1. ColdFusion Performance Troubleshooting and Tuning
Grant Straker Technical Director Straker Interactive
CFUNITED – The premier ColdFusion conference

2. What I’ll Cover Why we need to performance tune
Understanding the architecture
Principles of Troubleshooting / Tuning
How to setup a Test Rig
Troubleshooting / Tuning process
Caching Strategies
Memory Leaks
June 28th – July 1st 2006

3. Technology Gap Acceptable Deployment Time Technology Gap Time
Application Load / Complexity
1950
1980
2000
Year
June 28th – July 1st 2006

4. CFMX Architecture
June 28th – July 1st 2006

5. Principle One 3 Sources of performance problems
CPU Bottleneck (Threads)
Memory Management
Network / Disk (IO) problems
June 28th – July 1st 2006

6. Principle Two To find the issue you will have to:
Simulate the load under which the system is failing
Record the relevant diagnostics when the system is failing
Interpret the results and adjust the application code and/or server configuration accordingly
June 28th – July 1st 2006

7. Principle Three
There are 5 things you can adjust (tune) to try and resolve any issues:
Application Code
ColdFusion Administration Settings
Application Server Settings (JRun / JVM)
Web Server Settings
OS & Network Settings
June 28th – July 1st 2006

8. Troubleshooting Prerequisites
Getting up-to-date
ColdFusion
Jrun
June 28th – July 1st 2006

9. Metric Logs /CFusionMX/runtime/servers/default/SERVER-INF/jrun.xml
/jrun4/servers/[instance name]/SERVER-INF/jrun.xml
busy - Threads that are running (executing code) this number will not exceed jrpp active threads for JRun or simultaneous request set in the cfadmin
total - Total number or jrpp and web threads that are currently available.
June 28th – July 1st 2006

10. Create a trace log All requests not just current request (cfdebugging)
Can be added to give more granular details
Easily turn on/off
Low overhead
SeeFusion
June 28th – July 1st 2006

11. Load Testing Accurately Simulate Real Load
Benchmarks Input Users / Requests Output Throughput CPU
JVM
Threads
June 28th – July 1st 2006

12. Options Paessler Web Stress Microsft Web App Stress Tool
Mercury LoadRunner
Segue Silk Performer
Appperfect
June 28th – July 1st 2006

13. Test Rig - Debug Console
Garbage Collection
JRun Metrics
Server Stats
CF Error Log
Trace Log
June 28th – July 1st 2006

14. Thread Dumps
Tell us low level information about current running processes / Threads in the JVM
Give us diagnostics
Will pinpoint performance bottlenecks 99% of the time
Are easy to take but require a bit of understanding
Take 3, 15 seconds apart – check for common threads across all 3 dumps
June 28th – July 1st 2006

15. Troubleshooting Process
Simulate Load
Review Debug Output
Take Thread Dumps
Adjust Code
Repeat until resolved
June 28th – July 1st 2006

16. Tuning JRun
Jrun.xml
Scheduler Service internal Jrun service that handles the queuing of threads to the processor
Proxy Service internal Jrun service that handles the connection between native web servers (IIS, Apache) and Jrun
activeHandlerThreads is the most important attribute
June 28th – July 1st 2006

17. Tuning JRun Continued…
Active Handler Threads – 25 default for both SCHEDULER and PROXY services.
Recommend 25 Per processor (4 x processor = 100)
Set too low = bottlenecks, thread deadlocks
Set too high = excessive context switching
Needs to be tuned
June 28th – July 1st 2006

18. Tuning JVM -Xmx most important – 1GB max on windows
-Xmx too big = long GC cycles
-Xmx too small = OOM Errors
Permsize also important
GC monitoring
Various switches to assist
June 28th – July 1st 2006

19. Tuning JVM continued… Different Types of Collectors
Low Pause Parallel -XX:+UseConcMarkSweepGC -XX:+UseParNewGC
Parallel Scavenge -XX:+UseParallelGC -XX:+UseAdaptiveSizePolicy -XX:+AgreesiveHeap
June 28th – July 1st 2006

20. Alternate JVM’s JRockit (BEA) IBM
Not all JVM’s are the same and need to be thoroughly tested before switching.
June 28th – July 1st 2006

21. Java 1.5 Not a currently supported version of CFMX
Will run on CF7.1 and JRun updater 6
Much better performance
Excellent debugging
June 28th – July 1st 2006

22. Memory Leaks Prevention is easier than diagnostics
Requires Java profiling tool to accurately identify
Easier to find in Java 1.5 JVM’s
If memory increases after forcing GC
June 28th – July 1st 2006

23. Caching Strategies
Store instantiated objects in application scope – careful as incorrectly scoped variables may cause memory leaks
Memory Caching Limited by size of Heap Requires and architecture for clearing cached item
June 28th – July 1st 2006

24. Database Performance JDBC Trace Tools SeeFusion Maxrows
Only use “Select *” if you really have no option
Use cfqueryparam to increase query performance
Use blockFactor to increase query performance
June 28th – July 1st 2006

25. Coding for performance
Don’t Run a query larger than the size of the heap
Ensure all your variables and functions stored in persistent scope are var’ed.
Code to allow for slow or missing connections to the database or file system
Don’t run process intensive external calls on every request
Ensure you use all the caching options available
Tune your server for your application
June 28th – July 1st 2006