In the last three posts, I discussed the following:
1. Install Cloudera Hadoop Cluster using Cloudera Manager
2. Configurations after CDH Installation
3. Load Data to Hive Table.
This post will discuss a basic scenario in Hive: Dump some data from Oracle database, load to HDFS, and query the data using Hive. Sqoop is a tool designed for transferring bulk data between Hadoop and RDBMS, such as Oracle. It can be used to populated data to Hive or HBase on Hadoop. The import can be the entire table or the result from a query or incremental load. Ok, here is the example to show how to use sqoop to load data from Oracle.
1. Add the user to hive group on all hosts in the cluster. Otherwise, you could see the following error:
chgrp: changing ownership of ‘hdfs://vmhost1.local:8020/user/hive/warehouse/test_oracle.db/my_all_objects_sqoop/part-m-00004_copy_1’: User does not belong to hive
[root@vmhost1 mnt]# usermod -a -G hive wzhou
[root@vmhost1 mnt]# id wzhou
uid=502(wzhou) gid=502(wzhou) groups=502(wzhou),481(hive),501(bigdata)
2. Create the target directory, /tmp/sqoopimport, for the sqoop job.
[wzhou@vmhost1 data]$ hdfs dfs -mkdir /tmp/sqoopimport
3. Install Oracle JDBC driver. Check if Oracle JDBC exist or not, if not, do the following to install the driver. The Oracle JDBC driver file can be downloaded from Oracle web site at
http://www.oracle.com/technetwork/database/enterprise-edition/jdbc-112010-090769.html
The file name is ojdbc6.jar. Then copy this file to /usr/lib/sqoop/lib/ if using package, or /var/lib/sqoop/ if using parcel. Make sure to change file permission to 755 afterwards.
[root@vmhost1 mnt]# cp ojdbc6.jar /usr/lib/sqoop/lib/
[root@vmhost1 mnt]# ls -l /usr/lib/sqoop/lib/oj*.jar
-rw-r—– 1 root root 2739670 Sep 21 15:24 /usr/lib/sqoop/lib/ojdbc6.jar
[root@vmhost1 mnt]# chmod 755 /usr/lib/sqoop/lib/ojdbc6.jar
[root@vmhost1 mnt]# ls -l /usr/lib/sqoop/lib/oj*.jar
-rwxr-xr-x 1 root root 2739670 Sep 21 15:24 /usr/lib/sqoop/lib/ojdbc6.jar
Verify whether the JDBC connection is working or not, run sqoop with list-databases argument. It will connect to oracle database and list schemas in the dbm database. If don’t want to show the password in the commandline, use -P parameter to input the db password.
sqoop list-databases \
–connect jdbc:oracle:thin:@enkx3-scan:1521:dbm1 \
–username wzhou \
-P
Here are the execution result
[wzhou@vmhost1 data]$ sqoop list-databases \
> –connect jdbc:oracle:thin:@enkx3-scan:1521:dbm1 \
> –username wzhou \
> -P
Warning: /usr/lib/sqoop/../accumulo does not exist! Accumulo imports will fail.
Please set $ACCUMULO_HOME to the root of your Accumulo installation.
15/09/21 18:55:58 INFO sqoop.Sqoop: Running Sqoop version: 1.4.5-cdh5.4.3
Enter password:
15/09/21 18:56:02 INFO oracle.OraOopManagerFactory: Data Connector for Oracle and Hadoop is disabled.
15/09/21 18:56:02 INFO manager.SqlManager: Using default fetchSize of 1000
15/09/21 18:56:03 INFO manager.OracleManager: Time zone has been set to GMT
ORACLE
JBARBA
TANEL
WZHOU
MBH
MPAGANO
GSHEPPARD
ENKITEC
ACOLVIN
KARLARAO
KSO
MARTIN
KOSBORNE
ODI
RJOHNSON
ORACLE_OCM
. . . .
