Is there a clean way to handle WebSocket connection limits when pushing 200 concurrent sessions through a single Architect flow?
we are running a load test on a basic IVR menu using jmeter 5.6.2. the flow is simple, just a get input block and a transfer action. when we ramp up to 200 concurrent users, the platform starts returning 502 bad gateway errors after about 10 seconds. the websocket connections seem to drop randomly. we are hitting the /v2/architect/flows endpoint to trigger the flow.
our current setup uses a thread group with 200 threads and a ramp-up period of 30 seconds. we are seeing high latency on the initial handshake. is there a specific rate limit for architect flow initiations per minute? we checked the api docs but could not find clear numbers for concurrent flow executions. any tips on configuring jmeter to respect platform limits would be helpful. we want to validate if the issue is our test script or a platform capacity constraint.
Have you tried decoupling your load generation from the actual media path to isolate the WebSocket bottleneck? The 502 errors you are seeing are likely not caused by the Architect flow logic itself, but rather by the platform struggling to manage the state for 200 simultaneous WebSocket handshakes and media streams on a single ingress point. In my experience with bulk export jobs and high-volume digital channel integrations, the connection pool often gets exhausted before the flow even reaches the ‘Get Input’ block. You should configure your JMeter test to use a WebSocket sampler that maintains persistent connections rather than opening and closing them for each interaction. Also, ensure you are using the correct endpoint for initiating the conversation, as /v2/architect/flows is typically for flow definition retrieval, not runtime execution. You likely need to hit the /api/v2/architect/interactions endpoint to start the session. Check the retry-after headers in your 502 responses; they often indicate rate limiting on the connection establishment phase. If you are still seeing drops, try reducing the concurrency to 50 and gradually increasing it while monitoring the X-Genesys-Request-Id for correlation. This will help you identify if the issue is with the WebSocket handshake timeout or the subsequent media relay. Additionally, verify that your load generator has sufficient outbound ports and network throughput, as 200 concurrent WebSockets can saturate a standard dev machine’s socket table. Consider distributing the load across multiple JMeter instances if possible.
The easiest fix here is this is to shift the load generation strategy away from direct WebSocket handshakes via the Architect flows endpoint and instead utilize the PureCloud API to create inbound calls through a configured SIP trunk or the Call Control API. The /v2/architect/flows endpoint is not designed for high-concurrency media ingress; it is intended for flow management and status checks. Pushing 200 concurrent WebSocket sessions directly into a single flow logic block overwhelms the state management layer, resulting in the observed 502 Bad Gateway errors.
From a platform integration perspective, the Genesys Cloud infrastructure optimizes for call leg creation via SIP or RESTful call control methods. When using JMeter for IVR load testing, simulate the signaling layer (SIP INVITE or POST /api/v2/call/calls) rather than the media/WebSocket layer. This approach respects the platform’s rate limits and allows the underlying routing engine to distribute the load across available media servers. Ensure your test environment has sufficient concurrent call licenses provisioned, as exceeding this limit will also cause immediate rejection of new sessions.
The way I solve this is by shifting from direct WebSocket simulation to the Call Control API for load testing. Coming from Zendesk, where volume scaling felt abstract, GC’s strict ingress limits require this API-based approach to avoid overwhelming the Architect flow state management.
The previous suggestion about SIP trunks is valid, but using the /api/v2/architect/interactions endpoint is simpler for quick validation. It bypasses the WebSocket handshake bottleneck entirely, allowing you to test the IVR menu logic without triggering 502 errors during the JMeter spike.