simple prometheus metrics for gRPC-go that observes from the stats.Handler point in the gRPC stack.

Label explanations:

• grpc_type: one of unary, server_stream, client_stream, bidi_stream
• grpc_service: given full method name of /grpc.examples.echo.Echo/UnaryEcho, this will be set to grpc.examples.echo.Echo
• grpc_method: given full method name of /grpc.examples.echo.Echo/UnaryEcho, this will be set to UnaryEcho
• grpc_code: a grpc code in title case, eg. OK, PermissionDenied

• grpc_server_started_total: Total number of RPCs started on the server. Observed when the RPC first begins.
  • Labels: grpc_type, grpc_service, grpc_method
• grpc_server_handled_total: Total number of RPCs completed on the server, regardless of success or failure.
  • Labels: grpc_type, grpc_service, grpc_method, grpc_code
• grpc_server_msg_received_total: Total number of RPC stream messages received on the server. Only observes +1 on non-stream server input, +N, where N>=0 on streaming server input.
  • Labels: grpc_type, grpc_service, grpc_method
• grpc_server_msg_sent_total: Total number of gRPC stream messages sent by the server. Only observes +1 on non-stream server output, +N, where N>=0 on streaming server output.
  • Labels: grpc_type, grpc_service, grpc_method
• grpc_server_handling_seconds: Histogram of response latency (seconds) of gRPC that had been application-level handled by the server.
  • Labels: grpc_type, grpc_service, grpc_method

• grpc_client_started_total: Total number of RPCs started on the client. Observed when the RPC first begins.
  • Labels: grpc_type, grpc_service, grpc_method
• grpc_client_handled_total: Total number of RPCs completed by the client, regardless of success or failure.
  • Labels: grpc_type, grpc_service, grpc_method, grpc_code
• grpc_client_msg_received_total: Total number of RPC stream messages received by the client. Only observes +1 on non-stream server output, +N, where N>=0 on streaming server output.
  • Labels: grpc_type, grpc_service, grpc_method
• grpc_client_msg_sent_total: Total number of gRPC stream messages sent by the client. Only observes +1 on non-stream client input, +N, where N>=0 on streaming client input.
  • Labels: grpc_type, grpc_service, grpc_method
• grpc_client_handling_seconds: Histogram of response latency (seconds) of the gRPC until it is finished by the application.
  • Labels: grpc_type, grpc_service, grpc_method

MIT License: Copyright (c) 2024 Nicholas Comer