lazy loading build inside queue lock

[Surya Gaddipati]

Seems like jenkins lazy loads builds inside a queue lock which in turn freezes jenkins because so many places inside jenkins try to lock queue. 

Is recommended to force lazyload on *all* jobs after jenkins startup to avoid this kind of scenario ? 

hudson.util.XStream2.unmarshal(XStream2.java:114)

com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1173)

hudson.XmlFile.unmarshal(XmlFile.java:158)

hudson.model.Run.reload(Run.java:329)

hudson.model.Run.<init>(Run.java:317)

hudson.model.AbstractBuild.<init>(AbstractBuild.java:175)

hudson.model.Build.<init>(Build.java:103)

hudson.model.FreeStyleBuild.<init>(FreeStyleBuild.java:38)

sun.reflect.GeneratedConstructorAccessor250.newInstance(Unknown Source)

sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)

java.lang.reflect.Constructor.newInstance(Constructor.java:422)

jenkins.model.lazy.LazyBuildMixIn.loadBuild(LazyBuildMixIn.java:165)

jenkins.model.lazy.LazyBuildMixIn$1.create(LazyBuildMixIn.java:142)

hudson.model.RunMap.retrieve(RunMap.java:223)

hudson.model.RunMap.retrieve(RunMap.java:56)

jenkins.model.lazy.AbstractLazyLoadRunMap.load(AbstractLazyLoadRunMap.java:500)

jenkins.model.lazy.AbstractLazyLoadRunMap.load(AbstractLazyLoadRunMap.java:482)

jenkins.model.lazy.AbstractLazyLoadRunMap.getByNumber(AbstractLazyLoadRunMap.java:380)

jenkins.model.lazy.AbstractLazyLoadRunMap.search(AbstractLazyLoadRunMap.java:345)

jenkins.model.lazy.LazyBuildMixIn$RunMixIn.getPreviousBuild(LazyBuildMixIn.java:362)

hudson.model.AbstractBuild.getPreviousBuild(AbstractBuild.java:196)

hudson.model.AbstractBuild.getPreviousBuild(AbstractBuild.java:105)

hudson.model.Job.getEstimatedDurationCandidates(Job.java:1019)

hudson.model.Job.getEstimatedDuration(Job.java:1033)

hudson.model.queue.MappingWorksheet.<init>(MappingWorksheet.java:334)

hudson.model.queue.MappingWorksheet.<init>(MappingWorksheet.java:317)

hudson.model.Queue.maintain(Queue.java:1525)

hudson.model.Queue$1.call(Queue.java:294)

hudson.model.Queue$1.call(Queue.java:291)

jenkins.util.AtmostOneTaskExecutor$1.call(AtmostOneTaskExecutor.java:101)

jenkins.util.AtmostOneTaskExecutor$1.call(AtmostOneTaskExecutor.java:91)

[Oliver Gondža]

On 2017-01-19 01:53, Surya Gaddipati wrote:
> Seems like jenkins lazy loads builds inside a queue lock which in turn
> freezes jenkins because so many places inside jenkins try to lock queue.
>
> Is recommended to force lazyload on *all* jobs after jenkins startup to
> avoid this kind of scenario ?

That would not be lazy loading then. Though, I agree this can be a pain.
Note that you can at lease prevent constant re-loading using
`jenkins.model.lazy.BuildReference.MODE`
(https://issues.jenkins-ci.org/browse/JENKINS-19400).

--
oliver

[Surya Gaddipati]

Hi oliver, 

Yes thats the downside of 'preloading' but it would prevent Jenkins from completely freezing at unexpected times . 

There was some talk of writing lock free implementation of queue.  Wondering if  that is still on cards . 

[Jesse Glick]

On Wed, Jan 18, 2017 at 7:53 PM, Surya Gaddipati
<suryap...@gmail.com> wrote:
> jenkins.model.lazy.LazyBuildMixIn$RunMixIn.getPreviousBuild(LazyBuildMixIn.java:362)
> hudson.model.AbstractBuild.getPreviousBuild(AbstractBuild.java:196)
> hudson.model.AbstractBuild.getPreviousBuild(AbstractBuild.java:105)
> hudson.model.Job.getEstimatedDurationCandidates(Job.java:1019)
> hudson.model.Job.getEstimatedDuration(Job.java:1033)

Probably `getEstimatedDurationCandidates` should limit itself to
builds which have already been loaded anyway.