Duplicated event_id for different user_id

  • 30 October 2023
  • 3 replies


Hi, Based on seeking help here in communtiy.

In "CP-Production", I see same event_id is being tagged to multiple users. Is this even possible ? If yes under what scenarios ?

Example : 

event_id = 12345678

and event_type = 'app_open'


This is tagged to multiple users({"userId":"abcd3fgh1234"} and {"userId":"kjlmnop5678"}) at different event time. One at 2023-04-28 15:00:36.817 and other at 2023-09-15 00:27:98.023 accordingly.


Any one aware why this happens ?





Best answer by Saish Redkar 10 November 2023, 19:04

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3 replies

Userlevel 7
Badge +10

Hi @VivekHomage 

What’s your mode of data ingestion/instrumentation?

Per this, “Event IDs are associated with the device ID and are not unique to an organization. For example, device ID XYZ could have event IDs of 1, 2, 3, 4, etc. as the device fires those events. Another device ID, ABC, will also have event IDs of 1, 2, 3, 4, etc. as that particular device fires events.”

Amplitude de-duplicates data to prevent unique events from being logged multiple times. Amplitude checks the event ID, client event time, and device ID for every event. If the event isn't in the database, Amplitude writes it; otherwise, the event is dropped.

If you're using the Amplitude HTTP API,  insert_id field is recommended. Amplitude will ignore subsequent events sent with the same event ID/client event time/device ID or insert_id within a gap of seven days. 



Thanks @Saish Redkar for the response

What if 7 days have passed, what’s the proper approach to ensure no duplication?