class Mongo::Server

Represents a single server on the server side that can be standalone, part of a replica set, or a mongos.

@since 2.0.0

Constants

CONNECT_TIMEOUT

The default time in seconds to timeout a connection attempt.

@since 2.4.3

Attributes

address[R]

@return [ String ] The configured address for the server.

cluster[R]

@return [ Cluster ] cluster The server cluster.

description[R]

@return [ Server::Description ] description The server

description the monitor refreshes.
monitor[R]

@return [ nil | Monitor ] monitor The server monitor. nil if the servenr

was created with monitoring_io: false option.
monitoring[R]

@return [ Monitoring ] monitoring The monitoring.

options[R]

@return [ Hash ] The options hash.

round_trip_time_averager[R]

@return [ RoundTripTimeAverager ] Round trip time averager object. @api private

scan_semaphore[R]

@return [ Semaphore ] Semaphore to signal to request an immediate scan

of this server by its monitor, if one is running.

@api private

Public Class Methods

new(address, cluster, monitoring, event_listeners, options = {}) click to toggle source

Instantiate a new server object. Will start the background refresh and subscribe to the appropriate events.

@api private

@example Initialize the server.

Mongo::Server.new('127.0.0.1:27017', cluster, monitoring, listeners)

@note Server must never be directly instantiated outside of a Cluster.

@param [ Address ] address The host:port address to connect to. @param [ Cluster ] cluster The cluster the server belongs to. @param [ Monitoring ] monitoring The monitoring. @param [ Event::Listeners ] event_listeners The event listeners. @param [ Hash ] options The server options.

@option options [ Boolean ] :monitor For internal driver use only:

whether to monitor the server after instantiating it.

@option options [ true, false ] :monitoring_io For internal driver

use only. Set to false to prevent SDAM-related I/O from being
done by this server. Note: setting this option to false will make
the server non-functional. It is intended for use in tests which
manually invoke SDAM state transitions.

@option options [ true, false ] :populator_io For internal driver

use only. Set to false to prevent the populator threads from being
created and started in the server's connection pool. It is intended
for use in tests that also turn off monitoring_io, unless the populator
is explicitly needed. If monitoring_io is off, but the populator_io
is on, the populator needs to be manually closed at the end of the
test, since a cluster without monitoring is considered not connected,
and thus will not clean up the connection pool populator threads on
close.

@option options [ true | false ] :load_balancer Whether this server

is a load balancer.

@option options [ String ] :connect The client connection mode.

@since 2.0.0

# File lib/mongo/server.rb, line 71
def initialize(address, cluster, monitoring, event_listeners, options = {})
  @address = address
  @cluster = cluster
  @monitoring = monitoring
  options = options.dup
  _monitor = options.delete(:monitor)
  @options = options.freeze
  @event_listeners = event_listeners
  @connection_id_gen = Class.new do
    include Id
  end
  @scan_semaphore = DistinguishingSemaphore.new
  @round_trip_time_averager = RoundTripTimeAverager.new
  @description = Description.new(address, {},
    load_balancer: !!@options[:load_balancer],
    force_load_balancer: force_load_balancer?,
  )
  @last_scan = nil
  @last_scan_monotime = nil
  unless options[:monitoring_io] == false
    @monitor = Monitor.new(self, event_listeners, monitoring,
      options.merge(
        app_metadata: cluster.monitor_app_metadata,
        push_monitor_app_metadata: cluster.push_monitor_app_metadata,
        heartbeat_interval: cluster.heartbeat_interval,
    ))
    unless _monitor == false
      start_monitoring
    end
  end
  @connected = true
  @pool_lock = Mutex.new
end

Public Instance Methods

==(other) click to toggle source

Is this server equal to another?

@example Is the server equal to the other?

server == other

@param [ Object ] other The object to compare to.

@return [ true, false ] If the servers are equal.

@since 2.0.0

# File lib/mongo/server.rb, line 245
def ==(other)
  return false unless other.is_a?(Server)
  address == other.address
end
clear_connection_pool(service_id: nil, interrupt_in_use_connections: false) click to toggle source

@param [ Object ] :service_id Close connections with the specified

service id only.

@param [ true | false ] :interrupt_in_use_connections Whether or not the

cleared connections should be interrupted as well.

@api private

# File lib/mongo/server.rb, line 667
def clear_connection_pool(service_id: nil, interrupt_in_use_connections: false)
  @pool_lock.synchronize do
    # A server being marked unknown after it is closed is technically
    # incorrect but it does not meaningfully alter any state.
    # Because historically the driver permitted servers to be marked
    # unknown at any time, continue doing so even if the pool is closed.
    if @pool && !@pool.closed?
      @pool.disconnect!(service_id: service_id, interrupt_in_use_connections: interrupt_in_use_connections)
    end
  end
end
clear_description() click to toggle source

Clear the servers description so that it is considered unknown and can be safely disconnected.

@api private

# File lib/mongo/server.rb, line 657
def clear_description
  @description = Mongo::Server::Description.new(address, {})
end
close() click to toggle source
# File lib/mongo/server.rb, line 294
def close
  if monitor
    monitor.stop!
  end

  @connected = false

  _pool = nil
  @pool_lock.synchronize do
    _pool, @pool = @pool, nil
  end

  # TODO: change this to _pool.close in RUBY-3174.
  # Clear the pool. If the server is not unknown then the
  # pool will stay ready. Stop the background populator thread.
  _pool&.close(stay_ready: true)

  nil
end
compressor() click to toggle source

The compressor negotiated by the server monitor, if any.

