Scenario: You are trying to execute the OHSH, you already installed the Oracle Loader for Hadoop(OLH) but the tool still warning you that OLH is not installed.
If you think that install and set OLH_HOME is enough, surprise: it is not.
Actually, this problem can be related with your hadoop classapth. Ensure that your mapreduce libs are set in the HADOOP_CLASSPATH:
[oracle@bigdatalite ~]$ ohsh
OLH is not installed.
Oracle Shell for Hadoop Loaders Release 1.2.0 – Production (Build:20161118015057)
Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
Oracle SQL Connector for HDFS (3.7.0), The Copy to Hadoop feature of Oracle Big Data SQL (3.1.0) enabled.
ohsh>
The error above is telling you the OLH is not installed. But you checked the Oracle Loader for Hadoop variables and folder. So, what’s wrong?
Check if your mapreduce libs are present in the classpath. if not, just add it:
[oracle@bigdatalite ~]$ ls -ltr /usr/lib/hadoop-mapreduce/ | grep core
-rw-r–r–. 1 root root 85448 Oct 21 04:36 metrics-core-3.0.2.jar
-rw-r–r–. 1 root root 458739 Oct 21 04:36 jersey-core-1.9.jar
-rw-r–r–. 1 root root 227500 Oct 21 04:36 jackson-core-asl-1.8.8.jar
-rw-r–r–. 1 root root 192699 Oct 21 04:36 jackson-core-2.2.3.jar
-rw-r–r–. 1 root root 227708 Oct 21 04:36 httpcore-4.2.5.jar
-rw-r–r–. 1 root root 1485102 Oct 21 04:36 htrace-core4-4.0.1-incubating.jar
-rw-r–r–. 1 root root 45024 Oct 21 04:36 hamcrest-core-1.3.jar
-rw-r–r–. 1 root root 1549487 Oct 21 04:36 hadoop-mapreduce-client-core-2.6.0-cdh5.9.0.jar
-rw-r–r–. 1 root root 206035 Oct 21 04:36 commons-beanutils-core-1.8.0.jar
lrwxrwxrwx. 1 root root 47 Jan 15 14:24 hadoop-mapreduce-client-core.jar -> hadoop-mapreduce-client-core-2.6.0-cdh5.9.0.jar[oracle@bigdatalite ~]$ hadoop classpath
4/etc/hadoop/conf:/usr/lib/hadoop/lib/*:/usr/lib/hadoop/.//*:/usr/lib/hadoop-hdfs/./:/usr/lib/hadoop-hdfs/lib/*:/usr/lib/hadoop-hdfs/.//*:/usr/lib/hadoop-yarn/lib/*:/usr/lib/hadoop-yarn/.//*:/usr/lib/hadoop-mapreduce/lib/*:/usr/lib/hadoop-mapreduce/.//*:/u01/orahivedp/jlib/*:/u01/connectors/olh/jlib/*:/etc/hive/conf:/u01/connectors/osch/jlib/*:/u01/app/oracle/product/12.1.0.2/dbhome_1/jdbc/lib/*:/u01/nosql/kv-ee/lib/kvstore.jar
Tip: the library hadoop-mapreduce-client-core is mandatory if you need to run the OHSH. You always can start looking for this library. 😉
After set the classpath correctly, try it again:
[oracle@bigdatalite ~]$ ohsh
Oracle Shell for Hadoop Loaders Release 1.2.0 – Production (Build:20161118015057)
Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
Oracle Loader for Hadoop (3.8.0), Oracle SQL Connector for HDFS (3.7.0), The Copy to Hadoop feature of Oracle Big Data SQL (3.1.0) enabled.
ohsh>ohsh>show resource
hadoop0 : Hadoop Command Line Resource
HADOOP_HOME =
HADOOP_CONF_DIR = /etc/hadoop/conf
hive0 : Hive Command Line Resource
HIVE_HOME = /usr/lib/hive
HIVE_CONF_DIR = /etc/hive/conf
Connect to jdbc:hive2://10000/default;
hadoop resource id = hadoop0
bash0 : Bash Command Line Resource
path = /bin/bash
ohsh>
Cheers!
Marcello Morettoni 