobinExpansion()`. The above optimization accelerates the process of moving the compaction cursor, in which the write-amp can be further reduced. While a large compaction may lead to high write stall, we break this large compaction into several subcompactions regardless of the `max_subcompactions` limit. The number of subcompactions for round-robin compaction priority is determined through the following steps: * Step 1: Initialized against `max_output_file_limit`, the number of input files in the start level, and also the range size limit `ranges.size()` * Step 2: Call `AcquireSubcompactionResources()`when max subcompactions is not sufficient, but we may or may not obtain desired resources, additional number of resources is stored in `extra_num_subcompaction_threads_reserved_`). Subcompaction limit is changed and update `num_planned_subcompactions` with `GetSubcompactionLimit()` * Step 3: Call `ShrinkSubcompactionResources()` to ensure extra resources can be released (extra resources may exist for round-robin compaction when the number of actual number of subcompactions is less than the number of planned subcompactions) More details can be found in `CompactionJob::AcquireSubcompactionResources()`,`CompactionJob::ShrinkSubcompactionResources()`, and `CompactionJob::ReleaseSubcompactionResources()`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10341 Test Plan: Add `CompactionPriMultipleFilesRoundRobin[1-3]` unit test in `compaction_picker_test.cc` and `RoundRobinSubcompactionsAgainstResources.SubcompactionsUsingResources/[0-4]`, `RoundRobinSubcompactionsAgainstPressureToken.PressureTokenTest/[0-1]` in `db_compaction_test.cc` Reviewed By: ajkr, hx235 Differential Revision: D37792644 Pulled By: littlepig2013 fbshipit-source-id: 7fecb7c4ffd97b34bbf6e3b760b2c35a772a0657	2 years ago
sdong	252bea405e	Improve SubCompaction Partitioning (#10393 ) Summary: Unit tests still haven't been fixed. Also need to add more tests. But I ran some simple fillrandom db_bench and the partitioning feels reasonable. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10393 Test Plan: 1. Make sure existing tests pass. This should cover some basic sub compaction logic to be correct and the partitioning result is reasonable; 2. Add a new unit test to ApproximateKeyAnchors() 3. Run some db_bench with max_subcompaction = 4 and watch the compaction is indeed partitioned evenly. Reviewed By: jay-zhuang Differential Revision: D38043783 fbshipit-source-id: 085008e0f85f9b7c5abff7800307618320efb19f	2 years ago
Jay Zhuang	6ce0b2ca34	Tiered Compaction: per key placement support (#9964 ) Summary: Support per_key_placement for last level compaction, which will be used for tiered compaction. * compaction iterator reports which level a key should output to; * compaction get the output level information and check if it's safe to output the data to penultimate level; * all compaction output files will be installed. * extra internal compaction stats added for penultimate level. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9964 Test Plan: * Unittest * db_bench, no significate difference: https://gist.github.com/jay-zhuang/3645f8fb97ec0ab47c10704bb39fd6e4 * microbench manual compaction no significate difference: https://gist.github.com/jay-zhuang/ba679b3e89e24992615ee9eef310e6dd * run the db_stress multiple times (not covering the new feature) looks good (internal: https://fburl.com/sandcastle/9w84pp2m) Reviewed By: ajkr Differential Revision: D36249494 Pulled By: jay-zhuang fbshipit-source-id: a96da57c8031c1df83e4a7a8567b657a112b80a3	2 years ago

Author

SHA1

Message

Date

Zichen Zhu

8860fc902a

Support subcmpct using reserved resources for round-robin priority (#10341 )

Summary:
Earlier implementation of round-robin priority can only pick one file at a time and disallows parallel compactions within the same level. In this PR, round-robin compaction policy will expand towards more input files with respecting some additional constraints, which are summarized as follows:
 * Constraint 1: We can only pick consecutive files
   - Constraint 1a: When a file is being compacted (or some input files are being compacted after expanding), we cannot choose it and have to stop choosing more files
   - Constraint 1b: When we reach the last file (with the largest keys), we cannot choose more files (the next file will be the first one with small keys)
 * Constraint 2: We should ensure the total compaction bytes (including the overlapped files from the next level) is no more than `mutable_cf_options_.max_compaction_bytes`
 * Constraint 3: We try our best to pick as many files as possible so that the post-compaction level size can be just less than `MaxBytesForLevel(start_level_)`
 * Constraint 4: If trivial move is allowed, we reuse the logic of `TryNonL0TrivialMove()` instead of expanding files with Constraint 3

More details can be found in `LevelCompactionBuilder::SetupOtherFilesWithRoundRobinExpansion()`.

