Architect Flow Timeout during High Concurrency Load Test with JMeter

Architect & Flows
1

I’m completely stumped as to why the Architect flow is timing out when we hit a specific concurrency threshold during our load tests.

Background

We are using Genesys Cloud (US-East) and running a load test with JMeter 5.6.2. The goal is to simulate 500 concurrent inbound calls hitting a single IVR flow. The flow is simple: Greeting → Wait 5 seconds → Transfer to Queue. We are using the standard REST API to initiate calls and monitoring the WebSocket connections.

Issue

At around 150 concurrent calls, the Architect flow starts returning 504 Gateway Timeout errors. The calls are initiated successfully, but the media session drops before the greeting plays. The error occurs in the Architect logs as a timeout on the “Wait” action. This happens even though our agent capacity is not maxed out.

Troubleshooting

  • Checked API rate limits: No 429 Too Many Requests errors in the JMeter results.
  • Verified WebSocket connections: All connections appear stable in the dashboard.
  • Simplified the flow: Removed all actions except the greeting. The timeout still occurs at the same concurrency level.
  • Increased timeout settings in the Architect action: Did not resolve the issue.

Is there a hidden limit on concurrent media sessions per tenant or per region? Or is there a specific setting in the Architect flow that needs adjustment for high concurrency? Any help would be appreciated.