grpc实战示例

grpc 是rpc的一类。

grpc官网 ： http://www.grpc.io/docs/tutorials/basic/python.html

序列化使用的是:https://developers.google.com/protocol-buffers/

cs模式,stub校验 

四种模式,其实也就两种大模式有stream，没stream的；使用stream只不过是为了减少系统的开销 

以下例子是python版，其它版体是大同小异

 

使用步聚：

 

1)定义IDL

syntax = "proto3";

package hello;

service Greeter {
    rpc SayHello (HelloRequest) returns (stream HelloReply) {}
}


service ConnMysql {
    rpc ConnectMysql (MyqlRequest) returns (MysqlResponse) {}
}

message HelloRequest {
  string message = 1;
  int64 age = 2;
}

message HelloReply {
  string message = 1;
  int64 age = 2;
}


message MyqlRequest {
    string dbname = 1;

}

//连接mysql，响应返回值
message MysqlResponse {
    repeated string selectlist = 1;
}

 

  生成接口代码：

 python -m grpc.tools.protoc -I=. --python_out=/Users/admin/devops/logCenter/logops/grpc/  --grpc_python_out=/Users/admin/devops/logCenter/logops/grpc/  proto/log.proto

 

生成的是一个log_pb2.py

 

2)写server端代码

 

 

# coding:utf-8
import log_pb2
from concurrent import futures
import grpc
import time

_ONE_DAY_IN_SECONDS = 60 * 60 * 24
import MySQLdb


class Greeter(log_pb2.GreeterServicer):
    def SayHello(self, request, context):
        try:

            conn = MySQLdb.connect(
                host='127.0.0.1',
port=3306,
user='root',
passwd='hugo',
db='jiraconnector'
)
            cur = conn.cursor()
            sqli = "insert into api_taskid (task_id,task_name,task_env,create_time) VALUES (%s,%s,%s,%s)"
cur.execute(sqli, (request.message, request.age, '4', '2016-06-20 06:54:28.488573'))
            cur.close()
            conn.commit()
            conn.close()
            print request.message
            print request.age
            yield log_pb2.HelloReply(message='hello hugo', age=10)
        except Exception as e:
            print e


class ConnMysql(log_pb2.ConnMysqlServicer):
    def ConnectMysql(self, request, context):
        print request.dbname
        return log_pb2.MysqlResponse(selectlist='1')


def server():
    server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
    log_pb2.add_GreeterServicer_to_server(Greeter(), server)
    log_pb2.add_ConnMysqlServicer_to_server(ConnMysql(), server)
    server.add_insecure_port('127.0.0.1:15000')
    server.start()
    try:
        while True:
            time.sleep(_ONE_DAY_IN_SECONDS)
    except KeyboardInterrupt:
        server.stop(0)


if __name__ == '__main__':
    server()

 

3)写client端

 

# coding:utf-8
import grpc
import log_pb2

_TIMEOUT_SECONDS = 10


def run():
    try:
        # with log_pb2.beta_create_Greeter_stub(,'127.0.0.1',15000) as stub :
        #     response = stub.SayHello(log_pb2.HelloRequest(message='hello hugo',name='18'),_TIMEOUT_SECONDS)
        #     print response

        channel = grpc.insecure_channel('127.0.0.1:15000')
        stub = log_pb2.GreeterStub(channel)
        response = stub.SayHello(log_pb2.HelloRequest(message='hugo000000', age=19), _TIMEOUT_SECONDS)
        conn_mysql_stub = log_pb2.ConnMysqlStub(channel)
        res = conn_mysql_stub.ConnectMysql(log_pb2.MyqlRequest(dbname='jiraconnector'), _TIMEOUT_SECONDS)
        print res
        print response.next()
    except Exception as e:
        print e


if __name__ == '__main__':
    run()

 

4)结果

 

selectlist: "1"

 

message: "hello hugo"

age: 10

 

总结：简单易用，文档规范。

 

常见错误

<_Rendezvous of RPC that terminated with (StatusCode.UNIMPLEMENTED, Method not found!)>

 

<_Rendezvous of RPC that terminated with (StatusCode.UNKNOWN, Exception calling application: 'int' object is not iterable)

log.proto: Required fields are not allowed in proto3.

<!--?xml version="1.0" encoding="UTF-8" standalone="no"?-->

 

log.proto: Required fields are not allowed in proto3.

 reference :

http://maqiangthunder.github.io/2016/07/04/%E6%9D%82/gRPC/

https://github.com/geekan/grpc-python-demos/blob/master/helloworld/client.py

http://guojing.me/posts/grpc-python-bind-source-code-1/