Increased CPU usage and JVM live threads after migrating to Mendix 11

After upgrading an application to Mendix 11, monitoring tools may report:

• An increase in Java Virtual Machine (JVM) Live Threads.

• Higher Process CPU Usage compared to previous runtime versions.

These observations may raise concerns that the application is experiencing a performance issue, resource leak, or abnormal runtime behavior following the upgrade.

Mendix 11 introduces architectural changes in the way application tasks are executed. As part of these changes, the runtime makes greater use of modern thread management mechanisms.

As a result, the number of JVM threads reported by monitoring tools may be higher than in Mendix 10. This difference is expected behavior and is related to runtime architecture changes rather than an application issue.

The increased thread count alone should not be interpreted as a sign of degraded performance, memory leaks, or abnormal runtime behavior.

No action is required if:

• The thread count stabilizes over time.

• CPU utilization remains within acceptable limits for the workload.

• Application performance remains normal.

• No functional issues, instability, or excessive resource consumption are observed.

Further investigation should be considered if:

• The JVM thread count continues to increase without stabilizing.

• CPU utilization remains consistently elevated beyond expected levels.

• Application response times become degraded.

• Functional or performance-related issues are encountered.

When a higher thread count is observed without associated performance degradation or operational impact, the behavior can generally be considered an expected result of the architectural changes introduced in Mendix 11.