尝试连接到Mongo中的副本集时出错

Question

When I try to connect to mongo replica set in AWS I get this error:

slavenode:27017: [Errno -2] Name or service not known,ip-XXX-XX-XX-XX:27017: [Errno -2] Name or service not known

(where XXX-XX.. corresponds to my actual ip address)

The code to connect is shown below:

client = MongoClient("mongodb://Master-PublicIP:27017,Slave-PublicIP:27017/myFirstDB?replicaSet=rs0")
db = client.myFirstDB
try:
    db.command("serverStatus")
except Exception as e:
    print(e)
else:
    print("You are connected!")
client.close()

(where in Master-PublicIP and Slave-PublicIP I have the actual IPv4 Public IP's from AWS console)

I have already a replica set and the configuration is:

rs0:PRIMARY> rs.conf()

{
"_id" : "rs0",
"version" : 2,
"members" : [
    {
        "_id" : 0,
        "host" : "ip-XXX-XX-XX-XXX:27017",
        "arbiterOnly" : false,
        "buildIndexes" : true,
        "hidden" : false,
        "priority" : 1,
        "tags" : {

        },
        "slaveDelay" : 0,
        "votes" : 1
    },
    {
        "_id" : 1,
        "host" : "SlaveNode:27017",
        "arbiterOnly" : false,
        "buildIndexes" : true,
        "hidden" : false,
        "priority" : 1,
        "tags" : {

        },
        "slaveDelay" : 0,
        "votes" : 1
    }
],
"settings" : {
    "chainingAllowed" : true,
    "heartbeatTimeoutSecs" : 10,
    "getLastErrorModes" : {

    },
    "getLastErrorDefaults" : {
        "w" : 1,
        "wtimeout" : 0
    }
}

}

I have create the /data/db in PRIMARY and the /data/db1 in SECONDARY and I have give the proper ownership with sudo chmod -R 755 /data/db

My MongoDB version is 3.0.15. Is anyone know what is going wrong?

Thanks in advance.

Answer 1

Have you tried removing the myFirstDB from within the MongoClient()

 MongoClient("mongodb://Master-PublicIP:27017,Slave-PublicIP:27017/?replicaSet=rs0")

Because your next line then specifies which db you want to use

db = client.myFirstDB

Or I think you can specify the db by putting a dot after the closing brace on the MongoClient()

MongoClient("mongodb://Master-PublicIP:27017,Slave-PublicIP:27017/?replicaSet=rs0").myFirstDB

Answer 2

I manage to solve the problem. As @N3i1 suggests in commnets, I use the Public DNS (IPv4). There was an issue with the hosts that I had declare in /etc/hosts.

In this file I had define the ips of master/ slaves with some names. For some reason this didn't work. I delete them and then I reconfigure the replica set configuration.

In PRIMARY in mongo shell I did:

cfg = {"_id" : "rs0", "members" : [{"_id" : 0,"host" : "Public DNS (IPv4):27017"},{"_id" : 1,"host" : "Public DNS (IPv4):27017"}]}
rs.reconfig(cfg,{force: true});

Then I connect in the replica set with python with:

MongoClient("mongodb://Public DNS (IPv4):27017,Public DNS (IPv4):27017/?replicaSet=rs0")

Of course change the Public DNS (IPv4) adresses with yours.