Derby can enter infinite loop and consume 100% cpu when loading class when
running a stored procedure within Eclipse 3.2
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Key: DERBY-1446
URL: http://issues.apache.org/jira/browse/DERBY-1446
Project: Derby
Type: Bug
Components: JDBC
Versions: 10.1.2.5
Environment:
This problem was found on Windows XP. I haven't tried on
Linux, so I don't know if the problem appears there.
Reporter: Kathey Marsden
The problem occurs with the interaction between Derby and Eclipse
3.2 with WTP datatools.
If you try to run a Derby stored procedure using the connection that WTP
datatools establishes, the CallableStatement.execute() method never returns
and the
CPU utilization on your system goes to 100%. Simple SQL query
(e.g. SELECT, etc) which use java.sql.Statement can be
successfully executed using the connection that WTP obtains.
Geting a driver manager connection directly the problem does not occur.
Some change in eclipse 3.2 (perhaps related to the classloader context?) seems
to trigger the issue, but in this context 1) Derby can't find the class and 2)
It loops forever looking for it, which it shouldn't do. So I think there is a
Derby bug here, even if it ends up there is an Eclipse/OSGI bug as well.
Below are some details from the WTP expert looking at this.
1) I tested WTP 1.5 with both the Sun JRE 1.4.2 and IBM JRE 1.5 and the
problem occurs
2) I tested WTP 1.0.3 and the problem does not occur
3) I tested WTP 1.0.3 but installed it into Eclipse 3.2 and the problem occurs
Eclipse 3.2 seems to be the cause of the problem.
When the hang occurs, I paused the debugger and always got the same stack trace
which I have attached in its entirety. The top of the stack trace is as
follows. Note that the driver is interacting with the OSGI engine of Eclipse.
It looks like a defect in the OSGI runtime. It doesn't seem to find the jar
holding the stored procedure and then proceeds to go into an infinite loop in
filllnStackTrace(). I'll take this up with the Eclipse team and see what I can
find out.
Thread [main] (Suspended)
Throwable.fillInStackTrace() line: not available [native method]
ClassNotFoundException(Throwable).<init>(String, Throwable) line: not
available
ClassNotFoundException(Exception).<init>(String, Throwable) line: not
available
ClassNotFoundException.<init>(String) line: not available
ClasspathManager.findLocalClassImpl(String, ClassLoadingStatsHook[])
line: 442
ClasspathManager.findLocalClass(String) line: 410
DefaultClassLoader.findLocalClass(String) line: 188
BundleLoader.findLocalClass(String) line: 339
BundleLoader.findClass(String, boolean) line: 391
BundleLoader.findClass(String) line: 352
DefaultClassLoader.loadClass(String, boolean) line: 83
URLClassLoader(ClassLoader).loadClass(String, boolean) line: not
available
URLClassLoader(ClassLoader).loadClass(String) line: not available
ContextFinder.loadClass(String, boolean) line: 94
ContextFinder(ClassLoader).loadClass(String) line: not available
ReflectClassesJava2.loadClassNotInDatabaseJar(String) line: not
available
ReflectClassesJava2(DatabaseClasses).loadApplicationClass(String) line:
not available
REPRODUCTION INFO
The full reproduction information with setup for eclipse and WTP has other
components but should reproduce by isntalling Eclipse 3.2 with WTP and Derby.
>From the user:
To reproduce the problem, you have to execute a stored
procedure from within Eclipse, using the connection that WTP
obtains.
I've created a very simple plugin that adds a "RUN Stored Procedure" action to
stored procedures in the Database Explorer view of WTP. This
file contains a zipped Eclipse plugin development project.
Unzip the file and import the project into an Eclipse
workspace. You can then use the Eclipse debugger to run an
Eclipse application that will have the function to run a stored
procedure which has no parameters and returns a result set.
To produce the problem, after you have imported the
DerbySPRunTest project into your workspace,
set a breakpoint in
derbyspruntest.actions.RunRoutineAction.runRuntine() method
before the stmt.execute()
Start the Eclipse debugger on an Eclipse application.
Open a Database Explorer view (Windows->Show
view->Other->Data->Database Explorer) .
Right-click on Connections and select New Connection to make a
connection to a Derby database that contains a stored procedure
which has no parameters and returns a result set.
Expand the schemas and stored procedure folder to display the
stored procedure that you want to run.
Right click on the stored procedure and select "Run Stored
Procedure"
The debugger will stop and you can see that when stmt.execute()
is executed, it never returns and your CPU utilization is at
100%.
If I change the RunRoutineAction to use a connection that I
obtained directly, instead of the connection obtained by WTP,
(see commented out code), the stmt.execute() methods works
correctly and the output is displayed in the OutputView. The
DerbySPRunTest plugin contains the derby.jar only for this test
situation. When a connection is made via WTP, WTP dynamically
loads the driver specified on the connection dialog.
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