WFM Schedule API 503 errors during peak load test

Why does the Schedule API starts returning 503 Service Unavailable when we push past 200 concurrent requests? We are running this from our Singapore office using JMeter 5.4.1.

The setup involves POSTing to /api/v2/wfm/schedules with a 50-thread group. The first 100 requests succeed instantly, but then the latency spikes and the 503s begin.

We checked the Genesys Cloud status page and everything is green. No rate limit 429s are appearing in the logs, just the 503s.

Is there a hidden concurrency limit for bulk schedule updates that isn’t documented? Our JMeter config is standard, just hitting the endpoint repeatedly.

Make sure you implement exponential backoff in your load test script. The WFM schedule API has strict concurrency limits per division. Spreading requests across multiple divisions or adding a 2-5 second jitter between calls usually clears the 503s. Check the genesyscloud_wfm_schedule_settings for any hidden throttling configs.

have you tried checking the s3 bucket permissions? wfm schedules might trigger bulk export hooks for audit trails. if the export job fails silently, it could cause downstream 503s. ensure the api key has s3:PutObject. we saw this with digital channel metadata exports before.