Last week I took and passed the AWS Solutions Architect Associate exam. Other than the rather weird PSI test centre/environment/process (more on that later) I actually rather enjoy this examination.
Don’t worry – there’s no NDA-breaching here.
The exam itself presents 65 questions with just over two-hours to complete. Most of the questions are scenario based, rather than quick-win factoid answers. This is why I liked it. I’m terrible at remember factoids (ie, this thing costs $0.065/MB on a Wednesday when the sun is shining and the wind is from the north). But I am very good at putting things into practical use and designing around capabilities or intended functionality. What’s the best way to ensure maximum availability for static content used on customer X’s website? What’s the best way to provide maximum fault tolerance across availability zone’s when an application needs Y instances. These are all great questions that make you think about the capabilities of AWS’s services, how they are distributed and how you can exploit them.
I used a number of study aids in preparing for the exam.
Firstly; A Cloud Guru – has to be the best technical training platform I’ve ever encountered. The courses are delivered in chunks of 10~20 mins, so you’re never overloaded, and the majority have a practical element that you can follow-along with. The quizzes at the end of each module keep you on track and the exam simulations are a realistic enough to give you a view of your progress.
Secondly; read the whitepapers. I can’t stress this enough – the baseline should be a thorough read of the Well-Architected Framework and the Cloud Adoption Framework. You should also reading AWS blogs and design on solutions that have already been architected.
Finally; the AWS Free Tier. Exploit it! Tinker with everything. The more you get a practical view of AWS the more you understand how things hook together and where the limitations are (or aren’t).
The last point I have is around the PSI test experience. I’m very used to doing Pearson Vue exams – the way the test centres work and how the exams work, be the Cisco or VMware or whatever – they are very structured. The PSI experience was very lightweight. I was given a username and one-time-password to use at the exam machine and that was it. When the test is finished, you don’t get a score report (displayed or printed), you just get a “Congratulations” on an “Unsuccessful”. The screen then kinda leaves you hanging here – I recommend calling for a proctor at this point and get them to log the exam out.
Next up.. AWS SysOps Associate!
So my most recent post included some Visio-style diagrams but not done in Visio.. try draw.io out, it’s pretty good. Basic, but good.
I had absolutely no idea that AWS in its contemporary form came into existence in 2006, right around the time I started at Cisco and my first venture into the network industry. I was aware of AWS as a platform a few years later but like many (and with my lack of experience and insight) didn’t realise the impact or potential of it. Having worked in networking for 10-years now (Oct 2006-2016) and seen the dramatic change from old C6500 switching to modern SoC-based/merchant-silicon, as well as the more recent influx of ‘SDx’ technologies, I can see clearly now that platforms like AWS and Azure are quickly becoming the de-facto choice for future IT strategies for both infrastructure and services.
With this in mind, it’s time to upshift the skill set and move on. I had originally planned to complete the VCDX-NV qualification and I may well still do this over the long term but, in the short-term I’m going to focus on retaining my CCIE R&S until it becomes Emeritus and put significant efforts into training for AWS, Azure and some more general architecture specialisations such as TOGAF.
2017 will be the year of Architecture for me.
During my docker trials and tribulations, I found two great tools for storing measurement and then displaying them..
It’s not a complex database like MySQL – it’s a simple way of storing time-lapse measurements. I’ll late use it for storing temperature and humidity measurements, but for now we’ll get it setup and drop in some resource stats from the Pi.
Thankfully, someone’s already compiled Influx for the Raspberry Pi and Docker..
HypriotOS/armv7: pirate@black-pearl in ~ $ docker run -d -p 8083:8083 -p 8086:8086 --expose 8090 --expose 8099 -v /var/docker_data/influxdb:/data --name influxsrv sbiermann/rpi-influxdb
InfluxDB exposes two webports:
- 8083 – is a web-based UI for basic DB administration and querying
- 8086 – is a HTTP API for posting/getting data
The default username and password for influx is root/root.
Getting System Stats
It’s useful to know what your Pi is up to and how the resource utilisation looks, especially if you start pushing some heavy scripts or apps to it. Telegraf has been compiled for the Pi architecture here. Don’t follow the instructions about creating a dedicated data folder.. let Docker do this for you.
