Apache Tajo - OpenStack Swift Integration

Swift is a distributed and consistent object/blob store. Swift offers cloud storage software so that you can store and retrieve lots of data with a simple API. Tajo supports Swift integration.

The following are the prerequisites of Swift Integration −

• Swift
• Hadoop

Core-site.xml

Add the following changes to the hadoop “core-site.xml” file −

<property> 
   <name>fs.swift.impl</name> 
   <value>org.apache.hadoop.fs.swift.snative.SwiftNativeFileSystem</value> 
   <description>File system implementation for Swift</description> 
</property>  

<property> 
   <name>fs.swift.blocksize</name> 
   <value>131072</value> 
   <description>Split size in KB</description> 
</property> 

This will be used for Hadoop to access the Swift objects. After you made all the changes move to the Tajo directory to set Swift environment variable.

conf/tajo-env.h

Open the Tajo configuration file and add set the environment variable as follows −

$ vi conf/tajo-env.h  
export TAJO_CLASSPATH = $HADOOP_HOME/share/hadoop/tools/lib/hadoop-openstack-x.x.x.jar 

Now, Tajo will be able to query the data using Swift.

Create Table

Let’s create an external table to access Swift objects in Tajo as follows −

default> create external table swift(num1 int, num2 text, num3 float) 
   using text with ('text.delimiter' = '|') location 'swift://bucket-name/table1';

After the table has been created, you can run the SQL queries.