[ http://issues.apache.org/jira/browse/DERBY-1856?page=all ]
Bernt M. Johnsen updated DERBY-1856:
------------------------------------
Attachment: DERBY-1856-r126392-regressionfix.diff
The exception thrown is caused by a regression introduced in r126392
(2005-01-25) and is easily fixed by the attached
DERBY-1856-r126392-regressionfix.diff. The cause is that two session
states introduced (SECACC and CHKSEC) is missing in the switch in
DRDAConnThread.run().
Some comments:
1) Testing of maxThreads/timeSlice is obviously non-existing since a
regression can live for nearly two years. I'll file an issue on
this.
2) When timeSlice is defined, a timeout of the same size is set on the
socket. It has been like this since the dawn of times (which in
this case happens to be 2004-08-26 16:13:46), but Kathey added a
comment that the timeout is "highly suspect", and I agree. Since
SocketTimeoutException (introduced in J2SE 1.4) is not handled, the
socket will be closed down when the timeout expires. This may be ok
for applications using a connection pool which sanitychecks
connections before reusing them, but disastrous for other
applications. Without the timeout, a DRDAConnThread waiting for
input, will not yield until another request comes from the
client.
3) I experimented with catching the timeout in the DRDAConnThread as
the only other change, and that seems to work. If the timeslice is
setvery low (less than 100ms) I get problems which I guess stems
from missing corner cases which may well appear with higher
timeslices e.g. if the load is high or the query tekes a long time.
I guess the best approach is to let the timeout be as it is for the
moment and file a separate issue for proper handling of the
timeout.
Any comments?
> Multiple communication failures when starting server with derby.drda.timeSlice
> ------------------------------------------------------------------------------
>
> Key: DERBY-1856
> URL: http://issues.apache.org/jira/browse/DERBY-1856
> Project: Derby
> Issue Type: Bug
> Components: Network Server
> Affects Versions: 10.1.3.1, 10.1.2.1, 10.3.0.0
> Environment: any ( but I tried on windows/2k/t40 laptop/jdk142).
> Reporter: Sunitha Kambhampati
> Assigned To: Bernt M. Johnsen
> Attachments: DERBY-1856-r126392-regressionfix.diff
>
>
> In
> http://www.nabble.com/Problem%3A-Communication-Link-Failure--derby.drda.timeSlice-p5966781.html
> , Hannes Grund reported a problem with derby.drda.timeSlice property.
> I tried this property in my environment on trunk (10.3) and hit several
> communication failure problems with the following errors below.
> On server
> ------------
> trunk2>java -Dderby.drda.maxThreads=100 -Dderby.drda.timeSlice=10000
> org.apache.derby.drda.NetworkServerControl star>
> Apache Derby Network Server - 10.3.0.0 alpha started and ready to accept
> connections on port 1527 at 2006-09-15 18:41:51.750 GMT
> Execution failed because of Permanent Agent Error: SVRCOD = 40; RDBNAM =
> testdb5;create=true; diagnostic msg = Session in invalid state:4
> org.apache.derby.impl.drda.DRDAProtocolException: Execution failed because of
> Permanent Agent Error: SVRCOD = 40; RDBNAM = testdb5;create=true; diagnostic
> msg = Session in invalid state:4
> at
> org.apache.derby.impl.drda.DRDAProtocolException.newAgentError(DRDAProtocolException.java:328)
> at
> org.apache.derby.impl.drda.DRDAConnThread.agentError(DRDAConnThread.java:476)
> at
> org.apache.derby.impl.drda.DRDAConnThread.run(DRDAConnThread.java:278)
> Execution failed because of Permanent Agent Error: SVRCOD = 40; RDBNAM =
> testdb5;create=true; diagnostic msg = Session in invalid state:4
> org.apache.derby.impl.drda.DRDAProtocolException: Execution failed because of
> Permanent Agent Error: SVRCOD = 40; RDBNAM = testdb5;create=true; diagnostic
> msg = Session in invalid state:4
> at
> org.apache.derby.impl.drda.DRDAProtocolException.newAgentError(DRDAProtocolException.java:328)
> at
> org.apache.derby.impl.drda.DRDAConnThread.agentError(DRDAConnThread.java:476)
> at
> org.apache.derby.impl.drda.DRDAConnThread.run(DRDAConnThread.java:278)
> On client:
> -----------
> trunk2>java org.apache.derby.tools.ij
> ij version 10.3
> ij> connect 'jdbc:derby://localhost:1527/testdb5;create=true;';
> ij> select * from t1;
> ERROR 42X05: Table/View 'T1' does not exist.
> ij> select * from t1;
> ERROR 42X05: DERBY SQL error: SQLCODE: -1, SQLSTATE: 42X05, SQLERRMC: T1ΒΆ42X05
> ij> select * from t1;
> ERROR 58015: The DDM object 0x1232 is not supported. The connection has been
> terminated.
> ij> select * from t1;
> ERROR 08003: No current connection.
> In some cases, the client gets the 58009 communications error.
> trunk2>java org.apache.derby.tools.ij
> ij version 10.3
> ij> connect
> 'jdbc:derby://localhost:1527/testdb4;create=true;user=a;password=p';
> ij> create table t1(i1 int);
> ERROR 58009: A communications error has been detected: Software caused
> connection abort: recv failed.
> I am opening this jira because it seems like the basic problem may be just in
> the way the timeSlice property is being handled. As part of this jira, make
> sure that the timeSlice property behaves the way it is expected to and also
> clarify the documentation.
> The documentation currently states this "Use the derby.drda.timeslice
> property to set the number of milliseconds that each connection will use
> before yielding to another connection. " and the default value is 0. Not
> clear what it means to have a default of 0. I think it is good to explain the
> behavior here.
>
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