Oh one more good for duplicating that type of fail - run it in docker, or a VM, or maybe Multipass, and give it anemic resources (though enough that the test doesn't OOM or something)
On Thu, Jun 15, 2023 at 5:34 PM Mark Miller <markrmil...@gmail.com> wrote: > Why don't you see how it can return null? > > I'm looking at an older checkout, but I see JettySolrRunner checking for > null core containers all over, and I see it passing back null explicitly in > at least one case. > > When I peek at where that core container might be coming from, I see a > provider and a field that looks like it's home (which I note doesn't look > protected by any memory barrier? e.g., volatile, lock, sync). And I see > that it could start as null. Get set to null on close as well? > > So I wonder about that lack of a memory barrier, but there are probably > plenty of cases where some random jobs/threads are still running past that > close as well, is another thought I have. And I bet one of them comes in > and looks for that core container late, and he's already clocked out. > > Older checkout, so I don't know what you are looking at, but if it hasn't > changed drastically recently, it seems easy to return a null. > > If you want to duplicate a situation that might hit - try running the test > with 10-20 instances simultaneously looped. > > Or loop one, and hammer your system with some unrelated load for a while. > > On Thu, Jun 15, 2023 at 4:49 PM Alex Deparvu <stilla...@apache.org> wrote: > >> Hi, >> >> I wanted to take a look at the flaky DeleteReplicaTest test. >> >> Some background first: >> - Past 7 days trend: >> Class: org.apache.solr.cloud.DeleteReplicaTest >> Method: raceConditionOnDeleteAndRegisterReplica >> Failures: 15.56% (63 / 405) >> >> - Test failure is caused by a NullPointerException: >> ERROR (coreZkRegister-772-thread-1-processing-127.0.0.1:40471_solr) >> [n:127.0.0.1:40471_solr c:raceDeleteReplicaCollection s:shard1 >> r:core_node4 >> x:raceDeleteReplicaCollection_shard1_replica_n2] o.a.s.c.DeleteReplicaTest >> Failed to delete replica >> => java.lang.NullPointerException: Cannot invoke >> "org.apache.solr.core.CoreContainer.getZkController()" because the return >> value of "org.apache.solr.embedded.JettySolrRunner.getCoreContainer()" is >> null >> >> I am having some trouble reproducing on my local and I don't see how the >> getCoreContainer() method might return null. Could this be a timing issue >> somehow? >> If anyone has an idea on how to approach this, I would be happy to hear >> it. >> >> best, >> alex >> > > > -- > - MRM > -- - MRM
