Groovy script to display the current number of active Tomcat sessions. Useful if you don't have a Tomcat monitoring solution in place.

display_session_count.groovy

import java.lang.management.ManagementFactory
import javax.management.MBeanServer
import javax.management.ObjectName
import com.liferay.portal.kernel.util.StringUtil

MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
ObjectName objectName = new ObjectName("Catalina:type=Manager,context=/,host=localhost")
Object mbean = mbs.getMBeanInfo(objectName);
println "Found manager bean"
//println mbean.toString()

String ids = (String) mbs.invoke(objectName, "listSessionIds", null, null)
//println ids

String[] list = StringUtil.split(ids, " ")
println "Total number of sessions: " + list.size()