Wednesday 30 April 2014

AWS Cloud Summit 2014

I have started writing this before the start of AWS' Cloud Summit at the ExCel in London. The AWS Summit is usually a good event and as far as the big cloud players are concerned, is my favourite of the events. There is good attention to detail, lots of vendors, free food and coffee, which is always a major bonus. You get the chance to talk to some of the AWS staff and solution architects, which is always a huge bonus. This isn't going to be a live blog, as you can follow me @EtharUK for that, but at the same time, it will allow me to record some thoughts in more detail as the day progresses.

As it happens, I was at an AWS Bootstrap workshop yesterday and I am trying to hunt down a solution architect who can answer a question I had from that, Sabastian the trainer couldn't answer at the time. Best go find such a target...


I was worried that I wouldn't be able to sit through the keynote as it was going to be two hours long. However, Steve Schmidt's presentation was actually quite informative.

Carlos from Just-Eat showing how AWS has facilitated their agility

Carlos from Just Eat was here again, but Channel 4 put in an appearance, explaining how data drives their advertising decisions, which in turn have led to an 8-fold increase in benefit to customers.

The current AWS estate

The top-level AWS service catalogue hasn't seemingly changed much from last time. That said, the number of services, which include addtios to service offerings, which I would have liked to hear more about, has increased dramatically. So much so, they didn't fit on a standard linear graph, which could have had a much stronger impact. Oh well, they're techies :o)

Schmidt showing us the mis-scaled pace of innovaiion ;)

The one thing we heard a lot more of was governance. Whilst AWS provides enough tools to deliver a reasonable level of governance, there was much more a hint around how it was being used in the enterprise sphere.

There has recently been a lot of noise about hybrid-cloud solutions. Steve Schmidt spend a little bit of time mentioning the interoperability of cloud and on premise solutions. In my experience, there is a lot more to it.

My epic fail attempt to win a Kindle

What's the answer to my question?

Yesterday I was at an AWS workshop. In it, Sabastian the trainer, mentioned that records deployed to an AWS availability zone, with a slave availability zone, would synchronously commit changes on the master and the slave. It doesn't commit this to the master until it has been committed to the slave. This gave me some cause for concern.

The aim is if the master availability zone goes down, the slave doesn't goes down. This is sensible form the point of view of the master. However, if the slave availability goes down and the master doesn't commit unless the slave also commits, then unless there is a way for RDS to commit this to the master, you have an issue. Indeed, this situation could technically result in lower availability than running single instances of the DB.


Firstly, I am pretty sure that this is DB instance independent. Assuming you have a synchronous process that requires two activities to complete successfully. However, I have not seen or heard evidence to suggest this is a two-phase commit process. So to illustrate the issue, an example might be useful.

Supposing the two cloned platforms across the two availability zones each have a 99.95% availability. For a master-slave configuration where the commit of the master is dependent on the slave, this introduces a dependency chain and means that the whole uptime of your entire platform requires both services to be up in certain configurations. The result is this reduces the availability to about 99.90% (i.e. the probability of both systems being up). This is lower than any single server and certainly lower than systems running independently in parallel.

This doesn't mean that it is a problem. After all, you can architect to remove this risk and hence increase the availability of the data sources as a whole. However, I put this to our trainer yesterday and he said he'd go away and ask. Hence, I didn't receive an answer at the time.

I spoke to a solution architect this morning and he too didn't have an answer. So it would be good to get one. I am not too bothered whether it is positive or negative, but it would dictate the complexity of a system design and also provide a theoretical constraint to conduct trade-offs around . Known-unknowns can be troublesome, especially if you've only just discovered it, since it was an unknown-unknown before. I must get round to chasing this up.

