Hey everyone,
I am running a load test for our custom agent desktop integration to validate the WebRTC softphone performance under high concurrency. We are using JMeter 5.6.2 with the WebSocket sampler to simulate multiple agents logging in and initiating calls simultaneously. The environment is Genesys Cloud in the Asia/Singapore region.
When I push the concurrent user count above 200, I start seeing a significant number of WebSocket connections dropping with a 503 Service Unavailable error from the platform API. The error occurs specifically during the initial handshake phase before the media session is established. I have checked the API rate limits and ensured that the OAuth token refresh is handled correctly, but the issue persists.
Here is a snippet of the JMeter configuration:
- Thread Group: 500 threads, ramp-up 60 seconds, loop count 1
- WebSocket Sampler: Connection timeout 5000ms, response timeout 10000ms
- Endpoint: wss://api.c1.genesys.cloud/v1/platform/websocket
The error logs show:
WebSocket connection failed: 503 Service Unavailable
Error code: WS_503
Timestamp: 2023-10-27T14:30:00Z
I am not sure if this is due to a specific WebSocket connection limit on the Genesys Cloud platform or if there is a misconfiguration in my JMeter setup. Has anyone encountered similar issues during load testing? Any insights on how to handle these 503 errors or if there are known limits for concurrent WebRTC sessions would be greatly appreciated.
Thanks in advance!
From an AppFoundry partner perspective, seeing 503 Service Unavailable errors during high-concurrency WebRTC load tests is a common symptom of hitting platform-level rate limits or exhausting the WebSocket connection pool for your organization. Genesys Cloud enforces strict scaling policies to maintain service stability across all tenants, and simulating 200+ concurrent agents via JMeter often triggers these protective mechanisms before the actual softphone logic is even evaluated.
The issue is likely not with your WebSocket implementation but with how you are authenticating and maintaining the session state. Ensure you are using the Platform API to obtain valid JWT tokens for each simulated agent rather than reusing a single token, which will be invalidated immediately under load. Additionally, check if your organization has specific concurrency limits set in the Admin console under Organization > Settings > Scale.
To mitigate this, consider staggering the connection attempts in your JMeter script. Instead of a simultaneous ramp-up, use a constant throughput timer to space out the WebSocket handshake requests. This mimics real-world agent login patterns more accurately and prevents the initial burst from triggering the 503 responses.
Here is a recommended configuration adjustment for your JMeter WebSocket sampler:
- Set the “Reconnect” option to true.
- Implement a “Think Time” between connection attempts to respect the API rate limits.
- Monitor the Genesys Cloud Admin > Reporting > API Usage dashboard during the test to confirm if you are hitting the rate limit ceiling.
If the 503s persist after implementing these throttling measures, you may need to request a temporary scaling increase from Genesys Cloud Support, providing them with your test plan and expected concurrency metrics. This approach ensures you are testing the softphone performance rather than the platform’s rate-limiting infrastructure.