Stumbled on a weird bug today with Predictive Routing campaign activation. JMeter script hits POST /api/v2/predictiverouting/campaigns with 50 threads. Server returns 503 Service Unavailable immediately after thread 10 starts.
Endpoint is us-east-1. No rate limit headers in response. JMeter version 5.6.2. Config uses constant throughput timer set to 200 requests per minute. Should be well under limits.
Anyone see 503s on campaign creation? Is there a hidden concurrency limit for this API?
It varies, but usually the 503 Service Unavailable response during high-concurrency load testing indicates that the backend services managing Predictive Routing campaign states are temporarily overwhelmed, rather than a strict API rate limit being exceeded. In enterprise environments, rapid campaign activation triggers complex resource allocation checks across media servers and agent pools. The system likely enforces a soft concurrency threshold for state-changing operations to prevent data inconsistency.
To mitigate this, adjust the JMeter Constant Throughput Timer to stagger requests significantly. Instead of 200 requests per minute, consider reducing the burst to 20 or 30 per minute. Additionally, verify that the campaign_state transitions are handled asynchronously where possible. If the endpoint requires synchronous confirmation, implement exponential backoff logic in the test script upon receiving 503. This approach aligns with standard capacity planning for Architect-driven routing strategies.