Is this killing my server?

I got mail from my hosting guy today. I remember someone mentioning this before but we need to look into this - Alex Plz...

I'm {Cust Support}, {MyHosting} member staff, and I'm monitoring the server3 closely since yesterday as the server was acting up and down.
I just found there may have a problem with thej2ee.com : a lot of calls to your site suddenly happened (80+), making the server load jumping to 40+ in seconds.

Please have a look at your error log in your cPanel, you'll see many entries like that :
 
[Fri Feb 11 05:00:07 2005] [error] [client 203.101.44.94] File does not exist: /home/thej2ee/public_html/awdemo/jscalendar/menuarrow.gif
[Fri Feb 11 05:00:07 2005] [error] [client 203.101.44.94] File does not exist: /home/thej2ee/public_html/awdemo/jscalendar/menuarrow.gif

This already happened at least 3 or 4 times today, so please fix this issue asap as this kills the server.
 
Thanks for your cooperation.

I guess, few more people must have similar experience. Dynamically generated CSS code is making multiple request for same file and like the CS said more than 80 request at a time.

I'll try on my local machine and send more debugging info.

I guess in this particular case the file "menuarrow.gif" simply does not exist (in the expected location) and this is actually quite bad because then it cannot be cached at the client side and is requested again and again.

However this problem exists even when the filename is correct. If multiple references to the image file are created dynamically with script/CSS - IE is trying to retrieve the image multiple times. The solution is 1). make sure the images are cached by the browser AND 2). preload images BEFORE inserting them by script.

Here are some hints on IIS configuration:
http://aspnetresources.com/blog/cache_control_extensions.aspx

I am using Apache with the following line in .htaccess:
Header set Cache-Control "post-check=999, pre-check=1000"
AND I am preloading images on the main page BEFORE starting the grid. This fixes the problem in 95% of the cases. If somebody comes to your site with the browser cache switched off you are out of luck.

BTW: those images in your error log are not related to the grid :-)