[ http://issues.apache.org/jira/browse/DERBY-1090?page=all ]
Olav Sandstaa updated DERBY-1090:
---------------------------------
Attachment: client1090_patch2.diff
This patch (client1090_patch2.diff) addresses the problem of
Connection.isValid() hanging infinite if the server is either "hanging" or not
sending a reply.
The reason for the client to hang in these situations is that blocking read
(and write) is used for receiving replies from the Derby network server. To
avoid the client hanging infinite in the blocking read when the caller has
specified a timeout to isValid() we set a maximum timeout value on the socket
(by using java.net.socket.setSoTimeout()) before the query is sent to the
server. Thus, if the server does not respond within the specified timeout
period the blocking read will return with an exception.
If this exception is thrown, isValid will return false for this connection. The
timeout on the socket is reset to whatever value it had before the call to
isValid. Thus, this socket timeout should only influence on the query issued by
the isValid code.
The implementation has been tested by setting a very low timeout value and
introducing a delay in the network server.
svn status reports:
M java/client/org/apache/derby/client/net/NetAgent.java
M java/client/org/apache/derby/client/net/NetConnection40.java
I have run the JDBC4 tests and derbyall with the patch. Only failure was in
tools/derbyrunjartest.java.
The patch can be reviewed and committed.
> Implement Connection.isValid as defined by JDBC4
> ------------------------------------------------
>
> Key: DERBY-1090
> URL: http://issues.apache.org/jira/browse/DERBY-1090
> Project: Derby
> Type: Sub-task
> Components: JDBC
> Reporter: Olav Sandstaa
> Assignee: Olav Sandstaa
> Priority: Minor
> Fix For: 10.2.0.0
> Attachments: client1090_patch1.diff, client1090_patch2.diff,
> embedded1090-isclosed.diff, embedded1090-query.diff
>
> The Javadoc for JDBC4 says this about Connection.isValid:
> boolean isValid(int timeout) throws SQLException
> Returns true if the connection has not been closed and is still valid. The
> driver shall submit a query on the connection or use some other mechanism
> that positively verifies the connection is still valid when this method is
> called.
> The query submitted by the driver to validate the connection shall be
> executed in the context of the current transaction.
> Parameters: timeout - - The time in seconds to wait for the database
> operation used to validate the connection to complete. If the timeout period
> expires before the operation completes, this method returns false. A value of
> 0 indicates a timeout is not applied to the database operation.
> Returns: true if the connection is valid, false otherwise
--
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
