The following are some general tips that may be useful before performing any more detailed investigations:
Try pinging the node.
Try connecting to the Couchbase Server Web Console on the node.
Try to use telnet to connect to the various ports that Couchbase Server uses.
Try reloading the web page.
Check firewall settings (if any) on the node. Make sure there isn't a firewall between you and the node. On a Windows system, for example, the Windows firewall might be blocking the ports (Control Panel > Windows Firewall).
Make sure that the documented ports are open between nodes and make sure the data operation ports are available to clients.
Check your browser's security settings.
Check any other security software installed on your system, such as antivirus programs.
Generate a Diagnostic Report for use by Couchbase Technical Support to help determine what the problem is. There are two ways of collecting this information:
Click Generate Diagnostic Report on the Log page to obtain a snapshot of your system's configuration and log information for deeper analysis. You must send this file to Couchbase.
Run the cbcollect_info on each node within your cluster. To run, you must specify the name of the file to be generated:
This will create a Zip file with the specified name. You must run each command individually on each node within the cluster. You can then send each file to Couchbase for analysis.
For more information, see Section 7.7, “cbcollect_info Tool”.