eb3b237e05
When allocating tablets for table for the frist time their initial count is calculated so that each shard in a cluster gets one tablet. It may happen that more than one initial tablet per shard is better, e.g. perf tests typically rely on that. It's possible to specify the initial tablets count when creating a keyspace, this number doesn't take the cluster topology into consideration and may also be not very nice. As a temporary solution (e.g. for perf tests) we may add a configurable that scales the initial number of calculated tablets by some factor Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
51 lines
1.8 KiB
C++
51 lines
1.8 KiB
C++
/*
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* Copyright (C) 2023-present ScyllaDB
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*/
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/*
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* SPDX-License-Identifier: AGPL-3.0-or-later
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*/
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#pragma once
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#include "locator/abstract_replication_strategy.hh"
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#include "exceptions/exceptions.hh"
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#include "locator/token_metadata.hh"
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#include "locator/tablets.hh"
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#include <seastar/core/sstring.hh>
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#include <optional>
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#include <set>
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#include <string_view>
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namespace locator {
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/// Trait class which allows replication strategies to work in a mode which
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/// uses tablet-based replication.
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///
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/// Contains common logic, like parsing tablet options,
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/// and creating effective_replication_map for a given table which works with
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/// system's tablet_metadata.
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class tablet_aware_replication_strategy : public per_table_replication_strategy {
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private:
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size_t _initial_tablets = 1;
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size_t parse_initial_tablets(const sstring&) const;
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protected:
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void validate_tablet_options(const abstract_replication_strategy&, const gms::feature_service&, const replication_strategy_config_options&) const;
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void process_tablet_options(abstract_replication_strategy&, replication_strategy_config_options&, replication_strategy_params);
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std::unordered_set<sstring> recognized_tablet_options() const;
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size_t get_initial_tablets() const { return _initial_tablets; }
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effective_replication_map_ptr do_make_replication_map(table_id,
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replication_strategy_ptr,
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token_metadata_ptr,
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size_t replication_factor) const;
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public:
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/// Generates tablet_map for a new table.
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/// Runs under group0 guard.
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virtual future<tablet_map> allocate_tablets_for_new_table(schema_ptr, token_metadata_ptr, unsigned initial_scale) const = 0;
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};
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} // namespace locator
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