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

Michael Kopp

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Top Stories by Michael Kopp

Anyone who ever monitored or analyzed an application uses or has used averages. They are simple to understand and calculate. We tend to ignore just how wrong the picture is that averages paint of the world. To emphasis the point let me give you a real-world example outside of the performance space that I read recently in a newspaper. The article was explaining that the average salary in a certain region in Europe was 1900 Euro's (to be clear this would be quite good in that region!). However when looking closer they found out that the majority, namely 9 out of 10 people, only earned around 1000 Euros and one would earn 10.000 (I over simplified this of course, but you get the idea). If you do the math you will see that the average of this is indeed 1900, but we can all agree that this does not represent the "average" salary as we would use the word in day to day li... (more)

NoSQL or Traditional Database

Traditional Enterprise Database vendors often bring up the lack of professional monitoring and management tool support for NoSQL solutions. Their argument is that enterprise applications require sophisticated tuning and monitoring of the database in order to ensure a performant and smooth operation. NoSQL Vendors, while arguing that this lack is not enough to favor RDBMS over their respective solutions, do agree. Several vendors try to differentiate themselves by providing enterprise level monitoring and management software, for example, Cassandra, MongoDB, HBase or others. Both ... (more)

How to Identify a MongoDB Performance Anti Pattern in Five Minutes

The other day I was looking at a web application that was using MongoDB as its central database. We were analyzing the application for potential performance problems and inside five minutes I detected what I must consider to be a MongoDB anti pattern and had a 40% impact on response time. The funny thing: It was a Java best practice that triggered it. Analyzing the Application The first thing I always do is look at the topology of an application to get a feel for it. Overall Transaction Flow of the Application As we see it's a modestly complex web application and it's using Mongo... (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)

How Garbage Collection Differs in the Three Big JVMs

(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... (more)