Class Mongo::Connection
In: lib/mongo/connection.rb
Parent: Object

Instantiates and manages self.connections to MongoDB.

Methods

Included Modules

Mongo::Logging Mongo::Networking

Constants

TCPSocket = ::TCPSocket
Mutex = ::Mutex
ConditionVariable = ::ConditionVariable
DEFAULT_PORT = 27017

Attributes

auths  [R] 
connect_timeout  [R] 
host_to_try  [R] 
logger  [R] 
pool_size  [R] 
pool_timeout  [R] 
primary  [R] 
primary_pool  [R] 
safe  [R] 
size  [R] 
socket_class  [R] 

Public Class methods

Initialize a connection to MongoDB using the MongoDB URI spec:

@param uri [String]

  A string of the format mongodb://[username:password@]host1[:port1][,host2[:port2],...[,hostN[:portN]]][/database]

@param opts Any of the options available for Connection.new

@return [Mongo::Connection, Mongo::ReplSetConnection]

[Source]

# File lib/mongo/connection.rb, line 148
    def self.from_uri(string, extra_opts={})
      uri = URIParser.new(string)
      opts = uri.connection_options
      opts.merge!(extra_opts)

      if uri.nodes.length == 1
        opts.merge!({:auths => uri.auths})
        Connection.new(uri.nodes[0][0], uri.nodes[0][1], opts)
      elsif uri.nodes.length > 1
        nodes = uri.nodes.clone
        nodes_with_opts = nodes << opts
        ReplSetConnection.new(*nodes_with_opts)
      else
        raise MongoArgumentError, "No nodes specified. Please ensure that you've provided at least one node."
      end
    end

DEPRECATED

Initialize a connection to a MongoDB replica set using an array of seed nodes.

The seed nodes specified will be used on the initial connection to the replica set, but note that this list of nodes will be replced by the list of canonical nodes returned by running the is_master command on the replica set.

@param nodes [Array] An array of arrays, each of which specifies a host and port. @param opts [Hash] Any of the available options that can be passed to Connection.new.

@option opts [String] :rs_name (nil) The name of the replica set to connect to. An exception will be

  raised if unable to connect to a replica set with this name.

@option opts [Boolean] :read_secondary (false) When true, this connection object will pick a random slave

  to send reads to.

@example

  Connection.multi([["db1.example.com", 27017], ["db2.example.com", 27017]])

@example This connection will read from a random secondary node.

  Connection.multi([["db1.example.com", 27017], ["db2.example.com", 27017], ["db3.example.com", 27017]],
                  :read_secondary => true)

@return [Mongo::Connection]

@deprecated

[Source]

# File lib/mongo/connection.rb, line 133
    def self.multi(nodes, opts={})
      warn "Connection.multi is now deprecated and will be removed in v2.0. Please use ReplSetConnection.new instead."

      nodes << opts
      ReplSetConnection.new(*nodes)
    end

Create a connection to single MongoDB instance.

You may specify whether connection to slave is permitted. In all cases, the default host is "localhost" and the default port is 27017.

If you‘re connecting to a replica set, you‘ll need to use ReplSetConnection.new instead.

Once connected to a replica set, you can find out which nodes are primary, secondary, and arbiters with the corresponding accessors: Connection#primary, Connection#secondaries, and Connection#arbiters. This is useful if your application needs to connect manually to nodes other than the primary.

@param [String, Hash] host. @param [Integer] port specify a port number here if only one host is being specified.

@option opts [Boolean, Hash] :safe (false) Set the default safe-mode options

  propogated to DB objects instantiated off of this Connection. This
  default can be overridden upon instantiation of any DB by explicity setting a :safe value
  on initialization.

@option opts [Boolean] :slave_ok (false) Must be set to true when connecting

  to a single, slave node.

@option opts [Logger, debug] :logger (nil) A Logger instance for debugging driver ops. Note that

  logging negatively impacts performance; therefore, it should not be used for high-performance apps.

@option opts [Integer] :pool_size (1) The maximum number of socket self.connections allowed per

  connection pool. Note: this setting is relevant only for multi-threaded applications.

@option opts [Float] :pool_timeout (5.0) When all of the self.connections a pool are checked out,

  this is the number of seconds to wait for a new connection to be released before throwing an exception.
  Note: this setting is relevant only for multi-threaded applications (which in Ruby are rare).

@option opts [Float] :op_timeout (nil) The number of seconds to wait for a read operation to time out.

  Disabled by default.

@option opts [Float] :connect_timeout (nil) The number of seconds to wait before timing out a

  connection attempt.

