8ea0a2c1bd
Summary: Implement the ```WaitAll()``` interface in ```LRUCache``` to allow callers to issue multiple lookups in parallel and wait for all of them to complete. Modify ```MultiGet``` to use this to parallelize the secondary cache lookups in order to reduce the overall latency. A call to ```cache->Lookup()``` returns a handle that has an incomplete value (nullptr), and the caller can call ```cache->IsReady()``` to check whether the lookup is complete, and pass a vector of handles to ```WaitAll``` to wait for completion. If any of the lookups fail, ```MultiGet``` will read the block from the SST file. Another change in this PR is to rename ```SecondaryCacheHandle``` to ```SecondaryCacheResultHandle``` as it more accurately describes the return result of the secondary cache lookup, which is more like a future. Tests: 1. Add unit tests in lru_cache_test 2. Benchmark results with no secondary cache configured Master - ``` readrandom : 41.175 micros/op 388562 ops/sec; 106.7 MB/s (7277999 of 7277999 found) readrandom : 41.217 micros/op 388160 ops/sec; 106.6 MB/s (7274999 of 7274999 found) multireadrandom : 10.309 micros/op 1552082 ops/sec; (28908992 of 28908992 found) multireadrandom : 10.321 micros/op 1550218 ops/sec; (29081984 of 29081984 found) ``` This PR - ``` readrandom : 41.158 micros/op 388723 ops/sec; 106.8 MB/s (7290999 of 7290999 found) readrandom : 41.185 micros/op 388463 ops/sec; 106.7 MB/s (7287999 of 7287999 found) multireadrandom : 10.277 micros/op 1556801 ops/sec; (29346944 of 29346944 found) multireadrandom : 10.253 micros/op 1560539 ops/sec; (29274944 of 29274944 found) ``` Pull Request resolved: https://github.com/facebook/rocksdb/pull/8405 Reviewed By: zhichao-cao Differential Revision: D29190509 Pulled By: anand1976 fbshipit-source-id: 6f8eff6246712af8a297cfe22ea0d1c3b2a01bb0 |
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.. | ||
adaptive | ||
block_based | ||
cuckoo | ||
plain | ||
block_fetcher_test.cc | ||
block_fetcher.cc | ||
block_fetcher.h | ||
cleanable_test.cc | ||
format.cc | ||
format.h | ||
get_context.cc | ||
get_context.h | ||
internal_iterator.h | ||
iter_heap.h | ||
iterator_wrapper.h | ||
iterator.cc | ||
merger_test.cc | ||
merging_iterator.cc | ||
merging_iterator.h | ||
meta_blocks.cc | ||
meta_blocks.h | ||
mock_table.cc | ||
mock_table.h | ||
multiget_context.h | ||
persistent_cache_helper.cc | ||
persistent_cache_helper.h | ||
persistent_cache_options.h | ||
scoped_arena_iterator.h | ||
sst_file_dumper.cc | ||
sst_file_dumper.h | ||
sst_file_reader_test.cc | ||
sst_file_reader.cc | ||
sst_file_writer_collectors.h | ||
sst_file_writer.cc | ||
table_builder.h | ||
table_factory.cc | ||
table_properties_internal.h | ||
table_properties.cc | ||
table_reader_bench.cc | ||
table_reader_caller.h | ||
table_reader.h | ||
table_test.cc | ||
two_level_iterator.cc | ||
two_level_iterator.h |