On Jan 29, 2008 1:13 PM, Ruwan Linton <[EMAIL PROTECTED]> wrote: > Rajith, > > > > > > > > Most part of synapse is stateless and hence does not have any effect > > > over clustering, but Caching and Throttling does. So Caching and Throttle > > > mediators use the axis2-clustering implementation to replicate the state > > > of > > > those mediators among the cluster within the implementation of those > > > mediators it self. Other than that we do not replicate states of synapse > > > in > > > a global scope. I think this model fits for the moment and has performance > > > improvements over supporting clustering in a global scope. > > > > > > > Yep I am in agreement. The reason I asked about clustering is bcos of > > the recent thread on session mgt and the need to have the session-mediator > > state replicated across the cluster (I hope I didn't misunderstand the > > requirments here). I was wondering if this sort of thing is trivial to > > implement. Like can we replicate any mediator state if we choose to in a > > trivial way? > > > > Yes it is, I think the session-mediator has to take the replication in to > account (i.e. another state full mediator for synapse :)). If you are > using the ConfigurationContext of axis2 (basically the whole context > hierarchy) to store the data (for example, the session data table mapped > using a session id) ** you just need to call ConfigurationContext.flush(); > to replicate any data which has been changed after the last replication. > Additionally if you need to just replicate some of the properties of the > cfgCtx then you can call the the flush method with the property names (see > the clustering API for the exact signature of the method, I don't remember > that exactly). >
Ruwan, once again thank you for the detailed answer. I really appreciate it. The reason behind the question "can we replicate any mediator state if we choose to in a trivial way?" was to figure out if the current axis2 clustering support is sufficient. However we have to be careful when replicating mediator state especially when there are concurrent modifications on different nodes. This can cause undesired affects and it is a limitation in our current clustering implementation. So even for the session map, if two nodes modify the map concurrently we may have issues. This doc explains the limitations http://ws.apache.org/axis2/1_3/clustering-guide.html. So perhaps it's worthwhile to highlight these issues to synapse users who want to tap into the clustering support. thanks, Rajith Attapattu Red Hat blog: http://rajith.2rlabs.com/ > Or else to replicate the whole context hierarchy you could use > Replicator.replicate(); as well. One has to decide the proper method and > when to use which by evaluating the complexity and performance of the > implementation .... > > Thanks, > Ruwan > > -- > Ruwan Linton > http://www.wso2.org - "Oxygenating the Web Services Platform" >
