This document discusses using JMX (Java Management Extensions) for monitoring and feature toggling of applications. It describes how to use JMX to monitor custom business indicators by isolating monitoring logic. It also provides examples of accessing JMX data through tools like VisualVM and JSP pages. The document then covers using the feature toggle pattern to enable/disable features without redeploying, including coding patterns like using a dispatcher to hold the feature toggle state.

1. Monitoring and
Feature Toggle Pattern
with JMX
Bruno Bonfils
Cyrille Le Clerc 15/06/2011
Thursday, June 16, 2011

2. Speaker
@cyrilleleclerc
blog.xebia.fr
Cyrille Le Clerc
Large Scale
In Memory Data Grid
Open Source
(Apache CXF, ...)
“you build it, you run it”
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3. The use case
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4. The Use Case
Corporate Data Center
travel-ecommerce
anti-fraud
Tomcat
Tomcat
travel-ecommerce anti-fraud
Tomcat Tomcat
Credit Card Service
Travel e-commerce application
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5. The Use Case
 xebia-spring-travel source code
▶ http://xebia-france.googlecode.com/svn/training/xebia-spring-travel/tags/xebia-spring-travel-1.0.0/
▶ Groovy JMX scripts
» http://xebia-france.googlecode.com/svn/training/xebia-spring-travel/tags/xebia-spring-travel-1.0.0/xebia-spring-travel-
ecommerce/src/main/scripts/
▶ JMXTrans Configuration
» http://xebia-france.googlecode.com/svn/training/xebia-spring-travel/tags/xebia-spring-travel-1.0.0/xebia-spring-travel-
ecommerce/src/main/jmxtrans/
▶ JMeter plan
» http://xebia-france.googlecode.com/svn/training/xebia-spring-travel/tags/xebia-spring-travel-1.0.0/xebia-spring-travel-
ecommerce/src/main/jmeter/
 xebia-management-extras JMX library
▶ http://code.google.com/p/xebia-france/wiki/XebiaManagementExtras
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6. Part 1
Monitoring with JMX
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7. Simplified Use Case
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8. Simplified Use Case
Corporate Data Center
travel-ecommerce
Tomcat
Credit Card Service
Mock
Monitoring Booking and Credit Card Service
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9. Simplified Use Case
Corporate Data Center
travel-ecommerce
Tomcat
Credit Card Service
Mock
Monitoring Booking and Credit Card Service
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10. Custom/business indicator monitoring
with JMX
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11. Custom Indicator Monitoring with JMX
CreditCardService
#purchase()
CreditCardService MonitoringImpl CreditCardServiceImpl
#purchase() #purchase()
monitoring logic isolated with a delegate pattern
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12. Custom Indicator Monitoring with JMX
@ManagedResource
public class CreditCardServiceMonitoringImpl implements CreditCardService {
// delegate
private CreditCardService creditCardService;
// counters
private final AtomicInteger purchaseInvocationCounter = new AtomicInteger();
private final AtomicLong purchaseInvocationDurationInNanosCounter = new AtomicLong();
private final AtomicInteger threeDSecureVerificationExceptionCounter = new AtomicInteger();
@Override
public PaymentTransaction purchase(MonetaryAmount total, Order order, String requestId) {
long nanosBefore = System.nanoTime();
try {
return creditCardService.purchase(total, order, requestId);
} catch (ThreeDSecureVerificationException e) {
threeDSecureVerificationExceptionCounter.incrementAndGet();
throw e;
} finally {
purchaseInvocationCounter.incrementAndGet();
purchaseInvocationDurationInNanosCounter.addAndGet(System.nanoTime() - nanosBefore);
}
}
http://code.google.com/p/xebia-france/source/browse/training/xebia-spring-travel/tags/xebia-spring-travel-1.0.0/xebia-spring-travel-ecommerce/src/main/java/fr/
xebia/monitoring/demo/payment/CreditCardServiceMonitoringImpl.java
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13. Accessing JMX is not so difficult
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14. JMX Monitoring with Visual VM
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15. JMX Monitoring with JSP Pages
Powered by JMX !
