Mongoclient在叉子前打开.仅创建杂种

Question

myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["game"]
mycol = mydb["test_collection"]

class ProcessWork:
    res1 = []
    res2 = []
    def processwork1(request, res1):
        country = request.GET.get('country')
        qry = {'country': country}
        query = mycol.find(qry).limit(10)
        result = json.loads(dumps(query))
        res1.append(result)
    def processwork2(request, res2):
        country = request.GET.get('country')
        qry = {'country': country}
        query = mycol.find(qry).skip(10).limit(10)
        result = json.loads(dumps(query))
        res2.append(result)
    def process(request):
        t1 = multiprocessing.Process(target=ProcessWork.processwork1, args=((request), ProcessWork.res1))
        t2 = multiprocessing.Process(target=ProcessWork.processwork1, args=((request), ProcessWork.res2))
        t1.start()
        t1.join()
        t2.start()
        t2.join()
        # result = ProcessWork.res1[0] + ProcessWork.res2[0]
        return JsonResponse({})

终端中的错误：

    /home/fractaluser/Desktop/Dev/cache/env/lib/python3.5/site-packages/pymongo/topology.py:150: UserWarning: MongoClient opened before fork. Create MongoClient only after forking. See PyMongo's documentation for details: http://api.mongodb.org/python/current/faq.html#is-pymongo-fork-safe
      "MongoClient opened before fork. Create MongoClient only "
    /home/fractaluser/Desktop/Dev/cache/env/lib/python3.5/site-packages/pymongo/topology.py:150: UserWarning: MongoClient opened before fork. Create MongoClient only after forking. See PyMongo's documentation for details: http://api.mongodb.org/python/current/faq.html#is-pymongo-fork-safe
      "MongoClient opened before fork. Create MongoClient only "

在这里，我使用多处理在Python中运行多个任务。我正在使用Pymongo客户端从MongoDB获取数据。

我无法理解这个错误。因此，我也没有得到结果。

请看看

Answer 1

您是否尝试过在processwork2()和processwork1()方法中创建Mongo连接？

您要在fork()系统调用发生之前创建杂种型(可能是由OS创建新过程的一部分(。

只是将此部分放入方法的主体中：

myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["game"]
mycol = mydb["test_collection"]