Looking for advice on handling 503 Service Unavailable responses when hitting the /api/v2/wfm/forecasting/capacity endpoint under load. We are running a stress test from our Asia/Singapore data center using JMeter 5.6.2. The goal is to validate how the WFM module behaves when we simulate a sudden surge in concurrent API calls, mimicking a bulk schedule update scenario. We are not pushing media traffic here, just pure API throughput to check the backend capacity limits.
The issue appears when we ramp up the thread count to 100 concurrent users with a 5-second delay between iterations. The first batch of requests completes successfully with 200 OK status codes. However, once the concurrency hits 75 threads, we start seeing intermittent 503 errors. The response body usually contains a generic “Service Unavailable” message without specific retry-after headers or detailed error codes. This makes it difficult to implement an effective exponential backoff strategy in our load script.
Here is the relevant JMeter configuration: HTTP Request Defaults set to https://{org}.mygenesys.com, with headers including Authorization: Bearer <token> and Content-Type: application/json. We are using the default timeout of 30000ms. The token is refreshed every 45 minutes to avoid expiration issues. We have verified that the token has the necessary wfm:capacity:read and wfm:capacity:write scopes. No custom headers or query parameters are being added beyond the standard pagination limits.
Is this behavior expected due to platform rate limiting, or is there a specific header we need to include to handle high-concurrency WFM API calls better? We are trying to determine if the 503s are a hard limit on the Genesys Cloud side or if our request pattern is triggering a circuit breaker. Any insights on the actual concurrent request limits for the WFM Capacity API in the APAC region would be helpful. We want to ensure our load testing accurately reflects production constraints without triggering unnecessary throttling.