Just upgraded our client boothmed.com to the latest JoomSef plus Virtuemart extension and when you get 3-4 levels deep in the categories, MySQL takes a huge hit.

If I disable JoomSef, they are almost instant but, when enabled, CPU goes back up.

Thoughts?

www.boothmed.com/tuttnauer-autoclave-parts.html

Click on any one of the top links to see what I'm talking about.

Any thoughts? This is killing our performance right now.

OK, ran some more tests and we have confirmed that the deeper the category level in Virtuemart, the slower JoomSef MySQL queries get. When you get 4 levels deep, pages are taking 30-60 seconds to load vs instant for products 2 categories deep.

If you disable JoomSEF, everything loads instantly.

Hello,
make sure that the menu module uses functional caching. That is vital for the speed.

Thanks Jan, I found out late last night that my assumption of the virtuemart multi-level slowdown was the problem. It wasn't. We moved the virtuemart category to a 2nd level and it's still SUPER slow.

What would cause some virtuemart categories to be slow and others not?? If I disable Artio Joomsef, it flies.

Thanks

Well, I think it might be same as the problem that was already discussed here several times.

The problem is JS-based menu that has a bug in caching.
Depending on how much a specific category has subcategories (and the whole category tree belllow), JoomSEF is forced to SEO every link to each category again and again. Sometimes it may be dozens of categories, which means dozens of extra SQL queries. (and in case of nested categories quite complicated ones, because if you have set that all categories should be included in the URL, it needs to get from child category all the way to root category).

That can even multiply the number of categories by the ammount of levels in menu. So easily, the number of queries may get even to hundreds!

Normally, this should be suppresed by using cache (both for JoomSEF and the menu module).
But there exists number of menu modules for VirtueMart, where the caching does not work as supposed and all those queries are run with each request.

Therefore, my recommendation is to:
1. either do not use JS menu, that loads too many links at time; (or use AJAX menu, when the sub-categories are loaded on-fly)
2. or make sure that the caching for the menu module works as supposed (than means that the menu is cached as a piece of HTML code and the SQL queries are thus not run with every request)
3. do not use "include all categories" in URL, but use "use only last category"
4. get stronger SQL server :-)

ideally - combination of all

Anyway, the most effective of them all is to reduce the number of SQL queries and functional caching is the only way to achieve that.