Error
Error Code:
154
MongoDB Error 154: Shard Identity Mismatch
Description
This error indicates that a `mongod` instance attempting to join or operate as part of a sharded cluster has an identity that conflicts with the cluster's configuration. It typically occurs when a shard member's `shardspec` or data directory information doesn't match the expected shard identity, preventing it from correctly participating in the cluster.
Error Message
Inconsistent Shard Identity
Known Causes
3 known causesIncorrect `shardspec` or `clusterAuthMode`
A `mongod` instance for a shard member is started with `shardspec` or `clusterAuthMode` parameters that do not match the expected configuration for that shard within the cluster.
Data directory reuse with conflicting identity
The data directory used for a `mongod` instance previously contained data for a different shard or replica set member, leading to an identity mismatch upon restart.
Mismatch with Configuration Servers
The identity information held by a shard member does not align with the identity recorded and expected by the configuration servers for that shard.
Solutions
Coming SoonDetailed step-by-step solutions for this error are being prepared. In the meantime, try these general troubleshooting tips:
General Troubleshooting Tips
- Check the error message carefully for specific details
- Review recent changes that might have caused the error
- Search for the exact error code in the official documentation
- Check log files for additional context
- Try restarting the application or service