[infinispan-dev] SysAdmin operations for recovering transactions

[Manik Surtani]

On 18 Mar 2011, at 12:41, Mircea Markus wrote:

> 
> 
> 
> 
> On 18 Mar 2011, at 12:32, Manik Surtani <manik at jboss.org> wrote:
> 
>> 
>> On 18 Mar 2011, at 12:13, Mircea Markus wrote:
>> 
>>> Hi,
>>> 
>>> It's about the stage where TM's recovery  process finds a in-doubt transaction and notifies the sys admin about it: what hooks does ISPN provide to the sys admin in order to "fix" the tx.
>>> E.g. step >= 3.3 : http://community.jboss.org/servlet/JiveServlet/showImage/102-16552-14-11811/3_non_originator_failure.png
>>> 
>>> Here is what I have in mind:
>>> 
>>> Expose (JMX) two operations:
>>> 
>>>   //all the params together fully describe a xid.
>>>   replayTx(byte[] txBranch, byte[] txId, int formatId); 
>>>   forceRollbackTx(byte[] txBranch, byte[] txId, int formatId);
>> 
>> You expect a sysadmin to type a byte array into a JMX console?  :-)  You might get death threats from sysadmins... 
> I imagine untraceble threats, right?
> String then...

Can an XID be mapped to a String (and vice versa) reliably, in a TransactionManager-independent manner?

>> 
>>> Here is how these two ops would work:
>>> A. replayTx 
>>>    1. the node has locally the PrepareCommand associated with that XID
>>> 	- re-issues a prepare: TransactionXAResource.prepare
>>> 	- if successful re-issues a commit: TransactionXAResource.commit
>>>        -if failure happens at any step the user is informed and she/he can re-do the JMX call
>>> 	- if success the recovery information is removed from the cluster (async)
>>>    2. the node doesn't have the PrepareCommand associated with that XID
>>> 	- broadcast ReplayTxCommand (Xid)
>>>        - when a node receives ReplayTxCommand
>>> 		- if doesn't have a PreparedCommand associated with the Xid ignores it
>>> 		- if has a PreparedCommand...
>>> 			- is it the first in the view that has it [1]? 
>> 
>> How does a node know the answer to this question?  Is the list of nodes that holds the prepare replay info stored on the PrepareCommand?
> No, [1] explains it

Ok, as long as this is deterministic.

>> 
>>> 				- yes. Execute A.1then returns result to node that broadcasted ReplayTxCommand. This is guaranteed to happen on at most[2] one node in the cluster
>>> 				- no. Ignores it.
>>> 	- if success the recovery information is removed from the cluster (async)
>>> B.rollbackTx
>>>   - node broadcasts RollbackCommand
>>>   - each node that has the PrepareCommand forces a rollback
>>>   - each node that doesn't have the PreparedCommand ignores it
>>>   - if success the recovery information is removed from the cluster (async)
>>> 
>>> Cheers,
>>> Mircea
>>> 
>>> [1] this is determined by building the set of nodes on which tx spreads, based on tx's state. Then determine the first in the view. 
>>> [2] it is possible not to happen on any node as the PrepareCommand might had been removed from all nodes in between (node failures, expiration from the recovery cache). 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> infinispan-dev mailing list
>>> infinispan-dev at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/infinispan-dev
>> 
>> --
>> Manik Surtani
>> manik at jboss.org
>> twitter.com/maniksurtani
>> 
>> Lead, Infinispan
>> http://www.infinispan.org
>> 
>> 
>> 
>> _______________________________________________
>> infinispan-dev mailing list
>> infinispan-dev at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/infinispan-dev
> _______________________________________________
> infinispan-dev mailing list
> infinispan-dev at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/infinispan-dev

--
Manik Surtani
manik at jboss.org
twitter.com/maniksurtani

Lead, Infinispan
http://www.infinispan.org



-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/infinispan-dev/attachments/20110318/b2883a3f/attachment.html