Datadog - See metrics from all of your apps, tools & services in one place with Datadog's cloud monitoring as a service solution. Try it for free.
JavaMelody - JavaMelody is a powerful full tool that is used to monitor Java and Java EE application servers in production and QA environment.
Grafana - Data visualization & Monitoring with support for Graphite, InfluxDB, Prometheus, Elasticsearch and many more databases
Apache SkyWalking - Apache SkyWalking is an open-source application performance monitoring solution that provides tracking, metrics analysis, service mesh observability, alarm, and visualization.
NewRelic - New Relic is a Software Analytics company that makes sense of billions of metrics across millions of apps. We help the people who build modern software understand the stories their data is trying to tell them.
XHProf - XHProf is a function-level hierarchical profiler for PHP and has a simple HTML based user interface.