grpc：超時機制

工作中遇到一個問題，上游服務通過grpc調用下游服務，但是由於下游服務負載太高導致上游服務的調用會隨機出現超時的情況，但是有一點不太明確：超時之后，下游服務還會繼續進行計算么？

於是自己寫了一個damon試了一下：

client：

# Copyright 2015 gRPC authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""The Python implementation of the GRPC helloworld.Greeter client."""

from __future__ import print_function
import logging

import grpc

import helloworld_pb2
import helloworld_pb2_grpc


def run():
    # NOTE(gRPC Python Team): .close() is possible on a channel and should be
    # used in circumstances in which the with statement does not fit the needs
    # of the code.
    with grpc.insecure_channel('localhost:50051') as channel:
        stub = helloworld_pb2_grpc.GreeterStub(channel)
        response = stub.SayHello(helloworld_pb2.HelloRequest(name='you'), timeout=30)
    print("Greeter client received: " + response.message)


if __name__ == '__main__':
    logging.basicConfig()
    run()

server：

# Copyright 2015 gRPC authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""The Python implementation of the GRPC helloworld.Greeter server."""

from concurrent import futures
import time
import logging

import grpc

import helloworld_pb2
import helloworld_pb2_grpc

_ONE_DAY_IN_SECONDS = 60 * 60 * 24


class Greeter(helloworld_pb2_grpc.GreeterServicer):

    def SayHello(self, request, context):
    count = 0
    while count < 10:
        print('time:%s' % (time.time()))
        time.sleep(5)
        return helloworld_pb2.HelloReply(message='Hello, %s!' % request.name)


def serve():
    server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
    helloworld_pb2_grpc.add_GreeterServicer_to_server(Greeter(), server)
    server.add_insecure_port('[::]:50051')
    server.start()
    try:
        while True:
            time.sleep(_ONE_DAY_IN_SECONDS)
    except KeyboardInterrupt:
        server.stop(0)


if __name__ == '__main__':
    logging.basicConfig()
    serve()

 這兩個例子就是在grpc官方提供的python例子上做了一下小的改動，得到的結果是：當client超時報錯退出之后，server還是會繼續進行計算，直到結束，那如果是這樣的話，超時的機制對於server來說是沒有作用的，即使client已經不再等待這個結果了，但是server還是會繼續計算，浪費server的資源。