August 17, 2023

tHBaseInput – Docs for ESB 5.x

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tHBaseInput

tHBaseInput_icon32_white.png

Warning

This component will be available in the Palette of
Talend Studio on the condition that you have subscribed to one of
the Talend
solutions with Big Data.

tHBaseInput properties

Component family

Big Data / HBase

  

Function

tHBaseInput extracts columns
corresponding to schema definition. Then it passes these columns to
the next component via a Main row link.

If you have subscribed to one of the Talend solutions with Big Data, you are
able to use this component in a Talend Map/Reduce Job to generate
Map/Reduce code. In that situation, tHBaseInput belongs to the MapReduce component
family.

Purpose

tHBaseInput reads data from a
given HBase database and extracts columns of selection. Hbase is a
distributed, column-oriented database that hosts very large,
sparsely populated tables on clusters.

Basic settings

Property type

Either Built-in or Repository.

– Built-in : No property data
stored centrally.

– Repository : Select the
repository file in which the properties are stored. The fields that
follow are completed automatically using the data retrieved.

 
Save_Icon.png

Click this icon to open a database connection wizard and store the
database connection parameters you set in the component Basic settings view.

For more information about setting up and storing database
connection parameters, see Talend Studio User Guide.

 

Use an existing connection

Note

Not available for the Map/Reduce version of this
component.

Select this check box and in the Component List click the
relevant connection component to reuse the connection details you already defined.

Version

Distribution

Select the cluster you are using from the drop-down list. The options in the list vary
depending on the component you are using. Among these options, the following ones requires
specific configuration:

  • If available in this Distribution drop-down list, the
    Microsoft HD Insight option allows you to use a
    Microsoft HD Insight cluster. For this purpose, you need to configure the
    connections to the WebHCat service, the HD Insight service and the Windows Azure
    Storage service of that cluster in the areas that are displayed. A demonstration
    video about how to configure this connection is available in the following link:
    https://www.youtube.com/watch?v=A3QTT6VsNoM

  • The Custom option allows you to connect to a
    cluster different from any of the distributions given in this list, that is to
    say, to connect to a cluster not officially supported by Talend.

In order to connect to a custom distribution, once selecting Custom, click the dotbutton.png button to display the dialog box in which you can
alternatively:

  1. Select Import from existing version to import an
    officially supported distribution as base and then add other required jar files
    which the base distribution does not provide.

  2. Select Import from zip to import a custom
    distribution zip that, for example, you can download from http://www.talendforge.org/exchange/index.php.

    Note

    In this dialog box, the active check box must be kept selected so as to import
    the jar files pertinent to the connection to be created between the custom
    distribution and this component.

    For an step-by-step example about how to connect to a custom distribution and
    share this connection, see Connecting to a custom Hadoop distribution.

In the Map/Reduce version of this component, the distribution you
select must be the same as the one you need to define in the
Hadoop Configuration view for
the whole Job.
 

HBase version

Select the version of the Hadoop distribution you are using. The available options vary
depending on the component you are using. Along with the evolution of Hadoop, please note
the following changes:

  • If you use Hortonworks Data Platform V2.2, the
    configuration files of your cluster might be using environment variables such as
    ${hdp.version}. If this is your situation, you
    need to set the mapreduce.application.framework.path property in the Hadoop properties table of this component with the path value
    explicitly pointing to the MapReduce framework archive of your cluster. For
    example:

  • If you use Hortonworks Data Platform V2.0.0, the
    type of the operating system for running the distribution and a Talend
    Job must be the same, such as Windows or Linux. Otherwise, you have to use Talend
    Jobserver to execute the Job in the same type of operating system in which the
    Hortonworks Data Platform V2.0.0 distribution you
    are using is run. For further information about Talend Jobserver, see
    Talend Installation
    and Upgrade Guide    .
 

Hadoop version of the
distribution

This list is displayed only when you have selected Custom
from the distribution list to connect to a cluster not yet officially supported by the
Studio. In this situation, you need to select the Hadoop version of this custom cluster,
that is to say, Hadoop 1 or Hadoop
2.

