oow2013 ef final_4_3

Eugene Fedorenkoadfpractice-fedor.blogspot.com 2

About me


Performance Testing

Base Oracle Solution Center. Linlithgow, Scotland, UK.

Application JetB2. Core Banking System.ADF Faces, ADF Controller, ADF Model, ADF BCJDeveloper R2 11.1.2.3.0

Application ServerOracle WebLogic 10.3.6Jrockit VM R28.2.5-4.1.0

TargetsMaximum number of users per JVM, per BoxMinimum number of database connectionsDetect memory leaksCheck application scalabilityTune JVM to get the best response timeGet 6000 simultaneously working users

DatabaseOracle RDBMS 11g R2


Tools

JRockit Mission Control Online JVM monitoring and flight recording

JRockit Memory Leak Detector Analyzing heap contentsDetecting memory leaks

Oracle Enterprise Manager Cloud Control Monitoring database connectionsDetecting heavy SQL queries

Oracle Diagnostic Log Analyzer Exploring request structure and SQL executions

Oracle Application Testing Suite Load generatingResponse time monitoring

NMON Gathering operating system statistics


Mission


Let’s go!


The Heap

-Xms

0

-Xmx

Hard Reference Soft Reference Weak Reference

java –Xms:4G –Xmx:8G


Garbage Collector

Mark

Sweep

Reachable Softly Reachable Weakly Reachable Garbage

0

-Xmx


Parallel Garbage Collector

Frequent garbage collections (every ~40s)Long pauses (~8s and longer)Frequent and huge peaks in response time line


Generational Parallel Garbage CollectorNursery (Young Generation) Tenured (Old Generation)

Young Collection

Old Collection


0

-Xns -Xmx


Generational Parallel Garbage Collector

Frequent young GC (every ~8s). Rare old GC (every ~3min) Short pauses for young GC (<300ms). Quite long pauses for old GC (~3.5s-4s).Infrequent but still high peaks in response time line


2. Concurrent Marking

Weakly ReachableSoftly Reachable

Concurrent Garbage Collector: Mark

1. Initial Marking

3. Precleaning

4. Final Marking

Reachable Garbage

-Xns

-Xmx


Concurrent Garbage Collector: Sweep

1. Sweep first half

2. Switch halves

3. Sweep second half

4. Synchronize


-Xns

-Xmx


Generational Concurrent Garbage Collector

Frequent young GC (every ~8s). Rare old GC (every ~2min 40s) Short pauses for young GC (<300ms). Short pauses for old GC (<700ms).Long old GC duration (~12s)


Lessons

Parallel Garbage Collector High performance between collectionsShort collection duration but long pausesGood for applications with high throughput requirement. Batch processing

Concurrent Garbage Collector Sharing CPU between GC and Java threadsLong collection duration but short pausesGood for applications sensitive to long pauses. Transaction based systems

Single-generational Garbage CollectorAll garbage is collected at onceGood for set of stable long living objects

Two-generational Garbage CollectorShort-living objects live shortGood for applications with large number of temporary objects


What is good for ADF?

Sensitive to long pauses?

Yes No

A lot

of

tem

pora

ry o

bje

cts

?

No

Yes

Generational Concurrent

-Xgc:gencon

Single Concurrent

-Xgc:singlecon

Generational Parallel

-Xgc:genpar

Single Parallel

-Xgc:singlepar


Useful Links

Understanding Memory Managementhttp://docs.oracle.com/cd/E13150_01/jrockit_jvm/jrockit/geninfo/diagnos/garbage_collect.html

Tuning the Memory Management Systemhttp://docs.oracle.com/cd/E13150_01/jrockit_jvm/jrockit/geninfo/diagnos/memman.html

JRockit GC in Actionhttp://java.dzone.com/articles/jrockit-gc-action

http://docs.oracle.com/cd/E13150_01/jrockit_jvm/jrockit/geninfo/diagnos/garbage_collect.html

http://docs.oracle.com/cd/E13150_01/jrockit_jvm/jrockit/geninfo/diagnos/garbage_collect.html


Mission Completed

oow2013 ef final_4_3

Technology