tHCatalogOperation Standard properties

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

The Standard tHCatalogOperation component belongs to the Big Data family.

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 in which the properties are stored. The fields that follow are completed automatically using the data retrieved.
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 HD Insight cluster and the Windows Azure Storage service of that cluster in the areas that are displayed. For detailed explanation about these parameters, search for configuring the connection manually on Talend Help Center (https://help.talend.com). If you select Amazon EMR, find more details about Amazon EMR getting started in Talend Help Center (https://help.talend.com). 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 . 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. 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. 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.
HCatalog version	Select the version of the Hadoop distribution you are using. The available options vary depending on the component you are using.
Templeton hostname	Fill this field with the URL of Templeton Webservice. Note: Templeton is a webservice API for HCatalog. It has been renamed to WebHCat by the Apache community. This service facilitates the access to HCatalog and the related Hadoop elements such as Pig. For further information about Templeton (WebHCat), see https://cwiki.apache.org/confluence/display/Hive/WebHCat+UsingWebHCat.
Templeton port	Fill this field with the port of URL of Templeton Webservice. By default, the value for this field is 50111. Note: Templeton is a webservice API for HCatalog. It has been renamed to WebHCat by the Apache community. This service facilitates the access to HCatalog and the related Hadoop elements such as Pig. For further information about Templeton (WebHCat), see https://cwiki.apache.org/confluence/display/Hive/WebHCat+UsingWebHCat.
Use kerberos authentication	If you are accessing the Hadoop cluster running with Kerberos security, select this check box, then, enter the Kerberos principal name for the NameNode in the field displayed. This enables you to use your user name to authenticate against the credentials stored in Kerberos. 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 authentication check box and the Use Kerberos authentication check box clear, and then MapR should be able to automatically find that ticket on the fly. This check box is available depending on the Hadoop distribution you are connecting to.
Use a keytab to authenticate	Select the Use a keytab to authenticate check box to log into a Kerberos-enabled system using a given keytab file. 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 Jobserver. 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 username 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.
Operation on	Select an object from the list for the DB operation as follows: Database: The HCatalog managed database in HDFS. Table: The HCatalog managed table in HDFS. Partition: The partition specified by the user.
Operation	Select an action from the list for the DB operation. For further information about the DB operation in HDFS, see https://cwiki.apache.org/Hive/.
Create the table only it doesn't exist already	Select this check box to avoid creating duplicate table when you create a table. Note: This check box is enabled only when you have selected Table from the Operation on list.
Database	Fill this field with the name of the database in which the HCatalog managed tables are placed.
Table	Fill this field to operate on one or multiple tables in a database or on a specified HDFS location. Note: This field is enabled only when you have selected Table from the Operation on list. For further information about the operation on Table, see https://cwiki.apache.org/Hive/.
Partition	Fill this field to specify one or more partitions for the partition operation on a specified table. When you specify multiple partitions, use comma to separate every two partitions and use double quotation marks to quote the partition string. If you are reading a non-partitioned table, leave this field empty. Note: This field is enabled only when you select Partition from the Operation on list. For further information about the operation on Partition, see https://cwiki.apache.org/Hive/.
Username	Fill this field with the username for the DB authentication.
Database location	Fill this field with the location of the database file in HDFS. Note: This field is enabled only when you select Database from the Operation on list.
Database description	The description for the database to be created. Note: This field is enabled only when you select Database from the Operation on list.
Create an external table	Select this field to create an external table in an alternative path defined in the Set HDFS location field in the Advanced settings view. For further information about creating external table, see https://cwiki.apache.org/Hive/. Note: This check box is enabled only when you select Table from the Operation on list and Create/Drop and create/Drop if exist and create from the Operation list.
Format	Select a file format from the list to specify the format of the external table you want to create: TEXTFILE: Plain text files. RCFILE: Record Columnar files. For further information about RCFILE, see https://cwiki.apache.org/confluence/display/Hive/RCFile. Note: RCFILE is only available starting with Hive 0.6.0. This list is enabled only when you select Table from the Operation on list and Create/Drop and create/Drop if exist and create from the Operation list.
Set partitions	Select this check box to set the partition schema by clicking the Edit schema to the right of Set partitions check box. The partition schema is either built-in or remote in the Repository. Note: This check box is enabled only when you select Table from the Operation on list and Create/Drop and create/Drop if exist and create from the Operation list. You must follow the rules of using partition schema in HCatalog managed tables. For more information about the rules in using partition schema, see https://cwiki.apache.org/confluence/display/Hive/HCatalog.
	Built-in: The schema will be created and stored locally for this component only. Related topic: see Talend Studio User Guide.
	Repository: The schema already exists and is stored in the Repository, hence can be reused in various projects and Job designs. Related topic: see Talend Studio User Guide.
Set the user group to use	Select this check box to specify the user group. Note: This check box is enabled only when you select Drop/Drop if exist/Drop and create/Drop if exist and create from the Operation list. By default, the value for this field is root. For more information about the user group in the server, contact your system administrator.
Option	Select a clause when you drop a database. Note: This list is enabled only when you select Database from the Operation on list and Drop/Drop if exist/Drop and create/Drop if exist and create from the Operation list. For more information about Drop operation on database, see https://cwiki.apache.org/Hive/.
Set the permissions to use	Select this check box to specify the permissions needed by the operation you select from the Operation list. Note: This check box is enabled only when you select Drop/Drop if exist/Drop and create/Drop if exist and create from the Operation list. By default, the value for this field is rwxrw-r-x. For more information on user permissions, contact your system administrator.
Set File location	Enter the directory in which partitioned data is stored. Note: This check box is enabled only when you select Partition from the Operation on list and Create/Drop and create/Drop if exist and create from the Operation list. For further information about storing partitioned data in HDFS, see https://cwiki.apache.org/Hive/.
Die on error	This check box is cleared by default, meaning to skip the row on error and to complete the process for error-free rows.

