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4da34b97ee
Summary: ### Context: Background compactions and flush generate large reads and writes, and can be long running, especially for universal compaction. In some cases, this can impact foreground reads and writes by users. ### Solution User, Flush, and Compaction reads share some code path. For this task, we update the rate_limiter_priority in ReadOptions for code paths (e.g. FindTable (mainly in BlockBasedTable::Open()) and various iterators), and eventually update the rate_limiter_priority in IOOptions for FSRandomAccessFile. **This PR is for the Read path.** The **Read:** dynamic priority for different state are listed as follows: | State | Normal | Delayed | Stalled | | ----- | ------ | ------- | ------- | | Flush (verification read in BuildTable()) | IO_USER | IO_USER | IO_USER | | Compaction | IO_LOW | IO_USER | IO_USER | | User | User provided | User provided | User provided | We will respect the read_options that the user provided and will not set it. The only sst read for Flush is the verification read in BuildTable(). It claims to be "regard as user read". **Details** 1. Set read_options.rate_limiter_priority dynamically: - User: Do not update the read_options. Use the read_options that the user provided. - Compaction: Update read_options in CompactionJob::ProcessKeyValueCompaction(). - Flush: Update read_options in BuildTable(). 2. Pass the rate limiter priority to FSRandomAccessFile functions: - After calling the FindTable(), read_options is passed through GetTableReader(table_cache.cc), BlockBasedTableFactory::NewTableReader(block_based_table_factory.cc), and BlockBasedTable::Open(). The Open() needs some updates for the ReadOptions variable and the updates are also needed for the called functions, including PrefetchTail(), PrepareIOOptions(), ReadFooterFromFile(), ReadMetaIndexblock(), ReadPropertiesBlock(), PrefetchIndexAndFilterBlocks(), and ReadRangeDelBlock(). - In RandomAccessFileReader, the functions to be updated include Read(), MultiRead(), ReadAsync(), and Prefetch(). - Update the downstream functions of NewIndexIterator(), NewDataBlockIterator(), and BlockBasedTableIterator(). ### Test Plans Add unit tests. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9996 Reviewed By: anand1976 Differential Revision: D36452483 Pulled By: gitbw95 fbshipit-source-id: 60978204a4f849bb9261cb78d9bc1cb56d6008cf
75 lines
2.6 KiB
C++
75 lines
2.6 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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//
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// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#include "table/block_based/binary_search_index_reader.h"
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namespace ROCKSDB_NAMESPACE {
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Status BinarySearchIndexReader::Create(
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const BlockBasedTable* table, const ReadOptions& ro,
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FilePrefetchBuffer* prefetch_buffer, bool use_cache, bool prefetch,
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bool pin, BlockCacheLookupContext* lookup_context,
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std::unique_ptr<IndexReader>* index_reader) {
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assert(table != nullptr);
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assert(table->get_rep());
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assert(!pin || prefetch);
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assert(index_reader != nullptr);
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CachableEntry<Block> index_block;
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if (prefetch || !use_cache) {
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const Status s =
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ReadIndexBlock(table, prefetch_buffer, ro, use_cache,
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/*get_context=*/nullptr, lookup_context, &index_block);
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if (!s.ok()) {
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return s;
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}
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if (use_cache && !pin) {
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index_block.Reset();
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}
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}
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index_reader->reset(
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new BinarySearchIndexReader(table, std::move(index_block)));
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return Status::OK();
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}
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InternalIteratorBase<IndexValue>* BinarySearchIndexReader::NewIterator(
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const ReadOptions& read_options, bool /* disable_prefix_seek */,
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IndexBlockIter* iter, GetContext* get_context,
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BlockCacheLookupContext* lookup_context) {
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const BlockBasedTable::Rep* rep = table()->get_rep();
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const bool no_io = (read_options.read_tier == kBlockCacheTier);
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CachableEntry<Block> index_block;
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const Status s =
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GetOrReadIndexBlock(no_io, read_options.rate_limiter_priority,
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get_context, lookup_context, &index_block);
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if (!s.ok()) {
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if (iter != nullptr) {
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iter->Invalidate(s);
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return iter;
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}
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return NewErrorInternalIterator<IndexValue>(s);
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}
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Statistics* kNullStats = nullptr;
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// We don't return pinned data from index blocks, so no need
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// to set `block_contents_pinned`.
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auto it = index_block.GetValue()->NewIndexIterator(
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internal_comparator()->user_comparator(),
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rep->get_global_seqno(BlockType::kIndex), iter, kNullStats, true,
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index_has_first_key(), index_key_includes_seq(), index_value_is_full());
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assert(it != nullptr);
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index_block.TransferTo(it);
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return it;
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}
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} // namespace ROCKSDB_NAMESPACE
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