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• Scalability Best Practices: Lessons from eBay (466)

At eBay, one of the primary architectural forces we contend with every day is scalability. It colors and drives every architectural and design decision we make. With hundreds of millions of users worldwide, over two billion page views a day, and petabytes of data in our systems, this is not a choice - it is a necessity.

In a scalable architecture, resource usage should increase linearly (or better) with load, where load may be measured in user traffic, data volume, etc. Where performance is about the resource usage associated with a single unit of work, scalability is about how resource usage changes as units of work grow in number or size. Said another way, scalability is the shape of the price-performance curve, as opposed to its value at one point in that curve.

There are many facets to scalability - transactional, operational, development effort. In this article, I will outline several of the key best practices we have learned over time to scale the transactional throughput of a web-based system. Most of these best practices will be familiar to you. Some may not. All come from the collective experience of the people who develop and operate the eBay site.

Read the rest of the article on InfoQ.