c3b2623f12
Bloom filter loading and saving is slow with single-bit access to the bitmap, causing latency spikes of ~100ms for 20MB sstables. Larger sstables will be much worse. Fix by using the newly introduced large_bitmap bulk load/save methods. With this, the maximum observed task latency was 16ms. Fixes #299 (partially at least; larger bitmaps may require more work still).
51 lines
1.5 KiB
C++
51 lines
1.5 KiB
C++
/*
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* Copyright (C) 2015 Cloudius Systems, Ltd.
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*
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*/
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#include "core/future.hh"
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#include "core/future-util.hh"
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#include "core/shared_ptr.hh"
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#include "core/do_with.hh"
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#include <seastar/core/align.hh>
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#include "types.hh"
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#include "sstables.hh"
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#include "utils/bloom_filter.hh"
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namespace sstables {
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future<> sstable::read_filter() {
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if (!has_component(sstable::component_type::Filter)) {
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_filter = std::make_unique<utils::filter::always_present_filter>();
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return make_ready_future<>();
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}
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return do_with(sstables::filter(), [this] (auto& filter) {
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return this->read_simple<sstable::component_type::Filter>(filter).then([this, &filter] {
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large_bitset bs(filter.buckets.elements.size() * 64);
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bs.load(filter.buckets.elements.begin(), filter.buckets.elements.end());
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_filter = utils::filter::create_filter(filter.hashes, std::move(bs));
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}).then([this] {
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return engine().file_size(this->filename(sstable::component_type::Filter));
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});
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}).then([this] (auto size) {
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_filter_file_size = size;
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});
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}
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void sstable::write_filter() {
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if (!has_component(sstable::component_type::Filter)) {
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return;
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}
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auto f = static_cast<utils::filter::murmur3_bloom_filter *>(_filter.get());
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auto&& bs = f->bits();
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std::deque<uint64_t> v(align_up(bs.size(), size_t(64)) / 64);
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bs.save(v.begin());
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auto filter = sstables::filter(f->num_hashes(), std::move(v));
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write_simple<sstable::component_type::Filter>(filter);
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}
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}
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