Error Message:
cannot use non-local read concern until replica set is finished initializing.
Explanation:
This error message typically occurs when attempting to use a non-local read concern in MongoDB before the replica set finishes initializing. A read concern determines the level of isolation for read operations in a replica set, allowing you to prioritize consistency or performance.
When your replica set is in the initializing state, it means that one or more secondary members are still syncing data from the primary member. During this period, certain read concerns that require a consistent view of the data are not available.
Example:
Let’s assume we have a replica set with three members: a primary, and two secondaries. The secondaries are still syncing data from the primary due to either a recent deployment or a member restart.
If we attempt to perform a read operation with a non-local read concern, such as “majority” or “linearizable”, we may encounter the mentioned error message.