ARS Logging#

Compute node health check failures, ARS remedy suggestions, and remedy execution outcomes are published to MQTT and to the journalctl logs on the head node.

ARS MQTT Logging#

ARS log messages are emitted on MQTT topic ars/v1/logs/state_machine and include:

  • Suggested remedies for a compute node

  • Which remedy was selected and executed on a compute node

  • Node entering and leaving ARS states (provisioning, available, auto remediation, and so on)

You can subscribe to topics using an MQTT client. See Auditing for more details about MQTT.

ARS journalctl Logging#

The journalctl log files include details such as which health checks failed and which remedy was selected for each compute node. View the log by running the following on the head node:

journalctl --unit ars-auto-remediation

In a cluster with multiple head nodes, run the command on the compute node's parent head node to view node-specific logs. See Booting with Multiple Head Nodes for details about determining parent head node.