@option opts [Boolean] :ssl (false) If true, create the connection to the server using SSL.

@example localhost, 27017

  Connection.new

@example localhost, 27017

  Connection.new("localhost")

@example localhost, 3000, max 5 self.connections, with max 5 seconds of wait time.

  Connection.new("localhost", 3000, :pool_size => 5, :timeout => 5)

@example localhost, 3000, where this node may be a slave

  Connection.new("localhost", 3000, :slave_ok => true)

@see api.mongodb.org/ruby/current/file.REPLICA_SETS.html Replica sets in Ruby

@raise [ReplicaSetConnectionError] This is raised if a replica set name is specified and the

  driver fails to connect to a replica set with that name.

@core self.connections

[Source]

# File lib/mongo/connection.rb, line 95
    def initialize(host=nil, port=nil, opts={})
      @host_to_try = format_pair(host, port)

      # Host and port of current master.
      @host = @port = nil

      # slave_ok can be true only if one node is specified
      @slave_ok = opts[:slave_ok]

      setup(opts)
    end

Public Instance methods

Shortcut for returning a database. Use DB#db to accept options.

@param [String] db_name a valid database name.

@return [Mongo::DB]

@core databases []-instance_method

[Source]

# File lib/mongo/connection.rb, line 311
    def [](db_name)
      DB.new(db_name, self)
    end

Determine if the connection is active. In a normal case the server_info operation will be performed without issues, but if the connection was dropped by the server or for some reason the sockets are unsynchronized, a ConnectionFailure will be raised and the return will be false.

@return [Boolean]

[Source]

# File lib/mongo/connection.rb, line 435
    def active?
      return false unless connected?

      ping
      true

      rescue ConnectionFailure
      false
    end

Save an authentication to this connection. When connecting, the connection will attempt to re-authenticate on every db specificed in the list of auths. This method is called automatically by DB#authenticate.

Note: this method will not actually issue an authentication command. To do that, either run Connection#apply_saved_authentication or DB#authenticate.

@param [String] db_name @param [String] username @param [String] password

@return [Hash] a hash representing the authentication just added.

[Source]

# File lib/mongo/connection.rb, line 233
    def add_auth(db_name, username, password)
      remove_auth(db_name)
      auth = {}
      auth['db_name']  = db_name
      auth['username'] = username
      auth['password'] = password
      @auths << auth
      auth
    end

Apply each of the saved database authentications.

@return [Boolean] returns true if authentications exist and succeeed, false

  if none exists.

@raise [AuthenticationError] raises an exception if any one

  authentication fails.

[Source]

# File lib/mongo/connection.rb, line 211
    def apply_saved_authentication(opts={})
      return false if @auths.empty?
      @auths.each do |auth|
        self[auth['db_name']].issue_authentication(auth['username'], auth['password'], false,
          :socket => opts[:socket])
      end
      true
    end

[Source]

# File lib/mongo/connection.rb, line 265
    def authenticate_pools
      @primary_pool.authenticate_existing
    end

Check a socket back into its pool.

[Source]

# File lib/mongo/connection.rb, line 512
    def checkin(socket)
      if @primary_pool
        @primary_pool.checkin(socket)
      end
    end

Checkin a socket used for reading. Note: this is overridden in ReplSetConnection.

[Source]

# File lib/mongo/connection.rb, line 501
    def checkin_reader(socket)
      checkin(socket)
    end

Checkin a socket used for writing. Note: this is overridden in ReplSetConnection.

[Source]

# File lib/mongo/connection.rb, line 507
    def checkin_writer(socket)
      checkin(socket)
    end

Checkout a socket for reading (i.e., a secondary node). Note: this is overridden in ReplSetConnection.

[Source]

# File lib/mongo/connection.rb, line 487
    def checkout_reader
      connect unless connected?
      @primary_pool.checkout
    end

Checkout a socket for writing (i.e., a primary node). Note: this is overridden in ReplSetConnection.

[Source]

# File lib/mongo/connection.rb, line 494
    def checkout_writer
      connect unless connected?
      @primary_pool.checkout
    end

Remove all authenication information stored in this connection.

@return [true] this operation return true because it always succeeds.

[Source]

# File lib/mongo/connection.rb, line 260
    def clear_auths
      @auths = []
      true
    end

Close the connection to the database.

[Source]

# File lib/mongo/connection.rb, line 471
    def close
      @primary_pool.close if @primary_pool
      @primary_pool = nil
      @primary = nil
    end

Create a new socket and attempt to connect to master. If successful, sets host and port to master and returns the socket.

