Optimization problem and strange error

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narolis

Hi,

I have 2 big problems with the CMS i'm doing (we developed our own CMS)

1- We need to optimize it a lot because 1 of our client said that after about 30 min on Internet Explorer 8 the CMS is lagging and she must close the browser and reopen it.

2- The same client send us a very strange erreur I never saw:

Method not implemented
get to /index.html not supported
Additionaly, a 404 not found error was encountered while trying to use an ErrorDocument to handle the request.

Our CMS use PHP, ajax, jquery, prototype.
Can you please tell any optimization methode (ajax, jquery, prototype, method to use ans not to use, …) and any theories/solutions for both problem

Thank you

sohguanh

Optimization is a very big and complex task in IT system. Almost every tier or level can introduce the delay observed. Based on my working experience I can provide below but it is not complete by any means. Other veteran IT developers may want to add on.

Assume your CMS do talk to a database, check the SQL statement. Which SQL statement take the longest to finish. Check which SQL statement although execute very fast is called very often by the application layer.
Application layer sometimes depend on the programming language. For Java and PHP or others, garbage-collection can cause a noticeable delay if the application allocate memory in great abundance without resort to pooling/caching.
Application layer design also matter. If a task need to go through multiple layers due to OO design, it can matters especially if that task is called very often throughout the whole application life-time.
Client layer which has garbage-collection also have a part to play. This is especially so nowadays JavaScript has taken on an increasing prominent role in doing more computation and complex UI coding compared to 10 years ago.
With AJAX catching on fire, developers may get carried away by making extensive use of this technique to provide a more "smoother" web browsing experience but at the back-end HTTP request is "bombarding" the server and the server will be very busy serving all those request.

So essentially I group them into 3 layers. Client, Application, Database. Each layer need some investigation on it alone.

Long long time ago, client are "dumb" I call it the thin client technology so I usually focus on application and database but now at the rate JavaScript evolve, it is also time to focus attention on the client layer. Not to mention some JavaScript files can run into thousands of lines leading to loading issues on the web browser at times.

The thin-est client layer I could think of will be those Mainframe dumb terminals with the green characters on the black monitor. I cannot even use mouse to click on the screen :mad:

Stephen_Philbin

The first step towards finding the cause would be to figure out if the slowing down is in the browser or the server. From what you've said, I'd be inclined to think it's the browser (especially since the browser is IE )

Does this problem only occur when a user is logged in to the CMS as a user, or does this problem happen even if the user is just loading through page after page without being logged in? Is the problem always fixed by closing the browser, or does this slowing down sometimes persist even after the browser has been restarted?

If the problem is always fixed by restarting the browser and it happens regardless of whether or not the user is logged in, then it's almost certainly a problem with the browser.

If it is the browser, then the most likely culprit would be Javascript. When the slowing down starts to get bad, just close any tabs containing the site you're making without actually closing the browser. Just have another tab open on Google or something and then start trying to get your site to slow down in another tab. A lot has changed in browsers since I last did any amount of Javascript, but I would think that it is still true that all memory allocated for a site's Javascript should be purged when closing the tab. So if you can get your site to slow down and then speed back up by closing just the tab that it has been running in, and then opening a new tab and going back to your site in it then it'd go a long way to confirming that Javascript is the cause. Another way to check would be to go into Tools->Internet Options->and then untick the box for enabling Javascript. If your site stops slowing down after disabling Javascript then this will be a big clue.