Istio Standard Metrics

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The following are the standard service level metrics exported by Istio.

The telemetry component is implemented as a Proxy extension. A COUNTER is a strictly increasing integer. A DISTRIBUTION maps ranges of values to frequency. COUNTER and DISTRIBUTION correspond to the metrics counter and histogram in the Envoy document.

Metrics

For HTTP, HTTP/2, and GRPC traffic, Istio generates the following metrics:

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.

For TCP traffic, Istio generates the following metrics:

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.

Labels

Reporter: This identifies the reporter of the request. It is set to destination if report is from a server Istio proxy and source if report is from a client Istio proxy or a gateway.
Source Workload: This identifies the name of source workload which controls the source, or unknown if the source information is missing.
Source Workload Namespace: This identifies the namespace of the source workload, or unknown if the source information is missing.
Source Principal: This identifies the peer principal of the traffic source. It is set when peer authentication is used.
Source App: This identifies the source application based on app label of the source workload, or unknown if the source information is missing.
Source Version: This identifies the version of the source workload, or unknown if the source information is missing.
Destination Workload: This identifies the name of destination workload, or unknown if the destination information is missing.
Destination Workload Namespace: This identifies the namespace of the destination workload, or unknown if the destination information is missing.
Destination Principal: This identifies the peer principal of the traffic destination. It is set when peer authentication is used.
Destination App: This identifies the destination application based on app label of the destination workload, or unknown if the destination information is missing.
Destination Version: This identifies the version of the destination workload, or unknown if the destination information is missing.
Destination Service: This identifies destination service host responsible for an incoming request. Ex: details.default.svc.cluster.local.
Destination Service Name: This identifies the destination service name. Ex: details.
Destination Service Namespace: This identifies the namespace of destination service.
Request Protocol: This identifies the protocol of the request. It is set to request or connection protocol.
Response Code: This identifies the response code of the request. This label is present only on HTTP metrics.
Connection Security Policy: This identifies the service authentication policy of the request. It is set to mutual_tls when Istio is used to make communication secure and report is from destination. It is set to unknown when report is from source since security policy cannot be properly populated.
Response Flags: Additional details about the response or connection from proxy. In case of Envoy, see %RESPONSE_FLAGS% in Envoy Access Log for more detail.
Canonical Service: A workload belongs to exactly one canonical service, whereas it can belong to multiple services. A canonical service has a name and a revision so it results in the following labels.
```
source_canonical_service
source_canonical_revision
destination_canonical_service
destination_canonical_revision
```
Destination Cluster: This identifies the cluster of the destination workload. This is set by: global.multiCluster.clusterName at cluster install time.
Source Cluster: This identifies the cluster of the source workload. This is set by: global.multiCluster.clusterName at cluster install time.
gRPC Response Status: This identifies the response status of the gRPC. This label is present only on gRPC metrics.