Question

My Rails 4.1应用程序使用Sidekiq在Celluloid actor中运行测量。它不断耗尽数据库连接。看来Sidekiq每个作业打开2个连接，旧连接永远不能正常关闭。

系统做什么

每15分钟，我开始MeasurementWorker。致电MeasurementWorker.perform_async(measurement.id)。它这样做：

    class MeasurementWorker
      include Sidekiq::Worker
      sidekiq_options retry: false, backtrace: true

      def perform(measurement_id, force = false)
        ActiveRecord::Base.connection_pool.with_connection do
            Measurement.find(measurement_id).run
        end
      end
    end

在此测量中，当我拨打.run时，它会执行此操作：

    # various checks if measurement can be run at all, using AR
    # ...
    begin
      ActiveRecord::Base.connection_pool.with_connection do
      # (I used to have a Timeout.timeout here, but removed it for the
      # sake of simplification)
        @connection = MeasurementConnection.new do |event_info|
          event = Event.new
          event.assign_attributes(event_info)
          event.save
        end
        while @connection.measuring?; end
      end # with_connection
    rescue Exception => e
      # an exception happened, e.g. something during the measurement itself
      # log error (left out here for brevity)
    else
      # all went fine, 
      # save this measurement via AR
    ensure
      # Close and terminate the actor to free up the websocket,
      # if it is still actively measuring something.
      if @connection
        if @connection.alive? and @connection.measuring?
          @connection.close
        end
        while @connection.alive?
          @connection.terminate
          sleep(0.01)
        end
      end
    end

MeasurementConnection是一个简单的赛璐珞演员。此actor中没有与AR相关的代码。

配置

Unicorn：并发设置为3
Sidekiq 3.3.0：并发设置为50，并在初始化程序中：

    Sidekiq.configure_server do |config|
      if defined?(ActiveRecord::Base)
        config = Rails.application.config.database_configuration[Rails.env]
        config['pool']              = Sidekiq.options[:concurrency] + 2
        config['reaping_frequency'] = ENV['DB_REAP_FREQ'] || 5
        ActiveRecord::Base.establish_connection(config)
      end
    end

