How many posts have you seen about logging? And how many have your read about logging? Recently logging became cool again. Nowadays everybody talks about logstash, elasticsearch and kibana. It feels like everybody is playing with these tools. If you are not among the people playing around with it, than this is your blog post. I am going to help you get started with logstash, get familiar with the configuration and configuring the input as well as output. Than when you are familiar with the concepts and know how to play around with logstash, I move on to storing things in elasticsearch. There are some interesting steps to take there as well. When you have a way to put data in elasticsearch we move on to looking at the data. Before you can understand the power of Kibana, you have to create some queries on your own. I’ll help you there as well. In the end we will also have a look at Kibana.
Continue reading Oh no, more logs, start with logstash
For almost half a year now, I’ve been the proud owner of a Samsung Galaxy SIII Mini (bought it just before the release of the S4, because my phone died and I couldn’t wait for the S4). Since then I’ve got it doing most of what I want it to do, except sign my outgoing emails when I want it to (sign them cryptographically, obviously — I got it to add a text signature within two seconds). The problem here is that setting up the Samsung stock mail app (I don’t use the GMail app) is not immediately obvious. But today I finally got it working, after a long and frustrating day. Read on to find out how…
Continue reading Setting up keys to sign emails in Samsung’s Android email app
So I just bought myself a new laptop (an Asus N76VB-T4038H) which I love so far. It’s a great machine and real value for money. Of course it comes preloaded with Windows 8 — which I hate so far, but am holding on to for the occasional multimedia thingie and because I might have to install Microsoft Office at some point. But my main OS is still Linux and in particular OpenSuSE. And given the way I want to use this laptop in the near future, the idea hit me that it would be a good idea to virtualize my Linux machines so that I can clone them and set up new and separate environments when needed. So I installed VirtualBox on my guest OS, downloaded the OpenSuSE 12.3 ISO, set up a new machine to create a golden image, pointed it to the ISO and installed OpenSuSE. Smooth sailing, no problems. Even set up an encrypted home partition without any pain. And then I tried to clone the machine in VirtalBox and start the clone… and found that it couldn’t find my cloned hard drive.
This is actually a reasonably well-known problem in OpenSuSE and some other Linux distros. You’ll find another blog about what is going on here and there are several forum posts. But none of the ones I found cover a solution involving GRUB2, so I thought I’d post my experiences here.
Continue reading Cloning an OpenSuSE 12.3 virtual machine using GRUB2, VirtualBox and cryptfs
Recently I discovered the web socket capabilities of the Tomcat web container. I read a gist by chitan. This was a nice start, but not a complete solution. Some changes were made to the tomcat classes and I don’t really like the one class to contain everything structure. Therefore I set out to create my own solution.
The sample is the most basic chat client that you can create. When loading the page a socket connection is opened. When closing the page the socket connection is closed. The client makes use of standard html5 browser support.
If you want to learn more, continue by clicking the more link
Continue reading Make use of the WebSocket capabilities of Tomcat
I have written a short review of a book I read called: Confessions of a public speaker. This is again a book about improving your presenter skills.
In my previous blog posts I was working on reading data from wordpress blogs using groovy. This is nice, but of course there was a reason why I needed this. I wanted to create a tool or better a plugin for Elasticsearch. This plugin should make it easier to check the state of you cluster, play around with facets and query your data.
On my employers blog I started a series of blog posts that explain this plugin. I go into details for the libraries I used: AngularJS, Twitter Bootstrap and of course elastic.js.
Check my employers blog post if you are interested.
Introducing a query tool as an elasticsearch plugin (part 1)/
In my previous blog post I wrote about a groovy client for reading a wordpress blog. Than using this client I send the data to ElasticSearch to be indexed. Of course you cannot do anything with ElasticSearch if you do not read the data by executing queries. So that blog post also talks about executing search queries and doing count queries.
But what if you want to start playing with things like facets? What if we want to use a different analyzer to separate the keywords on a comma? Than you can use curl. No wait there is more. You can also use groovy of course.
That is what I discuss in this blog post, creating and removing indexes. Beware, this is not something you want to do on your production server. Deleting an index makes the index disappear, yes for real, you cannot get it back.
Read on if you want to learn more about groovy and ElasticSearch.
Continue reading Doing more ElasticSearch with groovy
This week I had a training at Trifork Amsterdam by Martijn and Uri from ElasticSearch. This training was a very nice in depth look at the capabilities of ElasticSearch. Like with all trainings and conferences I get motivated to try out the technology immediately. I am working on a plugin for ElasticSearch using AngularJS. More on this in a next blog at Trifork.
In this blog I am going to tell you the steps I took to get going with ElasticSearch. I show some of the steps for installing ElasticSearch, explain the first steps in using the groovy library. Next to that I’ll show you how to index this wordpress blog using ElasticSearch. When everything is indexed I will of course show some of the queries you can perform.
Let us get going.
Continue reading Learning about ElasticSearch