Import Set API insertMultiple timing out with large payloads

[VictorMont]

Hi team,

We are investigating an issue with the Import Set API (insertMultiple).

Small and medium payloads are processed successfully:

• 1 record ✅
• 27 records ✅
• 5,000 records ✅

However, payloads between ~18k and ~20k records remain in Loading state.

The records are inserted into the staging table, but the Import Set never completes, no Import Set Run is created, and the logs show:

1) Transaction cancelled: maximum execution time exceeded

and

2) Cancelling transaction .../insertMultiple

(maximum execution time exceeded)

after ~60 seconds

Questions:

1. Is there a supported way to increase the execution timeout for Import Set API insertMultiple requests?
2. From a ServiceNow best-practice perspective, would you recommend increasing the timeout or having the source system split the payload into smaller chunks?

Thanks in advance for any guidance.