Troubleshooting agent issues v8

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You can troubleshoot these issues that can occur with the PEM agent.

Restoring a deleted PEM agent

If an agent was deleted from the pem.agent table then you can't restore it. You need to use the pemworker utility to reregister the agent.

If an agent was deleted from the PEM web client but still has an entry in the pem.agent table with value of active = f, then you can restore the agent:

  1. Check the values of the id and active fields:

    pem=# SELECT * FROM pem.agent;

  2. Update the status for the agent to true in the pem.agent table:

    pem=# UPDATE pem.agent SET active=true WHERE id=<x>;

    Where x is the identifier that was displayed in the output of the query used in step 1.

  3. Refresh the PEM web client.

The deleted agent is restored. However, the servers that were bound to that agent might appear to be down. To resolve this issue, modify the PEM agent properties of the server to add the bound agent again. After the successful modification, the servers appear as running properly.

Using the command line to delete a PEM agent with down or unknown status

Using the PEM web interface to delete PEM agents with Down or Unknown status can be difficult if the number of such agents is large. In this situation, you can use the command line interface to delete Down or Unknown agents.

Use the following query to delete the agents that are Down for more than N number of hours:

```
UPDATE pem.agent SET active=false WHERE id IN
(SELECT a.id FROM pem.agent
a JOIN pem.agent_heartbeat b ON (b.agent_id=a.id)
WHERE a.id IN
(SELECT agent_id FROM pem.agent_heartbeat WHERE (EXTRACT (HOUR FROM now())-
EXTRACT (HOUR FROM last_heartbeat)) > <N> ));
```

Use the following query to delete the agents with an Unknown status:

```
UPDATE pem.agent SET active=false WHERE id IN
(SELECT id FROM pem.agent WHERE id NOT IN
(SELECT agent_id FROM pem.agent_heartbeat));
```