Problem:

My Collector shows a red icon on the Manage Data > Collection page, indicating that the Collector is unable to communicate with the Sumo Logic service, as shown in the screenshot below. The Collector agent could be up, but the Collector logs still show the following error message:

collector-red-icon.png  

2014-10-03 15:16:42,263 -0700 [Heartbeat Manager] WARN com.sumologic.scala.collector.auth.CollectorRegistrationManager - Service not available 
com.sun.jersey.api.client.ClientHandlerException: java.net.ConnectException: Connection refused 

What is wrong? 

Answer:

There are three possible issues that you can troubleshoot:

1. Make sure the service running. Check the Task Manager or services.msc in Windows or doing aps -ef |grep collin Linux to make sure the Java process is running.

2. If the service is running, verify that there is no connectivity issue with Sumo Logic, run the following tests from the host that the Collector is running on: 

$ curl -i https://collectors.sumologic.com
$ curl -i https://collectors.sumologic.com/rest/registry/ping
$  time nslookup collectors.sumologic.com

If the response is slow, that may cause the Collector's heartbeat requests to the Sumo Logic service to time out. You may need to investigate either a DNS or a network issue depending on the error symptom.

For more information on managing Collectors, see Collectors and Sources

3. If the connectivity is fine, the red icon issue could point to a collector malfunction. Restart the collector service as workaround.