HDFS Collection Agent Configuration(3.3)

Owned by Jenni Wallin
Oct 02, 2023
4 min read

HDFS Tab

The HDFS tab contains configurations related to the placement and handling of the source files to be collected by the agent.

ItemDescription
ProfileSelect the File System profile you want the agent to use, see File System Profile - HDFS (3.3) for further information about this profile.

Collection Strategy

If there are more than one collection strategy available in the system a Collection Strategy drop down list will also be visible. For more information about the nature of the collection strategy please refer to 11. Appendix 4 - Collection Strategies.

Directory

Absolute pathname of the directory on the remote file system, where the source files reside. 

Filename

Name of the source files on the local file system. Regular expressions according to Java syntax applies. For further information, see http://docs.oracle.com/javase/8/docs/api/java/util/regex/Pattern.html.

Example

To match all filenames beginning with TTFILE, type: TTFILE.*


Compression

Compression type of the source files. Determines if the agent will decompress the files before passing them on in the workflow.

  • No Compression - agent does not decompress the files. Default setting.

  • Gzip - agent decompresses the files using gzip.

Move to Temporary Directory

If enabled, the source files will be moved to the automatically created subdirectory DR_TMP_DIR in the source directory, prior to collection. This option supports safe collection of a source file reusing the same name.

Append Suffix to Filename

Enter the suffix that you want added to the file name prior to collecting it.

Important

Before you execute your workflow, make sure that none of the file names in the collection directory include this suffix.

Inactive Source Warning (hours)

If the specified value is greater than zero, and if no file has been collected during the specified number of hours, the following message is logged:

The source has been idle for more than <n> hours, the last
inserted file is <file>.

Move to

If enabled, the source files will be moved from the source directory (or from the directory DR_TMP_DIR, if using Move Before Collecting) to the directory specified in the Destination field, after the collection.

If the Prefix or Suffix fields are set, the file will be renamed as well.

Note

If it is desired to move files between file systems it is strongly recommended to route the HDFS collection agent directly to a HDFS forwarding agent, configuring the output agent to store the files in the desired directory. Refer to HDFS Forwarding Agent(3.3) for information.

This is because of the following reasons:

  • It is not always possible to move collected files from one file system to another.

  • Moving files between different file systems usually cause worse performance than having them on the same file system.

  • The workflow will not be transaction safe, because of the nature of the copy plus delete functionality.

Rename

If enabled, the source files will be renamed after the collection, remaining in the source directory from which they were collected (or moved back from the directory DR_TMP_DIR , if using Move Before Collecting).

Remove

If enabled, the source files will be removed from the source directory (or from the directory DR_TMP_DIR, if using Move Before Collecting), after the collection.

Ignore

If enabled, the source files will remain in the source directory after collection.

Destination

Absolute pathname of the directory on the local file system of the EC into which the source files will be moved after collection. The pathname might also be given relative to the $MZ_HOME environment variable.

This field is only enabled if Move to is selected.

Prefix/Suffix

Prefix and/or suffix that will be appended to the beginning respectively the end of the name of the source files, after the collection.

These fields are only enabled if Move to or Rename is selected.

Note

If Rename is enabled, the source files will be renamed in the current directory (source or DR_TMP_DIR). Be sure not to assign a Prefix or Suffix, giving files new names, still matching the filename regular expression, or else the files will be collected over and over again.

Search and Replace

Note

To apply Search and Replace, select either Move to or Rename.

  • Search: Enter the part of the filename that you want to replace.

  • Replace: Enter the replacement text.

Search and Replace operate on your entries in a way that is similar to the Unix sed utility. The identified filenames are modified and forwarded to the following agent in the workflow.

This functionality enables you to perform advanced filename modifications, as well:

  • Use regular expression in the Search entry to specify the part of the filename that you want to extract.

    Note

    A regular expression that fails to match the original file name will abort the workflow.

  • Enter Replace with characters and meta characters that define the pattern and content of the replacement text.


Search and Replace Examples

To rename the file file1.new to file1.old, use:

  • Search: .new
  • Replace: .old


To rename the file JAN2011_file to file_DONE, use:

  • Search: ([A-Z]*[0-9]*)_([a-z]*)
  • Replace: $2_DONE


Note that the search value divides the file name into two parts by using brackets. The replace value applies the second part by using the place holder $2.

Keep (days)

Number of days to keep source files after the collection. In order to delete the source files, the workflow has to be executed (scheduled or manually) again, after the configured number of days.

Note, a date tag is added to the filename, determining when the file may be removed. This field is only enabled if Move to or Rename is selected.