Hbase Standalone

This guide describes the setup of a standalone HBase instance running against the local filesystem. This is not an appropriate configuration for a production instance of HBase, but will allow you to experiment with HBase. This section shows you how to create a table in HBase using the hbase shell CLI, insert rows into the table, perform put and scan operations against the table, enable or disable the table, and start and stop HBase. Apart from downloading HBase, this procedure should take less than 10 minutes.

Local Filesystem and Durability The following is fixed in HBase 0.98.3 and beyond. See HBASE-11272 and HBASE-11218.

Using HBase with a local filesystem does not guarantee durability. The HDFS local filesystem implementation will lose edits if files are not properly closed. This is very likely to happen when you are experimenting with new software, starting and stopping the daemons often and not always cleanly. You need to run HBase on HDFS to ensure all writes are preserved. Running against the local filesystem is intended as a shortcut to get you familiar with how the general system works, as the very first phase of evaluation. See HBASE-3696 and its associated issues for more details about the issues of running on the local filesystem.

Loopback IP - HBase 0.94.x and earlier The below advice is for hbase-0.94.x and older versions only. This is fixed in hbase-0.96.0 and beyond.

Prior to HBase 0.94.x, HBase expected the loopback IP address to be 127.0.0.1. Ubuntu and some other distributions default to 127.0.1.1 and this will cause problems for you. See Why does HBase care about /etc/hosts? for detail

Example 1. Example /etc/hosts File for Ubuntu

The following /etc/hosts file works correctly for HBase 0.94.x and earlier, on Ubuntu. Use this as a template if you run into trouble.

127.0.0.1 localhost
127.0.0.1 ubuntu.ubuntu-domain ubuntu

2.1. JDK Version Requirements

HBase requires that a JDK be installed. See Java for information about supported JDK versions.

2.2. Get Started with HBase

Procedure: Download, Configure, and Start HBase

1. Choose a download site from this list of Apache Download Mirrors. Click on the suggested top link. This will take you to a mirror of HBase Releases. Click on the folder named stable and then download the binary file that ends in .tar.gz to your local filesystem. Prior to 1.x version, be sure to choose the version that corresponds with the version of Hadoop you are likely to use later (in most cases, you should choose the file for Hadoop 2, which will be called something like hbase-0.98.13-hadoop2-bin.tar.gz). Do not download the file ending in src.tar.gzfor now.

2. Extract the downloaded file, and change to the newly-created directory.

   $ tar xzvf hbase-<?eval ${project.version}?>-bin.tar.gz
   $ cd hbase-<?eval ${project.version}?>/

3. For HBase 0.98.5 and later, you are required to set the JAVA_HOME environment variable before starting HBase. Prior to 0.98.5, HBase attempted to detect the location of Java if the variables was not set. You can set the variable via your operating system’s usual mechanism, but HBase provides a central mechanism, conf/hbase-env.sh. Edit this file, uncomment the line starting with JAVA_HOME, and set it to the appropriate location for your operating system. The JAVA_HOME variable should be set to a directory which contains the executable filebin/java. Most modern Linux operating systems provide a mechanism, such as /usr/bin/alternatives on RHEL or CentOS, for transparently switching between versions of executables such as Java. In this case, you can setJAVA_HOME to the directory containing the symbolic link to bin/java, which is usually /usr.

   JAVA_HOME=/usr

   These instructions assume that each node of your cluster uses the same configuration. If this is not the case, you may need to set JAVA_HOME separately for each node.

4. Edit conf/hbase-site.xml, which is the main HBase configuration file. At this time, you only need to specify the directory on the local filesystem where HBase and ZooKeeper write data. By default, a new directory is created under /tmp. Many servers are configured to delete the contents of /tmp upon reboot, so you should store the data elsewhere. The following configuration will store HBase’s data in the hbase directory, in the home directory of the user called testuser. Paste the <property> tags beneath the <configuration> tags, which should be empty in a new HBase install.

   Example 2. Example hbase-site.xml for Standalone HBase

   <configuration>
     <property>
       <name>hbase.rootdir</name>
       <value>file:///home/testuser/hbase</value>
     </property>
     <property>
       <name>hbase.zookeeper.property.dataDir</name>
       <value>/home/testuser/zookeeper</value>
     </property>
   </configuration>

   You do not need to create the HBase data directory. HBase will do this for you. If you create the directory, HBase will attempt to do a migration, which is not what you want.

