429 Too Many Requests on /api/v2/outbound/predictors during JMeter ramp-up

General Discussion
1

Immediate 429 response when hitting /api/v2/outbound/predictors with only 10 concurrent threads.

Testing outbound dialer capacity planning for a new deployment. Using JMeter 5.6.2 to simulate concurrent predictor updates. The load is extremely light, yet the platform throttles instantly.

Environment Details:

  • Genesys Cloud Production Org
  • JMeter 5.6.2
  • 10 threads, 100ms ramp-up
  • 5s constant throughput timer

Request Payload:

{
 "id": "predictor-123",
 "name": "Test Predictor",
 "strategy": "PREDICTIVE",
 "dial_rate": 1.5
}

Response Headers:

  • Retry-After: 60
  • X-RateLimit-Remaining: 0

The rate limit header drops to zero after the first request completes. Subsequent requests get queued and fail. This happens even with a single campaign. Is there a hidden limit on predictor updates per minute? Or is the endpoint shared across all outbound resources?

Need to understand the exact throttle boundaries for API-driven campaign adjustments. Current setup breaks any attempt to automate dial rate adjustments based on real-time metrics.

2

It depends, but generally… this throttling is not about raw concurrency but about the specific rate limits assigned to the predictors resource class. The /api/v2/outbound/predictors endpoint has a stricter ceiling than standard archival jobs, often capped at 100 requests per minute for standard orgs.

When running JMeter tests, ensure you are respecting the Retry-After header in the 429 response. Ignoring this header causes immediate retry storms, which the gateway interprets as an attack. A better approach for capacity planning is to use the asynchronous bulk export pattern instead of synchronous updates.

Check the official rate limit documentation here: https://developer.genesys.cloud/api-docs/outbound/rate-limits

For legal discovery workflows, we typically schedule these jobs during off-peak hours (02:00 GMT) to avoid contention with live predictive campaigns. If you need higher throughput, open a support ticket to request a temporary rate limit increase for your testing window, citing the specific org ID and test duration.

3

Make sure you implement exponential backoff. The 429 is a tenant-level cap, not a thread limit.

Outbound Campaign API 429 during JMeter Load Test

Add this to your JMeter JSR223 PostProcessor:

def retryAfter = sampler.getResponseHeaders().get("Retry-After")
if (retryAfter) Thread.sleep(retryAfter.toLong() * 1000)