SYSMAN
DBSNMP
WMSYS
XDB
MGMT_VIEW
SYS
SYSTEM
5. Create the Hive table. The new Hive table is called my_all_objects_sqoop under test_oracle database.
First, just check no my_all_objects_sqoop table exist on HDFS
hdfs dfs -ls /user/hive/warehouse/test_oracle.db
Run the following commands to create hive table in test_oracle database.
hive
USE test_oracle;
CREATE TABLE my_all_objects_sqoop (
owner string,
object_name string,
object_id int,
object_type string,
create_date string
)
STORED AS TEXTFILE;
SHOW TABLES;
Check out the folders on HDFS.
hdfs dfs -ls /user/hive/warehouse/test_oracle.db
hdfs dfs -ls /user/hive/warehouse/test_oracle.db/my_all_objects_sqoop
Execution result.
[wzhou@vmhost1 data]$ hdfs dfs -ls /user/hive/warehouse/test_oracle.db
Found 1 items
drwxrwxrwt – wzhou hive 0 2015-09-21 11:55 /user/hive/warehouse/test_oracle.db/my_all_objects
hive> USE test_oracle;
OK
Time taken: 0.221 seconds
hive> CREATE TABLE my_all_objects_sqoop (
> owner string,
> object_name string,
> object_id int,
> object_type string,
> create_date string
> )
> STORED AS TEXTFILE;
OK
Time taken: 0.247 seconds
hive> SHOW TABLES;
OK
my_all_objects
my_all_objects_sqoop
Time taken: 0.154 seconds, Fetched: 2 row(s)
[wzhou@vmhost1 data]$ hdfs dfs -ls /user/hive/warehouse/test_oracle.db
Found 2 items
drwxrwxrwt – wzhou hive 0 2015-09-21 11:55 /user/hive/warehouse/test_oracle.db/my_all_objects
drwxrwxrwt – wzhou hive 0 2015-09-21 17:15 /user/hive/warehouse/test_oracle.db/my_all_objects_sqoop
[wzhou@vmhost1 data]$ hdfs dfs -ls /user/hive/warehouse/test_oracle.db/my_all_objects_sqoop
[wzhou@vmhost1 data]$
6. Run the sqoop to import the table directly to hive table. Please note, hive has a weird requirement and I had to add $CONDITIONS in the where clause although I am going to retrieve all rows from all_objects. -m or –num-mappers argument allows the parallel import. It specifies the number of map tasks (parallel processes) to use to perform the import. When running in parallel, sqoop needs a way to split the workload. This is where –split-by argument is used for. –split-by specify the column to used as a split column. By the default, the primary key of the table is used as the split column. But you can specify a different column by using –split-by argument.
sqoop import \
–connect jdbc:oracle:thin:@enkx3-scan:1521:dbm1 \
–username wzhou \
–password wzhou \
–query “select owner, object_name, object_id, object_type, to_char(created, ‘yyyy-mm-dd’) created_date from all_objects where \$CONDITIONS” \
-m 4 \
–split-by object_type \
–hive-import \
–target-dir ‘/tmp/sqoopimport’ \
–hive-table test_oracle.my_all_objects_sqoop
select * from my_all_objects_sqoop limit 3;
select count(*) from my_all_objects_sqoop;
hdfs dfs -ls /user/hive/warehouse/test_oracle.db/my_all_objects_sqoop
hdfs dfs -ls /user/hive/warehouse/test_oracle.db/my_all_objects
hdfs dfs -cat /user/hive/warehouse/test_oracle.db/my_all_objects_sqoop/part-m-00000 | head -n 10
Execution result.
[wzhou@vmhost1 data]$ <b>sqoop import \
> --connect jdbc:oracle:thin:@enkx3-scan:1521:dbm1 \
> --username wzhou \
> --password wzhou \
> --query "select owner, object_name, object_id, object_type, to_char(created, 'yyyy-mm-dd') created_date from all_objects where \$CONDITIONS" \
> -m 4 \
> --split-by object_type \
> --hive-import \
> --target-dir '/tmp/sqoopimport' \
> --hive-table test_oracle.my_all_objects_sqoop <b>
Warning: /usr/lib/sqoop/../accumulo does not exist! Accumulo imports will fail.
