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  1. Jenkins
  2. JENKINS-46460

Performance issue in AsyncResourceDisposer.persist

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      A thread dump of a Jenkins system suffering very poor performance showed many threads blocked in AsyncResourceDisposer.persist, here:

      "Computer.threadPoolForRemoting [#...]" ... waiting for monitor entry [...]
         java.lang.Thread.State: BLOCKED (on object monitor)
      	at com.thoughtworks.xstream.core.DefaultConverterLookup.lookupConverterForType(DefaultConverterLookup.java:49)
      	- waiting to lock <...> (a com.thoughtworks.xstream.core.DefaultConverterLookup)
      	at com.thoughtworks.xstream.XStream$1.lookupConverterForType(XStream.java:498)
      	at ...
      	at com.thoughtworks.xstream.XStream.toXML(XStream.java:988)
      	at hudson.XmlFile.write(XmlFile.java:170)
      	at org.jenkinsci.plugins.resourcedisposer.AsyncResourceDisposer.persist(AsyncResourceDisposer.java:175)
      	at org.jenkinsci.plugins.resourcedisposer.AsyncResourceDisposer.access$300(AsyncResourceDisposer.java:65)
      	at org.jenkinsci.plugins.resourcedisposer.AsyncResourceDisposer$WorkItem.run(AsyncResourceDisposer.java:262)
      	at ...
      

      This is written poorly and causing massive contention on a single lock in XStream; it should be coalescing calls to persist, and preferably even delaying them by a few seconds' grace period to try to batch up as much as possible.

      The workaround is to remove this plugin. It is typically used by ws-cleanup; better to, say, use the CleanBeforeCheckout option in Git.

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            jglick Jesse Glick added a comment -

            Problem likely aggravated by locks from JENKINS-19561.

            jglick Jesse Glick added a comment - Problem likely aggravated by locks from  JENKINS-19561 .
            jglick Jesse Glick added a comment -

            After some digging, found another case of a system with >4k threads blocked in this way.

            jglick Jesse Glick added a comment - After some digging, found another case of a system with >4k threads blocked in this way.

            Another approach would be to avoid persisting when the lastState have not changed after dispose was called.

            olivergondza Oliver Gondža added a comment - Another approach would be to avoid persisting when the lastState have not changed after dispose was called.

            After second though, I do not think the the benefit of having the lastState persisted reliably is worth the price. It was excluded from the persistence altogether (comment indicated I wanted to do that a long time ago) and every run of WorkItem does not initiate save any longer.

            olivergondza Oliver Gondža added a comment - After second though, I do not think the the benefit of having the lastState persisted reliably is worth the price. It was excluded from the persistence altogether (comment indicated I wanted to do that a long time ago) and every run of WorkItem does not initiate save any longer.

            Released on 0.8.

            olivergondza Oliver Gondža added a comment - Released on 0.8.

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              olivergondza Oliver Gondža
              jglick Jesse Glick
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                Updated:
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