A computer scientist learns Amazon Web Services (AWS)

Performance Modelling for DevOps: Integrating APM+Performance Modelling for DevOps, Paul Brebner It's been a few months since the WOPR25 workshop in NZ (Wellington) so I've finally got around to putting up my slides that I had prepared for my presentation.   WOPR is the Workshop in Performance and Reliability, and they had the 25th one in NZ, with the theme: Performance Tools for 2017 (and beyond) which I thought was a good fit for our performance modelling tool and presentation. I hadn't come across WORP before and it turns out to be a rather odd beast in some ways. It's run by practitioners for practitioners, is invitation only based on submitting an Abstract (which I had done), and has a limit of about 20 people and a rather formalised (in 1 sense) organisation which uses K-cards to ask questions.    On the other hand it is more informal (but more "controlled") than a typical academic workshop.  I assumed that by receiving an invitation I was being...

(A robot from a book, The Queen of France, see bottom of blog) I started a "books that I had in my office" blog a while back. That approach was a bit slow and I've unpacked some more today so I decided just to lay them all out on my deck and take a photo. So they are in no particular order or topic, and include computer science and a few philosophy and other random books (excluding novels and sci-fi as there are too many of them :-). The lighting was also a  bit odd (close to dusk).  There's 2 photos per row of books (with some duplication on the right/left edges). Row 1 (just one photo) Row 2 (2 photos from here) Row 3 Row 4 This row (1st photo, 3rd from the left at the top, open to colour graphics image) has an interesting old book, "Cybernetic Serendipity, the computer and the arts", Jasia Reichardt (Ed.), 1969. Yes, you read the date right, it's one of the oldest books on computer graphics and art that I...

Don't do this (unless you mean to). Whoops! So, I decided to be clever and use my AWS account from a mobile device yesterday. I logged on (for the first time from this device) and then decided to check/change some of the account settings. Having done that I came across a button at the bottom of the settings page that said something like "Close". I thought it meant "close this page and save settings changes" or something else equally harmless. Because I was using a mobile device and didn't have much screen real estate etc so I just hit the click box and the bottom without a second thought. Big mistake!!! It really does CLOSE YOUR ACCOUNT - immediately! No turning back! No change of mind! No going to another page which says "Are you really sure you want to do this?!", or having an email confirmation that you can change your mind at. How come? I managed to get the account re-instated after about 24 hours but contacting support. What if this had b...

My long term experience with large scale distributed systems monitoring, performance modelling and prediction etc is that "Evil next comes from where you are blind". I.e. The next major performance/scalability problem will always pop up from where you have the least visibility into your system (i.e. where you are blind). In that sense it is entirely predictable! If part of your system is a black box in terms of monitoring/visibility then inevitably that's where the next problem will occur. In Middle Earth the Evil will come from Mordor. Gaps in monitoring can be tier related (e.g. client/browser, networks, web, application, database, 3rd party services, cloud managed services), due to incomplete monitoring (e.g. some systems may not be able to have agents installed so may be "invisible"),  lack of ability to correlate monitoring data across heterogeneous systems (e.g. lack of transactional monitoring), or lack of breakdown times inside a system (e.g. using...

We've recently been doing a long term analysis of where the $'s go, and how to cut down on unnecessary expenditure. If you don't go out shopping or buying online it's still pretty hard to save money as most of it goes out in automatic payments for the Mortgage, insurance, rates, and utilities. Food is therefore an obvious area to try and cut down on. Here's a few tricks that I've been trying. Based on the Martian and some dietary advice it is possible to survive on Potatoes, Porridge, Kale and some fish and meat. E.g.  http://www.sbs.com.au/food/article/2016/02/19/can-you-survive-eating-nothing-potatoes We've been able to buy large bags of potatoes and porridge from Costco. Baked potatoes are yum (just poke a few holes in them with a skewer and cook in the oven without peeling them). Our garden produces some Kale and Spinach.  I like Vegemite (vitamin B), and I've been making bread and savoury muffins from scratch cheaply (corned ...

So I sat the exam today and past ok yippee. Guess there's no need to continue blogging about AWS certification stuff!? The AWS Certified Solutions Architect – Associate exam is intended for individuals with experience designing distributed applications and systems on the AWS platform. Some general observations. The real exam is somewhat harder than the practice tests and practice exam (about 10% harder?) NONE of the practice test questions appear in the real exam. The focus is only what I would call the legacy IaaS Amazon services. Almost no questions on managed services, Machine Learning, Data Analytics, Lambda, etc. Lots of questions on what I would call systems and networks admin stuff.  I spent a few months trying to learn this stuff but actually I don't think it helped, I'm not sure I got any of these questions right. E.g. the sort of qns were if you have this sort of set up (VPCs, subnets, ACLs, groups, EC2, etc) and this doesn...

Some of the Route 53 (DNS) questions that I got caught out with... What are all the different record types and what are they for? Here's the list: A Format AAAA Format CNAME Format MX Format NAPTR Format NS Format PTR Format SOA Format SPF Format SRV Format TXT Format A kids AWS Route 53 record types alphabet rhyme... A is for: an IPv4 address in dotted decimal notation. AAAA is for:   an IPv6 address in colon-separated hexadecimal format. (4A's are better than 1A!) CNAME is for:  (Wikipedia)    a  domain name  that is an alias for another domain, which is the " canonical " domain. MX is for:   a mail server responsible for accepting email messages on behalf of a recipient's domain, and a preference value used to prioritize mail delivery if multiple mail servers are available. (from wikipedia) NAPTR is for: who knows. NS is for:  the name servers for the hosted zone PTR is for:  Poi...