Stuck on a recurring 401 Unauthorized error when running load tests against the Genesys Cloud API endpoints for agent status updates. The setup involves simulating 500 concurrent agents changing their presence using JMeter. Each thread holds a valid access token initially, but after approximately 15 minutes of continuous operation, the refresh token mechanism begins to fail for a subset of connections.
The environment is US-East-1. We are using the standard OAuth2 client credentials flow combined with resource owner password credentials for agent simulation. The error appears in the response body as:
{
"status": 401,
"code": "unauthorized",
"message": "Access token expired or invalid"
}
This happens despite the JMeter script having a pre-processor configured to refresh tokens every 30 minutes. The issue seems to correlate with high throughput periods where we hit roughly 500 requests per minute across the batch. I suspect there might be a race condition or a specific rate limit on the /oauth/token endpoint that is not documented clearly for load testing scenarios.
Here is the relevant JMeter configuration snippet for the token refresh logic:
oauth_refresh:
endpoint: "https://api.mypurecloud.com/oauth/token"
method: "POST"
headers:
Content-Type: "application/x-www-form-urlencoded"
Authorization: "Basic <base64_encoded_client_id_secret>"
body:
grant_type: "refresh_token"
refresh_token: "${agent_refresh_token}"
timeout: 5000
retry_count: 2
The agent_refresh_token is stored in a JMeter variable per thread. When the error occurs, the logs show that the refresh request itself returns a 401, suggesting the refresh token might be invalidated prematurely or there is a concurrency limit on token rotation for a single client ID.
Has anyone faced similar token invalidation issues during sustained high-concurrency tests? Is there a recommended pattern for managing token lifecycles in load testing scripts to avoid hitting implicit limits on the OAuth service?