Edge Delta Parse Grok Processor

The Edge Delta parse grok processor parses a field into structured data based on a grok pattern.

6 minute read

Overview

The Grok parsing processor is used to extract structured fields from unstructured log data using Grok patterns. It processes the log body by matching it against a provided Grok pattern, either from the built-in Knowledge Library or a custom pattern. If a match is successful, the extracted fields are stored in the attributes field or custom field. If the destination field, such as attributes already exists, the new fields are merged into it using an upsert strategy. If no match is found (and strict matching is enabled), no new attributes are added.

Grok patterns themselves are human-readable regex macros. The parsing processor uses these patterns to identify meaningful fields like IP addresses, HTTP methods, status codes, etc. You can define your own, select one from the library, or use the AI assistant to generate one from a sample log.

Learn how to configure this in Pipeline Quickstart: Create Structured Attributes.

Configuration

Consider this log body:

<14> 1 2025-06-23T10:24:44.849103Z logserver01 monitor 28968 ID167 - New entry

This pattern will can be used to parse the log:

<%{NUMBER:syslog_priority}> %{NUMBER:syslog_version} %{TIMESTAMP_ISO8601:timestamp} %{WORD:hostname} %{WORD:appname} %{NUMBER:pid} %{WORD:log_id} - %{GREEDYDATA:message}

It will create the following structure:

%{NUMBER:syslog_priority}: Extracts the syslog priority number.
%{NUMBER:syslog_version}: Captures the syslog version number.
%{TIMESTAMP_ISO8601:timestamp}: Captures the ISO 8601 timestamp.
%{WORD:hostname}: Captures the hostname.
%{WORD:appname}: Captures the application or service name.
%{NUMBER:pid}: Captures the process ID.
%{WORD:log_id}: Captures the log ID.
%{GREEDYDATA:message}: Captures the rest of the log entry as the message.

The processor is configured as follows:

This configuration can be represented with the following YAML

- name: kubernetes_input_multiprocessor
  type: sequence
  processors:
  - type: ottl_transform
    metadata: '{"id":"jAV8KAUBPP8WQc1dXREQZ","type":"parse-grok","name":"Parse Grok"}'
    data_types:
    - log
    statements: |-
      merge_maps(attributes, ExtractGrokPatterns(body, "<%{NUMBER:syslog_priority}> %{NUMBER:syslog_version} %{TIMESTAMP_ISO8601:timestamp} %{WORD:hostname} %{WORD:appname} %{NUMBER:pid} %{WORD:log_id} - %{GREEDYDATA:message}", true), "upsert") where IsMap(attributes)
      set(attributes, ExtractGrokPatterns(body, "<%{NUMBER:syslog_priority}> %{NUMBER:syslog_version} %{TIMESTAMP_ISO8601:timestamp} %{WORD:hostname} %{WORD:appname} %{NUMBER:pid} %{WORD:log_id} - %{GREEDYDATA:message}", true)) where not IsMap(attributes)

From the YAML, you can see the logic applied by the processor:

These two statements ensure that attributes extracted from the log messages are properly incorporated into existing data:

If attributes is a map, it is enhanced with the new data using the merge_maps function to ensure data integrity through “upsert” operations.
If attributes is not a map, it is completely replaced by the new data map obtained from the log content, ensuring that the attributes are consistently structured following the Grok extraction.

The output data items has parsed the body using the named captures:

{
  "_type": "log",
  "timestamp": 1750674290981,
  "body": "<14> 1 2025-06-23T10:24:44.849103Z logserver01 monitor 28968 ID167 - New entry",
  "resource": {
    ...
  },
  "attributes": {
    "appname": "monitor",
    "hostname": "logserver01",
    "log_id": "ID167",
    "message": "New entry",
    "pid": "28968",
    "syslog_priority": "14",
    "syslog_version": "1",
    "timestamp": "2025-06-23T10:24:44.849103Z"
  }
}

Options

Select a telemetry type

You can specify, log, metric, trace or all. It is specified using the interface, which generates a YAML list item for you under the data_types parameter. This defines the data item types against which the processor must operate. If data_types is not specified, the default value is all. It is optional.

It is defined in YAML as follows:

- name: multiprocessor
  type: sequence
  processors:
  - type: <processor type>
    data_types:
    - log

condition

The condition parameter contains a conditional phrase of an OTTL statement. It restricts operation of the processor to only data items where the condition is met. Those data items that do not match the condition are passed without processing. You configure it in the interface and an OTTL condition is generated. It is optional. You can select one of the following operators:

Operator	Name	Description	Example
`==`	Equal to	Returns `true` if both values are exactly the same	`attributes["status"] == "OK"`
`!=`	Not equal to	Returns `true` if the values are not the same	`attributes["level"] != "debug"`
`>`	Greater than	Returns `true` if the left value is greater than the right	`attributes["duration_ms"] > 1000`
`>=`	Greater than or equal	Returns `true` if the left value is greater than or equal to the right	`attributes["score"] >= 90`
`<`	Less than	Returns `true` if the left value is less than the right	`attributes["load"] < 0.75`
`<=`	Less than or equal	Returns `true` if the left value is less than or equal to the right	`attributes["retries"] <= 3`
`matches`	Regex match	Returns `true` if the string matches a regular expression	`isMatch(attributes["name"], ".*\\.name$"`

It is defined in YAML as follows:

- name: _multiprocessor
  type: sequence
  processors:
  - type: <processor type>
    condition: attributes["request"]["path"] == "/json/view"

OTTL Statement

Parse from

This option specifies the field containing the text that needs to be parsed. It is specified using bracket notation and is optional. If left empty it defaults to body.

Assign to

Specify the field where you want the parsed object to be saved.

Grok Pattern

This option defines the log pattern that should be used to parse attributes. A Pattern or a Custom Pattern is required. Use the Knowledge Library to select a pattern, specify your own a custom pattern, or you use an AI assistant to generate a Grok pattern.

Final

Determines whether successfully processed data items should continue through the remaining processors in the same processor stack. If final is set to true, data items output by this processor are not passed to subsequent processors within the node—they are instead emitted to downstream nodes in the pipeline (e.g., a destination). Failed items are always passed to the next processor, regardless of this setting.

The UI provides a slider to configure this setting. The default is false. It is defined in YAML as follows:

- name: multiprocessor
  type: sequence
  processors:
    - type: <processor type>
    final: true

Keep original telemetry item

Controls whether the original, unmodified telemetry item is preserved after processing. If keep_item is set to true, the processor emits both:

The original telemetry item (e.g., a log), and
Any new item generated by the processor (e.g., a metric extracted from the log)

Both items are passed to the next processor in the stack unless final is also set.

Interaction with final

If final: true is enabled, any successfully processed data items, whether original, newly created, or both, exit the processor stack or node immediately. No subsequent processors within the same node are evaluated, although downstream processing elsewhere in the pipeline continues. This means:

If keep_item: true and final: true, both the original and processed items bypass the remaining processors in the current node and are forwarded to downstream nodes (such as destinations).
If keep_item: false and final: true, only the processed item continues beyond this processor, skipping subsequent processors in the stack, and the original item is discarded.

Note: If the data item fails to be processed, final has no effect, the item continues through the remaining processors in the node regardless of the keep_item setting.

The app provides a slider to configure keep_item. The default is false.

- name: ed_gateway_output_a3fa_multiprocessor
  type: sequence
  processors:
    - type: <processor_type>
      keep_item: true
      final: true