基于Grpc的健康检查

1. Grpc健康检查

Grpc健康检查是通过一个普通的用户rpc调用进行实现，Grpc的健康检查定义了如下的protobuf，这样就能实现所有的Grpc协议健康检查的互通。

Firstly, since it is a GRPC service itself, doing a health check is in the same format as a normal rpc. Secondly, it has rich semantics such as per-service health status. Thirdly, as a GRPC service, it is able reuse all the existing billing, quota infrastructure, etc, and thus the server has full control over the access of the health checking service.

  1. syntax = "proto3";
  3. package grpc.health.v1;
  5. message HealthCheckRequest {
  6.   string service = 1;
  7. }
  9. message HealthCheckResponse {
  10.   enum ServingStatus {
  11.     UNKNOWN = 0;
  12.     SERVING = 1;
  13.     NOT_SERVING = 2;
  14.     SERVICE_UNKNOWN = 3;  // Used only by the Watch method.
  15.   }
  16.   ServingStatus status = 1;
  17. }
  19. service Health {
  20.   rpc Check(HealthCheckRequest) returns (HealthCheckResponse);
  22.   rpc Watch(HealthCheckRequest) returns (stream HealthCheckResponse);
  23. }

2 triple健康检查服务

  • Dubbo-go框架在启动后会自动向框架中注册健康检查服务，提供基于grpc health proto的健康检查服务，无需在配置文件中额外配置。
  • triple健康检查服务可以通过grpc-health-probe检查框架中服务的状态，也可以通过grpc调用该健康检查服务，但是不能通过triple客户端调用该健康检查服务(基于grpc的健康检查服务不通过注册中心注册)，调用的服务名为“grpc.health.v1.Health”，接口为check。

2.1 通过gprc客户端调用健康检查服务：

  • 启动dubbo-go-samples中的triple服务，通过下面的grpc客户端便可以查看”org.apache.dubbogo.samples.api.Greeter”的状态。triple健康检查服务与grpc互通，所以可以通过grpc客户端查看基于triple协议服务的健康状态。
  1. package main
  3. import (
  4.     "context"
  5.     "fmt"
  6.     "log"
  7. )
  9. import (
  10.     "google.golang.org/grpc"
  11.     "google.golang.org/grpc/credentials/insecure"
  12.     healthpb "google.golang.org/grpc/health/grpc_health_v1"
  13. )
  15. const (
  16.     address = "localhost:20000"
  17. )
  19. func main() {
  20.     // Set up a connection to the server
  21.     conn, err := grpc.Dial(address, grpc.WithTransportCredentials(insecure.NewCredentials()))
  22.     if err != nil {
  23.         log.Fatalf("did not connect: %v", err)
  24.     }
  26.     defer func() {
  27.         _ = conn.Close()
  28.     }()
  30.     checkHealth("org.apache.dubbogo.samples.api.Greeter", conn)
  31. }
  33. func checkHealth(service string, conn *grpc.ClientConn) {
  34.     fmt.Printf(">>>>> gRPC-go check %s status", service)
  36.     req := &healthpb.HealthCheckRequest{
  37.         Service: service,
  38.     }
  39.     ctx := context.Background()
  40.     rsp, err := healthpb.NewHealthClient(conn).Check(ctx, req)
  41.     if err != nil {
  42.         panic(err)
  43.     }
  44.     fmt.Printf("get service status = %+v\n", rsp)
  45. }

2.2 grpc-health-probe调试健康检查服务：

  • 启动dubbo-go-samples中的triple服务，提供org.apache.dubbogo.samples.api.Greeter服务。使用grpc-health-probe检查该服务的健康状态，grpc-health-probe -addr=localhost:20000 -service "org.apache.dubbogo.samples.api.Greeter"

image-health-check

参考：

最后修改 December 16, 2022: Fix check (#1736) (97972c1)