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In the Cloud, you have to trust your instruments...

Michael Kopp

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Top Stories by Michael Kopp

(Note: If you’re interested in WebSphere in a production environment, check out Michael's upcoming webinar with The Bon-Ton Stores) Most articles about Garbage Collection ignore the fact that the Sun Hotspot JVM is not the only game in town. In fact whenever you have to work with either IBM WebSphere or Oracle WebLogic you will run on a different runtime. While the concept of Garbage Collection is the same, the implementation is not and neither are the default settings or how to tune it. This often leads to unexpected problems when running the first load tests or in the worst case when going live. So let’s look at the different JVMs, what makes them unique and how to ensure that Garbage Collection is running smooth. The Garbage Collection ergonomics of the Sun Hotspot JVM Everybody believes to know how Garbage Collection works in the Sun Hotspot JVM, but lets take a c... (more)

So What? – Monitoring Hadoop Beyond Ganglia

Over the last couple of months I have been talking to more and more customers who are either bringing their Hadoop clusters into production or have already done so and are now getting serious about operations. This leads to some interesting discussions about how to monitor Hadoop properly and one thing pops up quite often: Do they need anything beyond Ganglia? If yes, what should they do beyond it? The Basics As in every other system, monitoring in a Hadoop environment starts with the basics: System Metrics - CPU, Disk, Memory you know the drill. Of special importance in a Hadoo... (more)

Deep Insight and Collaboration in the Cloud: A Customer Story

Recently, one of our customers, let's call him PointInFact, had a very typical problem. After deploying a new version of its software, some user requests degraded horribly. Requests that should have taken half a second took up to a minute. Interestingly, the PointInFact team runs a multi-tenant SaaS solution in the AWS Cloud and relies heavily on cloud services. This reliance makes User Experience Management and fault domain isolation very challenging. Back Story: Application Running in the AWS Cloud PointInFact runs a SaaS service. Internally this results in a multi-tenant serv... (more)

The Impact of Garbage Collection on Java Performance

In my last article I explained what a major Garbage Collection is. While a major Collection certainly has a negative impact on performance it is not the only thing that we need to watch out for. And in case of the CMS we might not always be able to distinguish between major and minor GC. So before we start tuning the garbage collector we first need to know what we want to tune for. From a high level there are two main tuning goals. Execution Time vs. Throughput The first thing we need to clarify if we want to minimize the time the application needs to respond to a request or if we... (more)

Troubleshooting Response Time Problems

Production Monitoring is about ensuring the stability and health of our system, that also includes the application. A lot of times we encounter production systems that concentrate on System Monitoring, under the assumption that a stable system leads to stable and healthy applications. So let’s see what System Monitoring can tell us about our Application. Let’s take a very simple two-tier Web Application: A simple two tier web application This is a simple multi-tier eCommerce solution. Users are concerned about bad performance when they do a search. Let's see what we can find out a... (more)