Last year i’ve gave one of my sites to people who really enjoys from opening undesirable sites on multi-user blogging sites. The site was a Wordpress MU site.

After that day they opened about 5K blogs on that site. 5K site means about 55K tables and 165K files on a single mySQL database. Till last month the site worked fine but after that some problems started to occur.

The main problem was sleeping zombie mysql threads created by wordpress mu. They could not be closed until they reach default wait_timeout (which is about 28800 secs.). So after about 20 process or according to server load mySQL starts to not respond requests and reaches maksimum connection limit.

I searched a lot but could not find out a solution. Here are some explanations to improve performance on high volume wordpress mu sites but those solutions won’t help me much. Was trying to decrease wait_timeout to 30 secs won’t help so much too cause whenever server load reaches high values according to high volume of created threads this timeout value could not help you.

So what i did? I simply closed that site. That’s why that site is not important for me, i’m just making a stress test on Wordpress and Wordpress Mu.

But if you’re planning to use Wordpress MU and you are considering that your site will reach thousands of blogs i will not suggest you to use Wordpress MU. This is experimental ofcourse but i’m sure that it’ll end soon with a failure.

I searched a lot for a good working ajax upload script with simultaneous progress bar. At last i found one. File Chucker is the best i think.

If you need to save binary files to a mySQL database you must see this article first : Binary Data + MySQL + PHP. Thanks to writer for good article.

You know that Wordpress has a very well menu on blog entry pages. In fact that is not only a menu, that is a couple of blocks than can include lots of menus. The blocks are not static, you can drag and drop them. Don’t worry, the script will remember where you move and drop them! I searched for the script if it’s a lib. And at last i found that this is a script created by Brothercake.com. The name of the script is Docking Boxes. It has a lot of features than we can’t mention in here. ( And of course you can view all of the pages at brothercake. Very very nice site with very nice code! )

Wordpress blog software saves so much domain related data to database. For example it saves blogs that have pinged your posts (as you consider you can ping your posts also) , your blog url, a lot of permalinks, guids, etc.

So, if you move your blog to another domain you must update all of those. Without updating them most of your links will fail (=gives 404)

I searched Wordpress database to those kind of data. After understanding the database i wrote five mySQL queries to solve this sitiuation.

Here is the five query you must execute at the new server (by phpmyadmin or shell) :

Read the rest of this entry »