Now- the default rpi-telegraf configuration tries to send data to influx using localhost:8086 – this will fail as we’re not running influx inside the same container. To fix this we need to do two things..
Firstly – add the ‘–link’ command to the docker run CLI to link the influxdb container to the telegraf container.
- –link influxsrv:influxsrv – docker will create a DNS entry internally and map the influxsrv hostname to the dynamic IP of the influx container
Secondly – modify the telegraf configuration to point to the right influx hostname. To do this, you’ll need to run telegraf once and then use the docker inspect to find the data directory and edit the telegraf.conf file.
Run telegraf with the link:
HypriotOS/armv7: pirate@black-pearl in /var/docker_data
$ docker run -ti -v /data –link influxsrv:influxsrv –name telegraf apicht/rpi-telegraf
And then kill the process
Find the config config:
As we’ve been creating a dedicated store for our container’s data, you should find the telegraf data in /var/docker_data/telegraf
Edit the telegraf.conf file and the influxdb section:
## The full HTTP or UDP endpoint URL for your InfluxDB instance.
## Multiple urls can be specified as part of the same cluster,
## this means that only ONE of the urls will be written to each interval.
# urls = [“udp://localhost:8089”] # UDP endpoint example
urls = [“http://influxsrv:8086”] # required
## The target database for metrics (telegraf will create it if not exists).
database = “telegraf” # required
Now telegraf can be run as a daemon container:
HypriotOS/armv7: pirate@black-pearl in ~
$ docker run -d -v /data –link influxsrv:influxsrv –name telegraf apicht/rpi-telegraf
Setup Raspberry Pi2 with HypriotOS
Assign static addressing
auto eth0 iface eth0 inet static address 192.168.1.111/24 gateway 192.168.1.1 dns-nameservers 192.168.1.1 dns-search jimleach.co.uk
Docker instances are non-persistant, but for most of the things I want to use them for, I need some consistent storage I can present to them. Don’t do this if you want your containers to be portable! A better way would be to present some storage via NFS and map that instead.. something a bit less host-centric.
HypriotOS/armv7: pirate@black-pearl in /var/docker_data
Create directories for:
We’ll need these later as we build up our stack of containers..
HypriotOS/armv7: pirate@black-pearl in ~ $ docker run -d -p 9000:9000 -v /var/run/docker.sock:/var/run/docker.sock -v /var/docker_data/dockerui:/data --name dockerui hypriot/rpi-dockerui Unable to find image 'hypriot/rpi-dockerui:latest' locally latest: Pulling from hypriot/rpi-dockerui f550508d4a51: Pull complete a3ed95caeb02: Pull complete Digest:sha256:6e245629d222e15e648bfc054b9eb24ac253b1f607d3dd513491dd9d5d272cfb Status: Downloaded newer image for hypriot/rpi-dockerui:latest 34d0b3f00a25e847743fd04b59952d7870f2bebbd3b7524e009afd6d5fd0404c
By trying to run the image without first downloading, you prompt docker into pulling it automatically from the Docker Hub and then starting it.
- -d – Puts the instance into daemon mode
- -p 9000:9000 – maps port 9000 on the localhost (the RiPi) to port 9000 on the instance
- -v – Maps our local storage to a volume/directory in the container (local:container)
- –name – gives us a recognisable name to reference the container with
Now if you browse to the Pi’s address on port 9000 – you should get the Docker UI:
In the later-half of 2015 I was lucky enough to be invited to the NSX Ninja partner course at VMware in Staines. This is a course specifically to drive the knowledge-base of partner consultants and architect-types to enable them to seek out and position NSX oppertunities. With two weeks of training on the agenda and the assumption you’ve already spent some time on either a training course (ICM or Fast Track) and earned the VCP-NV; this course focuses first on low-level troubleshooting components and packet flows, then on the design side with the intention of preparing students for the VCIX-NV.
Attending an event today at Cisco I was blindsided by the lack of forsight with some ‘fellow’ VAR representatives.