Error
Error Code:
246
MongoDB Error 246: Snapshot Unavailable
Description
Error 246, 'Snapshot Unavailable', indicates that MongoDB cannot provide a consistent data view (snapshot) required for an ongoing operation or transaction. This typically occurs when a transaction or query runs for an extended period, causing its underlying snapshot to become invalid or unavailable due to subsequent data changes or resource constraints.
Error Message
Snapshot Unavailable
Known Causes
4 known causesTransaction Duration Exceeded
A multi-document transaction or long-running query held a snapshot for too long, causing it to be invalidated or dropped by the storage engine.
Storage Engine Snapshot Eviction
The WiredTiger storage engine's cache management evicted the snapshot data due to memory pressure or the snapshot becoming too old, making it unavailable for active operations.
Replica Set Read Inconsistency
When reading from a secondary, the required snapshot might be unavailable if the secondary is too far behind the primary or cannot maintain the requested consistent view.
MVCC Snapshot Invalidation
Underlying data modifications by other operations invalidated the specific Multi-Version Concurrency Control (MVCC) snapshot needed by an active operation.
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