My main use case for New Relic is to monitor application health on a daily basis. Starting with my day, I go to the dashboards to check how the application health is and any alerts already triggered for the application, whether it concerns disk, memory, CPU, or how the applications are running. Recently, we had a slow query running for the application, which was really the bottleneck as it took a long time for the application to respond, and we found it out by using New Relic to identify the slow query, which really helped me.
To troubleshoot and resolve the slow query issue once New Relic points it out, I generally go to the Application Performance Monitoring, which is APM, and then I check in APM for the query where there are different tabs, including one for the database. After that, I go and check the database, which shows what query is taking how much time. Since we are using Java applications, we can see how much time the queries take. We are also using some Cassandra for caching purposes, which can show that query. I checked with the developer about a simple select query that took a long time, and after I spoke with them, they fine-tuned that query, resolving the issue. New Relic proved really helpful in finding out the slow query.