Please set $ACCUMULO_HOME to the root of your Accumulo installation.
15/09/21 17:53:15 INFO sqoop.Sqoop: Running Sqoop version: 1.4.5-cdh5.4.3
15/09/21 17:53:15 WARN tool.BaseSqoopTool: Setting your password on the command-line is insecure. Consider using -P instead.
15/09/21 17:53:15 INFO tool.BaseSqoopTool: Using Hive-specific delimiters for output. You can override
15/09/21 17:53:15 INFO tool.BaseSqoopTool: delimiters with --fields-terminated-by, etc.
15/09/21 17:53:15 INFO oracle.OraOopManagerFactory: Data Connector for Oracle and Hadoop is disabled.
15/09/21 17:53:15 INFO manager.SqlManager: Using default fetchSize of 1000
15/09/21 17:53:15 INFO tool.CodeGenTool: Beginning code generation
15/09/21 17:53:18 INFO manager.OracleManager: Time zone has been set to GMT
15/09/21 17:53:18 INFO manager.SqlManager: Executing SQL statement: select owner, object_name, object_id, object_type, to_char(created, 'yyyy-mm-dd') created_date from all_objects where (1 = 0)
15/09/21 17:53:19 INFO manager.SqlManager: Executing SQL statement: select owner, object_name, object_id, object_type, to_char(created, 'yyyy-mm-dd') created_date from all_objects where (1 = 0)
15/09/21 17:53:19 INFO orm.CompilationManager: HADOOP_MAPRED_HOME is /usr/lib/hadoop-mapreduce
Note: /tmp/sqoop-wzhou/compile/d96bcc9fb5354b998f0db547e0ed17bc/QueryResult.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
15/09/21 17:53:21 INFO orm.CompilationManager: Writing jar file: /tmp/sqoop-wzhou/compile/d96bcc9fb5354b998f0db547e0ed17bc/QueryResult.jar
15/09/21 17:53:21 INFO mapreduce.ImportJobBase: Beginning query import.
15/09/21 17:53:21 INFO Configuration.deprecation: mapred.jar is deprecated. Instead, use mapreduce.job.jar
15/09/21 17:53:22 INFO Configuration.deprecation: mapred.map.tasks is deprecated. Instead, use mapreduce.job.maps
15/09/21 17:53:22 INFO client.RMProxy: Connecting to ResourceManager at vmhost1.local/192.168.56.71:8032
15/09/21 17:53:26 INFO db.DBInputFormat: Using read commited transaction isolation
15/09/21 17:53:26 INFO db.DataDrivenDBInputFormat: BoundingValsQuery: SELECT MIN(object_type), MAX(object_type) FROM (select owner, object_name, object_id, object_type, to_char(created, 'yyyy-mm-dd') created_date from all_objects where (1 = 1) ) t1
15/09/21 17:53:26 WARN db.TextSplitter: Generating splits for a textual index column.
15/09/21 17:53:26 WARN db.TextSplitter: If your database sorts in a case-insensitive order, this may result in a partial import or duplicate records.
15/09/21 17:53:26 WARN db.TextSplitter: You are strongly encouraged to choose an integral split column.
