Could someone explain the rate limit behavior for /oauth/token during high-concurrency load tests?
Running JMeter with 100 threads hitting Genesys Cloud in ap-southeast-1. Token refresh requests are getting throttled immediately with 429 errors, causing WebSocket drops.
Is there a specific header or retry logic required for the platform_api OAuth endpoints under load?
Running JMeter with 100 threads hitting Genesys Cloud in ap-southeast-1. Token refresh requests are getting throttled immediately with 429 errors, causing WebSocket drops.
The 429 response on /oauth/token is a hard limit enforcement by the identity provider, not a suggestion. Under high concurrency, the standard retry loop without exponential backoff will only exacerbate the throttle. The ServiceNow integration patterns we use for Data Actions handle this by implementing a jitter-based retry mechanism on the client side before any request hits the GC endpoint.
Here is the retry logic structure that prevents token exhaustion:
async function refreshTokenWithRetry(clientId, clientSecret, maxRetries = 5) {
let delay = 1000; // Start at 1 second
for (let i = 0; i < maxRetries; i++) {
try {
const response = await fetch('https://api.mypurecloud.com/oauth/token', {
method: 'POST',
headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
body: `grant_type=client_credentials&client_id=${clientId}&client_secret=${clientSecret}`
});
if (response.status === 429) {
// Exponential backoff with jitter
delay *= 2;
const jitter = Math.random() * 1000;
await new Promise(r => setTimeout(r, delay + jitter));
continue;
}
if (!response.ok) throw new Error(`HTTP ${response.status}`);
return await response.json();
} catch (error) {
if (i === maxRetries - 1) throw error;
await new Promise(r => setTimeout(r, delay));
}
}
}
The critical detail is the Retry-After header in the 429 response. The platform_api documentation specifies that ignoring this header results in permanent suspension of the client_id for 15 minutes. When configuring JMeter, ensure the HTTP Request Defaults include a custom header parser that extracts Retry-After and passes it to a JSR223 PostProcessor for the sleep duration. Do not use a fixed 500ms retry. The WebSocket drops are a symptom of the token service being overwhelmed; fixing the client-side retry logic stabilizes the connection pool. Cross-reference the OAuth 2.0 Rate Limits guide for the exact limits per region, as ap-southeast-1 has slightly lower thresholds than eu-west-1.