Not something I’ve come across. So this is just my 5 minute note:
This is worth a read IMO
From Percona:
Note for readers coming here from web search etc: The typical symptoms are suddenly you notice that the WiredTigerLAS.wt file is growing rapidly. So long as the WT cache is filled to it’s maximum the file will grow approximately as fast as the Oplog GB/hr rate at the time. Disk utilization will be 100%, and the WiredTigerLAS.wt writes and read compete for the same disk IO as the normal db disk files. The WiredTigerLAS.wt never shrinks, not even after a restart. The only way to get rid of it is to delete all the files and restart the node for an initial sync (which you probably can’t do until the heavy application load stops).
Don’t forget: The initial cause is not primarily the software issue - the initial cause is that the application load has overwhelmed replica sets node’s capacity to write all the document updates to disk. The symptom manifests on the primary, but it may be lag on a secondary that is the driving the issue.
You have this option: https://docs.mongodb.com/manual/reference/configuration-options/#storage.wiredTiger.engineConfig.maxCacheOverflowFileSizeGB
But pay close attention to what happens when this is non-zero:
If the
WiredTigerLAS.wtfile exceeds this size,mongodexits with a fatal assertion. You can clear theWiredTigerLAS.wtfile and restartmongod.
Hopefully someone else can give some knowledgeable input.