 

Zookeeper quorum

Type in the name or the URL of the Zookeeper service you use to coordinate the transaction
between Talend and HBase. Note that when you configure the Zookeeper, you
might need to set the zookeeper.znode.parent property to
define the root of the relative path of an HBase’s Zookeeper file; then select the Set Zookeeper znode parent check box to define this
property.

 

Zookeeper client port

Type in the number of the client listening port of the Zookeeper service you are
using.
 

Use kerberos authentication

If you are accessing an HBase database running with Kerberos security, select this check
box, then, enter the HBase related principal names in the corresponding fields. You should
be able to find the information in the hbase-site.xml
file of the cluster to be used.

If you need to use a Kerberos keytab file to log in, select Use a
keytab to authenticate. 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 the access path to the keytab file itself in the
Keytab field.

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.

 

Schema and Edit
schema

A schema is a row description. It defines the number of fields to be processed and passed on
to the next component. The schema is either Built-In or
stored remotely in the Repository.

Click Edit schema to make changes to the schema. If the
current schema is of the Repository type, three options are
available:

  • View schema: choose this option to view the
    schema only.

  • Change to built-in property: choose this option
    to change the schema to Built-in for local
    changes.

  • Update repository connection: choose this option to change
    the schema stored in the repository and decide whether to propagate the changes to
    all the Jobs upon completion. If you just want to propagate the changes to the
    current Job, you can select No upon completion and
    choose this schema metadata again in the [Repository
    Content]     window.

 

 

Built-In: You create and store the schema locally for this
component only. Related topic: see Talend Studio
User Guide.

 

 

Repository: You have already created the schema and
stored it in the Repository. You can reuse it in various projects and Job designs. Related
topic: see Talend Studio User Guide.
  Table name Type in the name of the HBase table from which you need to extract
columns.
 

Define a row selection

Select this check box and then in the Start
row and the End row
fields, enter the corresponding row keys to specify the range of the
rows you want tHBaseInput to
extract.

Different from the filters you can set in the Advanced settings tab requiring the
loading of all records before filtering the ones to be used, this
feature allows you to directly select only the rows of your
interest.
  Mapping

Complete this table to map the columns of the HBase table to be used with the schema
columns you have defined for the data flow to be processed.

 

Die on error

Select this check box to stop the execution of the Job when an error occurs.

Clear the check box to skip any rows on error and complete the process for error-free rows.
When errors are skipped, you can collect the rows on error using a Row
> Reject link.

 Advanced settings

tStatCatcher Statistics

Select this check box to collect log data at the component level.
Note that this check box is not available in the Map/Reduce version
of the component.
  Properties

If you need to use custom configuration for your HBase, complete
this table with the property or properties to be customized. Then at
runtime, the customized property or properties will override the
corresponding ones used by the Studio for its HBase engine.

For example, you need to define the value of the dfs.replication property as 1 for the HBase configuration. Then you
need to add one row to this table using the plus button and type in
the name and the value of this property in this row.

Note

This table is not available when you are using an existing
connection by selecting the Using an
existing connection check box in the Basic settings view.

Filter

Is by filter

Select this check box to use HBase filters to perform fine-grained
data selection from HBase, such as selection of keys, or values,
based on regular expressions.

Once selecting it, the Filter
table that is used to define filtering conditions becomes
available.

These filters are advanced features provided by HBase and subject
to constraints explained in Apache’s HBase documentation. Therefore,
advanced knowledge of HBase is required to make full use of these
filters.

 

Logical operation

Select the operator you need to use to define the logical relation
between filters. This available operators are:

  • And: every defined
    filtering conditions must be satisfied. It represents the
    relationship
    FilterList.Operator.MUST_PASS_ALL

  • Or: at least one of the
    defined filtering conditions must be satisfied. It
    represents the relationship:
    FilterList.Operator.MUST_PASS_ONE
 

Filter

Click the button under this table to add as many rows as required,
each row representing a filter. The parameters you may need to set
for a filter are:

  • Filter type: the
    drop-down list presents pre-existing filter types that are
    already defined by HBase. Select the type of the filter you
    need to use.

