mongo-ruby-driver/lib/mongo/connection.rb

636 lines
20 KiB
Ruby

# encoding: UTF-8
# --
# Copyright (C) 2008-2011 10gen Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ++
require 'set'
require 'socket'
require 'thread'
module Mongo
# Instantiates and manages self.connections to MongoDB.
class Connection
include Mongo::Logging
include Mongo::Networking
TCPSocket = Mongo::TCPSocket
Mutex = ::Mutex
ConditionVariable = ::ConditionVariable
Thread.abort_on_exception = true
DEFAULT_HOST = 'localhost'
DEFAULT_PORT = 27017
GENERIC_OPTS = [:ssl, :auths, :pool_size, :pool_timeout, :timeout, :op_timeout, :connect_timeout, :safe, :logger, :connect]
CONNECTION_OPTS = [:slave_ok]
mongo_thread_local_accessor :connections
attr_reader :logger, :size, :auths, :primary, :safe, :host_to_try,
:pool_size, :connect_timeout, :pool_timeout,
:primary_pool, :socket_class, :op_timeout
# Create a connection to single MongoDB instance.
#
# If no args are provided, it will check <code>ENV["MONGODB_URI"]</code>.
#
# 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] :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 (or <code>ENV["MONGODB_URI"]</code> if available)
# Mongo::Connection.new
#
# @example localhost, 27017
# Mongo::Connection.new("localhost")
#
# @example localhost, 3000, max 5 self.connections, with max 5 seconds of wait time.
# Mongo::Connection.new("localhost", 3000, :pool_size => 5, :timeout => 5)
#
# @example localhost, 3000, where this node may be a slave
# Mongo::Connection.new("localhost", 3000, :slave_ok => true)
#
# @see http://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.
#
# @raise [MongoArgumentError] If called with no arguments and <code>ENV["MONGODB_URI"]</code> implies a replica set.
#
# @core self.connections
def initialize(host=nil, port=nil, opts={})
if host.nil? and ENV.has_key?('MONGODB_URI')
parser = URIParser.new ENV['MONGODB_URI'], opts
if parser.replicaset?
raise MongoArgumentError, "Mongo::Connection.new called with no arguments, but ENV['MONGODB_URI'] implies a replica set."
end
opts = parser.connection_options
@host_to_try = [parser.host, parser.port]
elsif host.is_a?(String)
@host_to_try = [host, (port || DEFAULT_PORT).to_i]
else
@host_to_try = [DEFAULT_HOST, DEFAULT_PORT]
end
# Host and port of current master.
@host = @port = nil
# Default maximum BSON object size
@max_bson_size = Mongo::DEFAULT_MAX_BSON_SIZE
# Lock for request ids.
@id_lock = Mutex.new
# Connection pool for primay node
@primary = nil
@primary_pool = nil
check_opts(opts)
setup(opts)
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
# Mongo::Connection.multi([["db1.example.com", 27017], ["db2.example.com", 27017]])
#
# @example This connection will read from a random secondary node.
# Mongo::Connection.multi([["db1.example.com", 27017], ["db2.example.com", 27017], ["db3.example.com", 27017]],
# :read_secondary => true)
#
# @return [Mongo::Connection]
#
# @deprecated
def self.multi(nodes, opts={})
warn "Connection.multi is now deprecated and will be removed in v2.0. Please use ReplSetConnection.new instead."
ReplSetConnection.new(*(nodes+[opts]))
end
# Initialize a connection to MongoDB using the MongoDB URI spec.
#
# Since Connection.new cannot be used with any <code>ENV["MONGODB_URI"]</code> that has multiple hosts (implying a replicaset), you may use this when the type of your connection varies by environment and should be determined solely from <code>ENV["MONGODB_URI"]</code>.
#
# @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]
def self.from_uri(uri = ENV['MONGODB_URI'], extra_opts={})
parser = URIParser.new uri, extra_opts
parser.connection
end
# The host name used for this connection.
#
# @return [String]
def host
@primary_pool.host
end
# The port used for this connection.
#
# @return [Integer]
def port
@primary_pool.port
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
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]
def locked?
self['admin']['$cmd.sys.inprog'].find_one['fsyncLock'] == 1
end
# Unlock a previously fsync-locked mongod process.
#
# @return [BSON::OrderedHash] command response
def unlock!
self['admin']['$cmd.sys.unlock'].find_one
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.