**** UPDATE: After chasing this up, it appears that there isn't currently any documentation to corroborate the assertion from a few other SAs that the platform would prevent the saving of data in the event of an AZ failure. However, this also doesn't tell me if it wouldn't. I've had my details taken but no sticker given ;) ****

400 - EBS and EC2 Optimisation

This was a 400 track. There were some extremely useful slides in this track. AWS went through an intro explaining that EBS is basically a storage mechanism with a queue attached and is not like a normal disk. I still think it kind of is, when you include the buffers and caches. Both standard EBS and EBS PIOPS (Provisioned IOPS) were introduced and in the latter case, we briefly touched on the configuration of the IOPS provision.

However, importantly for me, the existence of a formal queue defines a specific need to understand the block size per IOP, as this can significantly affect the throughput of the system. The bigger the ECS instance, the more you can write (specifically, the faster you can write the data), the bigger the EBS queue, the faster it can write the standard 16K blocks.

This suggests that the best way to write the data to disk is to chunk them up in 16K blocks (or multiples thereof) and write them in parallel, which was suggested in yesterday's workshop.

200 - Hybrid Environments with AWS

This was an interesting track, however most of this is pretty standard. For indeed, some of my clients have done this for a while. I have a much greater appreciation of this via some of the security group work I've done since last year. So I am liking the way that hybrid and cloud solutions can work together. There didn't seem to be too much that was new though.

Hybrid Environments - Yes, I was a bit late to this one :-S

300 - Building for availability and cost

Fitz, a solution architect at Amazon presented's autoscaling solution. Through all Autoscaling demos at this conference, the mantra "scale up fast, scale down slow" was repeated. This is because it takes little time to prevent an AWS EC2 instance from receiving traffic, but it can take an age for it to get to a position to receive traffic. So that makes sense.

End of Day

Not a bad summit. I don't think I will take away as much from this as I did last year... aside from that my weight isn't appropriate for perspex chairs (Sorry Amazon). Amazon always put on a very good show. I'm sat here with a beer whilst I prep to tackle the tube 'struck' TFL public transport system before getting my train to Manchester. There is a lot to take away and I'll have to let that lot ferment as much as the beer before brewing up a new vat of ideas for the future of my architecture work with the new tools AWS provide. I am still to be convinced of the some of them, such as the need for schedule based autoscaling, which I see as a way to circumvent the 15 or 20 minute spin up of a new platform. However, they do solve some problems so are not at all without purpose. Especially in warming up environments for immediate use. 

Additionally, the EBS optimisation session has set off a few ideas around using queuing theory to try to explain some of the numbers Amazon have found in their testing. One thing that appeared time and time again was the experience of other speakers, a large proportion of whom spent a lot of time and effort creating PoC platforms to prove the viability of AWS.

Friday 11 April 2014

Google Cloud Platform Roadshow: Manchester

Welcome landing slide

I had the good fortune to be at Google's Cloud Platform Developer Roadshow, which kicked off in Manchester's TechHub this week. The combination of my early arrival, never having visited the old TechHub building, not being able to get into the new building, the TechHub website still showing the old address, Google showing the new one did make for an interesting rush as I did wonder where I was supposed to be. When I then incorrectly found myself back at the old TechHub offices, I wasn't alone it seemed as I met a few students who also didn't get that memo :)

In the end, we got ourselves back and were rewarded with coffee and breakfast pastries, which given I hadn't had breakfast, more than made up for it. Even if It did mean my name badge curled up almost instantly due to the amount of very brisk walking my 118kg frame (+7kg laptop bag) had done back and forth.

Curled up name-badge worn by Mr Radiator :-/
Having lost my original seat, I then initially got relegated to the cheap seats, so figured I best move :)

Not a great view :-D

Introduction to Beer and Salvation

Doug Ward (@SimplyDoug1987 on twitter) ran through the usual housekeeping and informed us that we mustn't stop to collect personal belongings but to save the beer. I thought that was a good point as nobody usually likes a warm beer. But as as Brad Abrams, Group Product Manager introduced the agenda, the Fireside chat did make me wonder if avoiding warm beers were really the motivation to save them after all :)

Doug Ward keeping house


Brad Abrams ran us through a quick whirlwind of the Google platform. I was pretty familiar with this already, though I don't use Google AppEngine much. I overheard Brad talking to a group and mentioning that they are in the process of supporting SQL Server 2008 R2. Not quite clear as to how as yet myself. Still quite intrigued and so I gather, was Mandy Waite when I approached her about it towards the end of the day.

