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

Michael Kopp

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Top Stories by Michael Kopp

Setting up Application Performance Monitoring is a big task, but like everything else it can be broken down into simple steps. You have to know what you want to achieve and subsequently where to start. So let’s start at the beginning and take a top-down approach Know What You Want The first thing to do is to be clear of what we want when monitoring the application. Let’s face it: we “do not want to” ensure CPU utilization to be below 90 percent or a network latency of under one millisecond. We are also not really interested in garbage collection activity or whether the database connection pool is utilized. We need to monitor all of these things in order to reach our main goal. And the main goal for this article series is to ensure the health and stability of our application and business services. To ensure that we need to leverage all of the mentioned metrics. What ... (more)

Why Averages Are Inadequate, and Percentiles Are Great

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 ea... (more)

Major Garbage Collections - Separating Myth from Reality

In a recent article we have shown how the Java Garbage Collection MXBean Counters have changed for the Concurrent Mark-and-Sweep Collector. It now reports all GC runs instead of just major collections. That prompted me to think about what a major GC actually is or what it should be. It is actually quite hard to find any definition of major and minor GCs. This well-known Java Memory Management Whitepaper only mentions  in passing that a full collection is sometimes referred to as major collection. Stop-the-world One of the more popular definitions is that a major GC is a stop-the-w... (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)

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)