Files
scylladb/utils/compaction_manager.hh
Raphael S. Carvalho ce855577b6 add compaction stats to collectd
With this change, we can see the number and length of compaction
activity per shard from collectd.

Signed-off-by: Raphael S. Carvalho <raphaelsc@cloudius-systems.com>
2015-09-24 16:51:11 +02:00

99 lines
3.1 KiB
C++

/*
* Copyright (C) 2015 Cloudius Systems, Ltd.
*/
/*
* This file is part of Scylla.
*
* Scylla is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Scylla is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include "core/semaphore.hh"
#include "core/sstring.hh"
#include "core/shared_ptr.hh"
#include "core/gate.hh"
#include "log.hh"
#include "utils/exponential_backoff_retry.hh"
#include <deque>
#include <vector>
#include <functional>
class column_family;
// Compaction manager is a feature used to manage compaction jobs from multiple
// column families pertaining to the same database.
// For each compaction job handler, there will be one fiber that will check for
// jobs, and if any, run it. FIFO ordering is implemented here.
class compaction_manager {
public:
struct stats {
int64_t pending_tasks = 0;
int64_t completed_tasks = 0;
uint64_t active_tasks = 0; // Number of compaction going on.
};
private:
struct task {
future<> compaction_done = make_ready_future<>();
semaphore compaction_sem = semaphore(0);
seastar::gate compaction_gate;
exponential_backoff_retry compaction_retry = exponential_backoff_retry(std::chrono::seconds(5), std::chrono::seconds(300));
// CF being currently compacted.
column_family* compacting_cf = nullptr;
bool stopping = false;
};
// compaction manager may have N fibers to allow parallel compaction per shard.
std::vector<lw_shared_ptr<task>> _tasks;
// Queue shared among all tasks containing all column families to be compacted.
std::deque<column_family*> _cfs_to_compact;
// Used to assert that compaction_manager was explicitly stopped, if started.
bool _stopped = true;
stats _stats;
std::vector<scollectd::registration> _registrations;
private:
void task_start(lw_shared_ptr<task>& task);
future<> task_stop(lw_shared_ptr<task>& task);
void add_column_family(column_family* cf);
public:
compaction_manager();
~compaction_manager();
void register_collectd_metrics();
// Creates N fibers that will allow N compaction jobs to run in parallel.
// Defaults to only one fiber.
void start(int task_nr = 1);
// Stop all fibers. Ongoing compactions will be waited.
future<> stop();
// Submit a column family to be compacted.
void submit(column_family* cf);
// Remove a column family from the compaction manager.
// Cancel requests on cf and wait for a possible ongoing compaction on cf.
future<> remove(column_family* cf);
const stats& get_stats() const {
return _stats;
}
};