Mule Runtime 4.9.16 and 4.9.17:4-java17 Experience High CPU, Memory, and Frequent Restarts Due to DataWeave Avro-to-JSON Memory Leak

CAUSE

A memory leak exists within Mule Runtime versions 4.9.16 and 4.9.17:4 when performing DataWeave transformations from Avro to JSON. This leak is attributed to a library upgrade introduced in runtime 4.9.16. As the application processes Avro data, memory is not properly released, leading to continuous heap growth. This excessive memory consumption triggers frequent and prolonged garbage collection cycles, consuming high CPU, and eventually results in OutOfMemoryError conditions, causing the application to restart.

This issue is documented in the Known Issue: [Memory Leak in DataWeave Avro-to-JSON Transformation Causing Heap Growth](https://help.salesforce.com/s/issue?id=a02Ka00000mGNv3IAG).

APPLIES TO

*   Mule Runtime 4.9.16
*   Mule Runtime 4.9.17
*   CloudHub deployment model
*   Applications performing DataWeave Avro-to-JSON transformations.

WORKAROUND

Downgrade your Mule runtime version to 4.9.15. This version does not contain the library upgrade causing the memory leak.

If your organization has auto-patching enabled for Mule runtimes, you may need to request an exception for your account to prevent automatic upgrades back to affected versions until a permanent fix is released.