Commit Graph

7 Commits

Author SHA1 Message Date
anand76 6cc7ad15b6 Implement secondary cache admission policy to allow all evicted blocks (#12599)
Summary:
Add a secondary cache admission policy to admit all blocks evicted from the block cache.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12599

Reviewed By: pdillinger

Differential Revision: D56891760

Pulled By: anand1976

fbshipit-source-id: 193c98c055aa3477f4e3a78e5d3daef27a5eacf4
2024-05-02 11:23:35 -07:00
yuzhangyu@fb.com 1cfdece85d Run internal cpp modernizer on RocksDB repo (#12398)
Summary:
When internal cpp modernizer attempts to format rocksdb code, it will replace macro `ROCKSDB_NAMESPACE`  with its default definition `rocksdb` when collapsing nested namespace. We filed a feedback for the tool T180254030 and the team filed a bug for this: https://github.com/llvm/llvm-project/issues/83452. At the same time, they suggested us to run the modernizer tool ourselves so future auto codemod attempts will be smaller. This diff contains:

Running
`xplat/scripts/codemod_service/cpp_modernizer.sh`
in fbcode/internal_repo_rocksdb/repo (excluding some directories in utilities/transactions/lock/range/range_tree/lib that has a non meta copyright comment)
without swapping out the namespace macro `ROCKSDB_NAMESPACE`

Followed by RocksDB's own
`make format`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12398

Test Plan: Auto tests

Reviewed By: hx235

Differential Revision: D54382532

Pulled By: jowlyzhang

fbshipit-source-id: e7d5b40f9b113b60e5a503558c181f080b9d02fa
2024-03-04 10:08:32 -08:00
anand76 cc069f25b3 Add some compressed and tiered secondary cache stats (#12150)
Summary:
Add statistics for more visibility.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12150

Reviewed By: akankshamahajan15

Differential Revision: D52184633

Pulled By: anand1976

fbshipit-source-id: 9969e05d65223811cd12627102b020bb6d229352
2023-12-15 11:34:08 -08:00
anand76 c1b84d0437 Fix false negative in TieredSecondaryCache nvm cache lookup (#12134)
Summary:
There is a bug in the `TieredSecondaryCache` that can result in a false negative. This can happen when a MultiGet does a cache lookup that gets a hit in the `TieredSecondaryCache` local nvm cache tier, and the result is available before MultiGet calls `WaitAll` (i.e the nvm cache `SecondaryCacheResultHandle` `IsReady` returns true).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12134

Test Plan: Add a new unit test in tiered_secondary_cache_test

Reviewed By: akankshamahajan15

Differential Revision: D52023309

Pulled By: anand1976

fbshipit-source-id: e5ae681226a0f12753fecb2f6acc7e5f254ae72b
2023-12-11 16:59:59 -08:00
anand76 35a0250293 Don't call InsertSaved on compressed only secondary cache (#11889)
Summary:
In https://github.com/facebook/rocksdb/issues/11812, the ```CacheWithSecondaryAdapter::Insert``` calls ```InsertSaved``` on the secondary cache to warm it up with the compressed blocks. This should only be done if its a stacked cache with compressed and nvm cache. If its in-memory compressed only, then don't call ```InsertSaved```.

Tests:
Add a new unit test

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11889

Reviewed By: akankshamahajan15

Differential Revision: D49615758

Pulled By: anand1976

fbshipit-source-id: 156ff968ad014ac319f8840da7a48193e4cebfa9
2023-09-27 12:08:08 -07:00
anand76 48589b961f Fix updating the capacity of a tiered cache (#11873)
Summary:
Updating the tiered cache (cache allocated using ```NewTieredCache()```) by calling ```SetCapacity()``` on it was not working properly. The initial creation would set the primary cache capacity to the combined primary and compressed secondary cache capacity. But ```SetCapacity()``` would just set the primary cache capacity, with no way to change the secondary cache capacity. Additionally, the API was confusing, since the primary and compressed secondary capacities would be specified separately during creation, but ```SetCapacity``` took the combined capacity.

With this fix, the user always specifies the total budget and compressed secondary cache ratio on creation. Subsequently, `SetCapacity` will distribute the new capacity across the two caches by the same ratio. The `NewTieredCache` API has been changed to take the total cache capacity (inclusive of both the primary and the compressed secondary cache) and the ratio of total capacity to allocate to the compressed cache. These are specified in `TieredCacheOptions`. Any capacity specified in `LRUCacheOptions`, `HyperClockCacheOptions` and `CompressedSecondaryCacheOptions` is ignored. A new API, `UpdateTieredCache` is provided to dynamically update the total capacity, ratio of compressed cache, and admission policy.

Tests:
New unit tests

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11873

Reviewed By: akankshamahajan15

Differential Revision: D49562250

Pulled By: anand1976

fbshipit-source-id: 57033bc713b68d5da6292207765a6b3dbe539ddf
2023-09-22 18:07:46 -07:00
anand76 269478ee46 Support compressed and local flash secondary cache stacking (#11812)
Summary:
This PR implements support for a three tier cache - primary block cache, compressed secondary cache, and a nvm (local flash) secondary cache. This allows more effective utilization of the nvm cache, and minimizes the number of reads from local flash by caching compressed blocks in the compressed secondary cache.

The basic design is as follows -
1. A new secondary cache implementation, ```TieredSecondaryCache```, is introduced. It keeps the compressed and nvm secondary caches and manages the movement of blocks between them and the primary block cache. To setup a three tier cache, we allocate a ```CacheWithSecondaryAdapter```, with a ```TieredSecondaryCache``` instance as the secondary cache.
2. The table reader passes both the uncompressed and compressed block to ```FullTypedCacheInterface::InsertFull```, allowing the block cache to optionally store the compressed block.
3. When there's a miss, the block object is constructed and inserted in the primary cache, and the compressed block is inserted into the nvm cache by calling ```InsertSaved```. This avoids the overhead of recompressing the block, as well as avoiding putting more memory pressure on the compressed secondary cache.
4. When there's a hit in the nvm cache, we attempt to insert the block in the compressed secondary cache and the primary cache, subject to the admission policy of those caches (i.e admit on second access). Blocks/items evicted from any tier are simply discarded.

We can easily implement additional admission policies if desired.

Todo (In a subsequent PR):
1. Add to db_bench and run benchmarks
2. Add to db_stress

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11812

Reviewed By: pdillinger

Differential Revision: D49461842

Pulled By: anand1976

fbshipit-source-id: b40ac1330ef7cd8c12efa0a3ca75128e602e3a0b
2023-09-21 20:30:53 -07:00