Problem:

My Collector shows a red icon on the Manage > Collection page, indicating that the Collector is unable to communicate with the Sumo Logic service, as shown in the screenshot below. And even though the Collector agent is up, the Collector logs 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:

To 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 timeout. 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