Yandex Application Load Balancer log reference

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Updated at December 26, 2023

This section describes the various fields of the logs generated by the L7 load balancer.

Logs are provided in JSON format. A single log entry represents one client request to the load balancer.

For more information, see Logging.

Field	Description
`type`	Request type. The possible values include: `http`: HTTP/1.0 or HTTP/1.1 without encryption `https`: HTTP/1.0 or HTTP/1.1 with TLS encryption (HTTPS, HTTP over TLS) `h2`: HTTP/2 `h3`: HTTP3 `grpc`: gRPC without encryption `grpcs`: gRPC with TLS encryption
`time`	Request date and time: receipt of the first byte from the client by the load balancer. Written in the following ISO 8601 format: `<YYYY>-<MM>-<DD>T<hh>:<mm>:<ss>Z`, where `Z` stands for Greenwich Mean Time, UTC.
`http_method`	HTTP request method.
`authority`	HTTP/1.0 and HTTP/1.1: The `Host` header value. For other supported protocols: the value of the `:authority` pseudo-header.
`request_uri`	Request path. For example, `/api/v1/foo`.
`http_status`	HTTP response (status) code.
`http_version`	HTTP protocol version, such as `HTTP/2`.
`rewritten_request_uri`	Request path following the substitution configured in the HTTP router's route. For example, `/api/backend/v1/foo`
`request_content_type`	Value of the `Content-Type` HTTP header in the client's request: the type of content requested.
`request_id`	Value of the `X-Request-ID` HTTP header in the client's request.
`user_agent`	Value of the `User-Agent` HTTP header: client app ID string.
`referer`	Value of the `Referer` HTTP header in the client's request: originating URL of the request.
`response_content_type`	Value of the `Content-Type` HTTP header in the load balancer's response: type of content requested.
`client_ip`	Client IP address.
`client_port`	Client TCP port used by the connection between the client and the load balancer.
`backend_ip`	Internal backend endpoint IP address: virtual machine from the target group or Object Storage bucket.
`backend_port`	Port used by the load balancer to access the backend.
`load_balancer_id`	ID of the network load balancer.
`http_router_id`	HTTP router ID.
`virtual_host_name`	Name of the virtual host.
`route_name`	Name of the route.
`backend_group_id`	Backend group ID.
`backend_name`	Backend name.
`request_headers_bytes`	Request header size in bytes.
`request_body_bytes`	Request body size in bytes.
`response_headers_bytes`	Response header size in bytes.
`response_body_bytes`	Response body size in bytes.
`error_details`	Error encountered by the load balancer when processing a request. The possible values include: `no_healthy_backend`: No healthy backends. For more information, see Health checks. `backend_request_timeout`: The backend request timeout specified in the route settings was exceeded. `balancer_reset`: The the connection between the client and the load balancer was reset. `backend_connection_closed_before_data_sent_to_client`: The connection between the load balancer and the backend was reset. `failed_to_connect_to_backend`: The load balancer failed to connect to the backend. `backend_connection_terminated`: The backend closed the connection to the load balancer. `no_route`: No match for the client's request among any routes configured in the load balancer HTTP routers. `client_disconnected`: The client closed the connection to the load balancer. `backend_stream_idle_timeout`: The idle timeout specified in the route settings was exceeded, the connection between the load balancer and backend was idle for too long with no data transmission. `backend_retry_limit_exceeded`: The load balancer exceeded the maximum number of backend connection attempts. `client_protocol_error`: Client protocol error.
`tls_version`	TLS protocol version, such as `TLSv1.3`.
`cipher_suite`	Set of ciphers used for the TLS encryption of the connection between client and load balancer.
`sni_hostname`	Domain name sent to the load balancer by the client using the TLS Server Name Indication (SNI) extension.
`server_certificate_subject`	Domain name on the TLS certificate sent to the client by the load balancer.
`grpc`	gRPC request information. Returned for gRPC requests only (`"type": "grpc"` or `"type": "grpcs"`).
`method`	gRPC request method.
`service`	Name of gRPC service.
`status`	Status of gRPC request.
`code`	gRPC request error code. For more information about the gRPC statuses that correspond to HTTP codes, see google.rpc.Code.
`message`	gRPC request error description.
`upstream_transport_failure_reason`	Error message regarding a transport-layer connection error between the load balancer and backend, such as in the TLS connection.
`request_processing_times`	Information about the time it took to process a request. All field values are specified in seconds.
`request_time`	Total time it took to handle a request.
`response_start_time`	Time before the start of a response: between when the first request byte is received from the client by the load balancer and when the first byte of the response is sent by the load balancer to the client.
`request_processing_time`	Time the load balancer takes to process a request: between receiving the first byte from the client and sending the first byte to the backend.
`backend_processing_time`	Time it takes the backend to process a request: between the load balancer sending the first byte to and receiving the first byte from the backend.
`response_processing_time`	Time it takes the load balancer to process a response: between receiving the first byte from the backend and sending the first byte to the client.
`request_rx_time`	Time it takes the load balancer to receive a request: between the first and the last bytes received from the client.
`request_tx_time`	Time it takes the backend to receive a request: between the first and the last bytes sent by the load balancer.
`backend_response_time`	Wait time for a backend response: between the load balancer sending the last byte of a request to and receiving the first byte of the response from the backend.
`response_rx_time`	Time it takes the backend to send a response: between the first and the last bytes received by the load balancer.
`response_tx_time`	Time it takes the load balancer to send a response: between the first and the last bytes sent by the load balancer.

Yandex Application Load Balancer log reference

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