When several threads are waiting to enter a critical section, a thread dump shows these threads waiting in the same procedure. If there is more traffic than the cluster can handle, will it queue and timeout gracefully?
Synchronization can often be reduced by: changing the code to only use synchronization when necessary; reducing the path length of the synchronized code; or reducing the frequency of invoking the synchronized code. Begin by understanding that one cannot solve all problems immediately.
Web Sphere Application Server workload management functions provide several ways to determine how the work is distributed.
Change tuning parameters to increase some resources, for example, the number of file handles, while other resources might need a hardware change, for example, more or faster CPUs, or additional application servers.
Key tuning parameters are described for each major Web Sphere Application Server component to facilitate solving performance problems.
A public developer Works forum exists for feedback and discussion: https://com/developerworks/community/forums/html/forum? Thank you to the IBM managers that helped support this project: Dave Schell, Melissa Modjeski, Keri Olson, Frank Schembari, Michael Stuy, Mike Morin, Sree Ratnasinghe, and others.
id=e76b33e9-07b8-4bb1-a8d1-ee672a3402e8 Copyright International Business Machines Corporation 2017. Every major section of this cookbook will have a recipe summarizing the key points.
The following recipe is for the whole cookbook: A 2008 survey of 160 organizations (average revenue $1.3 billion) found a typical impact of a one second delay in response times for web applications entailed a potential annual revenue loss of $117 million, 11% fewer page views, 7% fewer conversions, 16% lower customer satisfaction, brand damage, more support calls, and increased costs (Customers are Won or Lost in One Second, Aberdeen Group, 2008,
Other benefits include reduced hardware needs and reduced costs, reduced maintenance, reduced power consumption, knowing your breaking points, accurate system sizing, etc.
Some critical sections of the application and server code require synchronization to prevent multiple threads from running this code simultaneously and leading to incorrect results.
Synchronization preserves correctness, but it can also reduce throughput when several threads must wait for one thread to exit the critical section.
Also, the performance advisors page can provide advice on tuning a production system under a real or simulated load.
Workload distribution can affect performance when some resources are underutilized and others are overloaded.
Guide yourself primarily with tools and methodologies. For example, with a typical Web Sphere Application Server application, start with the operating system, then Java, then WAS, then the application, etc.