• Icon: Bug Bug
    • Resolution: Fixed
    • Icon: Minor Minor
    • core
    • None
    • linux java8 x64,
      jenkins 2.176.1,
      workflow-durable-task-step 2.30
    • Jenkins 2.274 - released 5 Jan 2021 and 2.277.1

      Having a large number of offline executors causes massive slowdown in  hudson.model.Queue. The maintain method is holding the queue lock over 80% of the time in some cases.

      "AtmostOneTaskExecutor[Periodic Jenkins queue maintenance] 
         java.lang.Thread.State: RUNNABLE
              at org.jenkinsci.plugins.durabletask.executors.ContinuedTask$Scheduler.canTake(ContinuedTask.java:66)
              at hudson.model.Queue$JobOffer.getCauseOfBlockage(Queue.java:278)
              at hudson.model.Queue.maintain(Queue.java:1616)
              at hudson.model.Queue$1.call(Queue.java:325)
              at hudson.model.Queue$1.call(Queue.java:322)
      

      Steps to reproduce:

      1. install jenkins + job-dsl-plugin + matrix-project-plugin + ssh-slaves-plugin + workflow-durable-task-step (Pipeline: nodes and processes)
      2. create a ssh node with 500 executors, add some random labels "a b c d e f g h i"
      3. mark the node offline using configure->availability->"bring online according to schedule"
      4. create the jobs using job dsl below
      5. wait for the jobs to start, observe the sluggish queue, fire up jvisualvm to analyze
      configs = []
      for (int i = 0; i < 100; i++) {
        configs.add(String.valueOf(i))
      }
      
      for (int i = 0; i < 10; i++) {
        matrixJob("matrix-"+i) {
          axes {
            text('cfg', configs)
          }
          triggers {
            cron('* * * * *')
          }
          steps {
            shell('sleep 30')
          }
        }
      }
      

      It seems each "parked executor" causes a Queue$JobOffer to be created, which is turn triggers some getCauseOfBlockage analysis. This seems to do blockedItems * buildableItems operations which can get quite slow for a large job queue.

      How it was found: We have ~80 nodes with 10 executors each. We took half of them offline during a hardware migration. Soon our jobs filled the queue with 2000 items. Jenkins started timing out due to queue lock contention - a single maintain() call took around 60sec.

          [JENKINS-58101] jenkins slowdown with many offline nodes

          Märt Bakhoff created issue -
          Märt Bakhoff made changes -
          Description Original: Having a large number of offline executors causes massive slowdown in  hudson.model.Queue. The maintain method is holding the queue lock over 80% of the time in some cases.

          {noformat}
          "AtmostOneTaskExecutor[Periodic Jenkins queue maintenance]
             java.lang.Thread.State: RUNNABLE
                  at org.jenkinsci.plugins.durabletask.executors.ContinuedTask$Scheduler.canTake(ContinuedTask.java:66)
                  at hudson.model.Queue$JobOffer.getCauseOfBlockage(Queue.java:278)
                  at hudson.model.Queue.maintain(Queue.java:1616)
                  at hudson.model.Queue$1.call(Queue.java:325)
                  at hudson.model.Queue$1.call(Queue.java:322)
          {noformat}

          Steps to reproduce:
          #1) install jenkins + job-dsl-plugin + matrix-project-plugin + ssh-slaves-plugin + workflow-durable-task-step (Pipeline: nodes and processes)
          # create a ssh node with 500 executors
          # mark the node offline using configure->availability->"bring online according to schedule"
          # create the jobs using job dsl below
          # wait for the jobs to start, observe the sluggish queue, fire up jvisualvm to analyze

          {code}
          configs = []
          for (int i = 0; i < 100; i++) {
            configs.add(String.valueOf(i))
          }

          for (int i = 0; i < 10; i++) {
            matrixJob("matrix-"+i) {
              axes {
                text('cfg', configs)
              }
              triggers {
                cron('* * * * *')
              }
              steps {
                shell('sleep 30')
              }
            }
          }
          {code}

          It seems each "parked executor" causes a Queue$JobOffer to be created, which is turn triggers some getCauseOfBlockage analysis. This seems to do blockedItems * buildableItems operations which can get quite slow for a large job queue.