Google's Cloud offering

Developer Advocates Mandy Waite and Laurence Moroney joined Brad after he presented the agenda, to walk us through a number of deep-dive demos of Google's AppEngine, including presenting the new OnDemand pricing and Sustained Use discounts for any usage over 25% of the month on each platform. This is a very useful discount and after I questioned Brad on whether or not it had to run continuously, he confirmed that it didn't. It just had to use 25% of the 10 minute blocks of a whole month of OnDemand use.

New Google AppEngine Pricing Model

For those outside the Microsoft sphere, together with the drop in OnDeman pricing, this suddenly makes the Google AppEngine a very attractive proposition. I intend to cover why in a later blog post, but like other models on the market, this has the ability to create a maximum amount of compute and storage costs that you have to pay per month, but applies it on what you actually use, unlike AWS and Azure, where you either commit to reserved instance pricing, or 6 to 12 month blocks up-front, which hits agility and also fixes your discount to a level above your real OnDemand usage (if you pay up-front and use significantly less than you forecast). See the Moz story for an example (though this appeared to be an issue with technical best-practise and inefficient use of AWS, which in my experience of PR and marketing agencies, is unfortunately all too common an occurrence).

The focus was very much on mobile development and there was a lot of mobile developers in the audience as well as some familiar faces on the Manchester tech scene (See the back of Saftag's head below).

Shaf Chaudry showing sponsors around  before the start


Mandy and Brad ran through the creation of a Sudoku solver and Meme Maker using Python, this was supplemented with an Andoird App written in Android Studio (which by the way, I really like! It's much better than Eclipse, which I've done a bit of work in before, and brings a lot of Resharper like functions to the IDE - which I really missed in Eclipse). Requests were made through JSON secured with OAuth tokens.

Mandy and Laurence both demo'ed the boilerplate for hosting through the AppEngine API, demonstrating the use of Python scripts and the gcloud CLI tool to manage the OAuth keys (which is a much more long long winded process) and testing functions through Google's Developer Console. I've used this before to generate requests and test access to Calendar info for some .NET projects I've done and to be honest, it's best of breed at the moment in this particular area, but AWS still hold the balance of power across the board IMO.

Brad explained that the environment gives Google developers a free Git instance and runs your unit tests if you have them. This then displays the results in the console for you to check on. This is a pre-ested commit (gated check-in) so if it fails, it doesn't deploy to live. This is nice, but AWS also has a free git instance. The key difference is that Google's Cloud Developer console has in browser editing, which automatically runs the tests again and deploys it to live, but also puts it in the Git repo for your team (or another dev team) to pull later. This is crucial, as cross team development needs up-to-date and common code bases to use and the ability to force changes for DevOps/App Support staff, but still maintain the consistency of the code base is essential!

Brad and Mandy run through the storage of images in buckets for the meme-maker demo app


All in all, there was a good number of take-aways. Given my current working platform (Microsoft) I don't see myself changing off AWS any time soon. That said, the MS hold has more or less lipped away from a large number of small business and start-up community groups. So I can see this featuring very heavily in interaction with those markets going forward.

Google AppEngine definitely offers a good (and quick) alternative to AWS if you want to host OSS platforms. I think they're still a little slow on the release of new language support, as they pretty much had the same languages on offer as two years ago. That said, there are some very nice touches in AppEngine, such as the ability to SSH into your Linux VMs and work on them locally. However, if your main work is PHP, Java and especially Python, you can be up and running with a fast platform, very quickly and cheaply.

All in all, a good half-day. The beers didn't need saving either :)