To deploy the Diagnostics extension during cluster creation, as shown in the following image, use the Diagnostics settings panel. To enable Reliable Actors or Reliable Services event collection, ensure that Diagnostics setting is set to On. After you create the cluster, you can't change these settings by using the portal:
Resource Manager templates can be used to enable diagnostics on an existing cluster or to update the configurations of an existing cluster.
After setting up diagnostics on your Service Fabric cluster, you can connect the log data storage to services such as Operations Management Suit (OMS), Elastic Search, and so on. You can also use Application Insights SDK to send telemetry data to application insights so that you can monitor your application and respond to errors.