Connecting to a replica set

Connecting to a replica set is not fundamentally different to connecting to a single server. In this section, we will show some examples using the official mongo-ruby-driver.

First we need to set our host and options objects:

client_host = ['hostname:port']
client_options = {
 database: 'signals',
 replica_set: 'xmr_btc'
}

In the preceding example, we are getting ready to connect to host:port hostname, in database signals in the replica_set xmr_btc.

Calling the initializer on Mongo::Client will now return a client object that contains a connection to our replica set and database:

client = Mongo::Client.new(client_host, client_options)

The client object then has the same options as it has when connecting to a single server.

Note

MongoDB uses auto-discovery after connecting to our client_host to identify the other members of our replica set, be they the primary or secondaries. The client object should be used as a singleton, created once and reused across our code base...