This document discusses performance tuning for Wildfly8 applications. It outlines reasons for tuning like contractual obligations and user experience. It describes benchmarking methodology like defining test objectives and harnessing test tools. Common bottlenecks like the web tier, EJB tier, and JMS/JDBC connections are discussed. Wildfly tuning controls like thread pools, bean instance counts, and pool sizes are covered. Ideal request flow and queuing with timeouts are addressed. Specific thread pool types like unbounded, bounded, and blocking-bounded are explained. The presentation ends with questions.

1. Performance Tuning
Applications with Wildfly8
Jeremy Whiting
Snr Performance Software Engineer
Red Hat

2. Agenda
• Identify reasons for tuning
• Methodology for tuning (benchmarking)
• Bottlenecks
• Wildfly tuning controls
• Demonstration
• Bigger Picture
• Question and Answers

3. Reasons for tuning
•
Contractual Obligations
•
User experience
•
Shared systems
•
Ops per second
•
Predictable system degradation
•
Career aspirations / credibility

4. Performance Benchmarking
• Methodology, Java Performance (book)
• Write “test objectives” (½ page)
• Harness test tools
– Gatling
– Faban
– Smart Frog
• Test one change at a time
• Observe system during tests

5. Crafting a performance test
• Use your “Test Objective” document
• Write your driver
• Set-up software / hardware
• Run tests
• Check for silly mistakes
– Verify using simple tools
– Driver checking for errors
– Recovery Manager activity

6. Ideal situation
• The Funnel
– Requests should queue at the top

7. Problems to consider
• Machines have finite resources
• Multi app deployment
• Shared hosting
• Greedy consumers
Let's take a look at some greedy
consumers....

8. Examples of greedy
consumers...

9. greedy consumers

10. greedy consumers ….
• Hungry hippos
Image: "Hippo Indigestion" by David Goehring from New York, NY, USA - Hippo Indigestion.

11. greedy consumers
while (true) {
System.out.println(“Chomp”);
}

12. Bottlenecks
• What are they
• Are they good ?
• Can they be helpful
– When
– Why

13. Bottleneck recognition
• Web tier
– Servlet
– Undertow
• EJB3 Tier
– SLSB / SFSB
– Bean methods
• JMS / JDBC Connection
– Pool stats

14. Bottleneck controls
• Thread pools
– Implementation type
– Sizing
– Characteristics
• Bean instance counts
• Pool sizes

15. Ideal situation (again)
• The Funnel
– Requests queue up at the top of the funnel

16. Queuing and Timeouts
• Acquisition timeout
– Bean instances
– JMS / Datasource connection
• Deadlock timeouts
– Recovery Manager

17. Thread pools
• Types available in Wildfly
– Unbounded, bounded, blocking-bounded,
queueless, blocking-queueless, scheduled
• Characteristics
• When to use them

18. unbounded
●
Characteristics
– Unknown latency
– Can support unlimited requests
– Can adapt to varying load
– Can cause OOM
• When to use
– Latency is a low requirement
– High throughput

19. bounded
• Characteristics
– OOM can be prevented
– Adaptable to demand and efficient
– Better latency guarantees
– Some requests may fail
• When to use
– Latency is a priority

20. Blocking-bounded
• Characteristics
– Reliable latency if not overloaded
– Can cope with load surges (predictable)
– Can be configured to prevent OOM
• When to use
– Latency is medium priority
– Load surges can be farmed out over time

21. Perf test demo
Bottleneck tuning
• Objective: Identify any bottlenecks
• Use a driver to create load (Faban)
• Sample application
• Run Perf test <---
• Take statistic samples |
• Draw conclusions |
• Change configuration ---
• Stop, reached objective or time box.

22. Bigger Picture
• Automated Metrics collection
• Derived metrics
• Feedback loop
• Responsive systems
– Changing world, users, hardware failures

23. Questions / Feedback
How to contact the performance team
#jbossperf at freenode
jeremy
jwhiting [at] redhat.com

24. References
• Java Performance by Charlie Hunt and Binu John, ISBN: 0137142528
• Byteman, http://byteman.jboss.org/
• dstat tool, http://dag.wiee.rs/home-made/dstat/
• Gatling, gatling.io
• Faban, www.faban.org