Robin Rosenberg wrote:
torsdag 13 november 2008 20:20:49 skrev Farrukh Najmi:
Does the gjit team have any plans to implement support for JTA in gjit
so as to allow distributed transactions using 2 phase commit? This would
be very powerful when git is being used in conjunction with other
transaction resource managers such as databases.
No such plans exist. We do not even have a J2EE Resource Manager yet. I
did some toying implementing one. As for XA support, I guess that would
not be very hard per se, but my thoughts on JEE support was more in the direction
of gitweb-like stuff, i.e. reading.
I am not an expert on this but what I thought could be done is to
enhance jgit so it can serve the role of a JTA compliant transactional
resource manager similar to that in JDBC, JMS etc. As part of that it
could serve resources as JTA XAResource.
Not sure how hard all this could be though.
Trying to involve git in distributed database transactions might be cool, but seriously: Do you
need it?
The problem I am trying to solve is this. In my service I need to store
metadata in a relational db and content in git such that both either
commit or not in a single transaction. If one commits and the other does
not that is a serious integrity issue. Seems to me, two phase commit
would be the right solution for that in the long run. This what JDBC +
JMS topologies do.
A totally separate issue I have to sort out is how to handle multiple
unrelated transactions that are modifying the same git repo. If a
transaction needs to be rolled back how do roll back exactly some
changes in some files in git that were impacted by the transaction. This
is not easy because git (and most VCS) do not have transaction isolation
like databases do. Any suggestions?
As for JEE my ideas are: A nice JSP tag library and a resource manager. When is
an entirely different question, as is who. Did you look at my experiment in a reply of mine
in another recent jgit thread?
I am not very well versed in tag libraries myself. My situation is one
where everything happens inside a SOAP service endpoint and so I suspect
JSP tag libraries are not likely to be useful in that situation. Let me
know if I am wrong in this assessment.
The term "distributed" in XA is not quite the same as in distributed verison control.
That is correct.
If it would,
then we'd send SQL commands over e-mail (now, /that/ would be cool :)
+1
Thanks very much for your help and that of other colleagues on the list.
--
Regards,
Farrukh Najmi
Web: http://www.wellfleetsoftware.com
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