Issue

Some of your events are failing to ingest or are intermittently dropping in Segment without throwing an explicit error in your client application. When reviewing your Segment source logs, you observe that certain event payloads fail to ingest.

Product

Segment

Environment

Segment Console

Cause

Segment requires every event payload to include either an anonymous_id or a user_id defined at the top level of the JSON object. If your system nests these properties inside child objects (for example, as user.id or triggered_by.user_id), Segment cannot identify the user and drops the event during ingestion.

Additional common reasons for dropped events in Segment include:

• Exceeding payload size limits
• Missing or empty event names
• Deduplication caused by duplicate messageId values

Resolution

To ensure your events are processed and ingested successfully, update your event payloads to comply with Segment requirements:

1. Locate a failed event in your application logs.
2. Verify if user_id or anonymous_id is nested inside a sub-object rather than placed at the top level.
3. Modify your payload structure to include either user_id or anonymous_id at the root level of the JSON payload.
4. Confirm that the payload includes a valid event name, stays within payload size limits, and uses a unique messageId if specified.
5. Resend the event to Segment and monitor the source logs to confirm successful ingestion.