15/09/21 17:53:26 INFO mapreduce.JobSubmitter: number of splits:5
15/09/21 17:53:26 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1442870712675_0012
15/09/21 17:53:27 INFO impl.YarnClientImpl: Submitted application application_1442870712675_0012
15/09/21 17:53:27 INFO mapreduce.Job: The url to track the job: http://vmhost1.local:8088/proxy/application_1442870712675_0012/
15/09/21 17:53:27 INFO mapreduce.Job: Running job: job_1442870712675_0012
15/09/21 17:53:40 INFO mapreduce.Job: Job job_1442870712675_0012 running in uber mode : false
15/09/21 17:53:40 INFO mapreduce.Job: map 0% reduce 0%
15/09/21 17:53:53 INFO mapreduce.Job: map 20% reduce 0%
15/09/21 17:54:25 INFO mapreduce.Job: map 40% reduce 0%
15/09/21 17:55:19 INFO mapreduce.Job: map 60% reduce 0%
15/09/21 17:55:49 INFO mapreduce.Job: map 80% reduce 0%
15/09/21 17:56:29 INFO mapreduce.Job: map 100% reduce 0%
15/09/21 17:56:29 INFO mapreduce.Job: Job job_1442870712675_0012 completed successfully
15/09/21 17:56:29 INFO mapreduce.Job: Counters: 30
File System Counters
FILE: Number of bytes read=0
FILE: Number of bytes written=680385
FILE: Number of read operations=0
FILE: Number of large read operations=0
FILE: Number of write operations=0
HDFS: Number of bytes read=728
HDFS: Number of bytes written=1089568
HDFS: Number of read operations=20
HDFS: Number of large read operations=0
HDFS: Number of write operations=10
Job Counters
Launched map tasks=5
Other local map tasks=5
Total time spent by all maps in occupied slots (ms)=160538
Total time spent by all reduces in occupied slots (ms)=0
Total time spent by all map tasks (ms)=160538
Total vcore-seconds taken by all map tasks=160538
Total megabyte-seconds taken by all map tasks=164390912
Map-Reduce Framework
Map input records=22519
Map output records=22519
Input split bytes=728
Spilled Records=0
Failed Shuffles=0
Merged Map outputs=0
GC time elapsed (ms)=641
CPU time spent (ms)=10540
Physical memory (bytes) snapshot=614903808
Virtual memory (bytes) snapshot=8024203264
Total committed heap usage (bytes)=159252480
File Input Format Counters
Bytes Read=0
File Output Format Counters
Bytes Written=1089568
15/09/21 17:56:29 INFO mapreduce.ImportJobBase: Transferred 1.0391 MB in 187.358 seconds (5.6791 KB/sec)
15/09/21 17:56:29 INFO mapreduce.ImportJobBase: Retrieved 22519 records.
15/09/21 17:56:29 INFO manager.OracleManager: Time zone has been set to GMT
15/09/21 17:56:29 INFO manager.SqlManager: Executing SQL statement: select owner, object_name, object_id, object_type, to_char(created, 'yyyy-mm-dd') created_date from all_objects where (1 = 0)
15/09/21 17:56:30 INFO manager.SqlManager: Executing SQL statement: select owner, object_name, object_id, object_type, to_char(created, 'yyyy-mm-dd') created_date from all_objects where (1 = 0)
15/09/21 17:56:30 WARN hive.TableDefWriter: Column OBJECT_ID had to be cast to a less precise type in Hive
15/09/21 17:56:30 INFO hive.HiveImport: Loading uploaded data into Hive
Logging initialized using configuration in jar:file:/usr/lib/hive/lib/hive-common-1.1.0-cdh5.4.3.jar!/hive-log4j.properties
OK
Time taken: 1.98 seconds
Loading data to table test_oracle.my_all_objects_sqoop
Table test_oracle.my_all_objects_sqoop stats: [numFiles=5, totalSize=1089568]
OK
Time taken: 0.886 seconds
Verify the result from Hive. You might need to exit Hive and re-enter hive to get the result from the new populated table. Otherwise, you could see 0 rows there.
