Archive for AWS

Juxtaposition Time! Join us at London VMUG to talk AWS! – January 19th 2017

Don’t panic, you’re not imagining things! You did indeed read that title right! If everything goes to plan, Chris Porter and I will be taking the January 2017 London VMUG to a whole new place, with a session on AWS!

Yes, that’s an AWS session at a VMUG! 😮

Why?

For those people who have been living in a bunker on the isle of Arran for the past few years, AWS has been taking the IT industry by storm. So much so, at VMworld 2016, VMware announced their new product “VMware Cloud on AWS“!

Whatever the reasons that VMware have decided to do this (and I’m not going to go into my opinions of that right now), it leaves VMware admins in a position where even if they aren’t already doing some AWS today, the likelihood of them doing so in the near future has just jumped by an order of magnitude!

Meanwhile in a parallel universe...

Meanwhile in a parallel universe…

What’s the session about then?

The session is planned to be a quick intro on the key features of AWS, some tips on how to learn more and get certified, as well as some of Chris and my experiences of working with and designing for AWS (which is rather different to doing things in VMware, for sure!).

Hopefully it should be a pretty interesting session, especially if you haven’t had much exposure to AWS yet!

What else can you see at the event?

As always, there will be many awesome speakers at the London VMUG event. Ricky El-Quasem is even doing two by himself!

There will also be a load of other sessions, so check out the agenda below:

LonVMUG Jan 2017Wrapping up the event there will also be the eponymous vBeers event at the Old Bank of England (194 Fleet St, London EC4A 2LT), so make sure you hang around after and join us for what is often the best part of the day!

Lastly, thanks very much to the LonVMUG sponsors, Rubrik, iLand and Stormagic, without whom it would not be possible to hold these events!

I’m in! How do I register?

You can register for the event at the London VMUG workspace here:

LonVMUG January 2017 Registration

The location is techUK, 10 St Bride St, London, EC4A, which is pretty easy to get to via your preferred public transport methods, though coming in via Waterloo I generally find the bus to be fastest…

If you do see me on the day (I’m 6’7” so you cant miss me), please do come and say hi! 🙂

AWS Certified Developer Associate (CDA) Exam Study Guide and Materials

Following on from my previous AWS exam experience post for the AWS Certified Developer Associate (CDA) exam from Amazon, the following describes the study materials I used towards the exam.

As a reminder, this is my second AWS exam, having completed the AWS Certified Solution Architect Associate exam earlier this year. As such the materials I used to study towards the AWS Certified Developer Associate exam are more sparse, due to the level of knowledge I already have.

For a really full picture of all of the materials I’ve used over the last 12 months, I highly recommend you check out the Certified Solution Architect Associate exam experience and the Certified Solution Architect Associate study guides, along with a number of tips, tricks and gotchas I have posted over the past few months. I also did a podcast recently with Scott Lowe on the subject of learning AWS. If you are new to AWS, I highly recommend you check it out!

AWS Certified Developer Associate CDA Full Stack Journey

Study Materials

Whilst studying for the exam, I used the following study materials:

