CODEWITHSUNDEEP
amazon-web-servicesamazon-ec2
firecasey
firecasey

Reputation: 97

Is it possible to auto scale with amazon web services, with ever changing AMI's?

Curious if this is possible:

We have a web application that at MOST times, works just fine with our single small instance. However, when we get multiple customers running simultaneously intense queries (we are a cloud scheduling service); our instance bogs way down to near 80% cpu load and becomes pretty unresponsive.

Is there a way to have AWS fire up another small instance (or a few), quickly, only for the times that its operating under this intense load? BUT, the real question is how does this work when we have very frequent programming updates to our application? Do we have to manually create a new image everytime we upload a code change???

Thanks

Upvotes: 0

Views: 537

Answers (1)

jamieb
jamieb

Reputation: 10033

You should never be running anything important on a single EC2 instance. Instances can--and do--go offline randomly. Always use an autoscaling (AS) group that spans multiple availability zones. An AS group will automatically bring new instances online when you hit a certain trigger (in your case, CPU utilization). And then it will scale down the instances when traffic subsides. Autoscaling is the heart and soul of AWS and if you're not using it, you might as well be using a cheaper (and more durable) VPS host.

No, you don't want to be creating a new AMI for each code release. Ideally you should use a base AMI (like one of Amazon's official ones) and then have it auto-provision at boot. You can use the "user data" field when you launch an AMI to bootstrap this process. It can be as simple as a bash script that pulls from your Git repo to as something as sophisticated as Puppet or Chef.

The only time I create custom AMI's is if the provisioning process just takes too long. However that can almost always be solved by storing the needed files in S3.

Upvotes: 4

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