Finalization of statements in client driver should handle sending of CLSQRY to
close result sets on network server
------------------------------------------------------------------------------------------------------------------
Key: DERBY-1104
URL: http://issues.apache.org/jira/browse/DERBY-1104
Project: Derby
Type: Sub-task
Components: Network Client
Reporter: Deepa Remesh
Priority: Minor
Currently, the finalizer in client driver's statement classes do only
client-side cleanup. Cleanup of statements and result sets on network server
will happen only when the client driver re-uses a section number for a new
statement. DRDA has CLSQRY command which can be sent to close the result sets
on the server. This command has to be sent as part of statement finalization so
that result sets will get cleaned up immediately on the server without waiting
for the re-use to happen.
The code to send CLSQRY needs to be synchronized. Hence it cannot be added
directly to finalize method. Dan pointed out that we should avoid any
synchronized operation in the finalizer since there is a potential to block the
finalizer thread and potentially the JVM. Embedded driver performs the cleanup
actions outside the finalizer. See EmbedPreparedStatement.finalize. A similar
mechanism needs to be used in client driver.
The comments in DERBY-210 has more details, specifically the following comments:
http://www.nabble.com/Re%3A-jira-Commented%3A-%28DERBY-210%29-Network-Server-will-leak-prepared-statements-if-not-explicitly-closed-by-the-user-until-the-connection-is-closed-p3039721.html
http://www.nabble.com/-jira-Commented%3A-%28DERBY-210%29-Network-Server-will-leak-prepared-statements-if-not-explicitly-closed-by-the-user-until-the-connection-is-closed-p3030678.html
http://www.nabble.com/-jira-Commented%3A-%28DERBY-210%29-Network-Server-will-leak-prepared-statements-if-not-explicitly-closed-by-the-user-until-the-connection-is-closed-p3039390.html
--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
http://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see:
http://www.atlassian.com/software/jira
