---
layout: default
title: grok
parent: Processors
grand_parent: Configuring Data Prepper
nav_order: 45
---

# grok

## Overview

Takes unstructured data and utilizes pattern matching to structure and extract important keys and make data more structured and queryable.

Option | Required | Type | Description
:--- | :--- | :--- | :---
match | No | Map | Specifies which keys to match specific patterns against. Default is an empty body.
keep_empty_captures | No | Boolean | Enables preserving `null` captures. Default value is `false`.
named_captures_only | No | Boolean | enables whether to keep only named captures. Default value is `true`.
break_on_match | No | Boolean | Specifies whether to match all patterns or stop once the first successful match is found. Default is `true`.
keys_to_overwrite | No | List | Specifies which existing keys are to be overwritten if there is a capture with the same key value. Default is `[]`.
pattern_definitions | No | Map | Allows for custom pattern use inline. Default value is an empty body.
patterns_directories | No | List | Specifies the path of directories that contain customer pattern files. Default value is an empty list.
pattern_files_glob | No | String | Specifies which pattern files to use from the directories specified for `pattern_directories`. Default is `*`.
target_key | No | String | Specifies a parent level key to store all captures. Default value is `null`.
timeout_millis | No | Integer | Maximum amount of time that should take place for the matching. Setting to `0` disables the timeout. Default value is `30,000`.

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## Metrics

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