On Thu, Jul 4, 2013 at 6:38 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?
>

If we replay the messages in original order, there should be no consistency
issue.


>
>> --
>> *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*
>>
>> _______________________________________________
>> 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
>
>


-- 
*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*
_______________________________________________
Architecture mailing list
[email protected]
https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture

Reply via email to