  • Exam Blueprint
    • This is always the go-to document for almost any current industry certification, and should be used as your primary guide for resources and areas to study. In the case of the AWS Exam Blueprint, they actually direct you to specific white papers to review as well as the content areas to study.
    • AWS CDA Exam Blueprint
  • ACloud.Guru AWS Certified Developer Associate training course.
    • As with the CSA course, the quality of the production (especially as Ryan and co are a small startup) is excellent. Remember that as Ryan says, they are focussed on teaching you the knowledge to pass the exam, not teaching you everything in AWS. There is no substitute for labbing and working with AWS day to day to become an expert, but you can certainly pass the exam based on this course! This might then help you get your first AWS job and gain the experience you need to be a real Cloud Guru! 🙂
    • The course has around about 10-12 hours or so of content, but I would say it took me 15-20 hours in total between all of the lab work, coming up with my own scenarios to practice configuring different elements, completing the quizzes, and researching any areas where I got a quiz answer incorrect or wasn’t sure of the reasons for a specific answer. Ryan also speaks quite slowly and very clearly, so I find that watching it at 1.5x speed or above can help get through the videos on the areas you know well already. Remember to slow it back down for new content areas of course!
  • QA Architecting on AWS & Advanced Architecting on AWS compressed training course
    • Myself and a number of colleagues completed both of the 3 day architecting courses (standard and advanced) in a rather intense, but very informative 5 day week! This was an awesome course, and really helped my gain breadth and depth of knowledge, but I would not say it was critical to passing the Developer exam itself.
  • White Papers
  • AWS CSA Official Practice Exam and Sample Exam Questions
    • I would say this is a good indicator of the level of difficulty of the actual exam.
    • Sample AWS CDA Exam
  • FAQs
  • Other Articles and Resources – The AWS documentation site is an absolute goldmine of information, and most of the articles are well written and easy to consume. Significantly more so than some of the best known “kb” and documentation sites in the industry IMHO. The following is a list of some of the articles I dipped in and out of while researching for the exam as well as my AWS Tips and Gotchas blog series:
  • And finally…
    • I say this about every single exam I have ever taken – lab it, lab it lab it! It is a million times easier to answer a question based on something you have actually done yourself! Don’t try to just learn the theory, spend a bit of time doing it in practice and you will reap the benefits in both the exam and real life!pass
Want to Learn More?

Don’t forget to check out my other AWS articles tips here:

Index of Tekhead.it Blog Posts on Amazon AWS

AWS Certified Developer Associate (CDA) Exam Experience & Tips

The information bellow covers my experience for the AWS Certified Developer Associate (CDA) exam from Amazon. Following this I will post a list of my study materials, so keep checking back for updates or check out my Index of AWS Posts.

Before you continue reading, I would first just say that this is my second AWS exam, having completed the AWS Certified Solution Architect Associate exam earlier this year. As such the materials I used to study towards the exam are more sparse, due to the level of knowledge I already have.

For a really full picture of all of the materials I’ve used over the last 12 months, I highly recommend you check out the Certified Solution Architect Associate exam experience and the Certified Solution Architect Associate study guides, along with a number of tips, tricks and gotchas I have posted over the past few months. I also did a podcast recently with Scott Lowe on the subject of learning AWS. If you are new to AWS, I highly recommend you check it out!

AWS Certified Developer Associate CDA Full Stack Journey

Certified Developer Associate Exam Experience

My personal experience of the AWS Certified Developer Associate exam was that it was quite a bit easier than the Solution Architect Associate exam. Now, I don’t know whether this is more because I have been doing quite a bit of AWS work, as well as writing about it quite a bit in the months since I passed the CSA, or if this was down to the exam being genuinely easier. Most likely a combination of the two, as many people seem to rate the three exams as Developer, Solutions Architect, then SysOps Associate in increasing difficulty.

Either way the exam itself was actually very reasonable if you have any experience working with AWS. The way that AWS seem to structure their exams, is with some general questions across their portfolio, then specific technologies taking precedence in each. The developer exam was no different; there is definitely a distinct bias towards DynamoDB, S3, SQS and authentication. All the things which AWS Developers are likely to use when building distributed and highly scalable applications of course!

It is worth noting that AWS do not expect you to be a developer to pass the exam. You don’t need to know how to code in any language or similar. It would be useful for you to understand the basic format of JSON, but again this isn’t critical to pass the exam. If you want to work hands on with any of the AWS tooling in real life however, this is pretty critical!

The exam itself is 80 minutes and 55 questions. Again AWS (as is their way) do some odd things like not giving you a passing grade requirement, but it’s generally safe to assume that if you get 70% or more, in the Certified Developer Associate exam then you will pass. The Kryterion exam environment is frankly a little poor / dated, but I already wrote about that in the CSA guide here, so I won’t repeat myself again! Suffice to say, read the other article for a detailed overview.

There’s not a huge amount of advice I can give regarding the exam itself, other than if you are stuck, go with your gut. Believe it or not, the most obvious answer is often the actual answer! Don’t second guess yourself and say “No way it couldn’t be that simple!”.AWS Certified Developer Associate CDA Gut Feeling

Things like the specific API syntax used by AWS is generally quite logical, however there are a few weird things! For example, the read commands GetItem and BatchGetItem match syntax with eachother and are logical, but the write equivalents, PutItem and BatchWriteItem, do not! Knowing these types of little weird things can potentially help you come exam time so make sure you memorise some of the more common API calls.

