Once you have begun collecting metric data in Prometheus, you will need to be able to work with that data in order to obtain information you can act upon. Prometheus provides a specialized query language known as Prometheus Query Language (PromQL) that allows you to write both simple and complex queries in order to retrieve and view your metric data in a useful way. In this hands-on lab, you will have the opportunity to work with Prometheus queries by writing and executing some simple queries.
Learning Objectives
Successfully complete this lab by achieving the following learning objectives:
- Get the Current Memory Usage for the LimeDrop Authentication Service
Access the Prometheus expression browser in a web browser (replacing
<PROMETHEUS_SERVER_PUBLIC_IP>
with the public IP address of the Prometheus server):http://<PROMETHEUS_SERVER_PUBLIC_IP>:9090
Run a query to obtain the available memory amount. Supply a label to search specifically for metrics for the
limedrop-auth:4455
instance.mem_available_total{instance="limedrop-auth:4455"}
Log in to the Prometheus server and open the output file:
vi /home/cloud_user/auth_service_data.md
Enter the current available memory on the
mem_available_total
line.
- Get the available memory range data over a five-minute period three minutes ago.
Run a query in the expression browser to obtain the data:
mem_available_total{instance="limedrop-auth:4455"}[5m] offset 3m
Copy the output, including the timestamps.
On the Prometheus server, open the output file:
vi /home/cloud_user/auth_service_data.md
Paste in the data at the end of the file.