My Splunk UI has become severely slow over the last few days. The previous day, logging in would take a few minutes, and any changes to the search head would make it freeze. Now it's so slow that I can't even log in, it tries to reach the login page for 10 minute or more, and then just hangs.
I've run df -h on the command line, nothing seems to be taking up too much space or memory. Other web services in my business are running fine. But Splunk is unusable in its current state. Besides restarting splunkd, what else could I do to check or fix the performance?