Rajith, By the way, would you like to contribute a guide on clustering and its limitations to synapse? (since you know the internals of axis2 clustering stuff very well, I think it is good if you can contribute to this)
Thanks, Ruwan On Jan 30, 2008 7:56 PM, Rajith Attapattu <[EMAIL PROTECTED]> wrote: > My bad, bcos I initially sent it to the wrong list :(. > > Rajith > > > On Jan 30, 2008 4:30 AM, Asankha C. Perera <[EMAIL PROTECTED]> wrote: > > > Guys > > > > Please do not CC: mails to the old synapse-dev@ mailing list.. The dev@ > > list now works fine and so you can all discontinue using the old lists.. :-) > > > > > > thanks > > asankha > > > > > > Ruwan Linton wrote: > > > > Rajith, > > > > > > > > > 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. > > > > > > > Yes, we know this limitation is there. Even we have a JIRA for the > > Throttle mediator [1]. This is because there is no distributed locking > > mechanism in axis2-clustering implementation. But again we have not came > > across any requirement to support that level of replication to happen from > > users and most of them are fine with this error. > > > > [1] - https://issues.apache.org/jira/browse/SYNAPSE-180 > > > > Thanks, > > Ruwan > > > > -- > > Ruwan Linton > > http://www.wso2.org - "Oxygenating the Web Services Platform" > > > > > > > -- > Regards, > > > Rajith Attapattu > Red Hat > blog: http://rajith.2rlabs.com/ > -- Ruwan Linton http://www.wso2.org - "Oxygenating the Web Services Platform"