database.yml：池设置为60，收获频率为5
PostgreSQL 9.3：最大连接数为2000，没有其他修改

问题：打开的连接太多

当我检查SELECT * FROM pg_stat_activity;时，我发现有一些旧的连接打开，没有Sidekiq工作人员忙着，还有一些新的地方：

16661 measurement 6354  16384 measurement unicorn worker[0] -c /home/web...E production -D -l0.0.0.0:8080 127.0.0.1   50775 2015-02-20 12:52:48.572551+01   2015-02-20 13:05:05.773178+01 2015-02-20 13:05:05.773565+01 f idle  SELECT COUNT(*) FROM "measurements"
16661 measurement 6406  16384 measurement unicorn worker[2] -c /home/web...E production -D -l0.0.0.0:8080 127.0.0.1   50776 2015-02-20 12:53:59.636414+01   2015-02-20 13:04:53.930305+01 2015-02-20 13:04:53.931+01  f idle  SELECT COUNT(*) FROM "measurements"
16661 measurement 6687  16384 measurement sidekiq 3.3.0 measurement [0 of 50 busy]  127.0.0.1   50801 2015-02-20 13:00:05.14621+01    2015-02-20 13:04:49.558589+01 2015-02-20 13:04:49.558835+01 f idle  COMMIT
16661 measurement 7042  16384 measurement unicorn worker[1] -c /home/web...E production -D -l0.0.0.0:8080 127.0.0.1   50997 2015-02-20 13:00:34.874675+01   2015-02-20 13:00:35.376593+01 2015-02-20 13:00:35.376979+01 f idle  SELECT COUNT(*) FROM "measurements"
16661 measurement 6668  16384 measurement sidekiq 3.3.0 measurement [0 of 50 busy]  127.0.0.1   50781 2015-02-20 13:00:04.883553+01   2015-02-20 13:04:19.108365+01 2015-02-20 13:04:19.108567+01 f idle  COMMIT
16661 measurement 6669  16384 measurement sidekiq 3.3.0 measurement [0 of 50 busy]  127.0.0.1   50782 2015-02-20 13:00:04.908349+01   2015-02-20 13:03:57.683036+01 2015-02-20 13:03:57.683236+01 f idle  COMMIT
16661 measurement 6672  16384 measurement sidekiq 3.3.0 measurement [0 of 50 busy]  127.0.0.1   50786 2015-02-20 13:00:04.962251+01   2015-02-20 13:04:32.395137+01 2015-02-20 13:04:32.395344+01 f idle  COMMIT
16661 measurement 6674  16384 measurement sidekiq 3.3.0 measurement [0 of 50 busy]  127.0.0.1   50788 2015-02-20 13:00:04.98456+01    2015-02-20 13:04:32.396335+01 2015-02-20 13:04:32.39652+01  f idle  COMMIT
16661 measurement 6676  16384 measurement sidekiq 3.3.0 measurement [0 of 50 busy]  127.0.0.1   50790 2015-02-20 13:00:05.006847+01   2015-02-20 13:04:19.059628+01 2015-02-20 13:04:19.059831+01 f idle  COMMIT
16661 measurement 6678  16384 measurement sidekiq 3.3.0 measurement [0 of 50 busy]  127.0.0.1   50792 2015-02-20 13:00:05.029448+01   2015-02-20 13:04:23.730293+01 2015-02-20 13:04:23.730523+01 f idle  COMMIT
16661 measurement 6680  16384 measurement sidekiq 3.3.0 measurement [0 of 50 busy]  127.0.0.1   50794 2015-02-20 13:00:05.051932+01   2015-02-20 13:04:49.557435+01 2015-02-20 13:04:49.557633+01 f idle  COMMIT
16661 measurement 6684  16384 measurement sidekiq 3.3.0 measurement [0 of 50 busy]  127.0.0.1   50798 2015-02-20 13:00:05.124225+01   2015-02-20 13:03:51.693799+01 2015-02-20 13:03:51.694034+01 f idle  COMMIT
16661 measurement 6690  16384 measurement sidekiq 3.3.0 measurement [0 of 50 busy]  127.0.0.1   50804 2015-02-20 13:00:05.168099+01   2015-02-20 13:04:54.849239+01 2015-02-20 13:04:54.849459+01 f idle  COMMIT
16661 measurement 6693  16384 measurement sidekiq 3.3.0 measurement [0 of 50 busy]  127.0.0.1   50807 2015-02-20 13:00:05.189661+01   2015-02-20 13:04:18.688459+01 2015-02-20 13:04:18.688732+01 f idle  COMMIT
16661 measurement 6696  16384 measurement sidekiq 3.3.0 measurement [0 of 50 busy]  127.0.0.1   50810 2015-02-20 13:00:05.210659+01   2015-02-20 13:03:57.68424+01  2015-02-20 13:03:57.684483+01 f idle  COMMIT
16661 measurement 6699  16384 measurement sidekiq 3.3.0 measurement [0 of 50 busy]  127.0.0.1   50813 2015-02-20 13:00:05.231641+01   2015-02-20 13:04:04.962397+01 2015-02-20 13:04:04.96258+01  f idle  COMMIT
