Hi, Thanks for reporting. Sounds you have enough supporting proof to create a JIRA (bug) issue, and we can continue discussion there.
Jan > 22. aug. 2023 kl. 21:51 skrev Paul McArthur > <pmcarthur-apa...@proton.me.INVALID>: > > Hi all, > > I’m creating a cluster singleton plugin and have found an issue with the > lifecycle management of the singleton if the plugin is updated via the API. > > When the /cluster/plugin api is called with an update payload, the > ClusterSingletons.modified method is called, which adds the new plugin to the > singletonMap (and starts it if applicable). Then it stops and removes the old > one. The order of these operations has a couple of side effects: > > 1. For a very brief period, there are 2 instances of the plugin running. This > may not really be a problem, but does seem to violate the Singleton principle > > 2. Given that the map is keyed on the plugin name, adding the replacement > first will overwrite the existing (old) entry in the map. Then when the old > one is removed, it actually removes the new one that was just added. This > leaves the singletonMap with no entry for the plugin. When the Overseer node > goes down, the stop method is not called for the plugin because it no longer > has an entry in the map. > > I’ve reproduced the issue by modifying the TestContainerPlugin test, and I > can create a Jira issue, but I wonder if there is any reason that the added > and deleted methods are called in this order that I haven’t understood. It > seems to me that reversing the order in which they are called will solve the > issue. > > Thanks, > Paul --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@solr.apache.org For additional commands, e-mail: dev-h...@solr.apache.org
