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Significance of metrics<br />Using Javamelody for perf. stats<br />23. May 2011<br />

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Who am I?<br />David Karlsen<br />Work at EDB Financial Services as a senior architect<br />david.karlsen@edb.com<br />http://www.linkedin.com/in/davidkarlsen<br />2<br />

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When to measurewhat<br />Profiling during development is nice (but heavy) – you need something to monitor ”in the long run”<br />Constant monitoring during development and testcycles can help you discover stuff before you go into production<br />But since production<br />is what we really care about<br />is where your app run<br />For a long time<br />Processing most data<br />THIS IS MOST IMPORTANT<br />“If you can’t measure it, you can’t improve it” - Lord Kelvin<br />3<br />

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Add value to the measures<br />Graphics are able to show the information better<br />When combining several measures in the same dashboard it becomes even more interesting<br />Can correlate events and see the impact as a whole<br />Make the stats available for ops so that you share this information<br />4<br />

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Javamelody<br />” The goal of JavaMelody is to monitor Java or Java EE application servers in QA and production environments”<br />http://code.google.com/p/javamelody/<br />Really easy to get started with<br />Add as a servlet filter<br />Or additionally add an interceptor/aspect to add additional measure points<br />Proxies for datasource to monitor all RDBS execution<br />Stores data in .rrd format locally on disk – robust<br />Can also have a central collector server<br />5<br />

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Example pointcuts<br />@Pointcut( "withinApplication() && anyPublicMethodExecution() && targetIsMainApplicationType()" )public void anyPublicMethodExecutionWithinApplication(){}<br />@Pointcut( "withinServices() || withinDaos() || withinIntegrationLayer() " )public void withinCoreLayer(){}<br />6<br />

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drilldown<br />

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Going further<br />Significance of metrics<br />Now that we have all this nice measures – wouldn’t it be nice to go further and use it even more proactively?<br />Check out http://code.google.com/p/rocksteady/<br />“Too often after collecting many metric and creating many pretty graphs, one realizes graph serves only as a good postmortem analytic aid. Staring at dozen of graph on a TV wall isn't monitoring, it's a waste of time!”<br />By analyzing several sources and using Esper – a Complex Event Processing (CEP) engine it’s possible to apply statistics realtime, and use this proactively to take actions.<br />12<br />

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Summary<br />Avoid black boxes - monitoring is easy and cheap – do it!<br />Measure production continuously<br />Graphs show the information in such a way that they provide more value<br />Javamelody is an excellent way to get you started<br />Hopefully leads to performance awareness by the team<br />As you get to know the application you can go even further and apply monitoring proactively.<br />14<br />