Issue
Accessing graphs on a Build History Trend page can cause Jenkins to become unresponsive

This is being manifested on:
-
At Browser, it can been seen at
HTTP 503 Service unavailable
. -
Jenkins is unresponsive but still running and cannot login via browser.
-
In Thread Dumps, it can been seen Requests containing /timeline/data/ as
BLOCKED
. For instance something similar to:
"Handling POST /view/Builds/timeline/data/ from example.com : ajp-bio-127.0.0.1-9009-exec-57" Id=7549 BLOCKED on hudson.model.RunMap@197b81f7 owned by "Handling POST /view/Builds/timeline/data/ from example.com : ajp-bio-127.0.0.1-9009-exec-28" Id=203 at jenkins.model.lazy.AbstractLazyLoadRunMap.getByNumber(AbstractLazyLoadRunMap.java:356) - blocked on hudson.model.RunMap@197b81f7 at jenkins.model.lazy.AbstractLazyLoadRunMap.search(AbstractLazyLoadRunMap.java:332) at jenkins.model.lazy.AbstractLazyLoadRunMap.newestBuild(AbstractLazyLoadRunMap.java:274) at jenkins.model.lazy.LazyLoadRunMapEntrySet$1.<init>(LazyLoadRunMapEntrySet.java:65) at jenkins.model.lazy.LazyLoadRunMapEntrySet.iterator(LazyLoadRunMapEntrySet.java:63) at java.util.AbstractMap$2$1.<init>(AbstractMap.java:389) at java.util.AbstractMap$2.iterator(AbstractMap.java:388) at hudson.util.RunList.iterator(RunList.java:97) ...
Resolution
Install the CloudBees Request Filter plugin >= 1.1 and block ./timeline/data/.
requests.
Please have a look at How Do I Use The CloudBees Request Filter Plugin.