It is also very worthwhile practicing your DynamoDB maths, as AWS expect you to be able to do this in your head. Memorising and practicing Ryan’s simple method really helped me to get my head around it.

Finally, if there is one thing I recommend you read, it’s the DynamoDB FAQ. This is a goldmine of information that will stand you in good stead for both the exam, and developing solutions on AWS!

Best of luck, and if you found this article useful, please leave a comment below! 🙂

Want to Learn More?

For part 2 of this article, the AWS Certified Developer Associate exam study guide and materials, see here:

AWS Certified Developer Associate (CDA) Exam Study Guide and Materials

Amazon AWS Tips and Gotchas – Part 10 – EFS (Elastic File System)

Continuing in this series of blog posts taking a bit of a “warts and all” view of a few Amazon AWS features, below are a handful more tips and gotchas when designing and implementing solutions on Amazon AWS. This week, we talk about the latest feature of AWS, EFS (aka Elastic File System).

For the first post in this series with a bit of background on where it all originated from, see here:
Amazon #AWS Tips and Gotchas – Part 1

For more posts in this series, see here:
Index of AWS Tips and Gotchas

20. Amazon AWS Tips and Gotchas – Part 10 – EFS (Elastic File System)

A big challenge when designing highly available web infrastructures is historically how to provide a centralised content store for static content without wasting resources.

A classic model for this is a pair of web / file servers with either rsync or Gluster to replicate the content between them. In Windows world, this would be something like either a WSFC (failover cluster) or perhaps something evil like a DFS replicated share. This means that not only are you wasting money on multiple virtual machines / instances just to serve file content, but you also add significant risk and complexity in the replication and failover between these machines.

Enter, AWS EFS!AWS EFSAt a simple level, EFS is basically an NFS (v4.1) share within the AWS cloud, which is replicated across all AZs in any one region. No need for managing and replicating between instances, or indeed paying for EC2 instances just to create file shares! Great!

As this is still a relatively immature product, there are still a few “features” to be aware of:

  1. There is no native EFS backup solution (yet!). I’m sure this will come very soon. As we have Re:invent coming up, it wouldn’t surprise me if something came out then. In the meantime, your main methods would be either to use Data Pipeline to backup to another EFS store or potentially mount EFS and backup through an EC2 instance using your own tools or scripts. I would be concerned about backing up EFS to EFS (if in the same region), as this is putting all your eggs in one basket. Hopefully, AWS will provide other target options in the future.
  2. There is no native encryption of EFS data as yet. If you need this right now, you could achieve it by simply pre-encrypting the data in your application first, before it is written to EFS. Alternatively, just hold your breath as AWS have already stated that:
    “Amazon EFS does not currently provide the option to encrypt data at rest, but we will offer this option soon”.AWS EFS Meme
  3. If you have less than about 100GB, then due to the way the performance burst credits work you may not get the performance you need. The more you buy, the more performance you get, so don’t short change your app for the sake of a few dollars!

    “Amazon EFS uses a credit system to determine when file systems can burst. Each file system earns credits over time at a baseline rate that is determined by the size of the file system, and uses credits whenever it reads or writes data”
    .

    In early testing, it has been seen that very small filesystems can lead to IO starvation and performance issues. I would recommend you start with 100GB as a minimum (subject to your workload requirements of course!). This is still pretty cheap at only about $30-33 a month; a lot less than even a pair of EC2 instances, never mind the complexity reduction benefits. KISS!

    Of course, the more caching you can do on that content, e.g. using CloudFront as a CDN, the lower the IO requirements on your EFS store.

    For more info on performance see here:
    Amazon EFS Performance

    kiss - Keep it simple stupid EFS

  4. And finally… being NFS based, this is obviously primarily aimed at Linux solutions. It would be nice to think that AWS will release an SMB version in the future… we can but hope!

Thanks to my learned colleague Tom Ellis for the tip! As he says, “The size needs to be determined by the throughput needs, and not the storage capacity needs. “

Find more posts in this series here:
Index of AWS Tips and Gotchas

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