Why you should always evaluate each new AWS region

Amazon Web Services launched another new hosting region last month, this time in Mumbia, India. The official press release is available at:

Based on our experiences from previous region launches (e.g. Sydney), where we discovered that not all of the services we use/require are available at the time of launch, we decided to compile a list of those features and put together a set of evaluation criteria for determining if/when we might be able to launch some new services from Mumbai.

And while it may seem excessive or wasteful to formally evaluate if all of the services you use are available (plus, the press release normally contains some information about this), we actually discovered that a number of Instance Types (that we were still using in other regions) we not in fact not being made available in Mumbai at all.

Findings

The items below are what we discovered were not as we expected (in the Mumbai region) but the list could, of course, be different for you or for the next region launch.  So there is still value in compiling a list of the services your organisation uses/requires also.

EC2 Instance Types

Not all instances types were available.

Elastic File System

At the time of Mumbai launch this was also not yet available in the Sydney region either.

EC2 API Version

It was actually when first evaluating the Frankfurt region (eu-central-1) that we discovered that AWS would not be supporting V1 of their APIs there (so we had to update some of our tooling). It was the same in Mumbai.

Availability Zones

The Mumbai region only had two Availability Zones at initial launch and this was insufficient for a Disaster Recovery (DR) deployment of MongoDB. This is because MongoDB requires a minimum of 3 members to form a valid Replica Set. And while you can still form a 3-member Replica Set using two AZs, you could lose access to two of those in the event of an AZ failure.

Summary

None of these issues were insurmountable for us but learning about these differences ahead of time did enable us to adjust our delivery timelines and manage customer expectations accordingly (e.g. to allow extra time for new AMI generation), which is a very valuable part of any planning process.