GRPC提供了健康检查机制
https://github.com/grpc/grpc/blob/master/doc/health-checking.md
syntax = "proto3";
package grpc.health.v1;
message HealthCheckRequest {
string service = 1;
}
message HealthCheckResponse {
enum ServingStatus {
UNKNOWN = 0;
SERVING = 1;
NOT_SERVING = 2;
SERVICE_UNKNOWN = 3; // Used only by the Watch method.
}
ServingStatus status = 1;
}
service Health {
rpc Check(HealthCheckRequest) returns (HealthCheckResponse);
rpc Watch(HealthCheckRequest) returns (stream HealthCheckResponse);
}
一个服务有4中状态
- UNKNOWN = 0;
- SERVING = 1;
- NOT_SERVING = 2;
- SERVICE_UNKNOWN = 3
健康检查机制提供了两个方法
- Check方法
查询服务的运行状况，服务名建议为package_names.ServiceName格式
服务端实现
HealthStatusManager healthStatusManager = new HealthStatusManager();
server = ServerBuilder.forPort(port)
.addService(new GreeterImpl())
.addService(healthStatusManager.getHealthService())
.build()
.start();
LOGGER.info("Server started, listening on " + port);
healthStatusManager.setStatus("com.github.edgar615.grpc.health.Greeter", HealthCheckResponse.ServingStatus.SERVING);
服务端应该使用空字符串作为服务器整体运行状况的键
客户端实现
HealthGrpc.HealthBlockingStub blockingStub = HealthGrpc.newBlockingStub(channel);
HealthCheckRequest request = HealthCheckRequest.newBuilder()
.setService("com.github.edgar615.grpc.health.GreeterGrpc").build();
HealthCheckResponse response = blockingStub.check(request);
logger.info("HealthCheck: " + response.getStatus());
如果客户端传入了服务端没有定义的服务会抛出StatusRuntimeException
new StatusException(Status.NOT_FOUND.withDescription("unknown service " + request.getService()))
- Watch方法
客户端可以调用Watch方法来执行流式运行状况检查。服务器将立即发回指示当前服务状态的消息。随后，每当服务的服务状态发生变化时，它将发送一条新消息。
HealthCheckRequest request = HealthCheckRequest.newBuilder()
.setService("com.github.edgar615.grpc.health.Greeter").build();
StreamObserver<HealthCheckResponse> responseStreamObserver = new StreamObserver<HealthCheckResponse>() {
@Override
public void onNext(HealthCheckResponse healthCheckResponse) {
logger.info("HealthCheck: " + healthCheckResponse.getStatus());
}
@Override
public void onError(Throwable throwable) {
}
@Override
public void onCompleted() {
}
};
stub.watch(request, responseStreamObserver);