          How it was found: We have ~80 nodes with 10 executors each. We took half of them offline during a hardware migration. Soon our jobs filled the queue with 2000 items. Jenkins started timing out due to queue lock contention - a single maintain() call took around 60sec.
          New: Having a large number of offline executors causes massive slowdown in  hudson.model.Queue. The maintain method is holding the queue lock over 80% of the time in some cases.

          {noformat}
          "AtmostOneTaskExecutor[Periodic Jenkins queue maintenance]
             java.lang.Thread.State: RUNNABLE
                  at org.jenkinsci.plugins.durabletask.executors.ContinuedTask$Scheduler.canTake(ContinuedTask.java:66)
                  at hudson.model.Queue$JobOffer.getCauseOfBlockage(Queue.java:278)
                  at hudson.model.Queue.maintain(Queue.java:1616)
                  at hudson.model.Queue$1.call(Queue.java:325)
                  at hudson.model.Queue$1.call(Queue.java:322)
          {noformat}

          Steps to reproduce:
          # install jenkins + job-dsl-plugin + matrix-project-plugin + ssh-slaves-plugin + workflow-durable-task-step (Pipeline: nodes and processes)
          # create a ssh node with 500 executors
          # mark the node offline using configure->availability->"bring online according to schedule"
          # create the jobs using job dsl below
          # wait for the jobs to start, observe the sluggish queue, fire up jvisualvm to analyze

          {code}
          configs = []
          for (int i = 0; i < 100; i++) {
            configs.add(String.valueOf(i))
          }

          for (int i = 0; i < 10; i++) {
            matrixJob("matrix-"+i) {
              axes {
                text('cfg', configs)
              }
              triggers {
                cron('* * * * *')
              }
              steps {
                shell('sleep 30')
              }
            }
          }
          {code}

          It seems each "parked executor" causes a Queue$JobOffer to be created, which is turn triggers some getCauseOfBlockage analysis. This seems to do blockedItems * buildableItems operations which can get quite slow for a large job queue.

          How it was found: We have ~80 nodes with 10 executors each. We took half of them offline during a hardware migration. Soon our jobs filled the queue with 2000 items. Jenkins started timing out due to queue lock contention - a single maintain() call took around 60sec.
          Märt Bakhoff made changes -
          Link New: This issue relates to JENKINS-20046 [ JENKINS-20046 ]
          Märt Bakhoff made changes -
          Description Original: Having a large number of offline executors causes massive slowdown in  hudson.model.Queue. The maintain method is holding the queue lock over 80% of the time in some cases.

          {noformat}
          "AtmostOneTaskExecutor[Periodic Jenkins queue maintenance]
             java.lang.Thread.State: RUNNABLE
                  at org.jenkinsci.plugins.durabletask.executors.ContinuedTask$Scheduler.canTake(ContinuedTask.java:66)
                  at hudson.model.Queue$JobOffer.getCauseOfBlockage(Queue.java:278)
                  at hudson.model.Queue.maintain(Queue.java:1616)
                  at hudson.model.Queue$1.call(Queue.java:325)
                  at hudson.model.Queue$1.call(Queue.java:322)
          {noformat}

          Steps to reproduce:
          # install jenkins + job-dsl-plugin + matrix-project-plugin + ssh-slaves-plugin + workflow-durable-task-step (Pipeline: nodes and processes)
          # create a ssh node with 500 executors
          # mark the node offline using configure->availability->"bring online according to schedule"
          # create the jobs using job dsl below
          # wait for the jobs to start, observe the sluggish queue, fire up jvisualvm to analyze

          {code}
          configs = []
          for (int i = 0; i < 100; i++) {
            configs.add(String.valueOf(i))
          }

          for (int i = 0; i < 10; i++) {
            matrixJob("matrix-"+i) {
              axes {
                text('cfg', configs)
              }
              triggers {
                cron('* * * * *')
              }
              steps {
                shell('sleep 30')
              }
            }
          }
          {code}

          It seems each "parked executor" causes a Queue$JobOffer to be created, which is turn triggers some getCauseOfBlockage analysis. This seems to do blockedItems * buildableItems operations which can get quite slow for a large job queue.

