Amazon announces beta functionality that will address the biggest hassle for using EC2 servers for running web applications — a file system that won’t vanish if an instance stops running.
Chief Evangelist Jeff Barr explains the issue the Amazon Web Services Blog:
If you have taken a close look at Amazon EC2, you know that the instances are ephemeral. The instances have anywhere from 160 GB to 1.7 TB of attached storage. The storage is there as long as the instance is running, but of course it disappears as soon as the instance is shut down. Applications with a need for persistent storage could store data in Amazon S3 or in Amazon SimpleDB, but they couldn’t readily access either one as if it was an actual file system.
For my experience and those of others, instances expectedly shutting down has been rare so far, the possibility of catastrophic proportions was real. If an instance were to unexpected shut down it would be the equivalent of a traditional server’s drive array catching on fire — the data would be lost forever unless you had a very good backup system in place.
This shortcoming was acceptable in that EC2 was created for computing power and not general usage hosting, but that’s not what a lot of
people wanted to do — many wanted to run web apps with SQL databases and other things.
So the ability to hosts sites or applications or run a SQL database server using EC2 instances was possible the onus has been on everyone using an instance to run file and database backups or even (multiple) replicated database servers even if high availability wasn’t a
requirement so data wouldn’t be lost in the event of a failure.
Later Barr continues:
…our forthcoming persistent storage feature will give you the ability to create reliable, persistent storage volumes for use with EC2. Once created, these volumes will be part of your account and will have a lifetime independent of any particular EC2 instance.
In addition to being able to create and then mount these volumes of persistent storage from any EC2 instance, Amazon will be releasing functionality that will take snapshots (backups) of volumes and store it in your S3 account.
I also assume that you can mount these persistent storage volumes from multiple EC2 instances.
This is addition is simply huge because it makes Amazon a viable hosting option for web applications by eliminating the biggest technical hurdles. With this shift from compute to more general purpose server resources, I think a seismic shift is certain for how web applications are developed and deployed and Amazon is poised to win big.
