spark shell启动多个客户端可能产生的问题

在启动spark shell的时候，产生如下错误
[mw_shl_code=bash,true]Caused by: java.sql.SQLException: Failed to start database 'metastore_db' with class loader org.apache.spark.sql.hive.client.IsolatedClientLoader$$anon$1@5984742f, see the next exception for details.
        at org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unknown Source)
        at org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unknown Source)
        at org.apache.derby.impl.jdbc.Util.seeNextException(Unknown Source)
        at org.apache.derby.impl.jdbc.EmbedConnection.bootDatabase(Unknown Source)
        at org.apache.derby.impl.jdbc.EmbedConnection.<init>(Unknown Source)
        at org.apache.derby.jdbc.InternalDriver$1.run(Unknown Source)
        at org.apache.derby.jdbc.InternalDriver$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.apache.derby.jdbc.InternalDriver.getNewEmbedConnection(Unknown Source)
        at org.apache.derby.jdbc.InternalDriver.connect(Unknown Source)
        at org.apache.derby.jdbc.InternalDriver.connect(Unknown Source)
        at org.apache.derby.jdbc.AutoloadedDriver.connect(Unknown Source)
        at java.sql.DriverManager.getConnection(DriverManager.java:664)
        at java.sql.DriverManager.getConnection(DriverManager.java:208)
        at org.apache.commons.dbcp.DriverManagerConnectionFactory.createConnection(DriverManagerConnectionFactory.java:78)
        at org.apache.commons.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:582)
        at org.apache.commons.pool.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:1148)
        at org.apache.commons.dbcp.PoolingDataSource.getConnection(PoolingDataSource.java:106)
        at org.datanucleus.store.rdbms.ConnectionFactoryImpl$ManagedConnectionImpl.getConnection(ConnectionFactoryImpl.java:501)
        at org.datanucleus.store.rdbms.RDBMSStoreManager.<init>(RDBMSStoreManager.java:298)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
        at org.datanucleus.plugin.NonManagedPluginRegistry.createExecutableExtension(NonManagedPluginRegistry.java:631)
        at org.datanucleus.plugin.PluginManager.createExecutableExtension(PluginManager.java:301)
        at org.datanucleus.NucleusContext.createStoreManagerForProperties(NucleusContext.java:1187)
        at org.datanucleus.NucleusContext.initialise(NucleusContext.java:356)
        at org.datanucleus.api.jdo.JDOPersistenceManagerFactory.freezeConfiguration(JDOPersistenceManagerFactory.java:775)
        ... 104 more
Caused by: ERROR XJ040: Failed to start database 'metastore_db' with class loader org.apache.spark.sql.hive.client.IsolatedClientLoader$$anon$1@5984742f, see the next exception for details.
        at org.apache.derby.iapi.error.StandardException.newException(Unknown Source)
        at org.apache.derby.impl.jdbc.SQLExceptionFactory.wrapArgsForTransportAcrossDRDA(Unknown Source)
        ... 133 more
Caused by: ERROR XSDB6: Another instance of Derby may have already booted the database /data/spark/metastore_db.
        at org.apache.derby.iapi.error.StandardException.newException(Unknown Source)
        at org.apache.derby.iapi.error.StandardException.newException(Unknown Source)
        at org.apache.derby.impl.store.raw.data.BaseDataFileFactory.privGetJBMSLockOnDB(Unknown Source)
        at org.apache.derby.impl.store.raw.data.BaseDataFileFactory.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.apache.derby.impl.store.raw.data.BaseDataFileFactory.getJBMSLockOnDB(Unknown Source)
        at org.apache.derby.impl.store.raw.data.BaseDataFileFactory.boot(Unknown Source)
        at org.apache.derby.impl.services.monitor.BaseMonitor.boot(Unknown Source)
        at org.apache.derby.impl.services.monitor.TopService.bootModule(Unknown Source)
        at org.apache.derby.impl.services.monitor.BaseMonitor.startModule(Unknown Source)
        at org.apache.derby.impl.services.monitor.FileMonitor.startModule(Unknown Source)
        at org.apache.derby.iapi.services.monitor.Monitor.bootServiceModule(Unknown Source)
        at org.apache.derby.impl.store.raw.RawStore$6.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.apache.derby.impl.store.raw.RawStore.bootServiceModule(Unknown Source)
        at org.apache.derby.impl.store.raw.RawStore.boot(Unknown Source)
        at org.apache.derby.impl.services.monitor.BaseMonitor.boot(Unknown Source)
        at org.apache.derby.impl.services.monitor.TopService.bootModule(Unknown Source)
        at org.apache.derby.impl.services.monitor.BaseMonitor.startModule(Unknown Source)
        at org.apache.derby.impl.services.monitor.FileMonitor.startModule(Unknown Source)
        at org.apache.derby.iapi.services.monitor.Monitor.bootServiceModule(Unknown Source)
        at org.apache.derby.impl.store.access.RAMAccessManager$5.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.apache.derby.impl.store.access.RAMAccessManager.bootServiceModule(Unknown Source)
        at org.apache.derby.impl.store.access.RAMAccessManager.boot(Unknown Source)
        at org.apache.derby.impl.services.monitor.BaseMonitor.boot(Unknown Source)
        at org.apache.derby.impl.services.monitor.TopService.bootModule(Unknown Source)
        at org.apache.derby.impl.services.monitor.BaseMonitor.startModule(Unknown Source)
        at org.apache.derby.impl.services.monitor.FileMonitor.startModule(Unknown Source)
        at org.apache.derby.iapi.services.monitor.Monitor.bootServiceModule(Unknown Source)
        at org.apache.derby.impl.db.BasicDatabase$5.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.apache.derby.impl.db.BasicDatabase.bootServiceModule(Unknown Source)
        at org.apache.derby.impl.db.BasicDatabase.bootStore(Unknown Source)
        at org.apache.derby.impl.db.BasicDatabase.boot(Unknown Source)
        at org.apache.derby.impl.services.monitor.BaseMonitor.boot(Unknown Source)
        at org.apache.derby.impl.services.monitor.TopService.bootModule(Unknown Source)
        at org.apache.derby.impl.services.monitor.BaseMonitor.bootService(Unknown Source)
        at org.apache.derby.impl.services.monitor.BaseMonitor.startProviderService(Unknown Source)
        at org.apache.derby.impl.services.monitor.BaseMonitor.findProviderAndStartService(Unknown Source)
        at org.apache.derby.impl.services.monitor.BaseMonitor.startPersistentService(Unknown Source)
        at org.apache.derby.iapi.services.monitor.Monitor.startPersistentService(Unknown Source)
        at org.apache.derby.impl.jdbc.EmbedConnection$4.run(Unknown Source)
        at org.apache.derby.impl.jdbc.EmbedConnection$4.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.apache.derby.impl.jdbc.EmbedConnection.startPersistentService(Unknown Source)
        ... 130 more

<console>:16: error: not found: value sqlContext
         import sqlContext.implicits._
                ^
<console>:16: error: not found: value sqlContext
         import sqlContext.sql
                ^
[/mw_shl_code]

通过命令
[mw_shl_code=bash,true] ps -ef | grep spark-shell
[/mw_shl_code]



将这个shell ID kill

kill -9 Spark-Shell-processID
例如
[mw_shl_code=bash,true]kill -9 7774[/mw_shl_code]


再次启动成功。

感谢分享