One of the most critical jobs a system administrator has to continuously be dealing with is the permission administration. The most small carelessness with the permissions can lead to a security hole in the system. This example will show how are changed the permissions, a task for which chmod command is used For this example, Linux Mint 17.3 has been ...

For the latter part of the week I’ve been running some tests against Neo4j which generate a bunch of log files and I wanted to filter those files based on the time they were created to do some further analysis. This is an example of what the directory listing looks like: $ ls -alh foo/database-agent-* -rw-r--r-- 1 markneedham wheel 2.5K ...

I recently wanted to parse some text out of a bunch of files so that I could do some sentiment analysis on it. Luckily the text I want is at the end of the file and doesn’t have anything after it but there is text before it that I want to get rid. The files look like this: # text ...

Spawning services across multiple Docker engines is a very cool thing, but those services need to connect each other and be found by public-facing nodes in order to be routed to users. A way to achieve that is to use NGINX as a reverse proxy by defining one or more public-facing nodes. These nodes are going to have NGINX configured ...

Course Overview Nagios, now known as Nagios Core, is a free and open source computer-software application that monitors systems, networks and infrastructure. Nagios offers monitoring and alerting services for servers, switches, applications and services. It alerts users when things go wrong and alerts them a second time when the problem has been resolved. Nagios was originally designed to run under ...

I recently found myself needing to iterate over a bunch of ‘/’ separated strings on the command line and extract just the text after the last ‘/’. e.g. an example of one of the strings A/B/C I wanted to write some code that could split on ‘/’ and then pick the 3rd item in the resulting collection. One way of ...

SSL is CPU Intensive If you haven’t already enabled SSL session caching, do that NOW. But what if you have many unique requests and your load balancer is maxing out it’s CPU? That was the case with WakaTime’s load balancer, because as you use the WakaTime plugins you are constantly making requests to our api saying you’re still working on ...

This article is part of our Academy Course titled Nagios Tutorial for IT Monitoring. In this course, we provide a compilation of Nagios tutorials that will help you set up your own monitoring infrastructure. We cover a wide range of topics, from installation and configuration, to plugins and NRPE. With our straightforward tutorials, you will be able to get your ...

Recent adventures in Zapierland had me in a somewhat scary predicament. Starting at some point last week I’d get an alert that the Elasticsearch cluster we run Graylog against had hit very high CPU, load and memory usage. I was confused… we had more than enough horsepower to handle queries and normally the cluster only uses about 10% of CPU ...