Extremely Slow WordPress Performance

[Flix]

I'm currently developing a site and I'm noticing extremely slow performance on WordPress, under any scenario. Here's the info:

• Shared account running on Jasmine
  
• WordPress 3.4.2, PHP 5.3, MySQL 5.5.27
  
• Default theme; no plugins
  
• A "clean" database with just a few posts for testing
  
• Zero external usage (no visitors yet)
  

The slowness apparently is not influenced by time-of-the-day or day-of-the-week; it happens randomly but very often... about once every 3-4 accesses. For example:

• Loading the home (or any other) page: 10 to 15 seconds
  
• Loading any admin (WP backend) page: 10 to 15 seconds
  
• Loading an item list (e.g. posts page): very slow, posts loading one-by-one*
  

* I've never seen anything like this before... please watch this video to see how slow posts are loading:

 

http://youtu.be/Y384pTeUc8s

 

Any suggestions? Like I said, I tried completely "fresh" WordPress installations but I get the exact same behavior.

[Michael D.]

I was able to reproduce the issue - I disabled all plugins and the issue disappeared entirely and everything worked as fast as expected. I then re-activated all of the previously enabled plugins, and the speed continued to remain. I suspect a bug or issue in one of your plug-ins - if it were a server issue, it wouldn't have changed when I disabled your plugins.

[Michael D.]

Upon further investigation, I was able to reproduce this issue in a vanilla WordPress blog that I created for testing purposes. I created 22 posts that were 120 paragraphs totaling 10,712 words and 72.1 KB each.

 

We performed some additional optimization on our MySQL Configuration based upon the current usage. I believe part of the problem was some cache figures that were actually set too high. The system was spending more time searching those caches than it would take to serve the request directly and then when there was a cache miss it still had to serve the request direct.

 

Along the way we've also adjusted the Query Cache settings a bit, upping the overall cache and upping the query size that can be cached. It's possible that further optimization will be required, as we need to allow at least 24 hours but preferrably a week or two in-between to see how things are performing statistically to identify what changes need to be made.

 

If you have any questions at all, let us know.

[Flix]

Problem fixed in record time! Amazing support; thank you!!!

 

Happy customer!

:)