[jboss-as7-dev] DataSource Enable/disable

[Jim Tyrrell]

But in a clustered example you could fail over to another node that still had that service available, so you would not get errors.

What if you wanted to gracefully update a datasource, what do you purpose?  To keep as near to 100% uptime as possible.  IE the database has not changed, the app has not changed, but in the back is a Oracle RAC that can now handle double the amount of threads?  You have four machines that need to be updated.

I would think you would want to disable the node datasource, then stop the node datasource.  Edit the config, and then start it back up, along with some pretty tooling that lets you know no more transactions are pending on that datasource before you stop it.  In a perfect world this is all automated in some tooling to give you 100% uptime and quicesing a server.

I fail to see how the paradigm of the web container load balancer does not apply, I freely admit I am stupid, but your answer to me confirms that it would apply.

Jim Tyrrell
Senior JBoss Solutions Architect

Did you see RHT on CNBC's Mad Money?
http://www.cnbc.com/id/39401056



On Apr 20, 2011, at 5:29 PM, David M. Lloyd wrote:

> Graceful shutdown will probably have to work somewhat differently than 
> that.  Generally the service simply stays available until nothing is 
> using it (or depending on it) anymore.  For example if I have a data 
> source being used by 3 EJBs, the data source is available until all the 
> EJBs are shut down and/or undeployed.  And the EJBs are available until 
> all their clients are shut down and/or undeployed, and so on down the line.
> 
> Having services start refusing requests makes shutdown be not very 
> graceful - it generally just results in error messages for users.  By 
> using the dependency system, in combination with clustering or load 
> balancing, the user experience is always smooth and we avoid errors and 
> broken transactions and that sort of thing.
> 
> On 04/20/2011 05:55 PM, Jim Tyrrell wrote:
>> Should like in web traffic routing for clustering their be a stopped stage:
>> add - adds
>> remove - kills it
>> enable - means it can accept new connections
>> disable - mean no new requests
>> stopped - means no request at all
>> 
>> Jim Tyrrell
>> Senior JBoss Solutions Architect
>> 
>> Did you see RHT on CNBC's Mad Money?
>> http://www.cnbc.com/id/39401056
>> 
>> 
>> 
>> On Apr 20, 2011, at 8:31 AM, Stefano Maestri wrote:
>> 
>>> When John have changed datasources subsystem he have created 4
>>> operations for them:
>>> - add
>>> - remove
>>> - enable
>>> - disable
>>> 
>>> I like them, now Heiko is asking to move enable/disable out in favour of
>>> a more standard r/w attribute enabled (note that this attribute is
>>> present in our xml). See There:
>>> 
>>> https://issues.jboss.org/browse/JBAS-9341
>>> 
>>> Since the operation don't just change the attribute, but also stop
>>> services and unbind ds from jndi I'd prefer to keep operations as is. I
>>> think an explicit operation make clearer to users that they are changing
>>> the status of the entire datasourrce
>>> 
>>> opinions?
>>> 
>>> S.
>>> _______________________________________________
>>> jboss-as7-dev mailing list
>>> jboss-as7-dev at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/jboss-as7-dev
>> 
>> 
>> 
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> 
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