mirror of https://github.com/facebook/rocksdb.git
a479c2c2b2
Summary: In case of non sequential reads with `async_io`, `FilePRefetchBuffer::TryReadFromCacheAsync` can be called for previous blocks with `offset < bufs_[curr_].offset_` which wasn't handled correctly resulting wrong data being returned from buffer. Since `FilePRefetchBuffer::PrefetchAsync` can be called for any data block, it sets `prev_len_` to 0 indicating `FilePRefetchBuffer::TryReadFromCacheAsync` to go for the prefetching even though offset < bufs_[curr_].offset_ This is because async prefetching is always done in second buffer (to avoid mutex) even though curr_ is empty leading to offset < bufs_[curr_].offset_ in some cases. If prev_len_ is non zero then `TryReadFromCacheAsync` returns false if `offset < bufs_[curr_].offset_ && prev_len != 0` indicating reads are not sequential and previous call wasn't PrefetchAsync. - This PR also simplifies `FilePRefetchBuffer::TryReadFromCacheAsync` as it was getting complicated covering different scenarios based on `async_io` enabled/disabled. If `for_compaction` is set true, it now calls `FilePRefetchBufferTryReadFromCache` following synchronous flow as before. Its decided in BlockFetcher.cc Pull Request resolved: https://github.com/facebook/rocksdb/pull/10032 Test Plan: 1. export CRASH_TEST_EXT_ARGS=" --async_io=1" make crash_test -j completed successfully locally 2. make crash_test -j completed successfully locally 3. Reran CircleCi mini crashtest job 4 - 5 times. 4. Updated prefetch_test for more coverage. Reviewed By: anand1976 Differential Revision: D36579858 Pulled By: akankshamahajan15 fbshipit-source-id: 0c428d62b45e12e082a83acf533a5e37a584bedf |
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|---|---|---|
| .. | ||
| adaptive | ||
| block_based | ||
| cuckoo | ||
| plain | ||
| block_fetcher.cc | ||
| block_fetcher.h | ||
| block_fetcher_test.cc | ||
| cleanable_test.cc | ||
| format.cc | ||
| format.h | ||
| get_context.cc | ||
| get_context.h | ||
| internal_iterator.h | ||
| iter_heap.h | ||
| iterator.cc | ||
| iterator_wrapper.h | ||
| 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.cc | ||
| sst_file_reader_test.cc | ||
| sst_file_writer.cc | ||
| sst_file_writer_collectors.h | ||
| table_builder.h | ||
| table_factory.cc | ||
| table_properties.cc | ||
| table_properties_internal.h | ||
| table_reader.h | ||
| table_reader_bench.cc | ||
| table_reader_caller.h | ||
| table_test.cc | ||
| two_level_iterator.cc | ||
| two_level_iterator.h | ||
| unique_id.cc | ||
| unique_id_impl.h | ||