Diagnostics page: Overall CPU usage chart shows a constant value on Windows

October 23, 2026 05:42 Updated

Symptoms

The Overall CPU usage chart on the Administration > Diagnostics page shows a constant value (e.g., 32%) rather than fluctuating with the actual system load. The Garbage collection and TeamCity process CPU usage charts continue to update normally. Restarting the server temporarily restores correct behavior.

Cause

This is caused by a JDK bug JDK-8351359, where OperatingSystemMXBean.getCpuLoad() returns stale values on Windows after long JVM uptime. The bug affects JDK 21.0.6 and earlier versions bundled with TeamCity 2025.11.x.

Resolution

Update the JRE used by the TeamCity server to Amazon Corretto 21.0.10 or later, which includes the fix for JDK-8351359.