如何在运行时获取打开的 Mongo 连接数？

Question

The way I connect to Mongo and disconnect:

class Database:
    def connect(self):
        self.client = MongoClient(self.uri)

    def close(self):
        if self.client:
            self.client.close()


    def __enter__(self):
        if self.is_not_connected():
            self.connect()
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.close()

And I use with to open and close a connection with Mongo. I want to track the number of opened connections, every time I open and close a connection. Just a simple print will do. But how do I get to the field that contains the number of connections? I looked at dir of self.client but it does not have a special method method for. I want to know the number of connections in runtime. How can I do it?

Answer 1

One way to approach it could be to add a counter as a class variable which increments and decrements the total number of connections upon calling the open och close methods. Something like the below:

class Database:
    num_of_connections = 0

    def connect(self):
        Database.num_of_connections += 1
        self.client = MongoClient(self.uri)

    def close(self):
        if self.client:
            Database.num_of_connections -= 1
            self.client.close()

    def __enter__(self):
        if self.is_not_connected():
            self.connect()
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.close()

    def active_connections(self):
        print(Database.num_of_connections)