What is the correct way to handle WebSocket connection limits during high-concurrency bot load testing?

What’s the best way to handle WebSocket connection limits during high-concurrency bot load testing?

We are currently running load tests for a new AI agent deployment using Genesys Cloud CXone. The goal is to validate the system’s capacity under peak concurrent user loads. Our test setup involves JMeter scripts simulating 500 simultaneous WebSocket connections initiating bot conversations via the v2/interactions API endpoint.

The environment is configured in the Asia Pacific region (Singapore). During the ramp-up phase, specifically when hitting around 300 concurrent active sessions, we start seeing a significant spike in 429 Too Many Requests errors. The response headers indicate that we are hitting the API rate limit for WebSocket upgrades.

Here is the relevant part of our JMeter configuration:

• Thread Group: 500 threads
• Loop Count: 1
• Ramp-up Period: 60 seconds
• Think Time: 5 seconds between messages

We have verified that the API keys and tokens are valid and have sufficient permissions. The error occurs consistently at the same concurrency threshold. We suspect that the WebSocket connection establishment is being throttled by the platform’s rate limiting mechanisms.

Is there a specific header or parameter we need to include in the WebSocket upgrade request to bypass or increase the rate limit for load testing purposes? We have reviewed the documentation on API rate limits, but it is not clear how they apply to WebSocket connections in this context.

Additionally, we noticed that some connections are dropped abruptly with a 1006 Abnormal Closure code after the 429 errors start appearing. This suggests that the server is terminating the connections due to rate limiting.

We need to understand the best practice for scaling WebSocket connections in this scenario. Should we be implementing exponential backoff in our JMeter scripts, or is there a configuration change required on the Genesys Cloud side? Any insights into the specific rate limit thresholds for WebSocket upgrades would be appreciated.

Thanks for the help.

Take a look at at how your load test mimics actual user behavior versus pure connection saturation. From a workforce management perspective, we see similar bottlenecks when agents log in simultaneously, but the system handles it via session pooling. For bot concurrency, consider these adjustments:

• Implement exponential backoff in your JMeter script. Instead of 500 simultaneous hits, stagger the connection requests over a 30-second window. This mirrors real-world traffic patterns and prevents immediate gateway rejection.
• Check the maxConcurrentSessions setting in your engagement profile. If this is set too low, the system will drop connections regardless of WebSocket limits. Increase it to match your expected peak load.
• Monitor the v2/interactions response codes closely. A 429 Too Many Requests indicates rate limiting, not a WebSocket failure. Adjust your ramp-up rate accordingly.

We usually see better stability when the load test respects the platform’s inherent pacing mechanisms rather than trying to brute-force the connection layer.