b9d65f5aa6
Summary: In level compaction, if the total size (even if compensated after taking account of the deletions) of a level hasn't exceeded the limit, but there are lots of deletion entries in some SST files of the level, these files should also be good candidates for compaction. Otherwise, queries for the deleted keys might be slow because they need to go over all the tombstones. This PR adds an option `deletion_ratio` to the factory of `CompactOnDeletionCollector` to configure it to trigger compaction when the ratio of tombstones >= `deletion_ratio`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/6806 Test Plan: Added new unit test in `compact_on_deletion_collector_test.cc`. make compact_on_deletion_collector_test && ./compact_on_deletion_collector_test Reviewed By: ajkr Differential Revision: D21511981 Pulled By: cheng-chang fbshipit-source-id: 65a9d0150e8c9c00337787686475252e4535a3e1
73 lines
2.6 KiB
C++
73 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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#pragma once
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#ifndef ROCKSDB_LITE
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#include "rocksdb/utilities/table_properties_collectors.h"
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namespace ROCKSDB_NAMESPACE {
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class CompactOnDeletionCollector : public TablePropertiesCollector {
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public:
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CompactOnDeletionCollector(size_t sliding_window_size,
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size_t deletion_trigger, double deletion_raatio);
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// AddUserKey() will be called when a new key/value pair is inserted into the
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// table.
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// @params key the user key that is inserted into the table.
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// @params value the value that is inserted into the table.
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// @params file_size file size up to now
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virtual Status AddUserKey(const Slice& key, const Slice& value,
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EntryType type, SequenceNumber seq,
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uint64_t file_size) override;
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// Finish() will be called when a table has already been built and is ready
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// for writing the properties block.
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// @params properties User will add their collected statistics to
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// `properties`.
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virtual Status Finish(UserCollectedProperties* /*properties*/) override;
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// Return the human-readable properties, where the key is property name and
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// the value is the human-readable form of value.
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virtual UserCollectedProperties GetReadableProperties() const override {
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return UserCollectedProperties();
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}
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// The name of the properties collector can be used for debugging purpose.
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virtual const char* Name() const override {
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return "CompactOnDeletionCollector";
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}
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// EXPERIMENTAL Return whether the output file should be further compacted
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virtual bool NeedCompact() const override {
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return need_compaction_;
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}
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static const int kNumBuckets = 128;
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private:
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void Reset();
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// A ring buffer that used to count the number of deletion entries for every
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// "bucket_size_" keys.
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size_t num_deletions_in_buckets_[kNumBuckets];
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// the number of keys in a bucket
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size_t bucket_size_;
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size_t current_bucket_;
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size_t num_keys_in_current_bucket_;
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size_t num_deletions_in_observation_window_;
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size_t deletion_trigger_;
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const double deletion_ratio_;
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const bool deletion_ratio_enabled_;
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size_t total_entries_ = 0;
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size_t deletion_entries_ = 0;
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// true if the current SST file needs to be compacted.
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bool need_compaction_;
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bool finished_;
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};
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} // namespace ROCKSDB_NAMESPACE
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#endif // !ROCKSDB_LITE
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