On 6/19/07, Venkata Krishnan <[EMAIL PROTECTED]> wrote:
Hi, I guess it should be a good start to have SCA domains span across runtimes and leave the runtimes being shared by SCA domains to the next iteration. As for the second point, is there a possibility of seeing this as replication of components across two runtimes instead of nodes? Anyways, to start with, I'd be happy to leave this out for the next iteration. Thanks - Venkat On 6/18/07, Simon Laws <[EMAIL PROTECTED]> wrote: > > Following on from recent discussion on the distributed binding (I've been > putting notes here [1])... In a Tuscany SCA runtime what do we expect the > cardinality between the various parts of it to be? > > A domain notionally runs on a runtime. In the case of a stand-alone > Tuscany > SCA runtime this will be a single process (C++ exe, Java VM etc.). In the > case of a distributed Tuscany SCA runtime, the runtime is made up of many > distributed nodes that each run parts of the domain. > > 1/ Can domains share runtimes/nodes? > > I.e can components from more than one domain be running inside a single > Tuscany SCA runtime or is the user expected to start up multiple runtimes > to > run multiple domains. > > 2/ How many nodes can a single component run on?. > > I.e. is the assignment of a component to multiple nodes, for performance, > reliability etc. reasons, explicitly supported as part of the topology > description of a distributed domain. If so then the SCA binding chooses > which node to use. If not then any distribution of workload is considered > to > be a job for the node implementation. > > I'd be interested to hear peoples views on this > > My starting point is... > > 1/ No, we will support multiple domains by starting multiple runtimes. We > could add the extra function to support sharing of runtimes between > domains > in the future if it's found to be required. > > 2/ We shouldn't restrict whatever structure we use to describe the > component/node association to be 1-1. But we can assume 1 in the first > instance and consider adding more complex node selection features to the > SCA > binding in the future. > > Regards > > Simon > > [1] http://cwiki.apache.org/confluence/pages/editpage.action?pageId=59826 >
OK, thanks for your comments. It seems like we agree. In the first instance then I've checked in my code with the assumption that a component only runs on one node a node only supports one domain Having said that I've built some topology model classes that allow for this simple case but don't restrict us to this. I'm not using these model classes yet (in the sample the component to node mapping is hard coded) but the next job is to plumb it in. I'm just about to post a quick summary of what I've checked in. Simon