hive> select * from my_all_objects_sqoop limit 3;
OK
SYS C_COBJ# 29 CLUSTER 2013-03-12
SYS C_TS# 6 CLUSTER 2013-03-12
SYS C_FILE#_BLOCK# 8 CLUSTER 2013-03-12
Time taken: 0.684 seconds, Fetched: 3 row(s)
hive> select count(*) from my_all_objects_sqoop;
Query ID = wzhou_20150921175858_c67bac9f-9cf0-437a-a90c-d3a891455f33
Total jobs = 1
Launching Job 1 out of 1
Number of reduce tasks determined at compile time: 1
In order to change the average load for a reducer (in bytes):
set hive.exec.reducers.bytes.per.reducer=<number>
In order to limit the maximum number of reducers:
set hive.exec.reducers.max=<number>
In order to set a constant number of reducers:
set mapreduce.job.reduces=<number>
Starting Job = job_1442870712675_0013, Tracking URL = http://vmhost1.local:8088/proxy/application_1442870712675_0013/
Kill Command = /usr/lib/hadoop/bin/hadoop job -kill job_1442870712675_0013
Hadoop job information for Stage-1: number of mappers: 1; number of reducers: 1
2015-09-21 17:58:57,446 Stage-1 map = 0%, reduce = 0%
2015-09-21 17:59:09,067 Stage-1 map = 100%, reduce = 0%, Cumulative CPU 2.68 sec
2015-09-21 17:59:19,506 Stage-1 map = 100%, reduce = 100%, Cumulative CPU 4.41 sec
MapReduce Total cumulative CPU time: 4 seconds 410 msec
Ended Job = job_1442870712675_0013
MapReduce Jobs Launched:
Stage-Stage-1: Map: 1 Reduce: 1 Cumulative CPU: 4.41 sec HDFS Read: 1096958 HDFS Write: 6 SUCCESS
Total MapReduce CPU Time Spent: 4 seconds 410 msec
OK
22519
Time taken: 37.941 seconds, Fetched: 1 row(s)
Check the hive file on HDFS.
[wzhou@vmhost1 ~]$ hdfs dfs -ls /user/hive/warehouse/test_oracle.db/my_all_objects_sqoop
Found 5 items
-rwxrwxrwt 2 wzhou hive 9927 2015-09-21 17:53 /user/hive/warehouse/test_oracle.db/my_all_objects_sqoop/part-m-00000
-rwxrwxrwt 2 wzhou hive 248584 2015-09-21 17:54 /user/hive/warehouse/test_oracle.db/my_all_objects_sqoop/part-m-00001
-rwxrwxrwt 2 wzhou hive 93915 2015-09-21 17:55 /user/hive/warehouse/test_oracle.db/my_all_objects_sqoop/part-m-00002
-rwxrwxrwt 2 wzhou hive 735608 2015-09-21 17:55 /user/hive/warehouse/test_oracle.db/my_all_objects_sqoop/part-m-00003
-rwxrwxrwt 2 wzhou hive 1534 2015-09-21 17:56 /user/hive/warehouse/test_oracle.db/my_all_objects_sqoop/part-m-00004
[wzhou@vmhost1 ~]$ hdfs dfs -ls /user/hive/warehouse/test_oracle.db/my_all_objects
Found 1 items
-rwxrwxrwt 2 wzhou bigdata 2050380 2015-09-21 11:28 /user/hive/warehouse/test_oracle.db/my_all_objects/all_objects_data.txt
[wzhou@vmhost1 ~]$ hdfs dfs -cat /user/hive/warehouse/test_oracle.db/my_all_objects_sqoop/part-m-00000 | head -n 10
SYSC_COBJ#29CLUSTER2013-03-12
SYSC_TS#6CLUSTER2013-03-12
SYSC_FILE#_BLOCK#8CLUSTER2013-03-12
SYSC_USER#10CLUSTER2013-03-12
SYSC_OBJ#2CLUSTER2013-03-12
SYSORA$BASE100EDITION2013-03-12
SYSSMON_SCN_TO_TIME_AUX268CLUSTER2013-03-12
SYSC_OBJ#_INTCOL#421CLUSTER2013-03-12
SYSC_TOID_VERSION#495CLUSTER2013-03-12
SYSC_MLOG#625CLUSTER2013-03-12
Ok, I am done with the import to Hive here. In the next post, I am going to discuss export from Hive directly to Oracle database.
