CODEWITHSUNDEEP
javamongodb
asaf app
asaf app

Reputation: 386

mongo couldn't connect to [localhost/127.0.0.1:27017]

I'm getting the following error:

נוב 08, 2013 12:05:46 PM com.mongodb.DBTCPConnector initDirectConnection
WARNING: Exception executing isMaster command on localhost/127.0.0.1:27017
java.io.IOException: couldn't connect to [localhost/127.0.0.1:27017] bc:java.net.ConnectException: Connection refused: connect
    at com.mongodb.DBPort._open(DBPort.java:214)
    at com.mongodb.DBPort.go(DBPort.java:107)
    at com.mongodb.DBPort.go(DBPort.java:88)
    at com.mongodb.DBPort.findOne(DBPort.java:143)
    at com.mongodb.DBPort.runCommand(DBPort.java:148)
    at com.mongodb.DBTCPConnector.initDirectConnection(DBTCPConnector.java:548)
    at com.mongodb.DBTCPConnector.checkMaster(DBTCPConnector.java:527)
    at com.mongodb.DBTCPConnector.innerCall(DBTCPConnector.java:277)
    at com.mongodb.DBTCPConnector.call(DBTCPConnector.java:257)
    at com.mongodb.DBApiLayer$MyCollection.__find(DBApiLayer.java:310)
    at com.mongodb.DBApiLayer$MyCollection.__find(DBApiLayer.java:295)
    at com.mongodb.DB.getCollectionNames(DB.java:412)
    at Main.Main.main(Main.java:26)

my code is simple (my first time with mongo):

        MongoClient Client = new MongoClient( "localhost" , 27017 );

        DB db = Client.getDB("qw");
        DBCollection coll[] = new DBCollection[4];
        Set<String> colls = db.getCollectionNames();
        for(String s: colls)
            System.out.println(s);

what is the problem?

Upvotes: 7

Views: 19642

Answers (5)

Mani
Mani

Reputation: 634

Seems to have the same problem when using the below code to the connection

MongoClient mongo = new MongoClient("localhost", 27017);

But worked out when changed to 

MongoClient mongo = new MongoClient("127.0.0.1", 27017);

Upvotes: 0

Konstantin Yovkov
Konstantin Yovkov

Reputation: 62864

Possibly you haven't started the Mongo server.

Open a shell and type

mongod

On the file system, you can start it from $MONGO_INSTALL_PATH/bin/mongod.

Don't close the shell and then try to run your code again.

More info:

Upvotes: 14

Leo Dagum
Leo Dagum

Reputation: 81

Probably not your problem, but I've seen this Exception raised when mongodb is refusing the connection because it hit a limit on the number of open connections. Check your mongodb log file for a statement like:

"connection refused because too many open connections".

This can mean you're leaving connections open, or you need to raise the limit on number of open files in the db server.

Upvotes: 0

avian
avian

Reputation: 353

Try restarting your mongo. I had the same problem, and restarting solved it for me.

Upvotes: 2

Aditya
Aditya

Reputation: 1344

You haven't started your MongoDB Server.

First start your mongodb server and then run your code.

Or

You can also create MongoDB service which will always be running in the background, so from next time onwards you don't have to start the MongoDB server.

Here are the steps to create MongoDB service:

  1. Create a folder named ‘log’ parallel to ‘data’ folder, inside mongodb folder.

  2. Copy the ‘mongo.config’ file parallel to log folder inside ‘mongodb’ folder.

    Here is the content for your mongo.config file:

    stores data here

    dbpath = your_drive\mongodb-win32-x86_64-2.2.3\data\db

    all output goes here

    logpath = your_drive\mongodb-win32-x86_64-2.2.3\log\mongo.log

    log read and write operations

    diaglog = 3

  3. Create a file MongoServer.bat,

    Here is the content for MongoServer.bat

    your_drive\mongodb-win32-x86_64-2.2.3\bin\mongod.exe --config "your_drive\mongodb-win32-x86_64-2.2.3\mongo.config"

  4. On your command prompt, go to your mongodb\bin directory and then write this command, mongod --config your_Drive\mongodb-win32-x86_64-2.2.3\mongo.config –install

    This will create the service named as ‘Mongo DB’.

  5. To start the service, type on command prompt net start MongoDB.

Hence, your service is created. Now you can perform your task.

For further information, you can visit website.

Upvotes: 1

Related Questions