Advanced settings

Comment	Fill this field with the comment for the table you want to create. Note: This field is enabled only when you select Table from the Operation on list and Create/Drop and create/Drop if exist and create from the Operation list in the Basic settings view.
Set HDFS location	Select this check box to specify an HDFS location to which the table you want to create is saved. Deselect it to save the table you want to create in the warehouse directory defined in the key hive.metastore.warehouse.dir in Hive configuration file hive-site.xml. Note: This check box is enabled only when you select Table from the Operation on list and Create/Drop and create/Drop if exist and create from the Operation list in the Basic settings view. For further information about saving data in HDFS, see https://cwiki.apache.org/Hive/.
Set row format(terminated by)	Select this check box to use and define the row formats when you want to create a table: Field: Select this check box to use Field as the row format. The default value for this field is "\u0001". You can also specify a customized char in this field. Collection Item: Select this check box to use Collection Item as the row format. The default value for this field is "\u0002". You can also specify a customized char in this field. Map Key: Select this check box to use Map Key as the row format. The default value for this field is "\u0003". You can also specify a customized char in this field. Line: Select this check box to use Line as the row format. The default value for this field is "\n". You can also specify a customized char in this field. Note: This check box is enabled only when you select Table from the Operation on list and Create/Drop and create/Drop if exist and create from the Operation list in the Basic settings view. For further information about row formats in the HCatalog managed table, see https://cwiki.apache.org/Hive/.
Properties	Click [+] to add one or more lines to define table properties. The table properties allow you to tag the table definition with your own metadata key/value pairs. Make sure that values in both Key row and Value row must be quoted in double quotation marks. Note: This table is enabled only when you select Database/Table from the Operation on list and Create/Drop and create/Drop if exist and create from the Operation list in the Basic settings view. For further information about table properties, see https://cwiki.apache.org/Hive/.
Retrieve the HCatalog logs	Select this check box to retrieve log files generated during HCatalog operations.
Standard Output Folder	Browse to, or enter the directory where the log files are stored. Note: This field is enabled only when you selected Retrieve the HCatalog logs check box.
Error Output Folder	Browse to, or enter the directory where the error log files are stored. Note: This field is enabled only when you selected Retrieve the HCatalog logs check box.
tStatCatcher Statistics	Select this check box to gather the Job processing metadata at the Job level as well as at each component level.

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 + Space to access the variable list and choose the variable to use from it. For further information about variables, see Talend Studio User Guide.

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

Usage rule	This component is commonly used in a single-component subJob. HCatalog is built on top of the Hive metastore to provide read and write interface for Pig and MapReduce, so that the latter systems can use the metadata of Hive to easily read and write data in HDFS. For further information, see Apache documentation about HCatalog: https://cwiki.apache.org/confluence/display/Hive/HCatalog.
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\ hadoop\hadoop-VERSION\lib\native. For example, the library for Windows is \lib\native\MapRClient.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.
Limitation	When Use kerberos authentication is selected, the component cannot work with IBM JVM.

Usage rule

This component is commonly used in a single-component subJob.

HCatalog is built on top of the Hive metastore to provide read and write interface for Pig and MapReduce, so that the latter systems can use the metadata of Hive to easily read and write data in HDFS.

For further information, see Apache documentation about HCatalog: https://cwiki.apache.org/confluence/display/Hive/HCatalog.

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\ hadoop\hadoop-VERSION\lib\native. For example, the library for Windows is \lib\native\MapRClient.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.

Limitation

When Use kerberos authentication is selected, the component cannot work with IBM JVM.