mastodon/app/lib/connection_pool/shared_timed_stack.rb
Eugen Rochko 0d9ffe56fb
Add request pool to improve delivery performance (#10353)
* Add request pool to improve delivery performance

Fix #7909

* Ensure connection is closed when exception interrupts execution

* Remove Timeout#timeout from socket connection

* Fix infinite retrial loop on HTTP::ConnectionError

* Close sockets on failure, reduce idle time to 90 seconds

* Add MAX_REQUEST_POOL_SIZE option to limit concurrent connections to the same server

* Use a shared pool size, 512 by default, to stay below open file limit

* Add some tests

* Add more tests

* Reduce MAX_IDLE_TIME from 90 to 30 seconds, reap every 30 seconds

* Use a shared pool that returns preferred connection but re-purposes other ones when needed

* Fix wrong connection being returned on subsequent calls within the same thread

* Reduce mutex calls on flushes from 2 to 1 and add test for reaping
2019-07-02 00:34:38 +02:00

95 lines
2.1 KiB
Ruby

# frozen_string_literal: true
class ConnectionPool::SharedTimedStack
def initialize(max = 0, &block)
@create_block = block
@max = max
@created = 0
@queue = []
@tagged_queue = Hash.new { |hash, key| hash[key] = [] }
@mutex = Mutex.new
@resource = ConditionVariable.new
end
def push(connection)
@mutex.synchronize do
store_connection(connection)
@resource.broadcast
end
end
alias << push
def pop(preferred_tag, timeout = 5.0)
deadline = current_time + timeout
@mutex.synchronize do
loop do
return fetch_preferred_connection(preferred_tag) unless @tagged_queue[preferred_tag].empty?
connection = try_create(preferred_tag)
return connection if connection
to_wait = deadline - current_time
raise Timeout::Error, "Waited #{timeout} sec" if to_wait <= 0
@resource.wait(@mutex, to_wait)
end
end
end
def empty?
size.zero?
end
def size
@mutex.synchronize do
@queue.size
end
end
def flush
@mutex.synchronize do
@queue.delete_if do |connection|
delete = !connection.in_use && (connection.dead || connection.seconds_idle >= RequestPool::MAX_IDLE_TIME)
if delete
@tagged_queue[connection.site].delete(connection)
connection.close
@created -= 1
end
delete
end
end
end
private
def try_create(preferred_tag)
if @created == @max && !@queue.empty?
throw_away_connection = @queue.pop
@tagged_queue[throw_away_connection.site].delete(throw_away_connection)
@create_block.call(preferred_tag)
elsif @created != @max
connection = @create_block.call(preferred_tag)
@created += 1
connection
end
end
def fetch_preferred_connection(preferred_tag)
connection = @tagged_queue[preferred_tag].pop
@queue.delete(connection)
connection
end
def current_time
Process.clock_gettime(Process::CLOCK_MONOTONIC)
end
def store_connection(connection)
@tagged_queue[connection.site].push(connection)
@queue.push(connection)
end
end