We have used a mongo v8.0.1 replicaSet (2 nodes + arbiter) on our production servers (Rocky 9.4 with 12 cores) since some weeks. I restartet the whole system of primary after RAM upgrade some days ago.
We have seen 100% cpu usage caused by mongo process on all cores since that.
We have tested folllowing steps:
- mongo service restart
- look for slow queries (We also tried to stop all our services calling mongo, but cpu usage won’t change.)
- node reinitilized
- switch primary to another node
- disable transparent huge page on os level
According to mongo, the connection count of node slowly increases overtime. The result of
following statement:
db.currentOp({“secs_running”: {$gte: 3}})
contains a lot of hello commands.
Does anyone has an idea?
Any help would be greatly appreciated
regards