16661 measurement 6701  16384 measurement sidekiq 3.3.0 measurement [0 of 50 busy]  127.0.0.1   50815 2015-02-20 13:00:05.252357+01   2015-02-20 13:04:41.685372+01 2015-02-20 13:04:41.685594+01 f idle  COMMIT
16661 measurement 6706  16384 measurement sidekiq 3.3.0 measurement [0 of 50 busy]  127.0.0.1   50820 2015-02-20 13:00:05.273301+01   2015-02-20 13:04:23.733488+01 2015-02-20 13:04:23.733681+01 f idle  COMMIT
16661 measurement 7003  16384 measurement sidekiq 3.3.0 measurement [15 of 50 busy] 127.0.0.1   50967 2015-02-20 13:00:09.004487+01   2015-02-20 13:02:02.036429+01 2015-02-20 13:02:02.036696+01 f idle  COMMIT
16661 measurement 7005  16384 measurement sidekiq 3.3.0 measurement [15 of 50 busy] 127.0.0.1   50969 2015-02-20 13:00:11.118961+01   2015-02-20 13:02:48.341078+01 2015-02-20 13:02:48.341294+01 f idle  COMMIT
16661 measurement 7006  16384 measurement sidekiq 3.3.0 measurement [15 of 50 busy] 127.0.0.1   50970 2015-02-20 13:00:12.245408+01   2015-02-20 13:03:04.300372+01 2015-02-20 13:03:04.300575+01 f idle  COMMIT
16661 measurement 7007  16384 measurement sidekiq 3.3.0 measurement [15 of 50 busy] 127.0.0.1   50971 2015-02-20 13:00:12.648636+01   2015-02-20 13:03:01.855616+01 2015-02-20 13:03:01.85588+01  f idle  COMMIT
16661 measurement 7008  16384 measurement sidekiq 3.3.0 measurement [15 of 50 busy] 127.0.0.1   50972 2015-02-20 13:00:12.956139+01   2015-02-20 13:03:13.840023+01 2015-02-20 13:03:13.840466+01 f idle  COMMIT
16661 measurement 7009  16384 measurement sidekiq 3.3.0 measurement [15 of 50 busy] 127.0.0.1   50973 2015-02-20 13:00:13.02424+01    2015-02-20 13:02:50.115996+01 2015-02-20 13:02:50.116259+01 f idle  COMMIT
16661 measurement 7010  16384 measurement sidekiq 3.3.0 measurement [15 of 50 busy] 127.0.0.1   50974 2015-02-20 13:00:13.0909+01   2015-02-20 13:03:09.968+01  2015-02-20 13:03:09.968284+01 f idle  COMMIT
16661 measurement 7014  16384 measurement sidekiq 3.3.0 measurement [15 of 50 busy] 127.0.0.1   50976 2015-02-20 13:00:14.929822+01   2015-02-20 13:03:20.183195+01 2015-02-20 13:03:20.183467+01 f idle  COMMIT
16661 measurement 7020  16384 measurement sidekiq 3.3.0 measurement [15 of 50 busy] 127.0.0.1   50980 2015-02-20 13:00:22.498892+01   2015-02-20 13:03:29.887257+01 2015-02-20 13:03:29.887599+01 f idle  COMMIT
16661 measurement 7021  16384 measurement sidekiq 3.3.0 measurement [15 of 50 busy] 127.0.0.1   50981 2015-02-20 13:00:22.898087+01   2015-02-20 13:03:39.689939+01 2015-02-20 13:03:39.69798+01  f idle  COMMIT
16661 measurement 7022  16384 measurement sidekiq 3.3.0 measurement [15 of 50 busy] 127.0.0.1   50982 2015-02-20 13:00:23.215846+01   2015-02-20 13:03:03.918339+01 2015-02-20 13:03:03.918613+01 f idle  COMMIT
16661 measurement 7023  16384 measurement sidekiq 3.3.0 measurement [15 of 50 busy] 127.0.0.1   50983 2015-02-20 13:00:23.930861+01   2015-02-20 13:03:51.504525+01 2015-02-20 13:03:51.512786+01 f idle  COMMIT
16661 measurement 7025  16384 measurement sidekiq 3.3.0 measurement [15 of 50 busy] 127.0.0.1   50985 2015-02-20 13:00:24.409999+01   2015-02-20 13:03:16.000375+01 2015-02-20 13:03:16.006178+01 f idle  COMMIT
16661 measurement 7027  16384 measurement sidekiq 3.3.0 measurement [15 of 50 busy] 127.0.0.1   50986 2015-02-20 13:00:25.786321+01   2015-02-20 13:03:22.631091+01 2015-02-20 13:03:22.631353+01 f idle  COMMIT
16661 measurement 7045  16384 measurement sidekiq 3.3.0 measurement [15 of 50 busy] 127.0.0.1   50998 2015-02-20 13:00:48.004036+01   2015-02-20 13:03:39.717124+01 2015-02-20 13:03:39.722956+01 f idle  COMMIT

