Danushka,

On Mon, Jul 21, 2014 at 6:13 PM, Danushka Fernando <[email protected]>
wrote:

> I think Paul's point is valid. And also in that case we don't have to
> handle the scenario that the web app is deployed in one appserver
> successfully and didn't in second appserver. We can let users know that its
> deployed correctly in this server and another message saying its not
> deployed successfully in this server. But somehow we need to say the server
> name in a abstract way like wso2 appserver 1 and wso2 appserver 2 not in
> this IP and that IP.
> Dimuthu / Anuruddha WDYT?
>

This is not valid. User does not and should not have any idea about how
many AppServers are there.

BTW, I was just wondering whether we can use the registry to maintain a
flag. So, the listener can check the flag before sending the notification.


> Thanks & Regards
> Danushka Fernando
> Software Engineer
> WSO2 inc. http://wso2.com/
> Mobile : +94716332729
>
>
> On Mon, Jul 21, 2014 at 6:02 PM, Paul Fremantle <[email protected]> wrote:
>
>> Isn't it better to send all the messages and then keep track of who has
>> successfully deployed or undeployed? In other words, don't we want all the
>> information rather than just getting one server's info?
>>
>> Paul
>>
>>
>> On 21 July 2014 12:58, Anuruddha Premalal <[email protected]> wrote:
>>
>>> Hi,
>>>
>>> *Problem:*
>>>
>>> In the current appfactory setup all the application containers (AS)
>>> notifies on application life cycle events (deployment, undeployment); this
>>> is because the deployment event listeners directly send messages to
>>> appfactory . This approach works well for a single node deployment . But it
>>> will cause unwanted noise (which will ultimately be several copies of the
>>> same message on the notification wall) in a clustered environment, also
>>> this will cause unwanted traffic towards appfactory. So it is important to
>>> limit notifications from the container level.
>>>
>>> *Solution:*
>>>
>>> Requirement is to send notifications only from a single appserver node
>>> in the cluster.
>>>
>>> For this we have to choose a single candidate from the cluster, and make
>>> him as the notifier node.
>>>
>>>  Candidate selection method:
>>>
>>> This can be achieved using Stratos topology information. Topology(which
>>> is published every 60secs) have information about currently active cluster
>>> nodes.
>>>
>>> Application notifiers will subscribe to this topology topic and choose
>>> to be the notifier based on the following criteria.
>>>
>>> 1.)  If the topology contains the IP of the node.
>>>       Note : This is important because there might be cases where IP is
>>> not in the topology but the instance is active.
>>>
>>> 2.)  If the IP is the highest IP in the available topology.
>>>
>>>
>>> Related Jira : https://wso2.org/jira/browse/APPFAC-2271
>>>
>>>
>>> Regards,
>>>
>>> --
>>> *Anuruddha Premalal*
>>> Software Eng. | WSO2 Inc.
>>> Mobile : +94710461070
>>> Web site : www.regilandvalley.com
>>>
>>> "Advances of technology should not leave behind the developing world"
>>>
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>>>
>>>
>>
>>
>> --
>> Paul Fremantle
>> CTO and Co-Founder, WSO2
>> OASIS WS-RX TC Co-chair, Apache Member
>>
>> UK: +44 207 096 0336
>> US: +1 646 595 7614
>>
>> blog: http://pzf.fremantle.org
>> twitter.com/pzfreo
>> [email protected]
>>
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-- 
*Amila Maharachchi*
Senior Technical Lead
WSO2, Inc.; http://wso2.com

Blog: http://maharachchi.blogspot.com
Mobile: +94719371446
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