We have been running mongod CE for years on a server. Recently, mongod was terminated by the OS because of memory issues and upon restart it gave the following error:
Upgrading from a WiredTiger version 10.0.0 database that was not shutdown cleanly is not allowed. Perform a clean shutdown on version 10.0.0 and then upgrade.
I’m not sure why this occurs. We have not recently upgraded, at least not intentionally. Is it possible we had done an apt update as part of general server maintenance and this caused it? Is there a way to figure out what mongo version we need to install to perform the clean shutdown as it suggests? Is there a way to get around this?
It turns out that the apt upgrade from 4.4.6 to 4.4.9 caused this issue. The upgrade was done without shutting down mongodb. Presumably if it had been shut down, then done the upgrade, then started 4.4.9, it would have been fine, but because the first restart was after the crash, it caused these issues. The remedy was to go back to 4.4.6.
I would have to warn you that MongoDB 4.4.2 to 4.4.8 are not recommended for production use due to critical bugs (see the Release Notes for MongoDB 4.4 series). One of which is WT-7995 that can cause a Duplicate Key error on startup and prevent the node from starting.
The latest version in the 4.4 series is currently 4.4.13. Please do upgrade to that version.
Thank you. Done. Based upon the description this does not seem to have been the issue we experienced. Not sure why a bug fix/patch release would cause an engine upgrade per the error I posted, which then failed because the shutdown was not clean.