stratos-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Imesh Gunaratne <im...@apache.org>
Subject Re: Cause of Scale Down Logic Issue was Identified
Date Fri, 18 Apr 2014 07:06:38 GMT
I have now verified the correction done in STRATOS-614 and the scale down
functionality is working as expected.

Thanks


On Fri, Apr 18, 2014 at 10:34 AM, Imesh Gunaratne <imesh@apache.org> wrote:

> Thanks Azeez! Yes, completely agree.
>
>
> On Fri, Apr 18, 2014 at 9:56 AM, Afkham Azeez <afkham@gmail.com> wrote:
>
>>
>>
>>
>> On Fri, Apr 18, 2014 at 1:12 AM, Imesh Gunaratne <imesh@apache.org>wrote:
>>
>>> Hi,
>>>
>>> During last few days we noticed an intermittent issue in scale down
>>> logic and it was reported in STRATOS-614.
>>>
>>> Today after doing some thorough tests we identified the cause of this
>>> issue. The problem was with the topology event receiver queue. Since this
>>> queue was designed as a singleton,
>>>
>>
>> Singletons should be avoided as much as possible, and used with caution.
>> Some even consider it an anti-pattern.
>>
>>
>>> it was being shared among multiple event receivers in Single JVM mode.
>>> As a result event messages were unevenly being dequeued to message
>>> processors and some event receivers were missing events randomly.
>>>
>>> This problem was also there in Tenant event receiver, Health Stat event
>>> receiver and Instance Notifier event receiver. I have now fixed this by
>>> introducing a message queue for each event receiver instance created.
>>>
>>> I have now committed this fix to master branch. Will do few more flow
>>> tests to verify the correction and update with the results soon.
>>>
>>> Thanks
>>>
>>> --
>>> Imesh Gunaratne
>>>
>>> Technical Lead, WSO2
>>> Committer & PPMC Member, Apache Stratos
>>>
>>
>>
>>
>> --
>> *Afkham Azeez*
>> Director of Architecture; WSO2, Inc.; http://wso2.com,
>> *Member; Apache Software Foundation; **http://www.apache.org/*<http://www.apache.org/>
>>
>> *email: **azeez@wso2.com* <azeez@wso2.com>
>> * cell: +94 77 3320919 <%2B94%2077%203320919> 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
>> <http://lk.linkedin.com/in/afkhamazeez>*
>>
>> *Lean . Enterprise . Middleware*
>>
>>
>
>
> --
> Imesh Gunaratne
>
> Technical Lead, WSO2
> Committer & PPMC Member, Apache Stratos
>



-- 
Imesh Gunaratne

Technical Lead, WSO2
Committer & PPMC Member, Apache Stratos

Mime
View raw message