mirror of https://github.com/facebook/rocksdb.git
ef6f025563
Summary:
* The plan is for AutoHyperClockCache to be selected when HyperClockCacheOptions::estimated_entry_charge == 0, and in that case to use a new configuration option min_avg_entry_charge for determining an extreme case maximum size for the hash table. For the placeholder, a hack is in place in HyperClockCacheOptions::MakeSharedCache() to make the unit tests happy despite the new options not really making sense with the current implementation.
* Mostly updating and refactoring tests to test both the current HCC (internal name FixedHyperClockCache) and a placeholder for the new version (internal name AutoHyperClockCache).
* Simplify some existing tests not to depend directly on cache type.
* Type-parameterize the shard-level unit tests, which unfortunately requires more syntax like `this->` in places for disambiguation.
* Added means of choosing auto_hyper_clock_cache to cache_bench, db_bench, and db_stress, including add to crash test.
* Add another templated class BaseHyperClockCache to reduce future copy-paste
* Added ReportProblems support to cache_bench
* Added a DEBUG-level diagnostic to ReportProblems for the variance in load factor throughout the table, which will become more of a concern with linear hashing to be used in the Auto implementation. Example with current Fixed HCC:
```
2023/08/10-13:41:41.602450 6ac36 [DEBUG] [che/clock_cache.cc:1507] Slot occupancy stats: Overall 49% (129008/262144), Min/Max/Window = 39%/60%/500, MaxRun{Pos/Neg} = 18/17
```
In other words, with overall occupancy of 49%, the lowest across any 500 contiguous cells is 39% and highest 60%. Longest run of occupied is 18 and longest run of unoccupied is 17. This seems consistent with random samples from a uniform distribution.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11692
Test Plan: Shouldn't be any meaningful changes yet to production code or to what is tested, but there is temporary redundancy in testing until the new implementation is plugged in.
Reviewed By: jowlyzhang
Differential Revision: D48247413
Pulled By: pdillinger
fbshipit-source-id: 11541f996d97af403c2e43c92fb67ff22dd0b5da
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| .. | ||
| cache.cc | ||
| cache_bench.cc | ||
| cache_bench_tool.cc | ||
| cache_entry_roles.cc | ||
| cache_entry_roles.h | ||
| cache_entry_stats.h | ||
| cache_helpers.cc | ||
| cache_helpers.h | ||
| cache_key.cc | ||
| cache_key.h | ||
| cache_reservation_manager.cc | ||
| cache_reservation_manager.h | ||
| cache_reservation_manager_test.cc | ||
| cache_test.cc | ||
| charged_cache.cc | ||
| charged_cache.h | ||
| clock_cache.cc | ||
| clock_cache.h | ||
| compressed_secondary_cache.cc | ||
| compressed_secondary_cache.h | ||
| compressed_secondary_cache_test.cc | ||
| lru_cache.cc | ||
| lru_cache.h | ||
| lru_cache_test.cc | ||
| secondary_cache.cc | ||
| secondary_cache_adapter.cc | ||
| secondary_cache_adapter.h | ||
| sharded_cache.cc | ||
| sharded_cache.h | ||
| typed_cache.h | ||