question about Derby exception in Hive Server 2 log

[Zhang Xiaoyu <zh...@gmail.com>]

Hi, guys,
When I using Hive Server 2 (0.12), sometimes I got a Derby exception.
Anyone know why the Derby exception showing up in Hive Server 2 log (I am
using MySQL as metastore)?

Thanks,
Johnny

2014-05-17 02:25:42,344 INFO [main]
org.apache.hadoop.hive.ql.exec.FileSinkOperator: 0 finished. closing...
2014-05-17 02:25:42,351 ERROR [main]
org.apache.hadoop.hive.ql.stats.jdbc.JDBCStatsPublisher: Error during
instantiating JDBC driver org.apache.derby.jdbc.EmbeddedDriver.
java.lang.ClassNotFoundException: org.apache.derby.jdbc.EmbeddedDriver
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
 at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
 at java.security.AccessController.doPrivileged(Native Method)
 at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
 at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
 at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
 at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
 at java.lang.Class.forName0(Native Method)
 at java.lang.Class.forName(Class.java:188)
 at
org.apache.hadoop.hive.ql.stats.jdbc.JDBCStatsPublisher.connect(JDBCStatsPublisher.java:68)
 at
org.apache.hadoop.hive.ql.exec.FileSinkOperator.publishStats(FileSinkOperator.java:976)
 at
org.apache.hadoop.hive.ql.exec.FileSinkOperator.closeOp(FileSinkOperator.java:873)
 at org.apache.hadoop.hive.ql.exec.Operator.close(Operator.java:596)
 at org.apache.hadoop.hive.ql.exec.Operator.close(Operator.java:613)
 at org.apache.hadoop.hive.ql.exec.Operator.close(Operator.java:613)
 at org.apache.hadoop.hive.ql.exec.Operator.close(Operator.java:613)
 at org.apache.hadoop.hive.ql.exec.mr.ExecMapper.close(ExecMapper.java:207)
 at org.apache.hadoop.mapred.MapRunner.run(MapRunner.java:61)
 at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:429)
 at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341)
 at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:162)
 at java.security.AccessController.doPrivileged(Native Method)
 at javax.security.auth.Subject.doAs(Subject.java:415)
 at
org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491)
 at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:157)
2014-05-17 02:25:42,351 ERROR [main]
org.apache.hadoop.hive.ql.exec.FileSinkOperator: StatsPublishing error:
cannot connect to database