Google/Yahoo Best Practices pointed out that Google and Yahoo created lists of best practices for website performance. Google and Yahoo are not alone. A recent web search for “performance tips for web applications”got over 30 million hits.It may be useful to break this topic down into subtopics. We could then classify tips according to subtopic, which would make it easier to find what we need. Instead of searching allthe tips, we could search only those that pertain to the problem we are facing. This article is my first attempt at creating a taxonomy (categorization) for this purpose. I will not be following the topic further in future articles, but perhaps this article will suggest an approach for those who do.
Chronological Basis
The first level of a taxonomy could start with the chronological chain of events that occur during an end-user’s transaction:
- the client issues the request,
- the request journeys to the server,
- the server processes the request,
- the server executes a script,
- the script requests services,
- the response journeys to the client,
- the page loads, and
- the client-side script executes.
If these events were processed serially, the overall response time would be the sum of the time spent at each link of the chain. This means that a slowdown in any one of these events will affect the overall response time. When the user perceives an unacceptable response time, it often means that only one, not all, of the above events are responsible. One event is often the weakest link in the chain.
Identifying the weakest link in the chain and fixing its problems gives us the best payback in terms of overall performance as a function of resources spent. If performance tips were classified according to the events they affect, it would be easier to focus in on the tips that give us the most bang for our buck.
Synchronicity
The above chain of events is mostly serial. There are exceptions, though. Example: A page can start to load before the entire web page has been received by the client.
If we can make any part of the above pro_cess asynchronous, that will improve performance, so this is another category we need to add to our taxonomy.
The Taxonomy
The left-hand column of the following table contains the nine categories introduced above. The right-hand column contains examples of tips that affect the categories to their left.
The tips are intended to aid in understanding the categories. They are not intended to be an exhaustive list, nor to be in sufficient detail to be usable. The detail will come in future articles.
