I’ve been working on an AWS hosted project and it’s been a lot of fun the only real problem has been keeping up with the changes that Amazon has introduced in the relatively short time span of the project
In traditional projects where we typically deploy to Data Centres the platform is pretty much fixed early in the development process. Essentially this is because a contract will have been engaged for a specific set of services up front, it takes longer for Traditional Data Centre suppliers to provision a platform and only small changes can be made subsequent to this such as network changes, maybe a few more virtual machines etc . So a lot of my time would typically be involved with negotiations with the DC supplier and trying to get the platform sorted as far ahead as possible. This is not ideal for a number of reasons so the arrival of the Public cloud, with self service portals, pay as you go approach, introduction of new features and the ability to try stuff out without a commitment up front has meant that the platform evolves as the application does. The platform within reasons is no longer a fixed constraint.
I will note here though that traditional Data Centres are stepping up to address the new levels of flexibility whether they are dressing this up as their own version of the cloud or just introducing a more appropriate pricing and servicing model .
This evolution doesn’t mean the platform is not defined up front as you do need to know what your platform will be not least because the developers need to know what they will be targeting; the scaling approach needs to be understood up front but also so the client needs to have some idea of costs. This may sound contradictory to my earlier statement but the difference is that although all the usual decision points that apply to the platform for any project are still made the boundaries around the platform are a lot looser. Certain key decisions can now be made a lot later and so more flexibility is inherent without impacting on the total cost of the solution.
Before this particular project I do not recall working on a project where the platform costs have gone down over the development cycle of the project. The scary thing is how fast the features have been pouring out of Amazon which has meant that the actual platform provisioning has had to be as agile as the rest of the development process reflecting how the approach to my role has had to adapt as a result. The Amazon AWS feature changes have not really affected the ultimate target platform in any major way as defined early in the project but there were a number of changes and subtle decisions made as a result of some of the additions. A few of which were considered and in most cases directly affected the solution I’ve listed below (all of which appeared since July).
IAM: identity & Access management:
This feature allows the creation of virtual users with delegated authorization all under a single AWS account
This arrived too late for us as we had to set up individual AWS accounts for the development & test team at the beginning of the project which we then set up consolidated billing for.
Micro instances:
A lower priced instance type that could satisfy the needs of their less demanding applications. , It is a low cost instance type designed for lower throughput applications and web sites. Micro instances provide 613 MB of. Micro instances provide a small amount of consistent CPU resources, and also allow you to burst CPU capacity when additional cycles are available.
Arrived just in time really. The scaled out topology meant the front end web servers could happily run on micro instances and the cost savings will make a significant difference.
Amazon AWS Linux AMI:
The Amazon Linux AMI is a supported and maintained Linux image optimized for use on EC2. It is designed to provide a stable, secure, and high performance execution environment. It also includes several packages that enable easy integration with AWS, including launch configuration tools and many popular AWS libraries and tools. Amazon Web Services also provides ongoing security and maintenance updates to all instances running the Amazon Linux AMI.
This also arrived just in time and although some time had been spent on creating a Linux AMI from scratch where I had adventures with kernel mismatches & creating a new Linux instance using EBS volumes the majority of work carried out was easily transferable to the Amazon Linux AMI.
RDS Reserved instances and Multi-AZ Deployments:
These were just two of a number of RDS enhancements over the lifespan of the project.
Reserved instances are similar to reserved Ec2 instances. Reserved RDS instances provide a significant discount if a one off fee is made up front. This made sense as reserved instances were part of the upfront commitments for the solution
RDS instances can be configured in multiple Availability Zones which provides asynchronous standby replica in a different availability zone. The primary DB Instance is synchronously replicated across Availability Zones to the standby replica to provide data redundancy, eliminate I/O freezes during system backups, enhance availability during planned system maintenance, and help protect the databases against DB Instance failure and Availability Zone disruption. This is a feature that also needs to be implemented.
Resource tagging:
The ability to tag the following types of resources: EC2 instances, Amazon Machine Images (AMIs), EBS volumes, EBS snapshots, and Amazon VPC resources such as VPCs, subnets, connections, and gateways.
With performance testing of different size instances, UAT, pre-prod , prod environments slave and master instances all running. A simple but needed feature to make it easy to identify what environment or size instances were running. Our Tester made copious use of this feature. It arrived in time for us
Downloadable invoices:
I had to include this one in as it was a step in the right direction for corporates to embrace AWS and it also made the financial part of the project a lot easier.
Free usage Tier:
AWS Free Usage Tier a new free usage tier. Beginning November 1, new AWS customers will be able to run a free Amazon EC2 Micro Instance for a year, while also leveraging a new free usage tier for Amazon S3, Amazon Elastic Block Store, Amazon Elastic Load Balancing, and AWS data transfer.
Bah humbug this arrived too late but I had to mention it as what an enticement to those too hesitant to step over the precipice to try out the public cloud go on give it a go .