[jbosscache-dev] CacheLoader preload with region based marshalling

[Manik Surtani]

On 5 Jun 2008, at 13:39, Brian Stansberry wrote:

> The regions are created/registered after start(); i.e. after the  
> point shown in the logs.  This is why I think it might just be a  
> configuration mistake that's been in AS 5 all along; just wasn't  
> exposed due to JBCACHE-1358. (In AS 4 there is no cacheloader  
> involved.)
>
> Perhaps w/ region-based marshalling I shouln't use <preload>/</ 
> preload>. A nice fix to http://jira.jboss.com/jira/browse/ 
> JBCACHE-1009 would include logic to defer the preload until regions  
> are activated.

Yes, agreed.  And this is not necessarily overly complex to do either:

When preloading stuff from cache loader:
1) Loop through all Fqns to be preloaded.
2) For each Fqn being preloaded, if any state is regionalised (i.e., a  
non-null region) check if the region is activated.  If so, proceed as  
normal, if not skip.

When a region is actvated:
1) Check if the region is a sub-region of any "preload" Fqns specified  
in your cache loader cfg.
2) If so, attempt to preload that Fqn, but only for regions that match  
the one being activated.  Skip others.

I wonder if it is worth fixing JBCACHE-1009 in 2.2.0.  It would  
warrant another CR in 2.2.0 though.  Thoughts?  Votes on this?

> TBH, I don't see why I want <preload>/</preload> at all for this  
> usage.

Yes - isn't lazy loading a virtue here anyway?  :-)

And re: 2.1.1.GA, since JBCACHE-1358 is an obvious bug in JBC, I may  
port this fix to 2.1.X which will cause future 2.1.X releases to break  
in the same way.

Cheers
Manik
--
Manik Surtani
Lead, JBoss Cache
manik at jboss.org