Learnings in performance testing (JBOSS Tuning, Windows TCP / IP Changes)

Tuning JBOSS performance by increasing the RAM, number of max threads to be used, increasing TCP / IP Connections limit. Below are good references for the same

• Configure the max limit for concurrent TCP connections (Number of ports are increased upto 60K to accept more connections)
• Avoid TCP/IP Port Exhaustion
• Java (JVM) Memory Model and Garbage Collection Monitoring Tuning 
• JBoss Performance Tuning part 1
• Configuring the Windows registry - Increase Memory Performance 
• 10 Examples of HotSpot JVM Options in Java
• Tuning Garbage Collection Outline
• Key Lesson - Set -Xms and -Xmx close to each other or equal for a faster startup (removes constant resizing of JVM). But if you make a poor choice the JVM can't compensate for it.
• Key Lesson - You may need to increase the MaxPermSize, eg: -XX:MaxPermSize=128m

JBOSS parameters tweaked

File	Property	Comments
run.bat	"-Xms"
		The -Xms value is the space in memory that is committed to the VM at init. The JVM can grow to the size of –Xmx
	"-Xmx"
		The -Xmx value determines the size of the heap to reserve at JVM initialization
	"-XX:MaxPermSize"
..\deploy\jboss-web.deployer\server.xml -> "<Connector>" tag	"maxThreads"	The maximum number of request processing threads to be created by this Connector, which therefore determines the maximum number of simultaneous requests that can be handled. If not specified, this attribute is set to 200.
	"acceptCount"	The maximum queue length for incoming connection requests when all possible request processing threads are in use
	"connectionTimeout"	The number of milliseconds this Connector will wait, after accepting a connection, for the request URI line to be presented
..\conf\jboss-service.xml -> "org.jboss.util.threadpool.BasicThreadPool"	"KeepAliveTime"	How long a thread will live without any tasks in milliseconds
	"MaximumPoolSize"	The max number of threads in the pool
	"MaximumQueueSize"	The max number of tasks before the queue is full
..\conf\jboss-service.xml -> "org.jboss.remoting.transport.Connector"	"numAcceptThreads"	The number of threads that exist for accepting client connections
	"maxPoolSize"	The number of server threads for processing client
	"clientMaxPoolSize"	Client side maximum number of active socket connections. This basically equates to the maximum number of concurrent client calls that can be made from the socket client invoker

More Reads

Big List Of 20 Common Bottlenecks

Memory Leaks, Load Balancing and Deployment Settings: Testing Lessons learned from the eCommerce industry

How to Approach Application Failures in Production

Hands-On Tutorial: 5 Steps to Identify Java and .NET Memory Leaks

Key Performance Metrics For Load Tests Beyond Response Time- Part II

Key Performance Metrics For Load Tests Beyond Response Time- Part I

Performance Considerations in Distributed Applications

Happy Learning!!!