The MongoDB Topology Management API

The MongoDB Topology Management API is an API to allow to programatically spin up a MongoDB instance, Replicaset or Sharded cluster on your local machine.

Setting up a single instance

It's very simple to create a single running MongoDB instance. All examples are using ES6.

var Server = require('mongodb-topology-manager').Server;
// Create new instance
var server = new Server('binary', {
  dbpath: './db'
});

const init = async () => {
  // Perform discovery
  var result = await server.discover();
  // Purge the directory
  await server.purge();
  // Start process
  await server.start();
  // Stop the process
  await server.stop();
}

// start the server
init();

Setting up a replicaset

It's equally easy to create a new Replicaset instance.

var ReplSet = require('mongodb-topology-manager').ReplSet;

// Create new instance
var topology = new ReplSet('mongod', [{
  // mongod process options
  options: {
    bind_ip: 'localhost', port: 31000, dbpath: './db-1'
  }
}, {
  // mongod process options
  options: {
    bind_ip: 'localhost', port: 31001, dbpath: './db-2'
  }
}, {
  // Type of node
  arbiterOnly: true,
  // mongod process options
  options: {
    bind_ip: 'localhost', port: 31002, dbpath: './db-3'
  }
}], {
  replSet: 'rs'
});

const init = async () => {
  // Perform discovery
  var result = await server.discover();
  // Purge the directory
  await server.purge();
  // Start process
  await server.start();
  // Stop the process
  await server.stop();
}

// start the replica set
init();

Each of the node objects can take the following options at the top level.

Field | Description ----------------------------------|------------------------- arbiter | node should become an arbiter. builIndexes | should build indexes on the node. hidden | node should be hidden. builIndexes | should build indexes on the node. priority | node should have the following priority. tags | tags for the node. slaveDelay | the node slaveDelay for replication. votes | additional votes for the specific node.

The object contains the options that are used to start up the actual mongod instance.

The Replicaset manager has the following methods

Method | Description ----------------------------------|------------------------- Replset.prototype.discover | Return the information from running mongod with --version flag. Replset.prototype.start | Start the Replicaset. Replset.prototype.primary | Return the current Primary server manager. Replset.prototype.shardUrl | Return a add shard url string. Replset.prototype.url | Return a connection url. Replset.prototype.arbiters | Return a list of arbiter managers. Replset.prototype.secondaries | Return a list of secondary managers. Replset.prototype.passives | Return a list of secondary passive managers. Replset.prototype.waitForPrimary | Wait for a new primary to be elected or for a specific timeout period. Replset.prototype.stepDownPrimary | Stepdown the primary. Replset.prototype.configuration | Return the replicaset configuration. Replset.prototype.reconfigure | Perform a reconfiguration of the replicaset. Replset.prototype.serverConfiguration | Get the initial node configuration for specific server manager. Replset.prototype.addMember | Add a new member to the set. Replset.prototype.removeMember | Remove a member to the set. Replset.prototype.maintenance | Put a node into maintenance mode. Replset.prototype.stop | Stop the replicaset. Replset.prototype.restart | Restart the replicaset. Replset.prototype.purge | Purge all the data directories for the replicaset.

Setting up a sharded system

It's a little bit more complicated to set up a Sharded system but not much more.

var Sharded = require('mongodb-topology-manager').Sharded;

const init = async () => {
  // Create new instance
  var topology = new Sharded({
    mongod: 'mongod', mongos: 'mongos'
  });

  // Add one shard
  await topology.addShard([{
    options: {
      bind_ip: 'localhost', port: 31000, dbpath: './db-1', shardsvr: null
    }
  }, {
    options: {
      bind_ip: 'localhost', port: 31001, dbpath: './db-2', shardsvr: null
  }, {
    // Type of node
    arbiter: true,
    // mongod process options
    options: {
      bind_ip: 'localhost', port: 31002, dbpath: './db-3', shardsvr: null
    }
  }], {
    replSet: 'rs1'
  });

  // Add one shard
  await topology.addShard([{
    options: {
      bind_ip: 'localhost', port: 31010, dbpath: './db-4', shardsvr: null
    }
  }, {
    options: {
      bind_ip: 'localhost', port: 31011, dbpath: './db-5', shardsvr: null
    }
  }, {
    // Type of node
    arbiter: true,
    // mongod process options
    options: {
      bind_ip: 'localhost', port: 31012, dbpath: './db-6', shardsvr: null
    }
  }], {
    replSet: 'rs2'
  });

  // Add configuration servers
  await topology.addConfigurationServers([{
    options: {
      bind_ip: 'localhost', port: 35000, dbpath: './db-7'
    }
  }, {
    options: {
      bind_ip: 'localhost', port: 35001, dbpath: './db-8'
    }
  }, {
    options: {
      bind_ip: 'localhost', port: 35002, dbpath: './db-9'
    }
  }], {
    replSet: 'rs3'
  });

  // Add proxies
  await topology.addProxies([{
    bind_ip: 'localhost', port: 51000, configdb: 'localhost:35000,localhost:35001,localhost:35002'
  }, {
    bind_ip: 'localhost', port: 51001, configdb: 'localhost:35000,localhost:35001,localhost:35002'
  }], {
    binary: 'mongos'
  });

  // Start up topology
  await topology.start();

  // Shard db
  await topology.enableSharding('test');

  // Shard a collection
  await topology.shardCollection('test', 'testcollection', {_id: 1});

  // Stop the topology
  await topology.stop();
}

// start the shards
init();

The Sharded manager has the following methods

Method | Description ----------------------------------|------------------------- Replset.prototype.discover | Return the information from running mongod with --version flag. Replset.prototype.start | Start the Sharded cluster. Replset.prototype.stop | Stop the replicaset. Replset.prototype.restart | Restart the replicaset. Replset.prototype.purge | Purge all the data directories for the replicaset. Replset.prototype.addShard | Add a new shard to the cluster. Replset.prototype.addConfigurationServers | Add a set of nodes to be configuration servers. ReplSet.prototype.addProxies | Add a set of mongo proxies to the cluster. ReplSet.prototype.enableSharding | Enable sharding on a specific db. ReplSet.prototype.shardCollection | Shard a collection.