 Human friendly or script friendly pages
 Beware of security
▶ BasicAuth
▶ Obfuscated URL : /my-app/seye5E7E/jmx/cxf.jsp
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16. Graphite - JMXTrans Style Reporting Tools
{
"servers" : [ {
"port" : "6969",
"host" : "my-server-1",
"alias" : "travel-ecommerce-1",
"queries" : [
{
"outputWriters" : [ {
"@class" : "com.googlecode.jmxtrans.model.output.GraphiteWriter",
"settings" : { "port" : 2003, "host" : "graphite-server" }
}],
"obj": "travel-ecommerce:name=CreditCardServiceMonitoringImpl,...",
Graphite
"resultAlias" : "CreditCardService",
"attr":["PurchaseInvocationCount", "ThreeDSecureVerificationExceptionCount", ...]
}
],
"numQueryThreads" : 2
JMX Trans Configuration
} ]
}
http://code.google.com/p/xebia-france/source/browse/training/xebia-spring-travel/tags/xebia-spring-travel-1.0.0/xebia-spring-travel-
ecommerce/src/main/jmxtrans/xebia-spring-travel-ecommerce-jmxtrans.json 16
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17. Monotoring systems
AppDynamics
Hyperic
All others ...
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18. JVM Based Scripting Language
http://code.google.com/p/xebia-france/source/browse/training/xebia-spring-travel/tags/xebia-spring-
travel-1.0.0/xebia-spring-travel-ecommerce/src/main/scripts/getAntiFraudVerificationStatus.groovy
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19. Part 2
Feature Toggle Pattern with JMX
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20. Simplified Use Case
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21. Simplified Use Case
Corporate Data Center
travel-ecommerce
anti-fraud
Tomcat
Tomcat
Credit Card Service
Enable anti-fraud
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22. What ? Why ?
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23. What is it ?
 Technique to enable/disable a feature without
redeploying
 Can be simple : on/off
 Can be sophisticated : f(user), f(server), etc
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24. Benefits of the Feature Toggle Pattern
 Dissociate deployment & feature activation
 Progressive activation of a feature
Canary Testing
 Measure impacts of a new version
A/B Testing
 Differ feature activation on production
 Trunk based development
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25. Coding Patterns
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26. Coding Patterns
Dispatcher
AntiFraudService
<<Interface>>
AntiFraudServiceV1Impl
AntiFraudService
DispatchingImpl
AntiFraudServiceV2Impl
JMX
transient persistent
The dispatcher holds the feature toggle
http://code.google.com/p/xebia-france/source/browse/training/xebia-spring-travel/tags/xebia-spring-
travel-1.0.0/xebia-spring-travel-ecommerce/src/main/java/fr/xebia/ws/travel/antifraud/v1_0/
AntiFraudServiceDispatchingImpl.java 26
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27. Coding Patterns
To duplicate or not to duplicate ?
Dispatching
Smart reuse and mutualization
Dispatching
Brutal duplication
Version 1
Version 2
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28. Coding Patterns
To duplicate or not to duplicate ?
Dispatching
Smart reuse and mutualization
Dispatching
Brutal duplication
Version 1
Version 2
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29. Coding Patterns
To duplicate or not to duplicate ?
Dispatching
Smart reuse and mutualization
Dispatching
Brutal duplication
Version 1
Version 2
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30. Coding Patterns
To duplicate or not to duplicate ?
Old version removal requires cleanup
Smart reuse and mutualization
Old version removal is clean
Brutal duplication
Version 1
Version 2
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31. Coding Patterns
To duplicate or not to duplicate ?
Old code removal is simpler with brutal duplication
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32. Demo
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33. Questions / Answers
?
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