Commit graph

3 commits

Author SHA1 Message Date
Yi Wu 4a16c32ece Option to cache index/filter blocks with priority
Summary:
Add option to block based table to insert index/filter blocks to block cache with priority. Combined with LRUCache with high_pri_pool_ratio, we can reserved space for index/filter blocks, make them less likely to be evicted.

Depends on D61977.

Test Plan: See unit test.

Reviewers: lightmark, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, march, leveldb

Differential Revision: https://reviews.facebook.net/D62241
2016-08-23 13:44:13 -07:00
Yi Wu 72f8cc703c LRU cache mid-point insertion
Summary:
Add mid-point insertion functionality to LRU cache. Caller of `Cache::Insert()` can set an additional parameter to make a cache entry have higher priority. The LRU cache will reserve at most `capacity * high_pri_pool_pct` bytes for high-pri cache entries. If `high_pri_pool_pct` is zero, the cache degenerates to normal LRU cache.

Context: If we are to put index and filter blocks into RocksDB block cache, index/filter block can be swap out too early. We want to add an option to RocksDB to reserve some capacity in block cache just for index/filter blocks, to mitigate the issue.

In later diffs I'll update block based table reader to use the interface to cache index/filter blocks at high priority, and expose the option to `DBOptions` and make it dynamic changeable.

Test Plan: unit test.

Reviewers: IslamAbdelRahman, sdong, lightmark

Reviewed By: lightmark

Subscribers: andrewkr, dhruba, march, leveldb

Differential Revision: https://reviews.facebook.net/D61977
2016-08-19 16:43:31 -07:00
Yi Wu 2a2ebb6f5e Move LRUCache structs to lru_cache.h header
Summary: ... so that I can include the header and create LRUCache specific tests for D61977

Test Plan:
   make check

Reviewers: lightmark, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62145
2016-08-16 14:43:41 -07:00