Tag Archives: BigData

[Solved] sqoop Error: jSQLException in nextKeyValue Caused by: ORA-24920:column size too large for client

Question

When importing Oracle data with sqoop, the following errors are reported:

INFO mapreduce.Job: Task Id : attempt_1646802944907_15460_m_000000_1, Status : FAILED
Error: java.io.IOException: SQLException in nextKeyValue
        at org.apache.sqoop.mapreduce.db.DBRecordReader.nextKeyValue(DBRecordReader.java:275)
        at org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.nextKeyValue(MapTask.java:568)
        at org.apache.hadoop.mapreduce.task.MapContextImpl.nextKeyValue(MapContextImpl.java:80)
        at org.apache.hadoop.mapreduce.lib.map.WrappedMapper$Context.nextKeyValue(WrappedMapper.java:91)
        at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:145)
        at org.apache.sqoop.mapreduce.AutoProgressMapper.run(AutoProgressMapper.java:64)
        at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:799)
        at org.apache.hadoop.mapred.MapTask.run(MapTask.java:347)
        at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:174)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:422)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1875)
        at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:168)
Caused by: java.sql.SQLException: ORA-24920: column size too large for client

reason

Before using sqoop import other database is normal, this time from the new database import data problems, first check what is the difference between the two databases, found an Oracle version is 11, the new Oracle database version is 19, which may be the cause of the problem.
Go online to check the ORA-24920 error, said to upgrade the oracle client, further speculation may be the problem of Oracle driver.
Under the lib file of sqoop tool, the Oracle JDBC driver found for sqoop is ojdbc6.jar, which does not match with Oracle version 19.
You can check the Oracle version and the corresponding Oracle JDBC driver version on this page:
https://www.oracle.com/database/technologies/faq-jdbc.html#02_03
The screenshot is as follows:

the link to the download page is as follows:
https://www.oracle.com/database/technologies/appdev/jdbc-downloads.html

Solution:

According to the version, ojdbc8.0.jar was downloaded. After uploading, delete the original version and re import the data.
the driver of the original version here needs to be deleted or moved, otherwise it will not succeed. Guess that if there are two versions, the old version may be read

Sparkcontext: error initializing sparkcontext workaround

Sparkcontext: error initializing sparkcontext workaround

Spark reports an error when configuring a highly available cluster
error sparkcontext: error initializing sparkcontext. Java.net.connectexception: call from Hadoop 102/192.168.10.102 to Hadoop 102: 8020 failed on connection exception: java.net.connectexception: connection rejected

This is because we configured spark logs to be stored in HDFS, but Hadoop was not opened after the spark cluster was started, resulting in an error when submitting tasks.

Solution:

    no longer store the event log
    find the spark installation directory/conf/spark-defaults.conf file, as shown in the figure, and comment out the corresponding event log part
    store the event log locally instead of in HDFS
    replace the directory in the second line in the figure above with the Linux local directory to start the Hadoop cluster (i.e. HDFS service)
    investigate the cause of the error, Or we configured the spark log to be stored in HDFS, but did not open HDFS, so start the Hadoop cluster

Centos8 modifying the host name

When you modify the host name, you can directly use the tools provided by the system.  

[[email protected] centos]# hostnamectl
   Static hostname: localhost.localdomain
         Icon name: computer-vm
           Chassis: vm
        Machine ID: 89bf177f78dc49f6b4954e1e9511e267
           Boot ID: 8f46edc8b7b648f58d5d4c1f3c15cbee
    Virtualization: vmware
  Operating System: CentOS Linux 8
       CPE OS Name: cpe:/o:centos:centos:8
            Kernel: Linux 4.18.0-240.10.1.el8_3.x86_64
      Architecture: x86-64
[[email protected] centos]# sudo hostnamectl set-hostname k8s-slave
[[email protected] centos]# hostnamectl
   Static hostname: k8s-slave
         Icon name: computer-vm
           Chassis: vm
        Machine ID: 89bf177f78dc49f6b4954e1e9511e267
           Boot ID: 8f46edc8b7b648f58d5d4c1f3c15cbee
    Virtualization: vmware
  Operating System: CentOS Linux 8
       CPE OS Name: cpe:/o:centos:centos:8
            Kernel: Linux 4.18.0-240.10.1.el8_3.x86_64
      Architecture: x86-64
[[email protected] centos]# cat /etc/hostname 
k8s-slave
[[email protected] centos]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
[[email protected] centos]# vi /etc/hosts
[[email protected] centos]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

192.168.187.151  k8s-slave
[[email protected] centos]#