JCS regions explanation or documentation

Hi,

I'm trying to understand what the JCS regions that are set on LiveSite runtime.

Component
Page
Stylesheet

From my testing, it looks like the Cache time setting in the component editor, is what causes an item to be added to the Component region. If you set to Do not cache nothing appears in that region. What is cached looks to be the component Content XML.

Page seems obvious enough, but unclear if you always need to clear the page, to see a component change, more testing required there.

The Stylesheet, from what I can see in the cache is a copy of the Appearance XSL, when you externalise the XSL for a component, and wish to update that XSL without republishing the component, its not clear how the cache is expired. The IW docs suggests externalising XSL but mentions nothing about the caching implications.

Could anyone point me to some docs that can explain this in more depth?

Thanks

Find more posts tagged with

Comments

Rick Poulin

The only description I've ever seen for this is in the cache.ccf config file itself. (Other than a slide in a webinar that repeated more or less the same thing). So, purely based on my own experience and emperical evidence:

* The component cache stores the final rendered component, i.e. the result of the XSL transformation in to an HTML blurb

* I have no idea what the page cache actually does, because to me it seems like it doesn't do much. Maybe it remembers page properties and the list of components within it.. not sure.

* The stylesheet cache appears to cache the externalized stylesheets that come from the workarea/webroot. In contrast, those stylesheets that come from the classpath are instead "cached" by the classloader rather than JCS.

I can do my best to answer more pointed questions or discuss a specific use case, if that's where this is going.

map.jpg

tbkeith

Hi,

I am trying to understand when I need to clear the cache regions.

My components all use external stylesheets that are located in the iw/xsl-includes folder.

All the components use DCR as main content, there are the odd config options that are setup as Datums in the Content XML section.

From my testing, it looks like component region in JCS is actually the component data, so the merged Content XML document that is produced when previewing a component.

Page as you say it looks to be an object that holds things like Title, Keywords, controllers, components

This would need to be cleared if you updated any of those items.

So I'm going with this:

Component region - holds the Content XML of the component

Page region - holds metadata about page including components

Stylesheet region - holds the Appearance XSL of the component

Page cache invalidation should be handled OOTB by workflow, but for component and stylesheet, I will need to write some custom code during the workflow that checks for certain files in the job and then clear the cache, I'm not clear how I would be able to identify the individual key, so will have to clear the region (subobtimal)

map.jpg

Rick Poulin

tbkeith wrote:
Page cache invalidation should be handled OOTB by workflow, but for component and stylesheet, I will need to write some custom code during the workflow that checks for certain files in the job and then clear the cache, I'm not clear how I would be able to identify the individual key, so will have to clear the region (subobtimal)

The OOTB cache clearing should also clear the components on the page(s) that were published, so the only use case you might have to custom code for is the case where you update the XSL and want to selectively clear areas of the cache that are using it.

map.jpg

tbkeith

Yeah I tihnk thats fine when you publish a page, but if its only a DCR then a custom workflow task would clear the cache.

Thanks for your help.

map.jpg

Rick Poulin

Ah yes, that's true.

map.jpg