Yes, each cluster message has a UUID, and at the receiver, duplicates are eliminated.
Azeez On Sat, Jul 6, 2013 at 5:25 PM, Sriskandarajah Suhothayan <[email protected]>wrote: > > On Jul 4, 2013 6:39 PM, "Isuru Haththotuwa" <[email protected]> wrote: > > > > Hi, > > > > On Thu, Jul 4, 2013 at 5:44 PM, Afkham Azeez <[email protected]> wrote: > >> > >> There could be a situation where when a cluster message is sent, a > member momentarily leaves the cluster, but joins immediately. This > generally could happen when the nodes slow down under load, or due to > intermittent network failures. However, this could lead to failures because > crucial cluster messages may not be received by members. > >> > >> To overcome this, or reduce the probability of loss of such messages, > we can replay a certain number of messages when a member joins. On the > sender side, messages over a particular time period can be buffered, and > then replayed when new members join. However, we should ensure that the > messages are idempotent, and messages should declare whether they are > idempotent or not. If a message is not idempotent, we will not replay it. > All the messages we have at the moment are idempotent, AFAIK. > >> > >> > >> How does this approach sound? > > > > > > +1. IMHO it is cleaner if we can replay a sequence of cluster messages > node which originally was a member of the cluster, and then got removed > (due to a network failure, etc) and got re-joint before a certain time > period. If we replay a set of messages whenever a new member joins, isn't > there a possibility that a newly joined member is updated to a false state? > > We can have sequence number in the messages so the message-receiver can > drop the duplicate messages > > Suho > > >> > >> > >> -- > >> Afkham Azeez > >> Director of Architecture; WSO2, Inc.; http://wso2.com > >> Member; Apache Software Foundation; http://www.apache.org/ > >> > >> email: [email protected] cell: +94 77 3320919 > >> blog: http://blog.afkham.org > >> twitter: http://twitter.com/afkham_azeez > >> linked-in: http://lk.linkedin.com/in/afkhamazeez > >> > >> Lean . Enterprise . Middleware > >> > >> _______________________________________________ > >> Architecture mailing list > >> [email protected] > >> https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture > >> > > > > > > > > -- > > Thanks and Regards, > > > > Isuru H. > > > > > > > > _______________________________________________ > > Architecture mailing list > > [email protected] > > https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture > > > > > _______________________________________________ > Architecture mailing list > [email protected] > https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture > > -- *Afkham Azeez* Director of Architecture; WSO2, Inc.; http://wso2.com Member; Apache Software Foundation; http://www.apache.org/ * <http://www.apache.org/>** email: **[email protected]* <[email protected]>* cell: +94 77 3320919 blog: **http://blog.afkham.org* <http://blog.afkham.org>* twitter: **http://twitter.com/afkham_azeez*<http://twitter.com/afkham_azeez> * linked-in: **http://lk.linkedin.com/in/afkhamazeez* * * *Lean . Enterprise . Middleware*
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