Hi,
Some of the metrics used for the technical monitoring come from the PUSH from the introscope, which you can check in the Solution Manager Administration workcenter > Alerting Framework > filter by IS* on the context column. So, if it is offline, some metrics will be missing in the monitoring.
I recommend you to check why it is offline in the IntroscopeEnterpriseManager.log.
Besides that, refer to KBA 2156320, there is a tool to analyze the "perflog" from the EM and check whether there is memory missing or other issues.
Best regards,
Daniel.