Archive for November, 2008

Performance !== Scalability

When we talk about performance, it is the response time of a single request, web page, SQL query, etc. It is the actual execution time for something in the absence of load. To illustrate, suppose you wanted to test the performance of a web page using Apache Bench. You should run something like:

% ab -n 1000 -c 1 http://www.whatever.com


The -n is the number of requests and the -c is the number of concurrent requests. Since we’re interested in end-to-end response time, we only need one concurrent request. Scalability is usually about throughput, or the number of concurrent requests within a certain period of time. Using the example above, the Apache Bench command should be something like:

% ab -c 100 -t 60 http://www.whatever.com


The -t is the amount of time to run the test. We can vary -c until individual response times begin to grow, at which point something in the system has reached its maximum capacity.

php|works 2008 Recap

Well, works was the first industry conference I ever attended other than Ohio Linuxfest, and the first conference of any kind since like ACM Sigmod 2000.  (Wow, that was 8  years ago.)  I had a blast and learned a lot.  I even learned about some things related to PHP.

Here are the talks I attended:

The most interesting one for me, uh, emotionally was probably the AI talk.  Brings me back to my days in SB.  The most useful topic which I could probably put to use at work tomorrow was the SMS/XMPP talk.

I managed to make it downtown one night, and got to meet some new people.

The last highlight I’ll mention were the Pecha Kucha talks on Thursday night.  It was interesting and a ton of fun.  The open bar didn’t hurt either.

IMG_2300

See a few more photos from php|works 2008.

Slides from php|works 2008 in Atlanta, GA.  If the Sliderocket version below is problematic, here is the more popular Slideshare version.

Front End Website Optimization

View SlideShare presentation or Upload your own. (tags: yslow php)

Slides From php|works 2008

Slides from php|works 2008 in Atlanta, GA.

Presenting At php|works 2008

Yours truly is presenting at this year’s php|works 2008 conference in Atlanta, GA.  The talk is entitled: “Optimising The Front-End Using YSlow And PHP In A Continuous Integration Environment.” (I prefer the Queen’s English in this case.)

Now, I’ve never even attended a conference of this size, much less presented at one.  So this will be interesting to say the least.  I’m filled with a range of emotions ranging from trepidation to excitement (which is true of most of the things in my life of late.)  I also hope to meet some of the PHP bloggers I read regularly.

But I feel ready.  I gave this talk in April to OINK-PUG.  The one for this week is virtually the same.  Then, for practice, I also gave the talk to the Columbus and Indianapolis PHP meetups in the last two weeks.

Slides for the talk are in the next post.