Here is a howto on why some blogs suddenly slow down and what you can do if it happens to you!
Reference : Testing Why My Site Is Slow Suddenly
You can test your own site by going to the login page for your blog. If this loads immeadiately then the chances are your site is using a script that is slowing the building of the page due to another server having problems. This is because typically the login page for a blog does not have any scripts calling to outside servers.
PHP creates the pages on the fly. This involves the webserver and the database. If you have scripts that generate content such as blog rolling, Eco System etc then your php page makes a call out to their servers and waits for the data response before it can continue finishing the build of your page. If those servers are slow then it will increase the time it takes for your page to load.
What can you do? Disable those scripts on your page in the template until such time that those overloaded servers are back up to full speed.
Read the error_log in the root of your account via FTP or CPanel. The error log will show timeouts etc that PHP reports.
Keep in mind for those of you that have instalaunches or powerlines etc that when you get instalaunched then so do all the scripts on your pages. We recently had an issue where a fun little script on justagirlintheworld.com
caused this very same issue when she was highly publicized on some blogs. It appeared as if her site was slow and that the server was having issues, however, upon checking the error_log in her account we saw that one little script plugin called audioscribbler that calls to its server was causing her entire front page to not display because they were unable to handle the traffic requests from justagirlintheworld.com
. Upon disabling this plugin her site immediately began displaying and handled the hundreds of requests coming in per minute. When we checked the traffic for her site that day she handled almost 250,000 hits.