Replay Queue holds all your erroneous events till you fix the issues and are ready to Replay them.
The errors can occur due to different reasons:
- Network failures. We might encounter network or connectivity failures with your destination at times. We might also encounter network problems in Hevo's infrastructure. Though we make the best efforts to eliminate all such errors they are still bound to appear once in a while.
- Schema incompatibility and conflicts. Schema changes in your Sources and Destinations may change without us knowing about those changes. Though we make the best efforts to keep ourselves in sync with all those changes, there can always be a certain lag in doing so.
- Bad transformation code. Transformation code provided by you may always have bugs.
- Incorrect mappings. There can be manual errors while mapping source and destination tables.
Below is an exhaustive list of errors that are visible on Replay Queue:
- Data type mismatch for the field: Occurs when we encounter a field whose expected and actual data types don't match. e.g. A 64 Bit Integer value for a 32 Bit Integer field, or a String value for Boolean field.
- Data validation failed for a field: Occurs when a value fails to validate a field's constraints. e.g. A null value in a non-nullable field, or a String with 256 characters in a char(128) field.
- Could not determine the data type for the field: Occurs when we are unable to identify the data type for a field. This should rarely happen.
- Transformation Code error: Occurs when the transformation code throws an error.
- Found unmapped event type: Occurs when an event type is not mapped to a destination table. All the events for such types are parked in Replay queue with this error
- Found unmapped fields: Occurs when a field in an event type is not mapped to a column in a destination table. To fix this error, you can uncheck such fields (to skip them) or map them to columns through the Schema Mapper.
- Fields: <Field Name> not found in destination table: Occurs when one or more destination columns specified in Schema Mapper are not physically present in the destination table. To fix this error, you can create these columns in your destination table or unmap the fields in the Schema Mapper.
- Table: <Table Name> doesn't exist: Occurs when a destination table specified in the Schema Mapper is not physically present in the destination. To fix this error, you can create this table in your destination or unmap the table in Schema Mapper.
- No values provided for non-null columns: Occurs when we encounter null values for non-null columns in a destination table.
- No partition key found for event type: Occurs when no partition key(s) are configured for an event type in file-based destinations (e.g. S3).
If you encounter issues other than the ones listed above, reach out to our support and they will happily help you out.