If connecting to a replica set, this method will replace the initially-provided seed list with any nodes known to the set.

@raise [ConnectionFailure] if unable to connect to any host or port.

[Source]

# File lib/mongo/connection.rb, line 397
    def connect
      close

      config = check_is_master(@host_to_try)
      if config
        if config['ismaster'] == 1 || config['ismaster'] == true
          @read_primary = true
        elsif @slave_ok
          @read_primary = false
        end

        @max_bson_size = config['maxBsonObjectSize'] || Mongo::DEFAULT_MAX_BSON_SIZE
        set_primary(@host_to_try)
      end

      if !connected?
        raise ConnectionFailure, "Failed to connect to a master node at #{@host_to_try[0]}:#{@host_to_try[1]}"
      end
    end

It‘s possible that we defined connected as all nodes being connected??? NOTE: Do check if this needs to be more stringent. Probably not since if any node raises a connection failure, all nodes will be closed.

[Source]

# File lib/mongo/connection.rb, line 425
    def connected?
      @primary_pool && !@primary_pool.closed?
    end

[Source]

# File lib/mongo/connection.rb, line 418
    def connecting?
      @nodes_to_try.length > 0
    end

Copy the database from to to on localhost. The from database is assumed to be on localhost, but an alternate host can be specified.

@param [String] from name of the database to copy from. @param [String] to name of the database to copy to. @param [String] from_host host of the ‘from’ database. @param [String] username username for authentication against from_db (>=1.3.x). @param [String] password password for authentication against from_db (>=1.3.x).

[Source]

# File lib/mongo/connection.rb, line 330
    def copy_database(from, to, from_host="localhost", username=nil, password=nil)
      oh = BSON::OrderedHash.new
      oh[:copydb]   = 1
      oh[:fromhost] = from_host
      oh[:fromdb]   = from
      oh[:todb]     = to
      if username || password
        unless username && password
          raise MongoArgumentError, "Both username and password must be supplied for authentication."
        end
        nonce_cmd = BSON::OrderedHash.new
        nonce_cmd[:copydbgetnonce] = 1
        nonce_cmd[:fromhost] = from_host
        result = self["admin"].command(nonce_cmd)
        oh[:nonce] = result["nonce"]
        oh[:username] = username
        oh[:key] = Mongo::Support.auth_key(username, password, oh[:nonce])
      end
      self["admin"].command(oh)
    end

Return a hash with all database names and their respective sizes on disk.

@return [Hash]

[Source]

# File lib/mongo/connection.rb, line 277
    def database_info
      doc = self['admin'].command({:listDatabases => 1})
      doc['databases'].each_with_object({}) do |db, info|
        info[db['name']] = db['sizeOnDisk'].to_i
      end
    end

Return an array of database names.

@return [Array]

[Source]

# File lib/mongo/connection.rb, line 287
    def database_names
      database_info.keys
    end

Return a database with the given name. See DB#new for valid options hash parameters.

@param [String] db_name a valid database name. @param [Hash] opts options to be passed to the DB constructor.

@return [Mongo::DB]

@core databases db-instance_method

[Source]

# File lib/mongo/connection.rb, line 300
    def db(db_name, opts={})
      DB.new(db_name, self, opts)
    end

Drop a database.

@param [String] name name of an existing database.

[Source]

# File lib/mongo/connection.rb, line 318
    def drop_database(name)
      self[name].command(:dropDatabase => 1)
    end

[Source]

# File lib/mongo/connection.rb, line 382
    def get_socket_from_thread_local
      Thread.current[:socket_map] ||= {}
      Thread.current[:socket_map][self] ||= {}
      Thread.current[:socket_map][self][:writer] ||= checkout_writer
      Thread.current[:socket_map][self][:reader] = 
        Thread.current[:socket_map][self][:writer]
    end

The host name used for this connection.

@return [String]

[Source]

# File lib/mongo/connection.rb, line 168
    def host
      @primary_pool.host
    end

Fsync, then lock the mongod process against writes. Use this to get the datafiles in a state safe for snapshotting, backing up, etc.

@return [BSON::OrderedHash] the command response

[Source]

# File lib/mongo/connection.rb, line 183
    def lock!
      cmd = BSON::OrderedHash.new
      cmd[:fsync] = 1
      cmd[:lock]  = true
      self['admin'].command(cmd)
    end

Is this database locked against writes?

