[infinispan-dev] Including CENTRAL_LOCK in our stacks, COUNTER

[Bela Ban]

On 10/17/12 1:11 PM, Sanne Grinovero wrote:
> Having my app introduce this on the stack leads to other kinds of
> problems, I think it would be way simpler if the protocols where
> always available on each participating node.


OK. So how about a separate stack that's available for OGM/HS etc 
including CENTRAL_LOCK and COUNTER ? These 2 protocols incur almost no 
overhead in passing messages down (as they pass every message down) and 
a small overhead in the up-direction (as they check for presence of a 
protocol-specific header).


> The Coordination election isn't good enough as
>   - that node might not have Search running
>   - I'd like to distribute the load of different indexes on different
> nodes, basically hashing on the index name to suggest a favourite
> node.


OK


> So if I have to add the stack at runtime.. the nodes not having my
> services deployed yet won't have the protocol, I assume CENTRAL_LOCK
> won't work properly if some nodes - especially the coordinator - don't
> have it installed?


Correct. But if all of the nodes running HibernateSearch create the same 
stack dynamically, and they're the only ones using it, then the view 
will be including only those nodes, so their coordinator is correct 
(although it may not be the same as the one of the main channel).


> I already have the option to create a new Channel and bypass any
> trouble, the point is I'd like to reuse the single channel, both for
> efficiency reasons but also to guarantee consistent views, consistency
> with mod_cluster, etc..

OK


-- 
Bela Ban, JGroups lead (http://www.jgroups.org)