Zabbix: Fixing Active Checks to Work With Zabbix Proxy

We’ve recently changed our Zabbix 1.8.1 setup to include Zabbix Proxy, which broke all our active checks (f.ex. monitoring of log files). The solution seems to be having the proxy first, before the Zabbix Server, in the Zabbix Agent’s config parameter Server, i.e. “Server=<proxy ip>,<server ip>”.

How to Add MapRed-Only Node to Hadoop

I was surprised not to be able to google an answer to this so I want to record my findings here. To add (a.k.a. commision) a node to Hadoop cluster that should be used only for map-reduce tasks and not for storing data, you have multiple options: Do not start the datanode service on the

Notify on Errors in a Log File with Zabbix 1.8

Situation: You want to get notified when a log entry marked ERROR appears in a log file. You want the corresponding trigger to reset back to the OK state if there are no more errors for 10 minutes. (This post assumes certain familiarity with Zabbix UI.)

Testing Zabbix Trigger Expressions

When defining a Zabbix (1.8.2) trigger e.g. to inform you that there are errors in a log file, how do you verify that it is correct? As somebody recommended in a forum, you can use a Calculated Item with a similar expression (the syntax is little different from triggers). Contrary to triggers, the value of

Getting Started with Amazon Web Services and Fully Automated Resource Provisioning in 15 Minutes

While waiting for a new project, I wanted to learn something useful. And because on many projects we need to assess and test the performance of the application being developed while only rarely there is enough hardware for generating a realistic load, I decided to learn more about provisioning virtual machines on demand in the

Most interesting links of October

Recommended Readings Steve Yegge’s Execution in the Kingdom of Nouns – I guess you’ve already read this one but if not – it is a well-written and amusing post about why not having functions as first class citizens in Java causes developers to suffer. Highly recommended. Reply to Comparing Java Web Frameworks – a very

Intro: Java Webapp Monitoring with Hyperic HQ + How to Alert on Too Many Errors in Logs

This post describes how to set up the Java-based open source monitoring tool Hyperic HQ to monitor application server error logs and send a single warning e-mail when there are more of them than a threshold. In the previous post Aggregating Error Logs to Send a Warning Email When Too Many of Them – Log4j,

Aggregating Error Logs to Send a Warning Email When Too Many of Them – Log4j, Stat4j, SMTPAppender

Our development team wanted to get notified as soon as something goes wrong in our production system, a critical Java web application serving thousands of customers daily. The idea was to let it send us an email when there are too many errors, indicating usually a problem with a database, an external web service, or