[HADOOP-9001] libhadoop.so links against wrong OpenJDK libjvm.so

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Assignee: Unassigned
• Reporter: Andy Isaacson
• Created: 31/Oct/12 23:42
• Updated: 31/Oct/12 23:42

Description

After building against OpenJDK 6b24-1.11.4-3 (Debian amd64) using

mvn -Pnative,dist clean package -Dmaven.javadoc.skip=true -DskipTests -Dtar

the resulting binaries libhadoop.so and libhdfs.so are linked to the wrong libjvm.so:

% LD_LIBRARY_PATH=/usr/lib/jvm/java-6-openjdk-amd64/jre/lib/amd64/server ldd hadoop-dist/target/hadoop-3.0.0-SNAPSHOT/lib/native/libhadoop.so.1.0.0
        linux-vdso.so.1 =>  (0x00007fff8c7ff000)
        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f31df30e000)
        libjvm.so.0 => not found
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f31def86000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f31df73d000)

Inspecting the build output it appears that JNIFlags.cmake decided, mysteriously, to link against /usr/lib/jvm/default-java/jre/lib/amd64/jamvm/libjvm.so, based on:

     [exec] JAVA_HOME=, JAVA_JVM_LIBRARY=/usr/lib/jvm/default-java/jre/lib/amd64/jamvm/libjvm.so
     [exec] JAVA_INCLUDE_PATH=/usr/lib/jvm/default-java/include, JAVA_INCLUDE_PATH2=/usr/lib/jvm/default-java/include/linux
     [exec] Located all JNI components successfully.

The "jamvm" is not mentioned anywhere in my environment or any symlinks in /usr, so apparently cmake iterated over the directories in /usr/lib/jvm/default-java/jre/lib/amd64 to find it. The following libjvm.so files are present on this machine:

-rw-r--r-- 1 root root  1050190 Sep  2 13:38 /usr/lib/jvm/java-6-openjdk-amd64/jre/lib/amd64/cacao/libjvm.so
-rw-r--r-- 1 root root  1554628 Sep  2 11:21 /usr/lib/jvm/java-6-openjdk-amd64/jre/lib/amd64/jamvm/libjvm.so
-rw-r--r-- 1 root root 12193850 Sep  2 13:38 /usr/lib/jvm/java-6-openjdk-amd64/jre/lib/amd64/server/libjvm.so

Note the difference between libjvm.so and libjvm.so.0; the latter seems to come from the DT_SONAME in jamvm/libjvm.so, but that library seems to just be broken since there's no libjvm.so.0 symlink anywhere on the filesystem. I suspect that is a bug in OpenJDK but we should just avoid the issue by finding the right value for JAVA_JVM_LIBRARY.