Files
scylladb/utils/compaction_manager.hh
Raphael S. Carvalho 74415f2772 compaction_manager: add stats for API
Signed-off-by: Raphael S. Carvalho <raphaelsc@cloudius-systems.com>
2015-08-12 15:10:24 -03:00

70 lines
2.1 KiB
C++

/*
* Copyright (C) 2015 Cloudius Systems, Ltd.
*/
#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 <queue>
#include <vector>
#include <functional>
// 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;
};
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));
// Compaction job being currently executed.
std::function<future<> ()> current_compaction_job;
};
// compaction manager may have N fibers to allow parallel compaction per shard.
std::vector<lw_shared_ptr<task>> _tasks;
// Job queue shared among all tasks.
std::queue<std::function<future<> ()>> _compaction_jobs;
// Used to assert that compaction_manager was explicitly stopped, if started.
bool _stopped = true;
stats _stats;
private:
void task_start(lw_shared_ptr<task>& task);
future<> task_stop(lw_shared_ptr<task>& task);
public:
compaction_manager();
~compaction_manager();
// 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 compaction job to a fiber with the lowest amount of pending jobs.
void submit(std::function<future<> ()> compaction_job);
const stats& get_stats() const {
return _stats;
}
};