What causes DELTA_WRITE_TIMEOUT?

The cluster does not have sufficient compute resources to complete the write within the timeout. A high volume of small files is causing the _delta_log commit to take too long. Cloud storage I/O latency is high (throttling, slow object store response). The transaction log has accumulated too many uncommitted entries, slowing commit operations

How do I fix DELTA_WRITE_TIMEOUT?

Increase the cluster size or use auto-scaling to provide more compute during large write operations.. Run OPTIMIZE on the table to compact small files and reduce commit overhead.. Check cloud storage metrics for throttling or elevated latency during the failure window.. Increase the Delta write timeout using `spark.databricks.delta.commitInfo.enabled` settings or contact Databricks support for transaction log tuning.. Batch smaller writes into larger transactions to reduce commit frequency.

High severitysql

Power BI Refresh Error:
DELTA_WRITE_TIMEOUT

What does this error mean?

A Delta Lake write transaction could not acquire the necessary resources or commit within the allowed time window. The transaction is aborted after the timeout expires.

Common causes

1The cluster does not have sufficient compute resources to complete the write within the timeout
2A high volume of small files is causing the _delta_log commit to take too long
3Cloud storage I/O latency is high (throttling, slow object store response)
4The transaction log has accumulated too many uncommitted entries, slowing commit operations

How to fix it

1Increase the cluster size or use auto-scaling to provide more compute during large write operations.
2Run OPTIMIZE on the table to compact small files and reduce commit overhead.
3Check cloud storage metrics for throttling or elevated latency during the failure window.
4Increase the Delta write timeout using `spark.databricks.delta.commitInfo.enabled` settings or contact Databricks support for transaction log tuning.
5Batch smaller writes into larger transactions to reduce commit frequency.

Frequently asked questions

Does OPTIMIZE need to be run manually?

On Databricks, Auto Optimize can be enabled per table via TBLPROPERTIES (delta.autoOptimize.optimizeWrite=true) to automatically compact writes without a manual OPTIMIZE schedule.