Using the HBase Delete Operator

Introduction

The TIBCO StreamBase® Delete Adapter for Apache HBase allows the system to delete rows from the HBase database. The adapter uses property values in the sbd.sbconf configuration file to set up the HBase connection. For details, see Configuration File Settings below. Multiple HBase adapters can share a single instance of the HBase connection by selecting the same HBase configuration setting.

The TIBCO StreamBase® Adapter for Apache HBase is implemented as a suite of five global Java operators, including the HBase Admin, Delete, Get, Put, and Scan operators.

This page describes the HBase Delete operator, which allows a StreamBase application to delete rows from a connected HBase database table. The operator uses property values in the project's server configuration file to set up the connection to the HBase database, as described in Configuration File Settings. Multiple HBase operators can share a single instance of an HBase connection by selecting the same HBase configuration setting ID.

Configuration File Settings

This section describes the configuration for an HBase database connection instance that you specify in your project's sbconf file. This configuration is the same for all HBase operator types.

HBase Operator Configuration

The <adapter-configurations> element of a project's sbconf file, despite its name, is used to specify configuration value groups for either operators or adapters.

The HBase configuration section of the sbconf file starts with an <adapter-configurations> element that contains one <adapter-configuration name="hbase"> element. This element, in turn, contains one or more <setting> elements.

Each <section name="hbase"> element must contain one element in the form <setting name="id" val="HBaseConfigName"/>, where HBaseConfigName is the name you assign to a group of settings that uniquely define an individual HBase database connection. All other <setting> elements are optional.

The example configuration below shows a basic configuration to connect to an HBase server. You can have as many configurations as your application requires, but each configuration must have a unique id.

Example 1. Example <adapter-configuration> Section for HBase

  <adapter-configurations>
    <adapter-configuration name="hbase">
      <section name="hbase">
        <setting name="id" val="HBase Sample"/>
        <setting name="connectAtStartup" val="true" />

        <!-- All values below are passed directly to the 
             HBaseConfiguration class unmodified --/>
        <setting name="hbase.master" val="127.0.0.1:60000" />
        <setting name="hbase.zookeeper.quorum" val="127.0.0.1" />
        <setting name="hbase.zookeeper.property.clientPort" val="2181" />
        <setting name="hbase.client.retries.number" val="5" />
        <setting name="zookeeper.session.timeout" val="5000" />
        <setting name="zookeeper.recovery.retry" val="5" />
      </section>
    </adapter-configuration>
  </adapter-configurations>


Configuration Settings

Setting Type Description
id string The value of the id setting displays in the drop-down list in the adapter's Properties view, and is used to uniquely identify this section of the configuration file.
connectAtStartup true or false If true, this operator instance connects to HBase on startup of this operator's containing module.
*** string All other values are directly sent to the HBaseConfiguration class, which is responsible for setting up a connection to the HBase server. See the Apache HBase documentation for the available client configuration options and for further information on setting up a connection to HBase.

Properties View Settings

This section describes the properties you can set for an HBase Delete operator, using the various tabs of the Properties view in StreamBase Studio.

General Tab

Name: Use this required field to specify or change the name of this instance of this component, which must be unique in the current EventFlow module. The name must contain only alphabetic characters, numbers, and underscores, and no hyphens or other special characters. The first character must be alphabetic or an underscore.

Operator: A read-only field that shows the formal name of the operator.

Class: Shows the fully qualified class name that implements the functionality of this operator. If you need to reference this class name elsewhere in your application, you can right-click this field and select Copy from the context menu to place the full class name in the system clipboard.

Start with application: If this field is set to Yes (default) or to a module parameter that evaluates to true, this instance of this operator starts as part of the JVM engine that runs this EventFlow fragment. If this field is set to No or to a module parameter that evaluates to false, the operator instance is loaded with the engine, but does not start until you send an epadmin container resume command (or its sbadmin equivalent), or until you start the component with StreamBase Manager.

Enable Error Output Port: Select this check box to add an Error Port to this component. In the EventFlow canvas, the Error Port shows as a red output port, always the last port for the component. See Using Error Ports to learn about Error Ports.

Description: Optionally enter text to briefly describe the component's purpose and function. In the EventFlow canvas, you can see the description by pressing Ctrl while the component's tooltip is displayed.

Operator Properties Tab

Property Type Description
HBase Config drop-down list The name of the HBase configuration to use with this operator. The value selected by this drop-down list determines the database connection this operator works against. The values that populate this list are stored in the project's sbconf file, as described in the Configuration File Settings section.
Table Name string The HBase table that this operation is to be performed against.
Row Id Field Name string The field in the inbound schema which represents the field which contains the Row Id to delete.
Enable Status Port check box If enabled, a status port is made available for this operator instance, which will emit status tuples for various events from this operator.
Log Level drop-down list Controls the level of verbosity the adapter uses to issue informational traces to the console. This setting is independent of the containing application's overall log level. Available values, in increasing order of verbosity, are: OFF, ERROR, WARN, INFO, DEBUG, TRACE.

Concurrency Tab

Use the Concurrency tab to specify parallel regions for this instance of this component, or multiplicity options, or both. The Concurrency tab settings are described in Concurrency Options, and dispatch styles are described in Dispatch Styles.

Caution

Concurrency settings are not suitable for every application, and using these settings requires a thorough analysis of your application. For details, see Execution Order and Concurrency, which includes important guidelines for using the concurrency options.