总共有34个连接，但我只进行了15次测量。

在sidekiq.log中，它们都显示为已完成：

2015-02-20T12:00:04.879Z 6235 TID-osgop8md0 MeasurementWorker JID-1cdcd44bf41fefe9ddca21ac INFO: start
2015-02-20T12:00:04.907Z 6235 TID-osgoox8hg MeasurementWorker JID-79f4d1ff6692248682ba93dd INFO: start
2015-02-20T12:00:04.939Z 6235 TID-osgoos38k MeasurementWorker JID-09f95fbccd2438d17916d425 INFO: start
2015-02-20T12:00:04.940Z 6235 TID-osgoorlmo MeasurementWorker JID-be1a57871f26146e9884107e INFO: start
2015-02-20T12:00:04.959Z 6235 TID-osgoow16k MeasurementWorker JID-e296efec897c23629b96e99f INFO: start
2015-02-20T12:00:04.968Z 6235 TID-osgoouytg MeasurementWorker JID-c6a57700872b7fe427e33664 INFO: start
2015-02-20T12:00:04.984Z 6235 TID-osgooz63k MeasurementWorker JID-f7448eaffe109882130497ca INFO: start
2015-02-20T12:00:04.998Z 6235 TID-osgoozvzs MeasurementWorker JID-c55c04f3424268fba50ec048 INFO: start
2015-02-20T12:00:05.014Z 6235 TID-osgooyr6c MeasurementWorker JID-01bd303e953fd2998fe3f8d1 INFO: start
2015-02-20T12:00:05.030Z 6235 TID-osgon0ums MeasurementWorker JID-6949c5c81b4c254046f0c585 INFO: start
2015-02-20T12:00:05.042Z 6235 TID-osgomw0g8 MeasurementWorker JID-cc03b717f81dd6fb0f58a946 INFO: start
2015-02-20T12:00:05.111Z 6235 TID-osgomlno8 MeasurementWorker JID-10eebcd76113f3565d8265ca INFO: start
2015-02-20T12:00:05.113Z 6235 TID-osgomjzzw MeasurementWorker JID-b0536d9a029faed0ba8eb5d3 INFO: start
2015-02-20T12:00:05.114Z 6235 TID-osgomhyms MeasurementWorker JID-1f6624314afd8e0ae611599f INFO: start
2015-02-20T12:00:05.115Z 6235 TID-osgolgzoc MeasurementWorker JID-24e87960d7e7fbd871037dd3 INFO: start
2015-02-20T12:02:02.333Z 6235 TID-osgomw0g8 MeasurementWorker JID-cc03b717f81dd6fb0f58a946 INFO: done: 117.291 sec
2015-02-20T12:02:48.983Z 6235 TID-osgoox8hg MeasurementWorker JID-79f4d1ff6692248682ba93dd INFO: done: 164.077 sec
2015-02-20T12:02:50.688Z 6235 TID-osgomlno8 MeasurementWorker JID-10eebcd76113f3565d8265ca INFO: done: 165.577 sec
2015-02-20T12:03:02.429Z 6235 TID-osgolgzoc MeasurementWorker JID-24e87960d7e7fbd871037dd3 INFO: done: 177.314 sec
2015-02-20T12:03:04.581Z 6235 TID-osgoorlmo MeasurementWorker JID-be1a57871f26146e9884107e INFO: done: 179.641 sec
2015-02-20T12:03:09.453Z 6235 TID-osgop8md0 MeasurementWorker JID-1cdcd44bf41fefe9ddca21ac INFO: done: 184.573 sec
2015-02-20T12:03:10.362Z 6235 TID-osgoouytg MeasurementWorker JID-c6a57700872b7fe427e33664 INFO: done: 185.394 sec
2015-02-20T12:03:14.232Z 6235 TID-osgomjzzw MeasurementWorker JID-b0536d9a029faed0ba8eb5d3 INFO: done: 189.118 sec
2015-02-20T12:03:16.347Z 6235 TID-osgoos38k MeasurementWorker JID-09f95fbccd2438d17916d425 INFO: done: 191.408 sec
2015-02-20T12:03:20.398Z 6235 TID-osgoow16k MeasurementWorker JID-e296efec897c23629b96e99f INFO: done: 195.439 sec
2015-02-20T12:03:22.947Z 6235 TID-osgomhyms MeasurementWorker JID-1f6624314afd8e0ae611599f INFO: done: 197.833 sec
2015-02-20T12:03:30.212Z 6235 TID-osgooz63k MeasurementWorker JID-f7448eaffe109882130497ca INFO: done: 205.228 sec
2015-02-20T12:03:39.931Z 6235 TID-osgooyr6c MeasurementWorker JID-01bd303e953fd2998fe3f8d1 INFO: done: 214.918 sec
2015-02-20T12:03:39.936Z 6235 TID-osgon0ums MeasurementWorker JID-6949c5c81b4c254046f0c585 INFO: done: 214.906 sec
2015-02-20T12:03:51.694Z 6235 TID-osgoozvzs MeasurementWorker JID-c55c04f3424268fba50ec048 INFO: done: 226.696 sec

因此，对于每次测量，Sidekiq似乎打开2个连接，但它永远不会关闭它们。我该怎么办？

Answer 1

问题是你的赛璐珞演员正在泄漏连接：当你在新线程中做一些需要活动记录连接的事情时（或者甚至更精细），AR会自动检出连接，但不会自动检查它。 / p>

如果您使用

括起数据库访问代码

ActiveRecord::Base.connection_pool.with_connection do
  # do stuff
end

应该清除在其中创建的任何连接（就像你在sidekiq工作中那样）。

或者，您可以尝试明确检出连接

@connection = ActiveRecord::Base.connection_pool.checkout

然后在你的终结器中重新检入

ActiveRecord::Base.connection_pool.checkin @connection

如果你的演员很长寿，你可能最终会比你需要的时间更长时间地占用连接（另一方面是：在一个紧密的循环中检查连接是否效率低）

Answer 2

删除Timeout.timeout，不要使用该API。使用with_connection。 Timeout.timeout非常破坏并在内部旋转它自己的线程，这就是为什么你的with_connection没有工作，连接仍在泄漏。

Answer 3

我最近和sidekiq合作并做了这个：

def perform(bulk_query)
  ActiveRecord::Base.connection_pool.with_connection do |connection|
   connection.execute(bulk_query)
  end
ensure
 # We make sure sidekiq closes the ActiveRecord connection
 ActiveRecord::Base.clear_active_connections!
 ActiveRecord::Base.connection.close
end

这对我很有用！

为什么Sidekiq没有关闭旧连接？

系统做什么

配置

问题：打开的连接太多

3 个答案: