Retrieve Apache Pulsar function statistics with pulsar-admin

Steps

1. Ensure your Pulsar function is deployed and running — verify with: pulsar-admin functions status --name {function-name} --namespace {tenant}/{namespace}
2. Retrieve aggregated function statistics using: pulsar-admin functions stats --name {function-name} --namespace {tenant}/{namespace} --tenant {tenant}
3. The stats output includes: receivedTotal, processedSuccessfullyTotal, systemExceptionsTotal, userExceptionsTotal, avgProcessLatencyMs, lastInvocationTime, and per-instance breakdowns.
4. For per-instance statistics (useful when parallelism > 1), add --instance-id {id} to the stats command to scope to a single function instance.
5. To monitor stats continuously, combine with a polling loop or configure Pulsar's built-in Prometheus metrics endpoint on the function worker.