  • Filter column: enter the
    column qualifier on which you need to apply the active
    filter. This parameter becomes mandatory depending on the
    type of the filter and of the comparator you are using. For
    example, it is not used by the Row
    Filter     type but is required by the Single Column Value Filter
    type.

  • Filter family: enter the
    column family on which you need to apply the active filter.
    This parameter becomes mandatory depending on the type of
    the filter and of the comparator you are using. For example,
    it is not used by the Row
    Filter     type but is required by the Single Column Value Filter
    type.

  • Filter operation: select
    from the drop-down list the operation to be used for the
    active filter.

  • Filter Value: enter the
    value on which you want to use the operator selected from
    the Filter operation
    drop-down list.

  • Filter comparator type:
    select the type of the comparator to be combined with the
    filter you are using.

Depending on the Filter type you
are using, some or each of the parameters become mandatory. For
further information, see HBase filters

Global Variables

NB_LINE: the number of rows read by an input component or
transferred to an output component. This is an After variable and it returns an
integer.

ERROR_MESSAGE: the error message generated by the
component when an error occurs. This is an After variable and it returns a string. This
variable functions only if the Die on error check box is
cleared, if the component has this check box.

A Flow variable functions during the execution of a component while an After variable
functions after the execution of the component.

To fill up a field or expression with a variable, press Ctrl +
Space to access the variable list and choose the variable to use from it.

For further information about variables, see Talend Studio
User Guide.

Usage

This component is a start component of a Job and always needs an
output link.

Usage in Map/Reduce Jobs

In a Talend Map/Reduce Job, it is used as a start component and requires
a transformation component as output link. The other components used along with it must be
Map/Reduce components, too. They generate native Map/Reduce code that can be executed
directly in Hadoop.

You need to use the Hadoop Configuration tab in the
Run view to define the connection to a given Hadoop
distribution for the whole Job.

The Hadoop configuration you use for the whole Job and the Hadoop distribution you use for
the HBase components must be the same. Actually, an HBase component requires that its Hadoop
distribution parameter be defined separately so as to launch its HBase driver only when that
component is used.

For further information about a Talend Map/Reduce Job, see the sections
describing how to create, convert and configure a Talend Map/Reduce Job of the
Talend Big Data Getting Started Guide.

Note that in this documentation, unless otherwise explicitly stated, a scenario presents
only Standard Jobs, that is to say traditional Talend data
integration Jobs, and non Map/Reduce Jobs.

Prerequisites

Before starting, ensure that you have met the Loopback IP prerequisites expected by HBase.
For further information, see Apache’s HBase documentation on http://hbase.apache.org/.

The Hadoop distribution must be properly installed, so as to guarantee the interaction
with Talend Studio. The following list presents MapR related information for
example.

  • Ensure that you have installed the MapR client in the machine where the Studio is,
    and added the MapR client library to the PATH variable of that machine. According
    to MapR’s documentation, the library or libraries of a MapR client corresponding to
    each OS version can be found under MAPR_INSTALL
    hadoophadoop-VERSIONlib
    ative    . For example, the library for
    Windows is lib
    ativeMapRClient.dll     in the MapR
    client jar file. For further information, see the following link from MapR: http://www.mapr.com/blog/basic-notes-on-configuring-eclipse-as-a-hadoop-development-environment-for-mapr.

    Without adding the specified library or libraries, you may encounter the following
    error: no MapRClient in java.library.path.

  • Set the -Djava.library.path argument, for example, in the Job Run VM arguments area
    of the Run/Debug view in the [Preferences] dialog box. This argument provides to the Studio the
    path to the native library of that MapR client. This allows the subscription-based
    users to make full use of the Data viewer to view
    locally in the Studio the data stored in MapR. For further information about how to
    set this argument, see the section describing how to view data of Talend Big Data Getting Started Guide.

For further information about how to install a Hadoop distribution, see the manuals
corresponding to the Hadoop distribution you are using.

Log4j

The activity of this component can be logged using the log4j feature. For more information on this feature, see Talend Studio User
Guide.

For more information on the log4j logging levels, see the Apache documentation at http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/Level.html.

HBase filters

This table presents the HBase filters available in Talend Studio and the parameters required by those filters.

Filter type

Filter column

 Filter family Filter operation Filter value Filter comparator type Objective

Single Column Value Filter

Yes

Yes

Yes

Yes

Yes

It compares the values of a given column against the value defined
for the Filter value parameter. If
the filtering condition is met, all columns of the row will be
returned.

Family filter

 

Yes

Yes

  

Yes

It returns the columns of the family that meets the filtering
condition.

Qualifier filter

Yes

  

Yes

  

Yes

It returns the columns whose column qualifiers match the filtering
condition.

Column prefix filter

Yes

Yes

      

It returns all columns of which the qualifiers have the prefix
defined for the Filter column parameter.

Multiple column prefix filter

Yes (Multiple prefixes are separated by coma, for
example, id,id_1,id_2)

Yes

      

It works the same way as a Column prefix
filter does but allows specifying multiple
prefixes.

Column range filter

Yes (The ends of a range are separated by coma. )

Yes

       It allows intra row scanning and returns all matching columns of a
scanned row.

Row filter

   

Yes

Yes

 Yes It filters on row keys and returns all rows that matches the
filtering condition.

Value filter

   

Yes

Yes

Yes

 It returns only columns that have a specific value.

The use explained above of the listed HBase filters is subject to revisions made by
Apache in its Apache HBase project; therefore, in order to fully understand how to use
these HBase filters, we recommend reading Apache’s HBase documentation.

Scenario: Exchanging customer data with HBase

In this scenario, a six-component Job is used to exchange customer data with a given
HBase.

use_case-thbaseinput.png

The six components are:

  • tHBaseConnection: creates a connection to
    your HBase database.

  • tFixedFlowInput: creates the data to be
    written into your HBase. In the real use case, this component could be
    replaced by the other input components like tFileInputDelimited.

  • tHBaseOutput: writes the data it receives
    from the preceding component into your HBase.

  • tHBaseInput: extracts the columns of
    interest from your HBase.

  • tLogRow: presents the execution
    result.

  • tHBaseClose: closes the
    transaction.

To replicate this scenario, proceed as the following sections illustrate.

Note

Before starting the replication, your Hbase and Zookeeper service should have been
correctly installed and well configured. This scenario explains only how to use
Talend solution to make data transaction with a given HBase.

Dropping and linking the components

To do this, proceed as follows:

  1. Drop tHBaseConnection, tFixedFlowInput, tHBaseOutput, tHBaseInput, tLogRow and
    tHBaseClose from Palette onto the
    Design workspace.

  2. Right-click tHBaseConnection to open its
    contextual menu and select the Trigger >
    On Subjob Ok link from this menu to
    connect this component to tFixedFlowInput.

  3. Do the same to create the OnSubjobOk link
    from tFixedFlowInput to tHBaseInput and then to tHBaseClose.

  4. Right-click tFixedFlowInput and select
    the Row > Main link to connect this component to tHBaseOutput.

  5. Do the same to create the Main link from
    tHBaseInput to tLogrow.

The components to be used in this scenario are all placed and linked. Then you
need continue to configure them sucessively.

Configuring the connection

To configure the connection to your Zookeeper service and thus to the HBase of
interest, proceed as follows:

  1. On the Design workspace of your Studio, double-click the tHBaseConnection component to open its Component view.

    use_case-thbaseinput_connection.png

  2. Select Hortonworks Data Platform 1.0 from
    the HBase version list.

  3. In the Zookeeper quorum field, type in
    the name or the URL of the Zookeeper service you are using. In this example,
    the name of the service in use is hbase.

  4. In the Zookeeper client port field, type
    in the number of client listening port. In this example, it is 2181.

  5. If the Zookeeper znode parent location has been defined in the Hadoop
    cluster you are connecting to, you need to select the Set zookeeper znode parent check box and enter the value of
    this property in the field that is displayed.

