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.

Use an existing connection

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

Distribution

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 the configuration zip for the custom distribution to be used. This zip
   file should contain the libraries of the different Hadoop elements and the index
   file of these libraries.

   In
   Talend
   
   Exchange, members of
   Talend
   community have shared some ready-for-use configuration zip files
   which you can download from this Hadoop configuration
   list and directly use them in your connection accordingly. However, because of
   the ongoing evolution of the different Hadoop-related projects, you might not be
   able to find the configuration zip corresponding to your distribution from this
   list; then it is recommended to use the Import from
   existing version option to take an existing distribution as base
   to add the jars required by your distribution.

   Note that custom versions are not officially supported by
   
   Talend
   .
   Talend
   and its community provide you with the opportunity to connect to
   custom versions from the Studio but cannot guarantee that the configuration of
   whichever version you choose will be easy, due to the wide range of different
   Hadoop distributions and versions that are available. As such, you should only
   attempt to set up such a connection if you have sufficient Hadoop experience to
   handle any issues on your own.

   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 a step-by-step example about how to connect to a custom
   distribution and share this connection, see Hortonworks.

Impala version

Select the version of the Hadoop distribution you are using. The available
options vary depending on the component you are using.

Host

Database server IP address.

Port

Listening port number of DB server.

Database

Fill this field with the name of the database.

Username

DB user authentication data.

Use kerberos authentication

This check box is available depending on the Hadoop distribution you are
connecting to.

Load action

Select the action you need to carry for writing data into the
specified destination.

• When you select LOAD, you
  are moving or copying data from a directory you specify.

• When you select INSERT,
  you are moving or copying data based on queries.

Target type

This drop-down list appears only when you have selected INSERT from the Load action list.

Select from this list the type of the location you need to write
data in.

• If you select Table as destination, you can still
  choose to append data to or overwrite the contents in the
  specified table. This is the only option in the current
  release.

Action

Select whether you want to OVERWRITE the old data already existing in the
destination or only APPEND the new
data to the existing one.

Table name

Enter the name of the Hive table you need to write data in.

Note that with the INSERT action,
this field is available only when you have selected Table from the Target type list.

File path

Enter the directory you need to read data from.

Query

This field appears when you have selected INSERT from the Load
action list.

Enter the appropriate query for selecting the data to be exported to the specified
Impala table or directory.

Select this check box to use the Impala Partition clause in loading or
inserting data in a Impala table. You need to enter the partition
keys and their values to be used in the field that appears.

For example, enter contry=’US’,
state=’CA’. This makes a partition clause reading
Partition (contry='US', state='CA'), that is to
say, a US and CA
partition.

Also, it is recommended to select the Create
partition if not exist check box that appears to
ensure that you will not create a duplicate partition.

Die on error

Select this check box to kill the Job when an error occurs.

tStatCatcher Statistics

Select this check box to collect log data at the component
level.

Global Variables

QUERY: the query statement being processed. This is a Flow
variable and it returns a string.

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 rule

This component works standalone.

Dynamic settings

Click the [+] button to add a row in the table
and fill the Code field with a context
variable to choose your database connection dynamically from multiple
connections planned in your Job. This feature is useful when you need to
access database tables having the same data structure but in different
databases, especially when you are working in an environment where you
cannot change your Job settings, for example, when your Job has to be
deployed and executed independent of Talend Studio.

The Dynamic settings table is
available only when the Use an existing
connection check box is selected in the Basic settings view. Once a dynamic parameter is
defined, the Component List box in the
Basic settings view becomes unusable.

For examples on using dynamic parameters, see Reading data from databases through context-based dynamic connections and Reading data from different MySQL databases using dynamically loaded connection parameters. For more information on Dynamic
settings and context variables, see Talend Studio
User Guide.

Prerequisites

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 in the Window menu. 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 install a Hadoop distribution, see the manuals
corresponding to the Hadoop distribution you are using.