Commit Graph

4 Commits

Author SHA1 Message Date
Yi Wu de47e2bd4d Fix ClockCache memory leak
Summary:
Fix ClockCache memory leak found by valgrind:
# Add destructor to cleanup cached values.
# Delete key with cache handle immediately after handle is recycled, and erase table entry immediately if duplicated cache entry is inserted.

Test Plan:
    make DISABLE_JEMALLOC=1 valgrind_check

Reviewers: IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62973
2016-08-31 08:56:34 -07:00
Yi Wu badbff65b7 Not insert into block cache if cache is full and not holding handle
Summary:
We used to allow insert into full block cache as long as `strict_capacity_limit=false`. This diff further restrict insert to full cache if caller don't intent to hold handle to the cache entry after insert.

Hope this diff fix the assertion failure with db_stress: https://our.intern.facebook.com/intern/sandcastle/log/?instance_id=211853102&step_id=2475070014

  db_stress: util/lru_cache.cc:278: virtual void rocksdb::LRUCacheShard::Release(rocksdb::Cache::Handle*): Assertion `lru_.next == &lru_' failed.

The assertion at lru_cache.cc:278 can fail when an entry is inserted into full cache and stay in LRU list.

Test Plan:
  make all check

Reviewers: IslamAbdelRahman, lightmark, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62325
2016-08-23 13:53:49 -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 4cc37f59e5 Introduce ClockCache
Summary:
Clock-based cache implemenetation aim to have better concurreny than
default LRU cache. See inline comments for implementation details.

Test Plan:
Update cache_test to run on both LRUCache and ClockCache. Adding some
new tests to catch some of the bugs that I fixed while implementing the
cache.

Reviewers: kradhakrishnan, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D61647
2016-08-19 12:28:19 -07:00