          How it was found: We have ~80 nodes with 10 executors each. We took half of them offline during a hardware migration. Soon our jobs filled the queue with 2000 items. Jenkins started timing out due to queue lock contention - a single maintain() call took around 60sec.
          New: Having a large number of offline executors causes massive slowdown in  hudson.model.Queue. The maintain method is holding the queue lock over 80% of the time in some cases.

          {noformat}
          "AtmostOneTaskExecutor[Periodic Jenkins queue maintenance]
             java.lang.Thread.State: RUNNABLE
                  at org.jenkinsci.plugins.durabletask.executors.ContinuedTask$Scheduler.canTake(ContinuedTask.java:66)
                  at hudson.model.Queue$JobOffer.getCauseOfBlockage(Queue.java:278)
                  at hudson.model.Queue.maintain(Queue.java:1616)
                  at hudson.model.Queue$1.call(Queue.java:325)
                  at hudson.model.Queue$1.call(Queue.java:322)
          {noformat}

          Steps to reproduce:
          # install jenkins + job-dsl-plugin + matrix-project-plugin + ssh-slaves-plugin + workflow-durable-task-step (Pipeline: nodes and processes)
          # create a ssh node with 500 executors, add some random labels "a b c d e f g h i"
          # mark the node offline using configure->availability->"bring online according to schedule"
          # create the jobs using job dsl below
          # wait for the jobs to start, observe the sluggish queue, fire up jvisualvm to analyze

          {code}
          configs = []
          for (int i = 0; i < 100; i++) {
            configs.add(String.valueOf(i))
          }

          for (int i = 0; i < 10; i++) {
            matrixJob("matrix-"+i) {
              axes {
                text('cfg', configs)
              }
              triggers {
                cron('* * * * *')
              }
              steps {
                shell('sleep 30')
              }
            }
          }
          {code}

          It seems each "parked executor" causes a Queue$JobOffer to be created, which is turn triggers some getCauseOfBlockage analysis. This seems to do blockedItems * buildableItems operations which can get quite slow for a large job queue.

          How it was found: We have ~80 nodes with 10 executors each. We took half of them offline during a hardware migration. Soon our jobs filled the queue with 2000 items. Jenkins started timing out due to queue lock contention - a single maintain() call took around 60sec.
          Raihaan Shouhell made changes -
          Assignee New: Raihaan Shouhell [ raihaan ]
          Raihaan Shouhell made changes -
          Status Original: Open [ 1 ] New: In Progress [ 3 ]
          Raihaan Shouhell made changes -
          Status Original: In Progress [ 3 ] New: In Review [ 10005 ]
          Raihaan Shouhell made changes -
          Remote Link New: This issue links to "PR-5082 (Web Link)" [ 26340 ]
          Mark Waite made changes -
          Released As New: Jenkins 2.274 - released 5 Jan 2021
          Resolution New: Fixed [ 1 ]
          Status Original: In Review [ 10005 ] New: Closed [ 6 ]
          Mark Waite made changes -
          Released As Original: Jenkins 2.274 - released 5 Jan 2021 New: Jenkins 2.274 - released 5 Jan 2021 and 2.277.1

            raihaan Raihaan Shouhell
            mbakhoff Märt Bakhoff
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            0 Vote for this issue
            Watchers:
            2 Start watching this issue

              Created:
              Updated:
              Resolved: