Akanksha Mahajan a0e0feca62 Improve BlockPrefetcher to prefetch only for sequential scans (#7394) ... Summary: BlockPrefetcher is used by iterators to prefetch data if they anticipate more data to be used in future and this is valid for forward sequential scans. But BlockPrefetcher tracks only num_file_reads_ and not if reads are sequential. This presents problem for MultiGet with large number of keys when it reseeks index iterator and data block. FilePrefetchBuffer can end up doing large readahead for reseeks as readahead size increases exponentially once readahead is enabled. Same issue is with BlockBasedTableIterator. Add previous length and offset read as well in BlockPrefetcher (creates FilePrefetchBuffer) and FilePrefetchBuffer (does prefetching of data) to determine if reads are sequential and then prefetch. Update the last block read after cache hit to take reads from cache also in account. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7394 Test Plan: Add new unit test case Reviewed By: anand1976 Differential Revision: D23737617 Pulled By: akankshamahajan15 fbshipit-source-id: 8e6917c25ed87b285ee495d1b68dc623d71205a3		2021-04-28 12:53:46 -07:00
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adaptive	Bring the Configurable options together (#5753)	2020-09-14 17:01:01 -07:00
block_based	Improve BlockPrefetcher to prefetch only for sequential scans (#7394)	2021-04-28 12:53:46 -07:00
cuckoo	Move RegisterOptions into the Configurable API (#8223)	2021-04-26 03:13:24 -07:00
plain	Rename variables in ImmutableCFOptions to avoid conflicts with ImmutableDBOptions (#8227)	2021-04-26 12:43:45 -07:00
block_fetcher_test.cc	Apply sample_for_compression to all block-based tables (#8105)	2021-03-25 15:00:45 -07:00
block_fetcher.cc	Rename variables in ImmutableCFOptions to avoid conflicts with ImmutableDBOptions (#8227)	2021-04-26 12:43:45 -07:00
block_fetcher.h	Replace Status with IOStatus for block fetcher IO function (#8130)	2021-04-01 10:07:55 -07:00
cleanable_test.cc	Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)	2020-02-20 12:09:57 -08:00
format.cc	Rename variables in ImmutableCFOptions to avoid conflicts with ImmutableDBOptions (#8227)	2021-04-26 12:43:45 -07:00
format.h	Add a host location property to TableProperties (#7479)	2020-10-19 11:38:48 -07:00
get_context.cc	Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033)	2021-03-15 04:34:11 -07:00
get_context.h	Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033)	2021-03-15 04:34:11 -07:00
internal_iterator.h	Clean up InternalIterator upper bound logic a little bit (#7200)	2020-08-05 10:44:57 -07:00
iter_heap.h	Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)	2020-02-20 12:09:57 -08:00
iterator_wrapper.h	Redesign block cache pinning API (#7520)	2020-10-11 14:58:24 -07:00
iterator.cc	Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)	2020-02-20 12:09:57 -08:00
merger_test.cc	More Makefile Cleanup (#7097)	2020-07-09 14:35:17 -07:00
merging_iterator.cc	Add some simulator cache and block tracer tests to ASSERT_STATUS_CHECKED (#7305)	2020-08-24 16:43:31 -07:00
merging_iterator.h	Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)	2020-02-20 12:09:57 -08:00
meta_blocks.cc	Rename variables in ImmutableCFOptions to avoid conflicts with ImmutableDBOptions (#8227)	2021-04-26 12:43:45 -07:00
meta_blocks.h	Make types of Immutable/Mutable Options fields match that of the underlying Option (#8176)	2021-04-22 20:43:54 -07:00
mock_table.cc	Remove Legacy and Custom FileWrapper classes from header files (#7851)	2021-01-28 22:10:32 -08:00
mock_table.h	No elide constructors (#7798)	2020-12-23 16:55:53 -08:00
multiget_context.h	Add initial blob support to batched MultiGet (#7766)	2020-12-14 13:48:22 -08:00
persistent_cache_helper.cc	Add more tests to ASSERT_STATUS_CHECKED (#7367)	2020-09-16 15:48:07 -07:00
persistent_cache_helper.h	Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)	2020-02-20 12:09:57 -08:00
persistent_cache_options.h	Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)	2020-02-20 12:09:57 -08:00
scoped_arena_iterator.h	Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)	2020-02-20 12:09:57 -08:00
sst_file_dumper.cc	Apply sample_for_compression to all block-based tables (#8105)	2021-03-25 15:00:45 -07:00
sst_file_dumper.h	Limit buffering for collecting samples for compression dictionary (#7970)	2021-02-19 14:09:54 -08:00
sst_file_reader_test.cc	Add a host location property to TableProperties (#7479)	2020-10-19 11:38:48 -07:00
sst_file_reader.cc	Remove Legacy and Custom FileWrapper classes from header files (#7851)	2021-01-28 22:10:32 -08:00
sst_file_writer_collectors.h	Apply sample_for_compression to all block-based tables (#8105)	2021-03-25 15:00:45 -07:00
sst_file_writer.cc	Make types of Immutable/Mutable Options fields match that of the underlying Option (#8176)	2021-04-22 20:43:54 -07:00
table_builder.h	Apply sample_for_compression to all block-based tables (#8105)	2021-03-25 15:00:45 -07:00
table_factory.cc	Create a Customizable class to load classes and configurations (#6590)	2020-11-11 15:10:41 -08:00
table_properties_internal.h	Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)	2020-02-20 12:09:57 -08:00
table_properties.cc	Add sample_for_compression results to table properties (#8139)	2021-03-31 18:21:50 -07:00
table_reader_bench.cc	Rename variables in ImmutableCFOptions to avoid conflicts with ImmutableDBOptions (#8227)	2021-04-26 12:43:45 -07:00
table_reader_caller.h	Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)	2020-02-20 12:09:57 -08:00
table_reader.h	dedup ReadOptions in iterator hierarchy (#7210)	2020-08-03 15:23:04 -07:00
table_test.cc	Rename variables in ImmutableCFOptions to avoid conflicts with ImmutableDBOptions (#8227)	2021-04-26 12:43:45 -07:00
two_level_iterator.cc	Redesign block cache pinning API (#7520)	2020-10-11 14:58:24 -07:00
two_level_iterator.h	Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)	2020-02-20 12:09:57 -08:00