sts status changed from green to red alarm triggered in vCenter Server

Products

• VMware vCenter Server
• VMware vCenter Server 8.0

Issue/Introduction

• The health status of the STS (Security Token Service) service temporarily changes to "RED" (critical) and returns to Green shortly after
• A fatal error (Out of Memory) indicating a failure to allocate memory for the Java Runtime is logged in sts-health.log (/var/log/vmware/sso/sts-health.log):
  

  # There is insufficient memory for the Java Runtime Environment to continue.
  # Native memory allocation (malloc) failed to allocate 32744 bytes for ChunkPool::allocate
  ...
  OpenJDK 64-Bit Server VM warning: INFO: os::commit_memory(...) failed; error='Cannot allocate memory' (errno=12)
  ...
  Failed to acquire token after 1.034682 seconds.
  Publishing health status as RED to vMon.

• Logs indicating that the STS service exited with Exit code 143 and was subsequently restarted automatically are recorded in vmon.log (/var/log/vmware/vmon/vmon.log):
  

  Wa(03) host-12095 <sts> Service exited. Exit code 143
  In(05) host-12095 <sts-prestart> Constructed command: ...
  In(05) host-12095 <sts> Service STARTED successfully.

Environment

VMware vCenter Server

Cause

This issue occurs when the vCenter Server Appliance (VCSA) experiences a temporary Out of Memory (OOM) condition due to a sudden workload spike.

The physical memory exhaustion prevents the STS Java process from allocating required memory, causing it to crash and report a "RED" health status. Additionally, environments experiencing this issue often show high Swap space usage, indicating a chronic memory shortage.

Resolution

The vCenter Server service management (vMon) automatically restarts the STS service to restore it to a normal state (Green).

Workaround:
If this is an isolated incident, the alarm can be safely ignored once the service is running normally.

Resolution (Recommended):
If the VCSA consistently uses high Swap space, it indicates a chronic memory shortage. Increasing the physical memory (RAM) of the VCSA is highly recommended to prevent recurrence.