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Drop

Control Flow Elastic Compatible

Synopsis​

Conditionally stops processing of a document by dropping it from the pipeline.

Schema​

drop:
  - if: <script>
  - description: <text>
  - ignore_failure: <boolean>
  - on_failure: <processor[]>
  - on_success: <processor[]>
  - tag: <string>

Configuration​

FieldRequiredDefaultDescription
ifN-Condition that determines whether to drop the document
descriptionN-Explanatory note
ignore_failureNfalseIf true, condition evaluation errors are ignored
on_failureN-See Handling Failures
on_successN-See Handling Success
tagN-Identifier

Details​

This processor is particularly useful for filtering out unwanted documents based on their content or metadata without raising exceptions.

Common uses are filtering debug logs, excluding health checks, and dropping internal traffic.

warning

Once dropped, a document cannot be recovered by the subsequent processors. Use caution with complex conditions to avoid accidentally dropping important documents.

Examples​

Basic Drop​

Dropping documents with a specific packet count...

{
  "source": {
    "packets": 10
  }
}
drop:
  - if: ctx.source.packets == 10

removes them from the pipeline:

Document dropped from pipeline

Multiple Conditions​

Specifying multiple criteria...

{
  "user": {
    "role": "guest",
    "access_level": 1
  }
}
drop:
  - if: ctx.user.role == 'guest' && ctx.user.access_level < 2
  - description: "Drop low-privilege guest access"

filters out documents that meet the combined conditions:

Document dropped from pipeline

Complex Filtering​

Using complex conditions...

{
  "http": {
    "request": {
      "method": "GET",
      "path": "/health",
      "source_ip": "10.0.0.1"
    }
  }
}
drop:
  - if: >
      ctx.http?.request?.method == 'GET' &&
      ctx.http.request.path == '/health' &&
      ctx.http.request.source_ip.startsWith('10.')
  - description: "Drop internal health checks"

filters out those traffic patterns:

Document dropped from pipeline

Error Handling​

Handling evaluation errors gracefully...

{
  "status": "active"
}
drop:
  - if: ctx.nonexistent.field == true
  - ignore_failure: true

continues the process on errors:

{
  "status": "active",
  "error": {
    "message": "failed to evaluate condition"
  }
}