I make about 1200 categories and subcategories.
5 main categories and 1195 subcategories.
When i click the link (one of the main category), the site is very long loaded.
I enable Debug Mode and have seen, that the system does 1225 queries to a DB.
When i click the other link (other of the main category), the site is very-very-very long loaded.
I enable Debug Mode and have seen, that the system does 4243 queries to a DB.

I think it is bug.

How can I reduce CPU load?

p.S. i use k2 2.1

Hi. Try to set "catalog mode" to yes in order to prevent K2 to check each subcategory for children. If you set this to yes and you want to display also items from the children categories try to create a menu link and select them manually. This way you will dramatically reduce the number of queries.

where can i change the "catalog mode"??? i have the same problem. my server blocked my site because it is loading a lot of CPU and it can damage other sites that are hosted there.

Catalog Mode is found in the category params. you assign it per category.

nuno miguel duarte santa antunes said:where can i change the "catalog mode"??? i have the same problem. my server blocked my site because it is loading a lot of CPU and it can damage other sites that are hosted there.

What else can be done to reduce the Resource utilization of K2 ? We have a pretty small site by K2 standards hosted on Rochen.. using K2 primarily because of the categorization flexibility it offers.

We have benchmarked the site & it seems only K2 is to blame.. there is practically nothing else on the site..

Total articles are only 110 ..

Need help ASAP !

Hi. K2 is designed with performance in mind. It powers gazzetta.gr and tnawrestling.com which are the second and thrid most popular, heavy traffic Joomla! sites around the world. So if you are sure that K2 is the reason your site is slow please try the following:

1. Make sure that Joomla! cache is enabled.
2. Enable the system cache plugin.
3. Switch catalog mode setting to "Yes".
4. Check for any other extension causing performance isuues.

Parth Lawate said:What else can be done to reduce the Resource utilization of K2 ? We have a pretty small site by K2 standards hosted on Rochen.. using K2 primarily because of the categorization flexibility it offers. We have benchmarked the site & it seems only K2 is to blame.. there is practically nothing else on the site..

Total articles are only 110 ..

Need help ASAP !

Hi,

We have catalog mode set to no for our News & Blogs Sections where it needs to be no. Everywhere else its set to yes. Regarding Cache we have the Joomla cache ( global config ) set to yes & also have the the system cache plugin enabled..

This could easily be optimized with the addition of a denormalized "hasChild" column to the k2_categories table. When a child is added or deleted, this flag would need to be updated. For situations like the ones described, it could be used to short circuit unnecessary queries for categories with no children.

By the same token it makes sense to also have a "hasItem" flag.

Makes sense..

Maybe one of the devs can make a comment on this ?

Parth

David R. said:This could easily be optimized with the addition of a denormalized "hasChild" column to the k2_categories table. When a child is added or deleted, this flag would need to be updated. For situations like the ones described, it could be used to short circuit unnecessary queries for categories with no children.
By the same token it makes sense to also have a "hasItem" flag.

General Question ,

For a site hosted at a Shared host like Rochen , should a site having around 250 visitors per day as per analytics and roughly 110 articles.. should it need a VPS ?

No, 250 visitors a day is very low traffic.

Parth Lawate said:General Question ,
For a site hosted at a Shared host like Rochen , should a site having around 250 visitors per day as per analytics and roughly 110 articles.. should it need a VPS ?

I thought so too..



David R. said:No, 250 visitors a day is very low traffic.
Parth Lawate said:General Question , For a site hosted at a Shared host like Rochen , should a site having around 250 visitors per day as per analytics and roughly 110 articles.. should it need a VPS ?

It also occurs to me that if this work is going to be done, each category could also store the number of items, which would relieve the necessity to do a SELECT COUNT(*) query for each one, and perhaps also in the process fix the mysterious subcategory count bug that has been reported by me and at least one other person. ;)

I feel strongly these are optimizations that would be very good for K2 performance since the ratio of read to write is typically going to be very high. Certainly caching is advisable, and "Catalog Mode -> Yes" is an acceptable switch for some people, but this would be far superior to that.

The only downside I can see to these suggestions is that there would need to be an integrity checker that goes through all the categories and items and validates the denormalized columns in the case that mysql has a problem, although that would not be a difficult utility to write at all.

So, in conclusion, storing a childcount and itemcount column in the categories would be all that's needed, and would provide great optimizations.

-No need to do count(*) for items
-No need to query for items when itemcount == 0
-No need to iterate on a subcategory if childcount == 0.

This could be *supercharged* with the addition of a category_item_xref table which would store a full list of all child categories for a category. It would simply flatten out the hierarchy so that you have a 1-M of all the child, subchild, subchild etc. categories for a particular category. Needless to say there would be no need to ever recurse given the availability of this table and associated index.

I haven't fully thought it through, but the itemcount in the category would eliminate concerns about displaying itemcount data, as you would be able to get everything required in one query/result set to display category and item data.

David R. said:This could easily be optimized with the addition of a denormalized "hasChild" column to the k2_categories table. When a child is added or deleted, this flag would need to be updated. For situations like the ones described, it could be used to short circuit unnecessary queries for categories with no children. By the same token it makes sense to also have a "hasItem" flag.

I agree that these optimizations would really help..

Catalog mode isnt really very useful when you want to use the full power of K2 as a cck..

Hi again. For all of you having performance issues with K2 please have in mind that K2 full of possibilities. The performance of K2 depends on your setup. When performance is an issue it is highly recommended that you set "catalog mode" to "Yes" (under category settings) and "Fetch items from children categories" to "No" (under menu settings). Also caching is very important. K2 can handle sites with million of visits. In any case to see what are the queries that the component is performing you can enable the system debugger and request a K2 page by adding tmpl=component in the URL. This way Joomla! will render only the component and you will see the number of queries that K2 performs.