Java and UIMA things holding on to objects loaded via Resource Manager fail
when switching to another Resource Manager class loader instance
--------------------------------------------------------------------------------------------------------------------------------------------
Key: UIMA-1713
URL: https://issues.apache.org/jira/browse/UIMA-1713
Project: UIMA
Issue Type: Bug
Components: Async Scaleout
Affects Versions: 2.3AS
Reporter: Marshall Schor
Assignee: Jerry Cwiklik
Priority: Blocker
JNDI and JMX both use "system-wide" "registries" of objects. These objects,
for uima-as, can be loaded from a Resource Manager in cases where the uima-as
classes are on the Resource Manager's classpath. A use case where this can
occur is a UIMA aggregate containg 2 PEAR descriptors, each having a
potentially different version of uima-as in the PEAR's classpath, being used as
a client to a remote uima-as service. (Note that the uima-as client for this
is represented in UIMA as a "custom resource specifier", so this use case can
also apply to future "custom resources".)
The system-wide registries for JNDI and JMX use a string handle to locate
objects, and cache found objects in the registry. The first use loads the
object, using the class loader in effect at the place where the lookup is
requested. For uima-as being used as a custom resource, the class loader used
is the UIMA class loader associated with the current resource manager.
If, subsequently, another resource manager instance (actually, another class
loader instance within the UIMA resource manager) is used to run the uima-as
classes, the lookups by name for objects in these registries will succeed, but
will return objects that were loaded under a different class loader. This
causes ClassCastExceptions, because the superclasses / interfaces used in the
currently running code (running under the 2nd classloader) no longer are the
superclasses / interfaces of the objects retrieved under the 1st classloader.
See http://markmail.org/message/2r5coddmuuprucyk for discussion of this issue
in the context of running the Configuration Descriptor Editor (CDE).
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
