Mongos 4.4.0 exception after upgrading from 4.2.7

Hey there,
I am trying to update a sharded cluster from 4.2.7 to 4.4.0.

So far I have updated the config and shard replica sets without any issue.

But when updating the mongos instances I get the Following exception:

{"t":{"$date":"2020-08-17T20:48:55.000+00:00"},"s":"F",  "c":"CONTROL",  "id":4757800, "ctx":"ftdc","msg":"Writing fatal message","attr":{"message":"DBException::toString(): NonExistentPath: \"/dev/\" could not be created: Permission denied\nActual exception type: mongo::error_details::ExceptionForImpl<(mongo::ErrorCodes::Error)29, mongo::AssertionException>\n"}}

My systemLog config looks like this:

    destination: file
    logAppend: true
    path: /dev/stdout

I am using /dev/stdout as I am running my mongod and mongos instances within docker containers. From the exception it seems that mongo is trying to create a file at /dev/ which obviously doesn’t work. Not sure what changed between 4.2.7 and 4.4.0 that broke this for me, as the only thing I have changed in my configuration is the mongo server version.

Anybody any insight on how to fix this?

Hi @Jascha_Brinkmann,

The systemLog.path expect a full file destination and not just a path:

Its not something new and for quite sometime it also create the diagnostic directory under that parent directory.

We suggest using the syslog option to centrelize logs rather then stdout.


1 Like