Hi,

 did you get a chance to look at this?

On Fri, May 27, 2011 at 9:57 AM, Jean-Baptiste Onofré <[email protected]> wrote:
> Hi Janne,
>
> this mechanism comes from Karaf. You can use the file system locking or a 
> JDBC locking.
>
> To be honest, I don't remember exactly the behavior of the JDBC locking. I'm 
> gonna take a look in Karaf and keep you posted.
>
> Regards
> JB
>
> On Fri 27/05/11 08:52 , janne postilista  wrote::
>
> ServiceMix JDBC locking
> http://servicemix.apache.org/kernel/67-configuring-failover-deployments-available-in-110.html
> can be used for configuring a master/slave failover setup.
> Documentation states that if master servicemix loses database
> connection, it shuts down:
>
> "If connection to the DB is lost then the master instance will attempt
> to gracefully shutdown, allowing a slave instance to become master
> when the DB service is restored. The former master will require manual
> restart."
>
> This would cause a problem.
> - we have a server A and server B with master-slave configured
> servicemix and database instances.
> - initially server A holds servicemix-master and database-master,
> while server B holds servicemix-slave and database-slave
> - some updates or problems may cause server B to become
> servicemix-master. server A is servicemix-slave. server A still has
> database-master.
> - so we have servicemix master in server B and database master in server A
> - now if whole server A shuts down, there is a delay when server B
> database-slave activates, and in the meanwhile database is
> inaccessible
> - server B had servicemix-master. Now it loses database connection and
> gracefully shuts itself down
> - end result: neither servicemix is running
>
> 1. does the JDBC locking failover mechanism indeed shutdown the master
> instance immediately when it loses the connection, or are there any
> retries or delays?
> 2. if there a way to prevent this "graceful shutdown" feature or
> otherwise prevent this scenario?
>
>
>
>

Reply via email to