Do these open source caching schemes not provide cache invalidation via
a URL call?
Previous teams I led developed a REST style (before REST had a name)
cache manager that could be called with a key. When called, it would
also read the list of hosts from a properties file and exercise the same
cache invalidation message on all other hosts in the cluster.
blogs.sun.com/invalidate_cache.jsp?key=foo_bar:123
when hit, that would clear the cache for localhost (say blogs2.sun.com),
and then call:
blogs1.sun.com/invalidate_cache.jsp?key=foo_bar:123
blogs3.sun.com/invalidate_cache.jsp?key=foo_bar:123
-John
Allen Gilliland wrote:
I think the short answer to his question is, no, we don't support clustered
environments. It's definitely something we are working towards though.
Why can't we run clustered? The main reason I know if is that our presentation
caches don't support clustering, so unless you are willing to set the timeout
value to something fairly low and let them get out of sync for a little while
then that's one roadblock. Currently we don't do object caching, but that is
going to change now, so that is another item that will need consideration.
File uploads are not something that I think Roller should have to worry about
actually. If someone wants to share their file uploads between machines then
they can do that via the filesystem, i.e. use something like nfs.
The other clustering issue is the scheduled tasks. There is no
locking/synchronization for multiple machines running scheduled tasks. It's
pretty easy to bypass this one by running the tasks outside the webapp though.
-- Allen
On Wed, 2006-01-11 at 14:22, Matt Raible wrote:
Right, for a clustered environment (which Roller should support - even
if file uploads and such don't work so well) - we'd need to use JBoss
TreeCache or OSCache. I've used OSCache (with JGroups) with good
success - but we did have to modify some files for Hibernate 3.
http://opensymphony.com/oscache/wiki/Hibernate.html
Matt
On 1/11/06, Jeff Blattman <[EMAIL PROTECTED]> wrote:
stupid newbie comment ... does roller support multi instances? if it
did, l2 cache becomes problematic unless it's a super-smart
implementation that sync's itself across instances.
Allen Gilliland wrote:
yes? no? anybody?
i'd like to commit a *very* modest version of a hibernate L2 cache which would
use ehcache and only apply to a few objects ... RollerPropertyData,
WebsiteData, and UserData.
-- Allen
On Mon, 2006-01-09 at 18:59, Allen Gilliland wrote:
One of the things that we currently do not take advantage of is object
level caching. Hibernate makes it pretty easy to add an L2 cache on a
class by class basis, so I'd like to start by adding an L2 cache for a
handful of classes like ... RollerPropertyData, WebsiteData, and
UserData. All three of those classes are highly used and seldomly
changed, so they are ideal for caching.
We can play with a variety of possible cache implementations, but
EhCache is the default and seems easiest to use at this point.
Would anyone object to this?
-- Allen
