I am running Personal MediaWiki (version 1.35.1) with CirrusSearch and elasticsearch (6.5.4). Two weeks ago, the elasticsearch index suddenly disappeared. Running UpdateSearchIndexConfig.php in CirrusSearch will recreate the index.
What could cause elasticsearch indexes to suddenly disappear?
See my post above yours on here. I was having the same problem, my indexes disappeared every two or three weeks. I think my server was being hit with a “meow” attack because port 9200 was accidentally open to the outside world.
It could be that you have port 9200 open. Or like me, you could have ES running in docker and think you’ve got it locked down since you’re using a firewall to block port 9200. The thing is, docker apparently bypasses the firewall rules by default. But there’s a solution for that in the link I provided.
I just implemented the fix today, so I don’t know if this is actually the fix, but reading about the meow attack, it seems to check out.
When an index is recreated (the suggestions index at least), a new index is created, the alias is updated to point to the new one, and the old index removed. I haven't seen Cirrus Search removing indices by itself without creating a replacement one.
This problem seems to be due to my wiki side. At that time, my wiki was sometimes overloaded while running runJobs.php and the page did not open, and in the process, the ElasticSearch index was broken. Currently, it is not recurring after adjusting the frequency.
