[KYLIN-2699] Tomcat LinkageError for curator-client jar file conflict

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: v2.0.0
• Fix Version/s: v2.1.0
• Component/s: Job Engine, Web
• Assignee: Dong Li
• Reporter: Mingming Qiu
• Created: 30/Jun/17 08:16
• Updated: 17/Aug/17 15:03
• Resolved: 14/Jul/17 08:22

Description

Exception: java.lang.LinkageError: loader constraint violation: loader (instance of sun/misc/Launcher$AppClassLoader) previously initiated loading for a different type with name "org/apache/curator/RetryPolicy"
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at org.apache.curator.CuratorZookeeperClient.<init>(CuratorZookeeperClient.java:97)
at org.apache.curator.framework.imps.CuratorFrameworkImpl.<init>(CuratorFrameworkImpl.java:108)
at org.apache.curator.framework.CuratorFrameworkFactory$Builder.build(CuratorFrameworkFactory.java:124)
at org.apache.kylin.storage.hbase.util.ZookeeperJobLock.lock(ZookeeperJobLock.java:70)
at org.apache.kylin.job.impl.threadpool.DefaultScheduler.init(DefaultScheduler.java:208)
at org.apache.kylin.rest.service.JobService$1.run(JobService.java:116)
at java.lang.Thread.run(Thread.java:745)

This exception will make kylin job engine does not work. And I found it occured because in the kylin/WEB-INF/lib contains the curator-client-2.7.1.jar which make some conflicts. In general, the HBase and Hadoop cluster always contain their own curator-client jar files. So there is no need to include the curator-client jar file in kylin/WEB-INF/lib.

Issue Links

• is duplicated by: KYLIN-2428 Cleanup unnecessary shaded libraries for job/coprocessor/jdbc/server