amazon have just released ebs, the final piece of technology that makes their ec2 platform really viable for running lamp stacks stuck as drupal.
ebs, the "elastic block store", provides sophisticated storage for your database instance, with features including:
- high io throughput
- data replication
- large storage capacity
- hot backups using snapshots
- instance type portability e.g. quickly swapping your database hardware for a bigger machine.
recently i posted a couple of introductory articles on jmeter, a great apache open-source tool that allows you to measure the performance and scalability of a wide variety of services, especially web-applications.
i wrote these articles because although the online documentation provides reasonable reference material, it doesn't serve well as a jmeter introduction or tutorial.
things have changed a bit since then. the uk-based publishing house packt publishing were kind enough to send me a copy of emily halili's newly published book on jmeter, which is as far as i can tell, is the first book dedicated to the subject.
amazon are quickly rectifying these problems, and recently announced elasic ip addresses; a "static" ip address that you own and can dynamically point at any of your instances.
today amazon indicated that persistent storage will soon be available.
in this article we get a sense of lamp performance on ec2 by running a series of benchmarks on the drupal cms system. these benchmarks establish read throughput numbers for logged-in and logged-out users, for each of amazon's hardware classes.
we also look at op-code caching, and gauge it's performance benefit in cpu-bound lamp deployments.
the previous article showed you how to set up jmeter and create a basic test. to produce a more realistic test you should simulate "real world" use of your site. this typically involves simulating logged-in and logged-out users browsing and creating content. jmeter has some great functionality to help you do this.
when making scalability modifications to your system, it's important to quantify their effect, since some changes may have no effect or even decrease your scalability. the value of advertised scalability techniques often depends greatly on your particular application and network infrastructure, sometimes creating additional complexity with little benefit.
apache jmeter is a great tool to simulate load on your system and measure performance under that load. in this article, i demonstrate how to setup a testing environment, create a simple test and evaluate the results.