SerializationFactory should use current context ClassLoader

• Key: HADOOP-4467
• Type: Bug
• Status: Closed
• Resolution: Fixed
• Priority: Blocker
• Assignee: Chris K Wensel
• Reporter: Chris K Wensel
• Affects Version/s: 0.18.1, 0.19.0
• Fix Version/s: 0.18.2

Description

SerializationFactory#add calls Class.forName without a ClassLoader instance. This prevents user-space Serialization classes from being loaded.

The resulting ClassNotFoundException is eaten after being logged, and a NPE is thrown further down the line when a Serializer is requested.

Comments

[Chris K Wensel]

I probably should have phrased this one differently, but it does seem to be standard practice to provide the context classloader when calling Class.forName.

I can submit a patch with the one line change. but I do not know if there should (or even could be) an accompanying unit test for this. please advise.

[Chris K Wensel]

added 0.19 as an affected version

[Chris K Wensel]

initial attempt, without unit tests

[Owen O'Malley]

Wouldn't it be better to use the class loader associated with the configuration rather than the current thread? Basically, use

conf.getClassByName(name);

Clearly the conf for the serializer would need to be saved from the constructor.

[Chris K Wensel]

agreed.

[Chris K Wensel]

delegates classloading back to Configuration

[Chris K Wensel]

delegates back to Configuration

[Tom White]

+1

[Chris K Wensel]

All but org.apache.hadoop.fs.TestLocalDirAllocator tests pass.

I think this is unrelated:
shell-init: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory

[Chris K Wensel]

via ant test-patch...

seems to be down on lack of tests. unsure, per previous comment, how to test classloader issues.

[exec] -1 overall.
[exec]
[exec] +1 @author. The patch does not contain any @author tags.
[exec]
[exec] -1 tests included. The patch doesn't appear to include any new or modified tests.
[exec] Please justify why no tests are needed for this patch.
[exec]
[exec] +1 javadoc. The javadoc tool did not generate any warning messages.
[exec]
[exec] +1 javac. The applied patch does not increase the total number of javac compiler warnings.
[exec]
[exec] +1 findbugs. The patch does not introduce any new Findbugs warnings.
[exec]

[Arun C Murthy]

I just committed this. Thanks, Chris!

[Hudson]

Integrated in Hadoop-trunk #640 (See http://hudson.zones.apache.org/hudson/job/Hadoop-trunk/640/)
. SerializationFactory now uses the current context ClassLoader allowing for user supplied Serialization instances. Contributed by Chris Wensel.