How to check the concurrent connection count in Tomcat?

To check the concurrent connection count of Tomcat, you can use the following method:

1. To access the Tomcat management interface, simply enter http://localhost:8080/manager/status in your browser. Then log in with the administrator username and password. You can view the current active connections and maximum concurrent connections in the “Connection” section.
2. Utilizing Tomcat’s JMX Interface: Tomcat offers a JMX interface that allows users to connect to Tomcat using a JMX client to query the number of connections. Tools like JConsole, VisualVM, or JVisualVM can be used to connect to Tomcat’s JMX interface. Within the MBeans tree, navigate to Catalina -> ThreadPool -> http-nio-8080 node, where http-nio-8080 is the name of Tomcat’s connector. Within this node, there is a property called currentThreadCount, which indicates the current number of active connections.
3. Check Tomcat’s access logs: The access logs in Tomcat record information such as the time of each request, the request path, and the response status. By analyzing the access logs, you can track the concurrent connection numbers. You can configure the format and path of the access logs in the conf/server.xml file.

It is important to note that the number of concurrent connections refers to the amount of connections being handled simultaneously, not the total number of connections. If you need to track the total number of connections, you can use tools provided by the operating system, like the netstat command, or use Tomcat’s JMX interface to check the ConnectionCount property.