The above optimization accelerates the process of moving the compaction cursor, in which the write-amp can be further reduced. While a large compaction may lead to high write stall, we break this large compaction into several subcompactions **regardless of** the `max_subcompactions` limit.  The number of subcompactions for round-robin compaction priority is determined through the following steps:
* Step 1: Initialized against `max_output_file_limit`, the number of input files in the start level, and also the range size limit `ranges.size()`
* Step 2: Call `AcquireSubcompactionResources()`when max subcompactions is not sufficient, but we may or may not obtain desired resources, additional number of resources is stored in `extra_num_subcompaction_threads_reserved_`). Subcompaction limit is changed and update `num_planned_subcompactions` with `GetSubcompactionLimit()`
* Step 3: Call `ShrinkSubcompactionResources()` to ensure extra resources can be released (extra resources may exist for round-robin compaction when the number of actual number of subcompactions is less than the number of planned subcompactions)

More details can be found in `CompactionJob::AcquireSubcompactionResources()`,`CompactionJob::ShrinkSubcompactionResources()`, and `CompactionJob::ReleaseSubcompactionResources()`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10341

Test Plan: Add `CompactionPriMultipleFilesRoundRobin[1-3]` unit test in `compaction_picker_test.cc` and `RoundRobinSubcompactionsAgainstResources.SubcompactionsUsingResources/[0-4]`, `RoundRobinSubcompactionsAgainstPressureToken.PressureTokenTest/[0-1]` in `db_compaction_test.cc`

Reviewed By: ajkr, hx235

Differential Revision: D37792644

Pulled By: littlepig2013

fbshipit-source-id: 7fecb7c4ffd97b34bbf6e3b760b2c35a772a0657

2 years ago

sdong

252bea405e

Improve SubCompaction Partitioning (#10393 )

Summary:
Unit tests still haven't been fixed. Also need to add more tests. But I ran some simple fillrandom db_bench and the partitioning feels reasonable.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10393

Test Plan:
1. Make sure existing tests pass. This should cover some basic sub compaction logic to be correct and the partitioning result is reasonable;
2. Add a new unit test to ApproximateKeyAnchors()
3. Run some db_bench with max_subcompaction = 4 and watch the compaction is indeed partitioned evenly.

Reviewed By: jay-zhuang

Differential Revision: D38043783

fbshipit-source-id: 085008e0f85f9b7c5abff7800307618320efb19f

2 years ago

Jay Zhuang

6ce0b2ca34

Tiered Compaction: per key placement support (#9964 )

Summary:
Support per_key_placement for last level compaction, which will
be used for tiered compaction.
* compaction iterator reports which level a key should output to;
* compaction get the output level information and check if it's safe to
  output the data to penultimate level;
* all compaction output files will be installed.
* extra internal compaction stats added for penultimate level.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9964

Test Plan:
* Unittest
* db_bench, no significate difference: https://gist.github.com/jay-zhuang/3645f8fb97ec0ab47c10704bb39fd6e4
* microbench manual compaction no significate difference: https://gist.github.com/jay-zhuang/ba679b3e89e24992615ee9eef310e6dd
* run the db_stress multiple times (not covering the new feature) looks good (internal: https://fburl.com/sandcastle/9w84pp2m)

Reviewed By: ajkr

Differential Revision: D36249494

Pulled By: jay-zhuang

fbshipit-source-id: a96da57c8031c1df83e4a7a8567b657a112b80a3

2 years ago

3 Commits (8860fc902a7c8fababcb44a6373a677135a63d14)