Query Application Metrics

Query application metrics manually

Open Web Terminal then run this command to query application metrics. You can also query metrics of other microservices as well by just change rest-villains hostname to other service hostnames i.e. rest-fights.

However, this way is not practical and really hard to understand what each metric value means. So, we'll do something better by using OpenShift platform monitoring.

curl http://rest-villains:8080/q/metrics

Query metric manually

Query application metrics via OpenShift web console

1. Go to Observe menu.

   

   Query application metrics
2. Click on Metrics tab.

   

   Query application metrics
3. Click Select query drop-down list menu then select Custom query.

   

   Query application metrics
4. Open Web Terminal and run following command to simulate load test to the Fight microservice.

   while(true); do curl http://rest-fights:8080/api/fights/randomfighters; sleep 0.2; done;

5. Let the curl command runs aside. Enter fillowing query in the Expression input text, then change zoom to 5m, and then check Stacked option.

   Click on the Expression input text then keep pressing Enter button on keyboard. You shold see the histogram moving.

   rate(http_server_requests_seconds_count{method="GET",uri="/api/fights/randomfighters"}[1m])

   

   Query application metrics
6. Click on Web Terminal window then press Ctrl + C button on keyboard to stop curl command.

What have you learnt?

1. How to query application metrics manually.

2. How to use OpenSHift built-in monitoring tool to query application metrics.