HIGH PERFORMANCE CONTROL APPLICATIONS WITH

JAVA

Matej Sekoranja, Mark PleskoJ. Stefan Institute, Slovenia, e-mail: matej.sekoranja@ijs.si, http://kgb.ijs.si/KGB

Marcel GrunderPaul Scherrer Institute, Switzerland, e-mail: marcel.grunder@psi.ch

Times have changed…

1996 2000

Java is state-of-the-art language

Object-oriented Portable Multi-threaded Garbage collected Dynamically loaded Exception-handling Powerful API

… but Java can be slow, too! Arrays are objects Runtime checks (nulls, bounds, types) Precise exception semantics Small methods, frequent calls (OO

programming) Synchronization costs Dynamic allocation, garbage collection Accessing system interface

Avoid these peculiarities!

Let’s optimize!

… Object pooling Buffering & pre-buffering … and many more

Synoptic viewer Displays CS of the Swiss Light Source CDEV-EPICS communication (JNI used) Graphics performance – problem !?

Double buffering – not enough! Additional buffer added – ‘triple buffering’

Powerful Java APIs make programming easier that ever!

Result completely flicker-free drawing

Alarm table Monitors properties of all devices & reports

possible alarm states (alarm = CORBA triggered event)

Approx. 1200 CORBA connections (whole CS of ANKA)

Goal: no blocking at critical situations! Threads, buffering & pre-buffering, filters

Java is able to run multi-connection, multi-threaded & event-enabled applications!

Using already optimized Abeans framework

Snapshot Archiving client SQL DB access

JDBC used 100% pure Java & native protocol driver

Buffered transfer (usage of prepared SQL statements)

Result archiving (retrieving & transferring data) whole ANKA CS takes approx. 3s (with normal CS network traffic)

Java is capable to do network tasks!

Conclusion

Which Java VM to choose?

HotSpot VM

On-the-fly "adaptive" compilation

Method in-lining Improved and

redesigned object layout

Fast and fully accurate garbage collection

Ultra-fast thread synchronization

HotSpot performance

Numerical benchmark

Network performance & scalability benchmark

Memory usage