Can we use one spyglass for multiple clusters . Does that make sense ?
Yes you can use Spyglass to monitor multiple clusters and yes it makes sense to do so.
Spyglass uses opentsdb and elasticsearch to store metric data and log data for Grafana and Kibana web interfaces (respectively). If you want Grafana and Kibana to be able to show data from multiple clusters, then you need to tell each cluster to use the same opentsdb and elasticsearch endpoints. You can specify these endpoints in the MapR web installer or with the -ES and -OT command-line options to the configure.sh script. For details on those command-line options, see http://maprdocs.mapr.com/home/AdvancedInstallation/InstallMonitoring.html?hl=ot.
To validate whether your opentsdb is seeing metrics from both clusters, query opentsdb like this and verify that you're seeing the CPU metric for all the nodes in each of your clusters:
If that works, then you should be able to access those metrics in Grafana (and log data in Kibana).
If you don't see all the nodes you're expecting, then here are some troubleshooting tips:
Per MapR documentation, yes.
A single dashboard can be used across multiple nodes in the cluster, for an entire cluster, or for multiple clusters.
Refer this link for more information - Metric Visualization
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