Broker Throttling Indicates Resource Exhaustion or Quota Breach
warningActive pulsar_broker_throttled_backend_global_limit signals that the broker is applying backpressure due to resource constraints or configured quotas, blocking producers and causing publish failures or timeouts.
Monitor pulsar_broker_throttled_backend_global_limit for active throttling events. Correlate with pulsar_rate_in and pulsar_throughput_out to identify whether throttling is due to publish rate limits or bandwidth constraints. Check pulsar_lb_bandwidth_out_usage and pulsar_lb_directmemory_usage for resource saturation. Review namespace-level quota policies.
Increase resource quotas at namespace or tenant level if throttling is policy-driven. Scale broker cluster horizontally to distribute load. Optimize producer batching and compression to reduce effective message rate and bandwidth usage. Review and adjust backlog quotas if storage limits are triggering throttling. Monitor pulsar_lb_unload_broker_count for load balancing effectiveness.