Agent log contains warning that collector peer list cannot be stored

Environment

  • Agent installer < v6.0 connected to >= v6.0 AppMon server
  • Missing filesystem permissions for monitored application user to write to <DT_HOME>/agent/conf/

Symptoms

The following log message appears in the agent log after connecting to the collector

warning [native] Exception storing collector peer list: Permission denied

Solution

  • Uninstall the old agent package and reinstall with an >= v6.0 agent installer (requirement for AppMon v6.5+ server anyways) or
  • Add write permissions in the filesystem for application user to the <DT_HOME>/agent/conf/ folder

Root cause

The collector failover and load balancing feature uses a collectorlist.<agentname> file, which is written to <DT_HOME>/agent/conf/. This is new since v6.0, so older agent installation packages do not care about setting filesystem permissions for that location. Also the older bootstrap agents cannot make use of this collectorlist file for a failover on the initial connection attempt, so the first solution step with uninstalling old and reinstalling new agent is highly recommended.