Security API 429s during JMeter load test on US1

Could someone explain…

  • Running JMeter 5.6 with 25 concurrent threads against POST /api/v2/security/users to validate user creation throughput for a new onboarding batch process.
  • Getting immediate 429 Too Many Requests errors on US1 environment.
  • The error response body contains: {“errors”:[{“code”:“too_many_requests”,“message”:“Rate limit exceeded”}]}.
  • Need to understand the specific rate limit for this endpoint. Documentation mentions general API limits but not specific per-endpoint values for security resources.
  • Testing from America/New_York timezone during EST business hours.
  • Using valid OAuth2 access token with required scopes: admin:security:users:write.
  • Request payload includes basic user attributes: name, email, and role IDs. No complex objects.
  • Previous tests with lower concurrency (10 threads) succeeded without errors.
  • Increasing concurrency beyond 15 threads triggers immediate 429 responses.
  • Want to validate if this is a hard limit for security APIs or if configuration options exist to increase throughput.
  • Checking if WebSocket connections or other API calls in the same tenant are contributing to the rate limit calculation.
  • Monitoring tenant API usage via Admin Dashboard shows low overall utilization during test window.
  • Question is whether security endpoints have stricter rate limits than standard configuration APIs.
  • Looking for best practices to structure load tests for user provisioning without hitting rate limits.
  • Considering adding delay between requests in JMeter but want to understand the actual limit first.
  • Any guidance on rate limit tiers for security vs. configuration APIs would be helpful.
  • Previous experience with WFM and Dialer APIs showed consistent 429s at similar concurrency levels.
  • Assuming pattern holds for Security APIs but need confirmation.
  • Testing against production-like environment to validate capacity planning assumptions.
  • Goal is to determine maximum sustainable user creation rate for bulk operations.
  • Appreciate any insights from team members familiar with security API rate limiting behavior.