Description:

Fetch sequence files from Hadoop Distributed File System (HDFS) into FlowFiles

Tags:

hadoop, HDFS, get, fetch, ingest, source, sequence file

Properties:

In the list below, the names of required properties appear in bold. Any other properties (not in bold) are considered optional. The table also indicates any default values.

NameDefault ValueAllowable ValuesDescription
Hadoop Configuration ResourcesA file or comma separated list of files which contains the Hadoop file system configuration. Without this, Hadoop will search the classpath for a 'core-site.xml' and 'hdfs-site.xml' file or will revert to a default configuration.
Kerberos PrincipalKerberos principal to authenticate as. Requires nifi.kerberos.krb5.file to be set in your nifi.properties
Kerberos KeytabKerberos keytab associated with the principal. Requires nifi.kerberos.krb5.file to be set in your nifi.properties
Kerberos Relogin Period4 hoursPeriod of time which should pass before attempting a kerberos relogin
DirectoryThe HDFS directory from which files should be read
Recurse Subdirectoriestrue
  • true
  • false
Indicates whether to pull files from subdirectories of the HDFS directory
Keep Source Filefalse
  • true
  • false
Determines whether to delete the file from HDFS after it has been successfully transferred. If true, the file will be fetched repeatedly. This is intended for testing only.
File Filter RegexA Java Regular Expression for filtering Filenames; if a filter is supplied then only files whose names match that Regular Expression will be fetched, otherwise all files will be fetched
Filter Match Name Onlytrue
  • true
  • false
If true then File Filter Regex will match on just the filename, otherwise subdirectory names will be included with filename in the regex comparison
Ignore Dotted Filestrue
  • true
  • false
If true, files whose names begin with a dot (".") will be ignored
Minimum File Age0 secThe minimum age that a file must be in order to be pulled; any file younger than this amount of time (based on last modification date) will be ignored
Maximum File AgeThe maximum age that a file must be in order to be pulled; any file older than this amount of time (based on last modification date) will be ignored
Polling Interval0 secIndicates how long to wait between performing directory listings
Batch Size100The maximum number of files to pull in each iteration, based on run schedule.
IO Buffer SizeAmount of memory to use to buffer file contents during IO. This overrides the Hadoop Configuration
Compression codecNONE
  • NONE
  • DEFAULT
  • BZIP
  • GZIP
  • LZ4
  • SNAPPY
  • AUTOMATIC
No Description Provided.
FlowFile ContentVALUE ONLY
  • VALUE ONLY
  • KEY VALUE PAIR
Indicate if the content is to be both the key and value of the Sequence File, or just the value.

Relationships:

NameDescription
passthroughIf this processor has an input queue for some reason, then FlowFiles arriving on that input are transferred to this relationship
successAll files retrieved from HDFS are transferred to this relationship

Reads Attributes:

None specified.

Writes Attributes:

NameDescription
filenameThe name of the file that was read from HDFS.
pathThe path is set to the relative path of the file's directory on HDFS. For example, if the Directory property is set to /tmp, then files picked up from /tmp will have the path attribute set to "./". If the Recurse Subdirectories property is set to true and a file is picked up from /tmp/abc/1/2/3, then the path attribute will be set to "abc/1/2/3".

See Also:

PutHDFS