# `IngestGrokProcessor` [interface-IngestGrokProcessor]

| Name | Type | Description |
| - | - | - |
| `ecs_compatibility` | string | Must be disabled or v1. If v1, the processor uses patterns with Elastic Common Schema (ECS) field names. |
| `field` | [Field](./Field.md) | The field to use for grok expression parsing. |
| `ignore_missing` | boolean | If `true` and `field` does not exist or is `null`, the processor quietly exits without modifying the document. |
| `pattern_definitions` | Record<string, string> | A map of pattern-name and pattern tuples defining custom patterns to be used by the current processor. Patterns matching existing names will override the pre-existing definition. |
| `patterns` | [GrokPattern](./GrokPattern.md)[] | An ordered list of grok expression to match and extract named captures with. Returns on the first expression in the list that matches. |
| `trace_match` | boolean | When `true`, `_ingest._grok_match_index` will be inserted into your matched document’s metadata with the index into the pattern found in `patterns` that matched. |