Monitoring Screens

We all know that it is important to monitor your servers and services, so you can spot issues before they become problems. I personally have spent a lot of time configuring nagios to email me about issues and I have recently been configuring various different alerts in Azure.

My old boss has this idea that I should have a big monitor screen displaying all the vital stats of my servers and services, I personally disagree with this idea and think that notifications on my phone and email alerts are sufficient. He will no doubt correct my thinking when he reads this, but I believe part of his thinking is to make the monitoring of your infrastructure move visible and make it obvious to anyone that walks past that you have your eye on everything.

For the purpose of this blog post lets assume he has convinced me and I have convinced my actual boss to spend money on the required technology to do this (No easy feat). What exactly would I display on this screen?

I have Google Chromecast that I use for streaming various things to my TV, this is a relatively cheap bit of technology that could allow a TV or monitor to display a web page with the required stats displayed. perf

The two main sources of information that I want to display are New Relic for monitoring my azure websites and Nagios for monitoring my internal servers. New Relic allows you to easily export live performance data as iframes so I quickly threw together a web page full of these graphs. However if you have a static screen on the wall you don’t want to have to scroll to see different information so I needed to come up with another way to display this information.

My first thought was a slide show. There are lots of javascript scripts that cycle through a series of images like a slideshow, this could be adapted to cycle through a series of iframes and display everything I want.

My script goes something like this and requires jquery as well as javascript. First of all the script waits for the page to load completely with the ready function, it then defines the urls which will be put into the iframe one at a time. It than counts the number of urls you have. It then loops through changing the contents of the src attribute in the iframe every few seconds, in my example it changes every 9 seconds but once this is used in production you may want to increase this.

<script type="text/javascript">
var locations = ["URL1", "URL2", "etc"];
var len = locations.length;
var iframe = $('#frame');
var i = 0;
setInterval(function () {
iframe.attr('src', locations[++i % len]);
}, 9000);

Now what information wants to be included in a script like this? Showing too much performance data can almost be as bad as not doing it at all as problems gets drowned out in the noise. For me I have performance of my websites, followed by Nagios problems, followed by the azure status page, followed by memory usage of all my servers and lastly showing number of connections to my databases. Another question to consider is what time scales do you want to graph over, too long and you don’t see what is happening now, but too short and you may only worry about an intermittent issue?


My Year of Code

There is no escaping the fact that we are in 2015 now. My new years resolution is to do more coding.

Over Christmas I thought I would have a go at I completed the javascript course and I was just wondering what I should try next when I saw a tweet about

Since then I have been addicted to doing the exercises that they have, almost everyday I have made a bit of progress.

But this site is not just about teaching you how to code, it has an active forum where you can ask questions and understand more about what it takes to become a developer.

Before I started these exercises I didn’t know much javascript or jquery but I am starting to learn quite a few commands that hopefully I can put into use at some point. Whatever development I end up doing I am sure I am going to need javascript at some point.

One of the tips I have learnt is that you need to practise daily. Did you ever use flash cards to help pass exams? Well there is an electronic version of them now called Anki. Just add a question/answer pair to your deck of cards and review them each day, the ones you find difficult you review more often than the ones you have learnt.

Hopefully I can keep this up and later in the year I will be well on way to writing lots of useful code.