Host metrics not available for agent due to issues with NFS file systems

Environment

Agents on Linux/Unix with file systems mounted via NFS (Network File System)

Symptoms

  1. Host metrics are unavailable from this agent or other malfunction of the agent
  2. The agent log contains the message
... warning [native] Unable to acquire mutex for updating inclusion/exclusion rules - collecting host metrics taking long or hanging?

Solution

  1. Using the mount command, verify if the agent host has file systems mounted via NFS.
  2. Check if the NFS file systems are operating properly. If the NFS server is unavailable, the NFS file system may be stalled.
  3. If the NFS file system is not operating properly, fix the NFS file system issue and restart the process which contains the agent.

Further reading: http://nfs.sourceforge.net/nfs-howto/ar01s07.html

Root cause

Unlike directly attached file systems, NFS file systems can be stalled if the NFS file server is unavailable. This prevents the agent from operating properly.