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http://issues.apache.org/jira/browse/DERBY-1219?page=comments#action_12378079 ]
Deepa Remesh commented on DERBY-1219:
-------------------------------------
Hi Bryan,
Here are the answers to your questions:
1) You said you were able to reproduce this outside the harness; can you post a
brief description of the steps, so that I can experiment with the code in my
environment?
To run the test jdbcapi/checkDataSource.java without using the test harness, I
started network server and then used the following command to run the test:
java -Dderby.system.home=C:\deepa\Derby\derby_testing\nwserver
-Dframework=DerbyNetClient
-Dij.database=jdbc:derby://localhost:1527/wombat;create=true
org.apache.derbyTesting.functionTests.tests.jdbcapi.checkDataSource
The test hangs intermittently and the place where the test hangs is in one of
the getConnection methods. The hang location varies in different runs but is
always in the getConnection method. I can repro it quite easily (~ 1 out of 5
runs hang) on my machine. I hope you are able to repro it too.
2) Were you running with sane=true, or sane=false? If sane=false, can you try
sane=true?
I was running with sane=true. The debug output can be seen in the derby.log in
the attached zip file (drda_traces_050206.zip)
3) You mentioned that the server does not get any data in DDMReader.fill, and
thinks the client has disconnected. Can you expand on how you came to that
conclusion? Were you able to see an IOException being thrown? Can you get a
dump of that exception? After the exception has been thrown (i.e., during the
hang), does netstat think that there is still an active TCP/IP connection
between the client and the server?
I was looking at the server debug trace from a normal run (without hang) and
when the test hangs. On comparing both and also looking at the client and
server traces, I found the following from the trace files:
* Client trace stops with send of EXCSAT and ACCSEC (client_trace.txt_sds_1)
* At the server side, I can see an empty trace file is created but cannot see
the EXCSAT and ACCSEC as the last entries in any trace file (Server10.trace,
Server9.trace)
* In the debug trace of server, the last trace is "Ending connection thread". I
added few other traces in DDMReader.fill and DRDAConnThread.run and found that
server is actually reaching the end of the input stream (actualBytesRead == -1)
without reading any data (totalBytesRead is 0) and hence calls
"agent.markCommunicationsFailure ("DDMReader.fill()", "InputStream.read()",
"insufficient data", "*");" The connection thread catches this disconnect
exception and exits normally thinking the client has disconnected. The debug
traces from a successful run show that network server starts a new connection
thread at this point.
>From the above, I thought of following possibilities:
* server is not getting a set of data from the client. data is lost. this looks
unlikely
* server thread is reading a wrong stream (from an already closed connection)
and thinking the client does not have more data and that it has disconnected.
* session state associated with the server thread is wrong. Instead of starting
new session, server is thinking it has an active session and tries to process
commands for the active session
I am just throwing in some ideas which come to me and could be totally off
here. I plan to look at this some more and will post if I find something else.
There are no IOExceptions at server or client. The IO exception seen in the
client trace file (client_trace.txt_sds_1) is because I killed network server
after the test was hanging for a long time. This was just to reconfirm where
the client is hanging.
In netstat output, I can see listening and established statuses for both client
and server process during the hang.
Ouput of runtimeinfo command:
--- Derby Network Server Runtime Information ---
---------- Session Information ---------------
Session # :10
-------------------------------------------------------------
# Connection Threads : 2
# Active Sessions : 1
# Waiting Sessions : 0
Total Memory : 3694592 Free Memory : 2649768
Hope this helps.
> jdbcapi/checkDataSource.java and jdbcapi/checkDataSource30.java hang
> intermittently with client
> -----------------------------------------------------------------------------------------------
>
> Key: DERBY-1219
> URL: http://issues.apache.org/jira/browse/DERBY-1219
> Project: Derby
> Type: Test
> Components: Network Server, Network Client
> Versions: 10.2.0.0
> Environment: More often on jdk 1.5 or jdk 1.6 but hangs on jdk 1.4.2 as well
> Reporter: Kathey Marsden
> Priority: Minor
> Attachments: client_stack_trace_050306.txt, drda_traces_050206.zip,
> server_stack_trace_050306.txt, testfiles_afterhang.zip, traces_on_hang.txt
>
> The tests checkDataSource.java and checkDataSource30.java
> hang intermittently especially with jdk 1.5.
> Attached is the test run output and traces when the server is started
> separately.
> 1) Enable checkDataSource30.java by taking it out of
> functionTests/suites/DerbyNetClient.exclude.
> 2) Run the test with client.
> java -Dij.exceptionTrace=true -Dkeepfiles=true -Dframework=DerbyNetClient
> org.apache.derbyTesting.functionTests.harness.RunTest
> jdbcapi/checkDataSource30.java
> Attachements:
> testfiles_after_hang.zip - Test directory.
> traces_on_hang.txt - Server side traces obtained by starting the server
> separately before running the test.
> I wish I had time to work on this right now as I would really like to see
> this valuable test in the suite, but hopefully someone else will pick it up.
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