July 30, 2023

tMapRDBConnection – Docs for ESB 7.x


Establishes a MapRDB connection to be reused by other MapRDB components in a same

tMapRDBConnection Standard properties

These properties are used to configure tMapRDBConnection running in the Standard Job framework.

The Standard
tMapRDBConnection component belongs to the Big Data and the Databases NoSQL families.

The component in this framework is available in all Talend products with Big Data
and in Talend Data Fabric.

Basic settings

Property type

Either Built-In or Repository.

Built-In: No property data stored centrally.

Repository: Select the repository file where the
properties are stored.

The properties are stored centrally under the Hadoop
node of the Repository

Distribution and

Select the MapR distribution to be used. Only MapR V5.2 onwards is supported
by the MapRDB components.

If the distribution you need to use with your MapRDB database is not
officially supported by this MapRBD component, that is to say, this distribution is MapR
but is not listed in the Version drop-down list of
this components or this distribution is not MapR at all, select Custom.

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

  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.


    Exchange, members of
    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

    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.


    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.

Hadoop version of the

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
or Hadoop 2.

Zookeeper quorum

Type in the name or the URL of the Zookeeper service you use to coordinate the transaction
between your Studio and your database. Note that when you configure the Zookeeper, you might
need to explicitly set the zookeeper.znode.parent
property to define the path to the root znode that contains all the znodes created and used
by your database; then select the Set Zookeeper znode
check box to define this property.

Zookeeper client port

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

Inspect the classpath for

Select this check box to allow the component to check the configuration
files in the directory you have set with the $HADOOP_CONF_DIR
variable and directly read parameters from these files in this directory. This
feature allows you to easily change the Hadoop configuration for the component to
switch between different environments, for example, from a test environment to a
production environment.

In this situation, the fields or options used to configure Hadoop
connection and/or Kerberos security are hidden.

If you want to use certain parameters such as the Kerberos parameters but
these parameters are not included in these Hadoop configuration files, you need to
create a file called talend-site.xml and put this file into the
same directory defined with $HADOOP_CONF_DIR. This talend-site.xml file should read as follows:

The parameters read from these configuration files override the default
ones used by the Studio. When a parameter does not exist in these configuration
files, the default one is used.

Use kerberos

If the database to be used is running with Kerberos security, select this
check box, then, enter the principal names in the displayed fields. You should be
able to find the information in the hbase-site.xml file of the
cluster to be used.

  • If this cluster is a MapR cluster of the version 5.0.0 or later, you can set the
    MapR ticket authentication configuration in addition or as an alternative by following
    the explanation in Connecting to a security-enabled MapR.

    Keep in mind that this configuration generates a new MapR security ticket for the username
    defined in the Job in each execution. If you need to reuse an existing ticket issued for the
    same username, leave both the Force MapR ticket
    check box and the Use Kerberos
    check box clear, and then MapR should be able to automatically
    find that ticket on the fly.

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. This keytab file must be stored in the machine in which your Job actually
runs, for example, on a Talend

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.

For further information about how Kerberos can be configured for your
database in a MapR cluster, see Configuring Kerberos

Advanced settings


If you need to use custom configuration for your database, complete this table with the
property or properties to be customized. Then at runtime, the customized
property or properties will override those corresponding ones defined
earlier for your database.

For example, you need to define the value of the dfs.replication property as 1 for the database 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.

tStatCatcher Statistics

Select this check box to collect the log data at a component

Global Variables

Global Variables

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 +
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 is generally used with other MapRDB components, particularly tMapRDBClose.


Before starting, ensure that you have met the Loopback IP prerequisites expected by your

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

  • 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
    . For example, the library for
    Windows is lib
    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.

Related scenario

This component is similar to tHBaseConnection. For a scenario about how to use tHBaseConnection, see Exchanging customer data with HBase.

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