tFileStreamInputXML properties for Apache Spark Streaming
These properties are used to configure tFileStreamInputXML running in the Spark Streaming Job framework.
The Spark Streaming tFileStreamInputXML component belongs to the File family.
The streaming version of this component is available in Talend Real Time Big Data Platform and in Talend Data Fabric.
Basic settings
Define a storage configuration component |
Select the configuration component to be used to provide the configuration information for the connection to the target file system such as HDFS. If you leave this check box clear, the target file system is the local system. The configuration component to be used must be present in the same Job. For example, if you have dropped a tHDFSConfiguration component in the Job, you can select it to write the result in a given HDFS system. |
Property type |
Either Built-In or Repository. |
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Built-In: No property data stored centrally. |
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Repository: Select the repository file where the properties are stored. The properties are stored centrally under the Hadoop Cluster node of the Repository tree. The fields that come after are pre-filled in using the fetched data. For further information about the Hadoop Cluster node, see the Getting Started Guide. |
Schema and Edit Schema |
A schema is a row description. It defines the number of fields (columns) to be processed and passed on to the next component. When you create a Spark Job, avoid the reserved word line when naming the fields. Click Edit schema to make changes to the schema. If the current schema is of the Repository type, three options are available:
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Built-In: You create and store the schema locally for this component only. |
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Repository: You have already created the schema and stored it in the Repository. You can reuse it in various projects and Job designs. |
Folder/File |
Browse to, or enter the path pointing to the data to be used in the file system. If the path you set points to a folder, this component will
read all of the files stored in that folder, for example,
/user/talend/in; if sub-folders exist, the sub-folders are automatically
ignored unless you define the property
spark.hadoop.mapreduce.input.fileinputformat.input.dir.recursive to be
true in the Advanced properties table in the
Spark configuration tab.
If you want to specify more than one files or directories in this field, separate each path using a comma (,). If the file to be read is a compressed one, enter the file name with its extension; then ttFileInputXML automatically decompresses it at runtime. The supported compression formats and their corresponding extensions are:
The button for browsing does not work with the Spark Local mode; if you are using the other Spark Yarn modes that the Studio supports with your distribution, ensure that you have correctly configured the connection in a configuration component in the same Job, such as tHDFSConfiguration. Use the configuration component depending on the filesystem to be used. |
Element to extract |
Enter the element from which you need to read the contents and the child elements of the input XML data. The element defined in this field is used at the root node of any XPath specified within this component. This element helps define the atomic units of the XML data to be used so that however big the original document is or wherever the input is split, the rows within this element can be correctly distributed to the mapper tasks. Note that any content outside this element is ignored and the child elements of this element cannot contain this element itself. |
Loop XPath query |
Node of the tree, which the loop is based on. Note its root is the element you have defined in the Element to extract field. |
Mapping |
Column: Columns to map. They reflect the schema as defined in the Schema type field. XPath Query: Enter the fields to be extracted from the structured input. Get nodes: Select this check box to recuperate the XML content of all current nodes specified in the Xpath query list, or select the check box next to specific XML nodes to recuperate only the content of the selected nodes. These nodes are important when the output flow from this component needs to use the XML structure, for example, the Document data type. For further information about the Document type, see Talend Studio User Guide. |
Die on error |
Select the check box to stop the execution of the Job when an error occurs. |
Advanced settings
Custom encoding |
You may encounter encoding issues when you process the stored data. In that situation, select this check box to display the Encoding list. Select the encoding from the list or select Custom and define it manually. This field is compulsory for database data handling. The supported encodings depend on the JVM that you are using. For more information, see https://docs.oracle.com. |
Usage
Usage rule |
This component is used as a start component and requires an output link. This component, along with the Spark Streaming component Palette it belongs to, appears only when you are creating a Spark Streaming Job. Note that in this documentation, unless otherwise explicitly stated, a scenario presents only Standard Jobs, that is to say traditional Talend data integration Jobs. |
Spark Connection |
In the Spark
Configuration tab in the Run
view, define the connection to a given Spark cluster for the whole Job. In
addition, since the Job expects its dependent jar files for execution, you must
specify the directory in the file system to which these jar files are
transferred so that Spark can access these files:
This connection is effective on a per-Job basis. |