GrokReader

GrokReader 2.0.0

Bundle: org.apache.nifi | nifi-record-serialization-services-nar
Description: Provides a mechanism for reading unstructured text data, such as log files, and structuring the data so that it can be processed. The service is configured using Grok patterns. The service reads from a stream of data and splits each message that it finds into a separate Record, each containing the fields that are configured. If a line in the input does not match the expected message pattern, the line of text is either considered to be part of the previous message or is skipped, depending on the configuration, with the exception of stack traces. A stack trace that is found at the end of a log message is considered to be part of the previous message but is added to the 'stackTrace' field of the Record. If a record has no stack trace, it will have a NULL value for the stackTrace field (assuming that the schema does in fact include a stackTrace field of type String). Assuming that the schema includes a '_raw' field of type String, the raw message will be included in the Record.
Tags: grok, logfiles, logs, logstash, parse, pattern, reader, record, regex, text, unstructured
Input Requirement
Supports Sensitive Dynamic Properties: false

Properties

Grok Expressions
Specifies the format of a log line in Grok format. This allows the Record Reader to understand how to parse each log line. The property supports one or more Grok expressions. The Reader attempts to parse input lines according to the configured order of the expressions.If a line in the log file does not match any expressions, the line will be assumed to belong to the previous log message.If other Grok patterns are referenced by this expression, they need to be supplied in the Grok Pattern File property.

Display Name

Grok Expressions

Description

Specifies the format of a log line in Grok format. This allows the Record Reader to understand how to parse each log line. The property supports one or more Grok expressions. The Reader attempts to parse input lines according to the configured order of the expressions.If a line in the log file does not match any expressions, the line will be assumed to belong to the previous log message.If other Grok patterns are referenced by this expression, they need to be supplied in the Grok Pattern File property.

API Name

Grok Expression

Expression Language Scope

Not Supported

Sensitive

false

Required

true
Grok Patterns
Grok Patterns to use for parsing logs. If not specified, a built-in default Pattern file will be used. If specified, all patterns specified will override the default patterns. See the Controller Service's Additional Details for a list of pre-defined patterns.

Display Name

Grok Patterns

Description

Grok Patterns to use for parsing logs. If not specified, a built-in default Pattern file will be used. If specified, all patterns specified will override the default patterns. See the Controller Service's Additional Details for a list of pre-defined patterns.

API Name

Grok Pattern File

Expression Language Scope

Environment variables defined at JVM level and system properties

Sensitive

false

Required

false
No Match Behavior
If a line of text is encountered and it does not match the given Grok Expression, and it is not part of a stack trace, this property specifies how the text should be processed.
Display Name

No Match Behavior

Description

If a line of text is encountered and it does not match the given Grok Expression, and it is not part of a stack trace, this property specifies how the text should be processed.

API Name

no-match-behavior

Default Value

append-to-previous-message

Allowable Values
- Append to Previous Message
- Skip Line
- Raw Line
Expression Language Scope

Not Supported

Sensitive

false

Required

true
Schema Access Strategy
Specifies how to obtain the schema that is to be used for interpreting the data.
Display Name

Schema Access Strategy

Description

Specifies how to obtain the schema that is to be used for interpreting the data.

API Name

schema-access-strategy

Default Value

string-fields-from-grok-expression

Allowable Values
- Use String Fields From Grok Expression
- Use 'Schema Name' Property
- Use 'Schema Text' Property
- Schema Reference Reader
Expression Language Scope

Not Supported

Sensitive

false

Required

true
Schema Branch
Specifies the name of the branch to use when looking up the schema in the Schema Registry property. If the chosen Schema Registry does not support branching, this value will be ignored.
Display Name

Schema Branch

Description

Specifies the name of the branch to use when looking up the schema in the Schema Registry property. If the chosen Schema Registry does not support branching, this value will be ignored.

API Name

schema-branch

Expression Language Scope

Environment variables and FlowFile Attributes

Sensitive

false

Required

false

Dependencies
- Schema Access Strategy is set to any of [schema-name]
Schema Name
Specifies the name of the schema to lookup in the Schema Registry property
Display Name

Schema Name

Description

Specifies the name of the schema to lookup in the Schema Registry property

API Name

schema-name

Default Value

${schema.name}

Expression Language Scope

Environment variables and FlowFile Attributes

Sensitive

false

Required

false

Dependencies
- Schema Access Strategy is set to any of [schema-name]
Schema Reference Reader
Service implementation responsible for reading FlowFile attributes or content to determine the Schema Reference Identifier
Display Name

Schema Reference Reader

Description

Service implementation responsible for reading FlowFile attributes or content to determine the Schema Reference Identifier

API Name

schema-reference-reader

Service Interface

org.apache.nifi.schemaregistry.services.SchemaReferenceReader

Service Implementations

org.apache.nifi.confluent.schemaregistry.ConfluentEncodedSchemaReferenceReader

Expression Language Scope

Not Supported

Sensitive

false

Required

true

Dependencies
- Schema Access Strategy is set to any of [schema-reference-reader]
Schema Registry
Specifies the Controller Service to use for the Schema Registry
Display Name

Schema Registry

Description

Specifies the Controller Service to use for the Schema Registry

API Name

schema-registry

Service Interface

org.apache.nifi.schemaregistry.services.SchemaRegistry

Service Implementations

org.apache.nifi.aws.schemaregistry.AmazonGlueSchemaRegistry

org.apache.nifi.apicurio.schemaregistry.ApicurioSchemaRegistry

org.apache.nifi.schemaregistry.services.AvroSchemaRegistry

org.apache.nifi.confluent.schemaregistry.ConfluentSchemaRegistry

org.apache.nifi.db.schemaregistry.DatabaseTableSchemaRegistry

Expression Language Scope

Not Supported

Sensitive

false

Required

false

Dependencies
- Schema Access Strategy is set to any of [schema-reference-reader, schema-name]
Schema Text
The text of an Avro-formatted Schema
Display Name

Schema Text

Description

The text of an Avro-formatted Schema

API Name

schema-text

Default Value

${avro.schema}

Expression Language Scope

Environment variables and FlowFile Attributes

Sensitive

false

Required

false

Dependencies
- Schema Access Strategy is set to any of [schema-text-property]
Schema Version
Specifies the version of the schema to lookup in the Schema Registry. If not specified then the latest version of the schema will be retrieved.
Display Name

Schema Version

Description

Specifies the version of the schema to lookup in the Schema Registry. If not specified then the latest version of the schema will be retrieved.

API Name

schema-version

Expression Language Scope

Environment variables and FlowFile Attributes

Sensitive

false

Required

false

Dependencies
- Schema Access Strategy is set to any of [schema-name]

Restrictions

Required Permission	Explanation
reference remote resources	Patterns and Expressions can reference resources over HTTP