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From Rajith Attapattu <rajit...@gmail.com>
Subject Re: Java failover manager
Date Tue, 03 Mar 2009 17:11:35 GMT
I too agree with Arnaud.
By default it makes sense to keep retrying the list of brokers until
all nodes are down.

Regards,

Rajith

On Tue, Mar 3, 2009 at 11:17 AM, Arnaud Simon <asimon@redhat.com> wrote:
> Hello,
>
> I have been playing with our 0.10 cluster. When testing it I used a java
> client and 2 brokers. I quickly ran into this issue:
>
> org.apache.qpid.transport.ConnectionException: connection closed
> at org.apache.qpid.transport.Connection.send(Connection.java:294)
> at org.apache.qpid.transport.Session.send(Session.java:455)
> at org.apache.qpid.transport.Session.invoke(Session.java:599)
>
>
> It appears that this is an expected behaviour of our default Java failover
> manager. The default heuristic is to go roundrobin through the list of
> brokers. This is fine really but our implementation does not reset the
>  cursor position after a successful failover. This means that if you
> failover from A to B you will never failover from B to A anymore (assuming
> that our list of broker only contains two brokers A and B).   So, there is
> an optional parameter "cyclecount" that can be used to define the number of
> times to loop through the list of available brokers before failure. If this
> parameter can be used to solve the issue of failing over to A after a
> successful failover from A to B, it does solve this issue only for
> "cyclecount" times :( Moreover, I believe that we don't really want to cycle
> through all the brokers more than once when all the nodes of the broker are
> down. We rather want to define a kind of back-retry mechanism.
>
> I would suggest that default implementation of our roundrobin failover
> manbager should be changed to reset the cursor position within the broker
> list to the current broker. Moreover, I believe that some people are
> currently implementing a failover manager that uses a failover exchange. I
> am wondering whether this manager shouldn't the default manager for our 0.10
> client?
>
> Please let me know what you think. Should we open a JIRA?
>
> Thanks
>
> Arnaud
>
>
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>



-- 
Regards,

Rajith Attapattu
Red Hat
http://rajith.2rlabs.com/

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