Nearly 30 processors are supported in the ingest pipeline. When the document is indexed, each processor executes as it is declared in the pipeline. A processor is defined with a name and configured with its own parameters. Before we introduce each processor, let's examine some of the common parameters as described in the following table:
| Parameter Name | Description |
| field | The name of the field to be accessed in the processor. Most of the processors require this parameter. |
| target_field | The name of the destined field to be accessed in the processor. The default value depends on individual parameters. About half of the processors support this optional parameter. |
| ignore_missing | If the field pointed by the field parameter is missing, or the value of the field is a null value in the indexing document, it fails the execution. If this boolean parameter is set... |
