Creating a connection to HBase - 7.1

Talend Real-time Big Data Platform Studio User Guide

author
Talend Documentation Team
EnrichVersion
7.1
EnrichProdName
Talend Real-Time Big Data Platform
task
Design and Development
EnrichPlatform
Talend Studio

Procedure

  1. Expand the Hadoop cluster node under the Metadata node of the Repository tree, right-click the Hadoop connection to be used and select Create HBase from the contextual menu.
  2. In the connection wizard that opens up, fill in the generic properties of the connection you need create, such as Name, Purpose and Description. The Status field is a customized field that you can define in File > Edit project properties.
  3. Click Next to proceed to the next step, which requires you to fill in the HBase connection details. Among them, DB Type, Hadoop cluster, Distribution, HBase version and Server are automatically pre-filled with the properties inherited from the Hadoop connection you selected in the previous steps.
    Note that if you choose None from the Hadoop cluster list, you are actually switching to a manual mode in which the inherited properties are abandoned and instead you have to configure every property yourself, with the result that the created connection appears under the Db connection node only.
  4. In the Port field, fill in the port number of the HBase database to be connected to.
    Note:

    In order to make the host name of the Hadoop server recognizable by the client and the host computers, you have to establish an IP address/hostname mapping entry for that host name in the related hosts files of the client and the host computers. For example, the host name of the Hadoop server is talend-all-hdp, and its IP address is 192.168.x.x, then the mapping entry reads 192.168.x.x talend-all-hdp. For the Windows system, you need to add the entry to the file C:\WINDOWS\system32\drivers\etc\hosts (assuming Windows is installed on drive C). For the Linux system, you need to add the entry to the file /etc/hosts.

  5. In the Column family field, enter the column family if you want to filter columns, and click Check to check your connection
  6. If you are accessing a Hadoop distribution running with Kerberos security, select this check box, then, enter the Kerberos principal name for the NameNode in the field activated. This enables you to use your user name to authenticate against the credentials stored in Kerberos.
    If you need to use a keytab file to log in, select the Use a keytab to authenticate check box. A keytab file contains pairs of Kerberos principals and encrypted keys. You need to enter the principal to be used in the Principal field and in the Keytab field, browse to the keytab file to be used.
    Note that the user that executes a keytab-enabled Job is not necessarily the one a principal designates but must have the right to read the keytab file being used. For example, the user name you are using to execute a Job is user1 and the principal to be used is guest; in this situation, ensure that user1 has the right to read the keytab file to be used.
  7. If you need to use custom configuration for the Hadoop or HBase distribution to be used, click the [...] button next to Hadoop properties to open the properties table and add the property or properties to be customized. Then at runtime, these changes will override the corresponding default properties used by the Studio for its Hadoop engine.
    Note a Parent Hadoop properties table is displayed above the current properties table you are editing. This parent table is read-only and lists the Hadoop properties that have been defined in the wizard of the parent Hadoop connection on which the current HBase connection is based.
    For further information about the properties of Hadoop, see Apache's Hadoop documentation on http://hadoop.apache.org/docs/current/, or the documentation of the Hadoop distribution you need to use. For example, the following page lists some of the default Hadoop properties: https://hadoop.apache.org/docs/current/hadoop-project-dist/hadoop-common/core-default.xml.
    For further information about the properties of HBase, see Apache's documentation for HBase. For example, the following page describes some of the HBase configuration properties: http://hbase.apache.org/book.html#_configuration_files.
    For further information about how to leverage this properties table, see Setting reusable Hadoop properties.
  8. Click Finish to validate the changes.
    The newly created HBase connection appears under the Hadoop cluster node of the Repository tree. In addition, as an HBase connection is a database connection, this new connection appears under the Db connections node, too.
    Note:

    This Repository view may vary depending on the edition of the Studio you are using.

Results

If you need to use an environmental context to define the parameters of this connection, click the Export as context button to open the corresponding wizard and make the choice from the following options:
  • Create a new repository context: create this environmental context out of the current Hadoop connection, that is to say, the parameters to be set in the wizard are taken as context variables with the values you have given to these parameters.

  • Reuse an existing repository context: use the variables of a given environmental context to configure the current connection.

If you need to cancel the implementation of the context, click Revert context. Then the values of the context variables being used are directly put in this wizard.

For a step-by-step example about how to use this Export as context feature, see Exporting metadata as context and reusing context parameters to set up a connection.