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stack commented on HBASE-14783: ------------------------------- We do not support downgrade. Never have. Its a bunch of work -- code-wise and testing-wise. Suggest we close this issue as invalid. > Proc-V2: Master aborts when downgrading from 1.3 to 1.1 > ------------------------------------------------------- > > Key: HBASE-14783 > URL: https://issues.apache.org/jira/browse/HBASE-14783 > Project: HBase > Issue Type: Bug > Reporter: Ted Yu > Assignee: Stephen Yuan Jiang > > I was running ITBLL with 1.3 deployed on a 6 node cluster. > Then I stopped the cluster, deployed 1.1 release and tried to start cluster. > However, master failed to start due to: > {code} > 2015-11-06 00:58:40,351 FATAL [eval-test-2:20000.activeMasterManager] > master.HMaster: Failed to become active master > java.io.IOException: The procedure class > org.apache.hadoop.hbase.master.procedure.ServerCrashProcedure must be > accessible and have an empty constructor > at > org.apache.hadoop.hbase.procedure2.Procedure.newInstance(Procedure.java:548) > at org.apache.hadoop.hbase.procedure2.Procedure.convert(Procedure.java:640) > at > org.apache.hadoop.hbase.procedure2.store.wal.ProcedureWALFormatReader.read(ProcedureWALFormatReader.java:105) > at > org.apache.hadoop.hbase.procedure2.store.wal.ProcedureWALFormat.load(ProcedureWALFormat.java:82) > at > org.apache.hadoop.hbase.procedure2.store.wal.WALProcedureStore.load(WALProcedureStore.java:298) > at > org.apache.hadoop.hbase.procedure2.ProcedureExecutor.load(ProcedureExecutor.java:275) > at > org.apache.hadoop.hbase.procedure2.ProcedureExecutor.start(ProcedureExecutor.java:434) > at > org.apache.hadoop.hbase.master.HMaster.startProcedureExecutor(HMaster.java:1208) > at > org.apache.hadoop.hbase.master.HMaster.startServiceThreads(HMaster.java:1107) > at > org.apache.hadoop.hbase.master.HMaster.finishActiveMasterInitialization(HMaster.java:694) > at org.apache.hadoop.hbase.master.HMaster.access$500(HMaster.java:186) > at org.apache.hadoop.hbase.master.HMaster$1.run(HMaster.java:1713) > at java.lang.Thread.run(Thread.java:745) > Caused by: java.lang.ClassNotFoundException: > org.apache.hadoop.hbase.master.procedure.ServerCrashProcedure > at java.net.URLClassLoader$1.run(URLClassLoader.java:366) > at java.net.URLClassLoader$1.run(URLClassLoader.java:355) > at java.security.AccessController.doPrivileged(Native Method) > at java.net.URLClassLoader.findClass(URLClassLoader.java:354) > at java.lang.ClassLoader.loadClass(ClassLoader.java:425) > at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) > at java.lang.ClassLoader.loadClass(ClassLoader.java:358) > at java.lang.Class.forName0(Native Method) > at java.lang.Class.forName(Class.java:191) > at > org.apache.hadoop.hbase.procedure2.Procedure.newInstance(Procedure.java:536) > ... 12 more > {code} > The cause was that ServerCrashProcedure, written in some WAL file under > MasterProcWALs from first run, was absent in 1.1 release. > After a brief discussion with Stephen, I am logging this JIRA to solicit > discussion on how customer experience can be improved if downgrade of hbase > is performed. -- This message was sent by Atlassian JIRA (v6.3.4#6332)