On 1/30/2013 8:38 AM, Oskar Zinger wrote:
Hi Kathey,
Here is what happens...
Yes, this is a multi-threaded system. No, only one shutdown request is
happening. I have not tried with deregister=true.
The new finding is...
This NullPointerException is only happening in a Single CPU (or single
Core) system. When the system and Kernel is upgraded to 2 CPU / core
system - the NullPointerException no longer happens, also the same has
been tried on a 4 CPU / core system and it does not happen there
again. So strangely this is only happening on a single processor system.
I feel that there should be a check for null in
org.apache.derby.impl.store.raw.xact.XactFactory.add() method to check
for ttab for null.
It seems to me that there is something hapenning that we don't
understand. Although I would certainly accept a patch to put a null
check here, my guess is that there might be another NPE that you will
hit down the line if you fix that one, so worth taking a little time to
understand what is going on and try to get a stand alone reproduction if
there is a bug. It has the feel of two shutdowns at once or maybe
some post commit action still happening during the shutdown.
Can you describe what is going on when this happens and try to make a
reproduction you can post?
I'd say go ahead and file a Jira and put the information there and
attach logs and such for help from the community as you debug. It would
be helpful too to use debug jars so we get line numbers in the stack trace.
Best
Kathey
Regards,
Oskar
------------------------------------------------------------------------
*From:* Katherine Marsden <[email protected]>
*To:* Derby Discussion <[email protected]>
*Cc:* Oskar Zinger <[email protected]>
*Sent:* Tuesday, January 29, 2013 12:22 AM
*Subject:* Re: NullPointerException when Shuting Down Derby
On 1/28/2013 3:04 PM, Oskar Zinger wrote:
I just upgraded to 10.8.3 and I am still running into the same
NullPointerException (NPE).
This is actually different, it comes from:
org.apache.derby.impl.store.raw.xact.XactFactory.add(Unknown Source)
Hi Oskar,
Thank you for upgrading to the latest. That always makes things easier
to debug.
I guess the next step is to understand how you get into this state.
Is there a stand alone reproduction that you can post in Jira?
Is there something in the log prior to this NPE that might give us an
indication of what was going on when you got the NPE?
Is your program multi-threaded? Is there possibly more than one thread
shutting down at once? Do you have the same problem if you use
deregister=true?
Best
Kathey
Thanks,
Oskar
------------------------------------------------------------------------
*From:* Katherine Marsden <[email protected]>
<mailto:[email protected]>
*To:* Derby Discussion <[email protected]>
<mailto:[email protected]>
*Cc:* Oskar Zinger <[email protected]> <mailto:[email protected]>
*Sent:* Monday, January 28, 2013 4:28 PM
*Subject:* Re: NullPointerException when Shuting Down Derby
On 1/28/2013 12:52 PM, Oskar Zinger wrote:
When I do the following it sometimes returns a NullPointerException:
DriverManager.getConnection("jdbc:derby:;shutdown=true;deregister=false");
Here is the exception stack trace:
Caused by: java.lang.NullPointerException
at org.apache.derby.impl.store.raw.xact.XactFactory.add(Unknown Source)
at
org.apache.derby.impl.store.raw.xact.XactFactory.pushTransactionContext(Unknown
Source)
at
org.apache.derby.impl.store.raw.xact.XactFactory.startInternalTransaction(Unknown
Source)
at
org.apache.derby.impl.store.raw.log.LogToFile.checkpointWithTran(Unknown
Source)
at
org.apache.derby.impl.store.raw.log.LogToFile.checkpoint(Unknown Source)
at org.apache.derby.impl.store.raw.RawStore.stop(Unknown Source)
at
org.apache.derby.impl.services.monitor.TopService.stop(Unknown Source)
at
org.apache.derby.impl.services.monitor.TopService.shutdown(Unknown
Source)
at
org.apache.derby.impl.services.monitor.BaseMonitor.shutdown(Unknown
Source)
at
org.apache.derby.impl.services.monitor.BaseMonitor.shutdown(Unknown
Source)
at org.apache.derby.jdbc.InternalDriver.connect(Unknown Source)
at org.apache.derby.jdbc.AutoloadedDriver.connect(Unknown Source)
at java.sql.DriverManager.getConnection(DriverManager.java:399)
at java.sql.DriverManager.getConnection(DriverManager.java:350)
Does anyone know why this is happening?
I am using Derby 10.8.2.3
Thanks,
Oskar Zinger
https://issues.apache.org/jira/browse/DERBY-5916 was backported to
10.8 with revision 1395186 and looks similar
I suggest you pick up 10.8.3 that has that fix.
