postgres-xc-developers Mailing List for Postgres-XC

HI all,

Please find attached a patch for the support of session parameters in XC.
This patch supports both LOCAL and SESSION parameters through the pooler.

When a SET command is executed on Coordinator, pooler executes this command
on the connections it holds in the pooler agent for the session in an
asynchronous way.
The command is also saved in agent such as when new connectionsare acquired
for this agent on pooler, the pooler is able to replay the SET commands
launched previously, for both local and session parameters if necessary.

When user finishes a transaction, connections are not sent back to pool if
session parameter have been launched, and the list of session parameters is
kept saved in the pooler agent.
However, the list of local parameters is reset each time a transaction is
finished.

When a user logs out from Coordinator, the list of connections that this
user used for XC transactions are put back to pull after launching a "RESET
ALL" query on each connection to be sure to reset everything.

There is still in this patch a bug when logging out.
If assertions are enabled, Coordinator crashes but I am looking into that.

This patch does not take into account user-default session parameters but
this code can easily be used as a base for this extension, but this may be a
next step.

Also note that I haven't taken the time to test this patch with regressions,
so there may be some other issues.
-- 
Thanks,

Michael Paquier
http://michael.otacoo.com