Configuring the process of writing data into the HBase

To do this, proceed as follows:

  1. On the Design workspace, double-click the tFixedFlowInput component to open its Component view.

    use_case-thbaseinput_inflow.png

  2. In this view, click the three-dot button next to Edit schema to open the schema editor.

    use_case-thbaseinput_inflow_schema.png

  3. Click the plus button three times to add three rows and in the Column column, rename the three rows respectively
    as: id,
    name     and age.

  4. In the Type column, click each of these
    rows and from the drop-down list, select the data type of every row. In this
    scenario, they are Integer for id and age,
    String for name.

  5. Click OK to validate these changes and
    accept the propagation prompted by the pop-up dialog box.

  6. In the Mode area, select the Use Inline Content (delimited file) to display
    the fields for editing.

  7. In the Content field, type in the
    delimited data to be written into the HBase, separated with the semicolon
    “;“. In this example, they are:

  8. Double-click tHBaseOutput to open its
    Component view.

    Note

    If this component does not have the same schema of the preceding
    component, a warning icon appears. In this case, click the Sync columns button to retrieve the schema
    from the preceding one and once done, the warning icon disappears.

    use_case-thbaseoutput.png

  9. Select the Use an existing connection
    check box and then select the connection you have configured earlier. In
    this example, it is tHBaseConnection_1.

  10. In the Table name field, type in the name
    of the table to be created in the HBase. In this example, it is customer.

  11. In the Action on table field, select the
    action of interest from the drop-down list. In this scenario, select
    Drop table if exists and create. This
    way, if a table named customer exists already in the HBase, it will be
    disabled and deleted before creating this current table.

  12. Click the Advanced settings tab to open
    the corresponding view.

    use_case-thbaseoutput-advanced.png

  13. In the Family parameters table, add two
    rows by clicking the plus button, rename them as family1 and family2
    respectively and then leave the other columns empty. These two column
    families will be created in the HBase using the default family performance
    options.

    Note

    The Family parameters table is
    available only when the action you have selected in the Action on table field is to create a table in
    HBase. For further information about this Family
    parameters     table, see tHBaseOutput.

  14. In the Families table of the Basic settings view, enter the family names in
    the Family name column, each corresponding
    to the column this family contains. In this example, the id and the age columns belong to family1 and the name
    column to family2.

    Note

    These column families should already exist in the HBase to be
    connected to; if not, you need to define them in the Family parameters table of the Advanced settings view for creating them at
    runtime.

Configuring the process of extracting data from the HBase

To do this, perform the following operations:

  1. Double-click tHBaseInput to open its
    Component view.

    use_case-thbaseinput_config.png

  2. Select the Use an existing connection
    check box and then select the connection you have configured earlier. In
    this example, it is tHBaseConnection_1.

  3. Click the three-dot button next to Edit
    schema     to open the schema editor.

    use_case-tHBaseInput_schema.png

  4. Click the plus button three times to add three rows and rename them as
    id, name and age respectively
    in the Column column. This means that you
    extract these three columns from the HBase.

  5. Select the types for each of the three columns. In this example, Integer for id
    and age, String for name.

  6. Click OK to validate these changes and
    accept the propagation prompted by the pop-up dialog box.

  7. In the Table name field, type in the
    table from which you extract the columns of interest. In this scenario, the
    table is customer.

  8. In the Mapping table, the Column column has been already filled
    automatically since the schema was defined, so simply enter the name of
    every family in the Column family column,
    each corresponding to the column it contains.

  9. Double-click tHBaseClose to open its
    Component view.

    use_case-thbaseclose.png

  10. In the Component List field, select the
    connection you need to close. In this example, this connection is tHBaseConnection_1.

Executing the Job

To execute this Job, press F6.

Once done, the Run view is opened automatically,
where you can check the execution result.

use_case-result-processed_data.png

These columns of interest are extracted and you can process them according to
your needs.

Login to your HBase database, you can check the customer table this Job has created.

Document get from Talend https://help.talend.com
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