FetchParquet

Description:

Reads from a given Parquet file and writes records to the content of the flow file using the selected record writer. The original Parquet file will remain unchanged, and the content of the flow file will be replaced with records of the selected type. This processor can be used with ListHDFS or ListFile to obtain a listing of files to fetch.

Tags:

parquet, hadoop, HDFS, get, ingest, fetch, source, record

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, and whether a property supports the NiFi Expression Language.

Display NameAPI NameDefault ValueAllowable ValuesDescription
Hadoop Configuration ResourcesHadoop 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. To use swebhdfs, see 'Additional Details' section of PutHDFS's documentation.

This property expects a comma-separated list of file resources.

Supports Expression Language: true (will be evaluated using variable registry only)
Kerberos Credentials Servicekerberos-credentials-serviceController Service API:
KerberosCredentialsService
Implementation: KeytabCredentialsService
Specifies the Kerberos Credentials Controller Service that should be used for authenticating with Kerberos
Kerberos User Servicekerberos-user-serviceController Service API:
KerberosUserService
Implementations: KerberosKeytabUserService
KerberosTicketCacheUserService
KerberosPasswordUserService
Specifies the Kerberos User Controller Service that should be used for authenticating with Kerberos
Kerberos PrincipalKerberos PrincipalKerberos principal to authenticate as. Requires nifi.kerberos.krb5.file to be set in your nifi.properties
Supports Expression Language: true (will be evaluated using variable registry only)
Kerberos KeytabKerberos KeytabKerberos keytab associated with the principal. Requires nifi.kerberos.krb5.file to be set in your nifi.properties

This property requires exactly one file to be provided..

Supports Expression Language: true (will be evaluated using variable registry only)
Kerberos PasswordKerberos PasswordKerberos password associated with the principal.
Sensitive Property: true
Kerberos Relogin PeriodKerberos Relogin Period4 hoursPeriod of time which should pass before attempting a kerberos relogin. This property has been deprecated, and has no effect on processing. Relogins now occur automatically.
Supports Expression Language: true (will be evaluated using variable registry only)
Additional Classpath ResourcesAdditional Classpath ResourcesA comma-separated list of paths to files and/or directories that will be added to the classpath and used for loading native libraries. When specifying a directory, all files with in the directory will be added to the classpath, but further sub-directories will not be included.

This property expects a comma-separated list of resources. Each of the resources may be of any of the following types: directory, file.
Filenamefilename${path}/${filename}The name of the file to retrieve
Supports Expression Language: true (will be evaluated using flow file attributes and variable registry)
Record Writerrecord-writerController Service API:
RecordSetWriterFactory
Implementations: RecordSetWriterLookup
XMLRecordSetWriter
FreeFormTextRecordSetWriter
CSVRecordSetWriter
ScriptedRecordSetWriter
AvroRecordSetWriter
JsonRecordSetWriter
ParquetRecordSetWriter
The service for writing records to the FlowFile content

Relationships:

NameDescription
retryFlowFiles will be routed to this relationship if the content of the file cannot be retrieved, but might be able to be in the future if tried again. This generally indicates that the Fetch should be tried again.
successFlowFiles will be routed to this relationship once they have been updated with the content of the file
failureFlowFiles will be routed to this relationship if the content of the file cannot be retrieved and trying again will likely not be helpful. This would occur, for instance, if the file is not found or if there is a permissions issue

Reads Attributes:

None specified.

Writes Attributes:

NameDescription
fetch.failure.reasonWhen a FlowFile is routed to 'failure', this attribute is added indicating why the file could not be fetched from the given filesystem.
record.countThe number of records in the resulting flow file

State management:

This component does not store state.

Restricted:

Required PermissionExplanation
read distributed filesystemProvides operator the ability to retrieve any file that NiFi has access to in HDFS or the local filesystem.

Input requirement:

This component requires an incoming relationship.

System Resource Considerations:

None specified.

See Also:

PutParquet