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Exception in DBCPConnectionPool when using ExecuteSQL

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New Member

I use DBCPConnectionPool to connect to impala with JDBC. I've pointed to a folder containing the Impala JDBC Driver from Cloudera and all of its dependencies.

I've set the Driver Class name as:

com.cloudera.impala.jdbc41.Driver
The Connection URL looks something like that:
 jdbc:impala://server:port/default;AuthMech=0;

Enabling the Controller Service causes no error but when I enable the ExecuteSQL it throws an exception:
 failed to process session due to java.lang.NoClassDefFoundError: Could not initialize class com.cloudera.impala.core.ImpalaJDBCDriver: Could not initialize class com.cloudera.impala.core.ImpalaJDBCDriver

When I've updated the drivers, I received a different exception:

Unable to execute query select * from table_name limit 1; due to org.apache.nifi.processor.exception.ProcessException: org.apache.commons.dbcp.SQLNestedException: Cannot create JDBC driver of class 'com.cloudera.impala.jdbc41.Driver' for connect URL 'jdbc:impala://server:port/db;AuthMech=0;'. No FlowFile to route to failure: org.apache.commons.dbcp.SQLNestedException: Cannot create JDBC driver of class 'com.cloudera.impala.jdbc41.Driver' for connect URL 'jdbc:impala://server:port/db;AuthMech=0;'. 

stack trace from nifi-app.log:

 java.lang.NoClassDefFoundError: Could not initialize class com.cloudera.impala.core.ImpalaJDBCDriver
 at java.lang.Classs.forName0(Native Method)
at java.lang.Class.forName(Class.java:264)
at com.cloudera.dsi.core.impl.DSIDriverFactory.createDriver(Unknown Source)
at com.cloudera.jdbc.common.AbstractDriver.doInitialize(Unknown Source)
at com.cloudera.jdbc.common.AbstractDriver.connect(Unknown Source)
at org.apache.nifi.dbcp.DriverShim.connect(DriverShim.java:46)
at org.apache.commons.dbcpDriverConnectionFactory.createConnection(DriverConnectionFactory.java:38)
at org.apache.commons.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory:1556)
at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1388)
at org.apache.comons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:1044)
at org.apache.nifi.dbcp.DBCPConnectionPool.getConnection(DBCPConnectionPool.java:272)
at sun.reflect.Method.invoke(Method.java:498)
at org.apache.nifi.controller.service.StandardControllerServiceInvocationHandler.invoke(StandardControllerServiceInvocationHandler:89)
at com.sun.proxy.$Proxy453.getConnection(Unknown Source)
at org.apache.nifi.processors.standarad.ExecuteSQL.onTrigger(ExecuteSQL.java:199)
at org.apache.nifi.processor.AbsractProcessor.onTrigger(AbstractProcessor.java:27)
at org.apache.nifi.controller.StandardProcessorNode.onTrigger(StandardProcessorNode.java:1119)
at org.apache.nifi.controller.tasks.ContinuallyRunPRocessorTask.call(ContinuallyRunProcessorTask.java:147)
org.apache.nifi.controller.tasks.ContinuallyRunPRocessorTask.call(ContinuallyRunProcessorTask.java:47)
at or.apache.controller.scheduling.TimerDrivenSchedulingAgent$1.run(TimerDrivenSchedulingAgent.java:128)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.runAndREset(FutureTask.java:308)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPool.Executor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)


I'm using NiFi 1.4.0 and I have all of the dependencies in one folder with the jdbc driver, with no sub folders.
Any thoughts?

1 ACCEPTED SOLUTION

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New Member

After restarting the servers it suddenly worked. Really strange. Thanks anyway!

View solution in original post

4 REPLIES 4

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Master Guru

Is there anything else underneath that stack trace in nifi-app.log? There is usually a Caused By with a ClassNotFoundException or something like that.

avatar
New Member

Unfortunately no..

avatar
Master Guru

Is it possible to share your nifi-app.log on this question? Also, does this driver work from other utilities (Squirrel SQL, e.g.)?

avatar
New Member

After restarting the servers it suddenly worked. Really strange. Thanks anyway!