Istio會默認生成監控指標，每個監控指標包含標簽。以下介紹Istio會生成的指標：

• 對于HTTP、HTTP/2和GRPC流量，Istio會生成以下指標：

  Request Count (istio_requests_total): This is a COUNTER incremented for every request handled by an Istio proxy.
  Request Duration (istio_request_duration_milliseconds): This is a DISTRIBUTION which measures the duration of requests.
  Request Size (istio_request_bytes): This is a DISTRIBUTION which measures HTTP request body sizes.
  Response Size (istio_response_bytes): This is a DISTRIBUTION which measures HTTP response body sizes.
  gRPC Request Message Count (istio_request_messages_total): This is a COUNTER incremented for every gRPC message sent from a client.
  gRPC Response Message Count (istio_response_messages_total): This is a COUNTER incremented for every gRPC message sent from a server.

• 對于TCP流量，Istio生成以下指標：

  Tcp Bytes Sent (istio_tcp_sent_bytes_total): This is a COUNTER which measures the size of total bytes sent during response in case of a TCP connection.
  Tcp Bytes Received (istio_tcp_received_bytes_total): This is a COUNTER which measures the size of total bytes received during request in case of a TCP connection.
  Tcp Connections Opened (istio_tcp_connections_opened_total): This is a COUNTER incremented for every opened connection.
  Tcp Connections Closed (istio_tcp_connections_closed_total): This is a COUNTER incremented for every closed connection.

每個指標都會包含標簽，以下為每個Istio指標默認包含的標簽：

DefaultStatTags=["reporter"，"source_namespace","source_workload","source_workload_namespace","source_principal","source_app","source_version","source_app","source_version","source_cluster",destination_namespace","destination_principal","destination_app","destination_version","destination_service","destination_service_name","destination_service_namespace","destination_port","destination_cluster","request_protocol","request_operation","request_host","response_flags","grpc_response_status","connection_security_policy","source_canonical_service","destination_canonical_service","source_canonical_revision","destination_canonical_revision"]