@return [Boolean]

[Source]

# File lib/mongo/connection.rb, line 193
    def locked?
      self['admin']['$cmd.sys.inprog'].find_one['fsyncLock'] == 1
    end

[Source]

# File lib/mongo/connection.rb, line 269
    def logout_pools(db)
      @primary_pool.logout_existing(db)
    end

Returns the maximum BSON object size as returned by the core server. Use the 4MB default when the server doesn‘t report this.

@return [Integer]

[Source]

# File lib/mongo/connection.rb, line 481
    def max_bson_size
      @max_bson_size
    end

Checks if a server is alive. This command will return immediately even if the server is in a lock.

@return [Hash]

[Source]

# File lib/mongo/connection.rb, line 355
    def ping
      self["admin"].command({:ping => 1})
    end

The port used for this connection.

@return [Integer]

[Source]

# File lib/mongo/connection.rb, line 175
    def port
      @primary_pool.port
    end
primary?()

Alias for read_primary?

The socket pool that this connection reads from.

@return [Mongo::Pool]

[Source]

# File lib/mongo/connection.rb, line 457
    def read_pool
      @primary_pool
    end

The value of the read preference.

[Source]

# File lib/mongo/connection.rb, line 462
    def read_preference
      if slave_ok?
        :secondary
      else
        :primary
      end
    end

Determine whether we‘re reading from a primary node. If false, this connection connects to a secondary node and @slave_ok is true.

@return [Boolean]

[Source]

# File lib/mongo/connection.rb, line 449
    def read_primary?
      @read_primary
    end
reconnect()

Alias for connect

Remove a saved authentication for this connection.

@param [String] db_name

@return [Boolean]

[Source]

# File lib/mongo/connection.rb, line 248
    def remove_auth(db_name)
      return unless @auths
      if @auths.reject! { |a| a['db_name'] == db_name }
        true
      else
        false
      end
    end

Get the build information for the current connection.

@return [Hash]

[Source]

# File lib/mongo/connection.rb, line 362
    def server_info
      self["admin"].command({:buildinfo => 1})
    end

Get the build version of the current server.

@return [Mongo::ServerVersion]

  object allowing easy comparability of version.

[Source]

# File lib/mongo/connection.rb, line 371
    def server_version
      ServerVersion.new(server_info["version"])
    end

Is it okay to connect to a slave?

@return [Boolean]

[Source]

# File lib/mongo/connection.rb, line 378
    def slave_ok?
      @slave_ok
    end

Unlock a previously fsync-locked mongod process.

@return [BSON::OrderedHash] command response

[Source]

# File lib/mongo/connection.rb, line 200
    def unlock!
      self['admin']['$cmd.sys.unlock'].find_one
    end

Protected Instance methods

Returns a host-port pair.

@return [Array]

@private

[Source]

# File lib/mongo/connection.rb, line 584
    def format_pair(host, port)
      case host
        when String
          [host, port ? port.to_i : DEFAULT_PORT]
        when nil
          ['localhost', DEFAULT_PORT]
      end
    end

Generic initialization code.

[Source]

# File lib/mongo/connection.rb, line 521
    def setup(opts)
      # Default maximum BSON object size
      @max_bson_size = Mongo::DEFAULT_MAX_BSON_SIZE

      # Determine whether to use SSL.
      @ssl = opts.fetch(:ssl, false)
      if @ssl
        @socket_class = Mongo::SSLSocket
      else
        @socket_class = ::TCPSocket
      end

      # Authentication objects
      @auths = opts.fetch(:auths, [])

      # Lock for request ids.
      @id_lock = Mutex.new

      # Pool size and timeout.
      @pool_size = opts[:pool_size] || 1
      if opts[:timeout]
        warn "The :timeout option has been deprecated " +
          "and will be removed in the 2.0 release. Use :pool_timeout instead."
      end
      @pool_timeout = opts[:pool_timeout] || opts[:timeout] || 5.0

      # Timeout on socket read operation.
      @op_timeout = opts[:op_timeout] || nil

      # Timeout on socket connect.
      @connect_timeout = opts[:connect_timeout] || nil

      # Mutex for synchronizing pool access
      # TODO: remove this.
      @connection_mutex = Mutex.new

      # Global safe option. This is false by default.
      @safe = opts[:safe] || false

      # Condition variable for signal and wait
      @queue = ConditionVariable.new

      # Connection pool for primay node
      @primary      = nil
      @primary_pool = nil

      @logger = opts[:logger] || nil

      if @logger
        write_logging_startup_message
      end

      should_connect = opts.fetch(:connect, true)
      connect if should_connect
    end

[Validate]