I’m trying to figure out why the BYOC edge returns 503 Service Unavailable when JMeter threads exceed 200. api/v2/architect/flows works fine at 100 threads but fails immediately at 250. Is this a hard limit on the edge capacity or a timeout issue in the load script?
If you check the docs, they mention that BYOC edges have specific rate limiting configurations that differ from the standard public cloud offerings. When JMeter threads exceed 200, the 503 error often indicates that the edge has hit its maximum concurrent connection threshold rather than a simple timeout. This is particularly relevant when testing digital channel integrations, as the metadata processing overhead can be higher than voice traffic.
To mitigate this, you should adjust the JMeter thread group settings to include a ramp-up period. This prevents the edge from being overwhelmed by simultaneous connections. Additionally, verify that the BYOC edge configuration in the Genesys Cloud admin portal allows for the expected concurrency. The default settings might be conservative to protect system stability.
Here is an example of how to structure the JMeter thread group:
| Parameter | Value |
|---|---|
| Threads (users) | 250 |
| Ramp-Up Period (seconds) | 60 |
| Loop Count | 1 |
If the issue persists, check the edge logs for any specific error messages related to resource exhaustion. The Recording API and bulk export jobs also consume significant resources, so ensure that no other heavy processes are running concurrently during the load test. This helps isolate whether the 503 is due to edge capacity or backend processing limits.
For legal discovery requests, maintaining a clear chain of custody for these logs is crucial. Ensure that the edge configuration includes detailed audit trails for all connection attempts. This data can be exported via the Recording API for further analysis. If the edge is still failing, consider scaling up the edge resources or distributing the load across multiple edges if your BYOC setup supports it. This approach provides a more robust testing environment and helps identify true capacity limits.
This has the hallmarks of a classic case of hitting the WebSocket handshake rate limit on the edge gateway, rather than a hard infrastructure cap. The 503 response is often a protective measure against sudden spikes in concurrent connect requests. When managing multiple BYOC trunks, we see this frequently if the load generator does not stagger the initial burst.
You should implement a ramp-up period in your thread group configuration. Instead of launching 250 threads instantly, spread them over 30-60 seconds. Additionally, verify that your JMeter script is reusing existing WebSocket connections via connection pooling rather than opening new ones for each request. The edge nodes in APAC regions sometimes enforce stricter idle_timeout values, so keeping connections alive is critical. Check the SIP registration logs for any 488 Not Acceptable Here errors that might precede the 503, as this indicates SDP negotiation failures under load. Adjusting the keep-alive interval to 15 seconds usually stabilizes the throughput significantly.
It depends, but generally… this behavior aligns with the rate-limiting profiles applied to BYOC edge instances, which differ significantly from standard public cloud allocations. When building integrations that interact with these endpoints, we often encounter similar thresholds where the gateway rejects concurrent bursts to protect backend stability. The 503 indicates the edge has exhausted its available connection slots for that specific time window, rather than a simple timeout.
To resolve this in your JMeter configuration:
- Implement a staggered ramp-up period. Launching 250 threads simultaneously overwhelms the WebSocket handshake queue. Set the ramp-up to at least 60 seconds to distribute the load.
- Verify your OAuth token refresh logic. Ensure tokens are not expiring mid-test, which can trigger additional authentication overhead and compound the connection exhaustion.
- Check the
X-Genesys-Trace-Idin the response headers. This helps confirm if the rejection occurs at the edge gateway or if it is being passed through to the architect engine.
Adjusting these parameters usually stabilizes the load test within the expected limits for multi-org tenants.