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Config: Parse Section
Some of the Fluentd plugins support the <parse> section to specify how to parse the raw data.

Parse Section Overview

The parse section can be under <source>, <match> or <filter> section. It is enabled for the plugins that support parser plugin features.
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<source>
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@type tail
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# ...
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<parse>
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# ...
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</parse>
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</source>
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Parser Plugin Type

The @type parameter of <parse> section specifies the type of the parser plugin. Fluentd core bundles some useful parser plugins.
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<parse>
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@type apache2
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</parse>
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Third-party plugins may also be installed and configured.
For more details, see plugins documentation.

Parameters

@type

The @type parameter specifies the type of the parser plugin.
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<parse>
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@type regexp
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# ...
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</parse>
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Here's the list of built-in parser plugins:

Parse Parameters

The default value of the following parameters will be overridden by the individual parser plugins:
  • types (hash) (optional): Specify types for converting field into another
    type. See below "The detail of types parameter" section.
    • Default: nil
    • string-based hash: `field1:type, field2:type, field3:type:option,
      field4:type:option`
    • JSON format: `{"field1":"type", "field2":"type", "field3":"type:option",
      "field4":"type:option"}`
    • example: types user_id:integer,paid:bool,paid_usd_amount:float
  • time_key (string) (optional): Specify time field for event time. If
    the event doesn't have this field, current time is used.
    • Default: nil
    • Note that json,
      ltsv and
      regexp override the default value of this
      parameter and set it to time by default.
  • null_value_pattern (regexp) (optional): Specify null value pattern.
    • Default: nil
  • null_empty_string (bool) (optional): If true, empty string field is
    replaced with nil.
    • Default: false
  • estimate_current_event (bool) (optional): If true, use
    Fluent::EventTime.now(current time) as a timestamp when time_key is
    specified.
    • Default: true
  • keep_time_key (bool) (optional): If true, keep time field in the
    record.
    • Default: false
  • timeout (time) (optional): Specify timeout for parse processing. This
    is mainly for detecting wrong regexp pattern.
    • Default: nil

types Parameter

For the types parameter, the following types are supported:
  • string: Converts the field into String type. This uses to_s method for conversion.
  • bool: Converts the string "true", "yes" or "1" into true. Otherwise, false.
  • integer (not int): Converts the field into the Integer type. This uses to_i method for conversion. For example, the string "1000" converts into 1000.
  • float: Converts the field into Float type. This uses to_f method for conversion. For example, the string "7.45" converts into 7.45.
  • time: Converts the field into Fluent::EventTime type. This uses Fluentd time parser for conversion. For the time type, the third field specifies the time format similar to time_format.
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    date:time:%d/%b/%Y:%H:%M:%S %z # for string with time format
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    date:time:unixtime # for integer time
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    date:time:float # for float time
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    See time_type and time_format parameters in Time parameters section.
  • array: Converts the string field into Array type. For the array type, the third field specifies the delimiter (the default is comma ","). For example, if a field item_ids contains the value "3,4,5", types item_ids:array parses it as ["3", "4", "5"]. Alternatively, if the value is "Adam|Alice|Bob", types item_ids:array:| parses it as ["Adam", "Alice", "Bob"].

Time Parameters

  • time_type (enum) (optional): parses/formats value according to this
    type
    • Default: string
    • Available values: float, unixtime, string, mixed
      • float: seconds from Epoch + nano seconds (e.g.
        1510544836.154709804)
      • unixtime: seconds from Epoch (e.g. 1510544815)
      • string: use format specified by time_format, local time or time
        zone
      • mixed: enable time_format_fallbacks option. (Since Fluentd v1.12.2)
  • time_format (string) (optional): processes value according to the
    specified format. This is available only when time_type is string.
    • Default: nil
    • Available time format:
      • For more details about formatting, see
      • For more details about parsing, see
      • %iso8601 (only for parsing)
      • Use %N to parse/format with sub-second precision, because
        strptime does not support
        %3N, %6N, %9N, and %L.
  • localtime (bool) (optional): if true, uses local time. Otherwise,
    UTC is used. This is exclusive with utc.
    • Default: true
  • utc (bool) (optional): if true, uses UTC. Otherwise, local time is
    used. This is exclusive with localtime.
    • Default: false
  • timezone (string) (optional): uses the specified timezone. One can
    parse/format the time value in the specified timezone format.
    • Default: nil
    • Available time zone format:
      1. 1.
        [+-]HH:MM (e.g. "+09:00") (recommended)
      2. 2.
        [+-]HHMM (e.g. "+0900")
      3. 3.
        [+-]HH (e.g. "+09")
      4. 4.
        Region/Zone (e.g. Asia/Tokyo)
      5. 5.
        Region/Zone/Zone (e.g. America/Argentina/Buenos_Aires)
  • time_format_fallbacks () (optional): uses the specified time format as a fallback in the specified order.
    You can parse undetermined time format by using time_format_fallbacks. This options is enabled when time_type is mixed.
    • Default: nil
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    time_type mixed
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    time_format unixtime
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    time_format_fallbacks %iso8601
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    In the above use case, the timestamp is parsed as unixtime at first, if it fails, then it is parsed as %iso8601 secondary. Note that time_format_fallbacks is the last resort to parse mixed timestamp format. There is a performance penalty (Typically, N fallbacks are specified in time_format_fallbacks and if the last specified format is used as a fallback, N times slower in the worst case).
If this article is incorrect or outdated, or omits critical information, please let us know. Fluentd is an open-source project under Cloud Native Computing Foundation (CNCF). All components are available under the Apache 2 License.