It does look a bit like the agent is not working properly, as suggested by @AnandVyas. I had this last week. Try stopping and starting the agent on the compute server. We're on a Windows platform and I've taken to doing this at the command line using hq-agent.bat in config\Levx\Web\SASEnvironmentManager\agent-5.8.0-EE\bin because it seems to work better than using Windows Services. If this doesn't work, try again but rename the data directory in the agent-5.8.0-EE directory so it is recreated. You'll lose a bit of the monitoring data. This is what finally worked for me.
Note: directory names are based on 9.4M5 on Windows so if you're on a different version or OS they might not be the same.