what is /data/configdb path used for in mongodb?

Question

I am running a docker of mongodb, and notice a volume created and mounted to /data/configdb. this is in addition to another volume mapped to /data/db which I know is where my actual data is stored.

I am trying to find out what is stored in /data/configdb, and searched google for it. surprisingly enough I didn't find anything explaining what is stored there.

what is stored there (/data/configdb), and can it be discarded everytime I restart my mongodb container?

Answer 1

To summarize from the docs, config servers store the metadata for a sharded cluster, and /data/configdb is the default path where a config server stores its data files. So if you're not dealing with sharded clusters, removing any references to it should be ok.

From the docs:

--configsvr

Declares that this mongod instance serves as the config server of a sharded cluster. When running with this option, clients (i.e. other cluster components) will not be able to write data to any database other than config and admin. The default port for a mongod with this option is 27019 and the default --dbpathdirectory is /data/configdb, unless specified.

References:

https://docs.mongodb.com/manual/core/sharded-cluster-config-servers/

https://docs.mongodb.com/v3.4/reference/program/mongod/#cmdoption-configsvr

Hope this helps!