5. The bin/start-hbase.sh script is provided as a convenient way to start HBase. Issue the command, and if all goes well, a message is logged to standard output showing that HBase started successfully. You can use the jpscommand to verify that you have one running process called HMaster. In standalone mode HBase runs all daemons within this single JVM, i.e. the HMaster, a single HRegionServer, and the ZooKeeper daemon.

   Java needs to be installed and available. If you get an error indicating that Java is not installed, but it is on your system, perhaps in a non-standard location, edit the conf/hbase-env.sh file and modify the JAVA_HOME setting to point to the directory that contains bin/javayour system.

Procedure: Use HBase For the First Time

1. Connect to HBase.

   Connect to your running instance of HBase using the hbase shell command, located in the bin/ directory of your HBase install. In this example, some usage and version information that is printed when you start HBase Shell has been omitted. The HBase Shell prompt ends with a > character.

   $ ./bin/hbase shell
   hbase(main):001:0>

2. Display HBase Shell Help Text.

   Type help and press Enter, to display some basic usage information for HBase Shell, as well as several example commands. Notice that table names, rows, columns all must be enclosed in quote characters.

3. Create a table.

   Use the create command to create a new table. You must specify the table name and the ColumnFamily name.

   hbase(main):001:0> create 'test', 'cf'
   0 row(s) in 0.4170 seconds
   
   => Hbase::Table - test

4. List Information About your Table

   Use the list command to

   hbase(main):002:0> list 'test'
   TABLE
   test
   1 row(s) in 0.0180 seconds
   
   => ["test"]

5. Put data into your table.

   To put data into your table, use the put command.

   hbase(main):003:0> put 'test', 'row1', 'cf:a', 'value1'
   0 row(s) in 0.0850 seconds
   
   hbase(main):004:0> put 'test', 'row2', 'cf:b', 'value2'
   0 row(s) in 0.0110 seconds
   
   hbase(main):005:0> put 'test', 'row3', 'cf:c', 'value3'
   0 row(s) in 0.0100 seconds

   Here, we insert three values, one at a time. The first insert is at row1, column cf:a, with a value ofvalue1. Columns in HBase are comprised of a column family prefix, cf in this example, followed by a colon and then a column qualifier suffix, a in this case.

6. Scan the table for all data at once.

   One of the ways to get data from HBase is to scan. Use the scan command to scan the table for data. You can limit your scan, but for now, all data is fetched.

   hbase(main):006:0> scan 'test'
   ROW                                      COLUMN+CELL
    row1                                    column=cf:a, timestamp=1421762485768, value=value1
    row2                                    column=cf:b, timestamp=1421762491785, value=value2
    row3                                    column=cf:c, timestamp=1421762496210, value=value3
   3 row(s) in 0.0230 seconds

7. Get a single row of data.

   To get a single row of data at a time, use the get command.

   hbase(main):007:0> get 'test', 'row1'
   COLUMN                                   CELL
    cf:a                                    timestamp=1421762485768, value=value1
   1 row(s) in 0.0350 seconds

8. Disable a table.

   If you want to delete a table or change its settings, as well as in some other situations, you need to disable the table first, using the disable command. You can re-enable it using the enable command.

   hbase(main):008:0> disable 'test'
   0 row(s) in 1.1820 seconds
   
   hbase(main):009:0> enable 'test'
   0 row(s) in 0.1770 seconds

   Disable the table again if you tested the enable command above:

   hbase(main):010:0> disable 'test'
   0 row(s) in 1.1820 seconds

9. Drop the table.

   To drop (delete) a table, use the drop command.

   hbase(main):011:0> drop 'test'
   0 row(s) in 0.1370 seconds

10. Exit the HBase Shell.

    To exit the HBase Shell and disconnect from your cluster, use the quit command. HBase is still running in the background.

Procedure: Stop HBase

1. In the same way that the bin/start-hbase.sh script is provided to conveniently start all HBase daemons, thebin/stop-hbase.sh script stops them.

   $ ./bin/stop-hbase.sh
   stopping hbase....................
   $

2. After issuing the command, it can take several minutes for the processes to shut down. Use the jps to be sure that the HMaster and HRegionServer processes are shut down.