What’s in an instance

I’m happy with the performance of the web site on the new AWS Instance.   The initial instance was the ‘t1.micro’ which is the old option from Amazon using para-virtualisation (PVM), unfortunately performance on this instance was terrible as access was capped at 10% of the CPU and the cycles ‘stolen’ exceeded 90%.

Instead of sticking with the poor performing PVM I’ve opted to moved to a HVM instance which allows for bursts in processing capability above the subscription level, providing you have sufficient cpu credits available that is..   A CPU Credit is simply an accounting of when your not using the full amount of CPU your subscribed to, so you can use it to burst later.

I’ve also enabled caching via Amazon CloudFront, which will cost a little extra but delivers all the large content (images, style sheets, etc) via the AWS Cache and Proxy servers reducing load time for the user and reducing performance overheads on the virtual server.

The change in performance with both of these changes is significant with page rendering times down under 5 seconds for all content.   I’m hopeful that this will continue to be the case.

The site has been fully migrated to the new instance, and the mailing list migration will likely occur next week.

If you experience any issues, please let me know.

Jason (vk2vjb).