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
# 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.
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
# Remove a saved authentication for this connection.
#
# @param [String] db_name
#
# @return [Boolean]
def remove_auth(db_name)
return unless @auths
if @auths.reject! { |a| a['db_name'] == db_name }
true
else
false
end
end
# Remove all authenication information stored in this connection.
#
# @return [true] this operation return true because it always succeeds.
def clear_auths
@auths = []
true
end
def authenticate_pools
@primary_pool.authenticate_existing
end
def logout_pools(db)
@primary_pool.logout_existing(db)
end
# Return a hash with all database names
# and their respective sizes on disk.
#
# @return [Hash]
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]
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
def db(db_name, opts={})
DB.new(db_name, self, opts)
end
# 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
def [](db_name)
DB.new(db_name, self)
end
# Drop a database.
#
# @param [String] name name of an existing database.
def drop_database(name)
self[name].command(:dropDatabase => 1)
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).
def copy_database(from, to, from_host=DEFAULT_HOST, 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
# Checks if a server is alive. This command will return immediately
# even if the server is in a lock.
#
# @return [Hash]
def ping
self["admin"].command({:ping => 1})
end
# Get the build information for the current connection.
#
# @return [Hash]
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.
def server_version
ServerVersion.new(server_info["version"])
end
# Is it okay to connect to a slave?
#
# @return [Boolean]
def slave_ok?
@slave_ok
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.
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
alias :reconnect :connect
# 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.
def connected?
@primary_pool && !@primary_pool.closed?
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]
def active?
return false unless connected?
ping
true
rescue ConnectionFailure
false
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]
def read_primary?
@read_primary
end
alias :primary? :read_primary?
# The socket pool that this connection reads from.
#
# @return [Mongo::Pool]
def read_pool
@primary_pool
end
# The value of the read preference.
def read_preference
if slave_ok?
:secondary
else
:primary
end
end
# Close the connection to the database.
def close
@primary_pool.close if @primary_pool
@primary_pool = nil
@primary = nil
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]
def max_bson_size
@max_bson_size
end
# Prefer primary pool but fall back to secondary
def checkout_best
connect unless connected?
@primary_pool.checkout
end
# Checkout a socket for reading (i.e., a secondary node).
# Note: this is overridden in ReplSetConnection.
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.
def checkout_writer
connect unless connected?
@primary_pool.checkout
end
# Checkin a socket used for reading.
# Note: this is overridden in ReplSetConnection.
def checkin_reader(socket)
checkin(socket)
end
# Checkin a socket used for writing.
# Note: this is overridden in ReplSetConnection.
def checkin_writer(socket)
checkin(socket)
end
# Check a socket back into its pool.
def checkin(socket)
if @primary_pool && socket
socket.pool.checkin(socket)
end
end
# Excecutes block with the best available socket
def best_available_socket
socket = nil
begin
socket = checkout_best
yield socket
ensure
if socket
socket.pool.checkin(socket)
end
end
end
protected
def valid_opts
GENERIC_OPTS + CONNECTION_OPTS
end
def check_opts(opts)
bad_opts = opts.keys.reject { |opt| valid_opts.include?(opt) }
unless bad_opts.empty?
bad_opts.each {|opt| warn "#{opt} is not a valid option for #{self.class}"}
end
end
# Parse option hash
def setup(opts)
# slave_ok can be true only if one node is specified
@slave_ok = opts[:slave_ok]
# Determine whether to use SSL.
@ssl = opts.fetch(:ssl, false)
if @ssl
@socket_class = Mongo::SSLSocket
else
@socket_class = Mongo::TCPSocket
end
# Authentication objects
@auths = opts.fetch(:auths, [])
# 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
# Global safe option. This is false by default.
@safe = opts[:safe] || false
@logger = opts.fetch(:logger, nil)
if @logger
write_logging_startup_message
end
if opts.fetch(:connect, true)
connect
end
end
private
## Methods for establishing a connection:
# If a ConnectionFailure is raised, this method will be called
# to close the connection and reset connection values.
# TODO: evaluate whether this method is actually necessary
def reset_connection
close
end
def check_is_master(node)
begin
host, port = *node
socket = nil
config = nil
socket = @socket_class.new(host, port, @op_timeout, @connect_timeout)
config = self['admin'].command({:ismaster => 1}, :socket => socket)
rescue OperationFailure, SocketError, SystemCallError, IOError
close
ensure
if socket
socket.close unless socket.closed?
end
end
config
end
# Set the specified node as primary.
def set_primary(node)
host, port = *node
@primary = [host, port]
@primary_pool = Pool.new(self, host, port, :size => @pool_size, :timeout => @pool_timeout)
end
end
end