ForkJoinPool vs. ThreadPoolExecutor

Scaling an Elasticsearch Index – Introduction

A well-known design decision of Elasticsearch is that a fixed number of shards has to be specified when creating an index. It is not possible to start out with just one or only a few shards and add more shards later as the data increases. Now what to...

30.3.2015 | 7 minutes reading time

Transactions in Elasticsearch

Earlier this year a customer mentioned a search requirement that I hadn’t really thought about before: How to achieve transactions in Elasticsearch? Recently, the same requirement popped up again in a conversation I had with other search aficionados....

6.10.2014 | 8 minutes reading time

Elasticsearch Indexing Performance Cheatsheet

You plan to index large amounts of data in Elasticsearch? Or you are already trying to do so but it turns out that throughput is too low? Here is a collection of tips and ideas to increase indexing throughput with Elasticsearch. Some of them I have successfully...

• NoSQL

8.5.2014 | 8 minutes reading time

Elasticsearch Monitoring and Management Plugins

Elasticsearch offers a highly useful plugin mechanism as a standard way for extending its core. Plugins enable developers to add new functionality, e.g., a custom analyzer, or provide alternatives to existing functionality, like swapping in another transport...

30.3.2014 | 11 minutes reading time

Useful JVM Flags – Part 8 (GC Logging)

The last part of this series is about garbage collection logging and associated flags. The GC log is a highly important tool for revealing potential improvements to the heap and GC configuration or the object allocation pattern of the application. For...

3.1.2014 | 8 minutes reading time

Useful JVM Flags – Part 7 (CMS Collector)

The Concurrent Mark Sweep Collector (“CMS Collector”) of the HotSpot JVM has one primary goal: low application pause times. This goal is important for most interactive applications like web applications. Before we take a look at the relevant JVM flags...

4.3.2013 | 10 minutes reading time

Useful JVM Flags – Part 6 (Throughput Collector)

For most application areas that we find in practice, a garbage collection (GC) algorithm is being evaluated according to two criteria: The higher the achieved throughput, the better the algorithm.The smaller the resulting pause times, the better the ...

4.1.2012 | 10 minutes reading time

Useful JVM Flags – Part 5 (Young Generation Garbage Collection)

In this part of our series we focus on one of the major areas of the heap, the “young generation”. First of all, we discuss why an adequate configuration of the young generation is so important for the performance of our applications. Then we move on...

18.8.2011 | 13 minutes reading time

Useful JVM Flags – Part 4 (Heap Tuning)

Ideally, a Java application runs just fine with the default JVM settings so that there is no need to set any flags at all. However, in case of performance problems (which unfortunately arise quite often) some knowledge about relevant JVM flags is a welcome...

2.7.2011 | 6 minutes reading time

Useful JVM Flags – Part 3 (Printing all XX Flags and their Values)

With a recent update of Java 6 (must have been update 20 oder 21), the HotSpot JVM offers two new command line flags which print a table of all XX flags and their values to the command line right after JVM startup. As many HotSpot users were longing ...

• Java
• APM

10.4.2011 | 4 minutes reading time

Useful JVM Flags – Part 2 (Flag Categories and JIT Compiler Diagnostics...

In the second part of this series, I give an introduction to the different categories of flags offered by the HotSpot JVM. Also, I am going to discuss some interesting flags regarding JIT compiler diagnostics. JVM flag categories The HotSpot JVM offers...

• Java
• APM

23.3.2011 | 9 minutes reading time

Useful JVM Flags – Part 1 (JVM Types and Compiler Modes)

Modern JVMs do an amazing job at running Java applications (and those of other compatible languages) in an efficient and stable manner. Adaptive memory management, garbage collection, just-in-time compilation, dynamic classloading, lock optimization ...

• Java
• APM

8.3.2011 | 6 minutes reading time