Gianny Damour has got me thinking about how services relate to the cluster.
There are a couple of issues here:
a) how do we provide the cluster connection to multiple clustered
services within the same node ?
b) do we want to address a node (assuming one Connection/Destination per
node) or a service ?
(a) Either, every service contains its own private cluster Connection,
in which case we would expect overhead to increase as we start more and
more services within a node, Or, we come up with e.g. a multiplexed
Cluster or Connection Factory, which can hand out what look like Cluster
or Connection objects to these services which are then able to multiplex
their conversations down a single Connection, in which case we would
expect no increase in overhead but rather in contention as the number of
services in a node increase. By remaining with the original
Cluster/Connection API we could allow these two approaches to be
deploy-time pluggable....
(b) if we go with the multiplexing idea, then I guess it would be cheap
enough that every service might be able to think that it owns a private
cluster connection, whilst it is actually sharing it with all other
services within the node... - This allows us to dispatch messages at
service rather than connection level and simplifies the decoupling of
services since the same code will now run happily on a private or shared
Connection.
Of course, ActiveCluster may already support this sort of thing - I am
just dumping thoughts into the ether.... James, have you anything to add
? Can you e.g. run more than one ActiveSpace Space/Cache instance on the
same node in the same Cluster, without making more than one Connection ?
Or are Connections already doing this sort of stuff internally to the
point that you would not want to ?
cheers,
Jules
--
"Open Source is a self-assembling organism. You dangle a piece of
string into a super-saturated solution and a whole operating-system
crystallises out around it."
/**********************************
* Jules Gosnell
* Partner
* Core Developers Network (Europe)
*
* www.coredevelopers.net
*
* Open Source Training & Support.
**********************************/