This attribute is nil if no server check has not yet completed, and if no compression was negatiated.

@note Compression is negotiated for each connection separately.

@return [ String | nil ] The negotiated compressor.

@deprecated

# File lib/mongo/server.rb, line 181
def compressor
  if monitor
    monitor.compressor
  else
    nil
  end
end
connectable?() click to toggle source

Determine if a connection to the server is able to be established and messages can be sent to it.

@example Is the server connectable?

server.connectable?

@return [ true, false ] If the server is connectable.

@since 2.1.0

@deprecated No longer necessary with Server Selection specification.

# File lib/mongo/server.rb, line 261
def connectable?; end
connected?() click to toggle source

Whether the server is connected.

@return [ true|false ] Whether the server is connected.

@api private @since 2.7.0

# File lib/mongo/server.rb, line 320
def connected?
  @connected
end
disconnect!() click to toggle source

Disconnect the driver from this server.

Disconnects all idle connections to this server in its connection pool, if any exist. Stops the populator of the connection pool, if it is running. Does not immediately close connections which are presently checked out (i.e. in use) - such connections will be closed when they are returned to their respective connection pools. Stop the server’s background monitor.

@return [ true ] Always true.

@since 2.0.0

# File lib/mongo/server.rb, line 275
def disconnect!
  if monitor
    monitor.stop!
  end

  @connected = false

  # The current CMAP spec requires a pool to be mostly unusable
  # if its server is unknown (or, therefore, disconnected).
  # However any outstanding operations should continue to completion,
  # and their connections need to be checked into the pool to be
  # torn down. Because of this cleanup requirement we cannot just
  # close the pool and set it to nil here, to be recreated the next
  # time the server is discovered.
  pool_internal&.clear

  true
end
force_load_balancer?() click to toggle source

Returns whether this server is forced to be a load balancer.

@return [ true | false ] Whether this server is forced to be a load balancer.

@api private

# File lib/mongo/server.rb, line 130
def force_load_balancer?
  options[:connect] == :load_balanced
end
handle_auth_failure!() { || ... } click to toggle source

Handle authentication failure.

@example Handle possible authentication failure.

server.handle_auth_failure! do
  Auth.get(user).login(self)
end

@raise [ Auth::Unauthorized ] If the authentication failed.

@return [ Object ] The result of the block execution.

@since 2.3.0

# File lib/mongo/server.rb, line 524
def handle_auth_failure!
  yield
rescue Mongo::Error::SocketTimeoutError
  # possibly cluster is slow, do not give up on it
  raise
rescue Mongo::Error::SocketError, Auth::Unauthorized => e
  # non-timeout network error or auth error, clear the pool and mark the
  # topology as unknown
  unknown!(
    generation: e.generation,
    service_id: e.service_id,
    stop_push_monitor: true,
  )
  raise
end
handle_handshake_failure!() { || ... } click to toggle source

Handle handshake failure.

@since 2.7.0 @api private

# File lib/mongo/server.rb, line 501
def handle_handshake_failure!
  yield
rescue Mongo::Error::SocketError, Mongo::Error::SocketTimeoutError => e
  unknown!(
    generation: e.generation,
    service_id: e.service_id,
    stop_push_monitor: true,
  )
  raise
end
heartbeat_frequency() click to toggle source

@deprecated

# File lib/mongo/server.rb, line 159
def heartbeat_frequency
  cluster.heartbeat_interval
end
Also aliased as: heartbeat_frequency_seconds
heartbeat_frequency_seconds()

@deprecated

Alias for: heartbeat_frequency
inspect() click to toggle source

Get a pretty printed server inspection.

@example Get the server inspection.

server.inspect

@return [ String ] The nice inspection string.

@since 2.0.0

# File lib/mongo/server.rb, line 355
def inspect
  "#<Mongo::Server:0x#{object_id} address=#{address.host}:#{address.port} #{status}>"
end
last_scan() click to toggle source

@return [ Time | nil ] last_scan The time when the last server scan

completed, or nil if the server has not been scanned yet.

@since 2.4.0

# File lib/mongo/server.rb, line 138
def last_scan
  if description && !description.config.empty?
    description.last_update_time
  else
    @last_scan
  end
end
last_scan_monotime() click to toggle source

@return [ Float | nil ] last_scan_monotime The monotonic time when the last server scan

completed, or nil if the server has not been scanned yet.

@api private

# File lib/mongo/server.rb, line 149
def last_scan_monotime
  if description && !description.config.empty?
    description.last_update_monotime
  else
    @last_scan_monotime
  end
end
matches_tag_set?(tag_set) click to toggle source

Determine if the provided tags are a subset of the server’s tags.

@example Are the provided tags a subset of the server’s tags.

server.matches_tag_set?({ 'rack' => 'a', 'dc' => 'nyc' })

@param [ Hash ] tag_set The tag set to compare to the server’s tags.

@return [ true, false ] If the provided tags are a subset of the server’s tags.

@since 2.0.0

# File lib/mongo/server.rb, line 461
def matches_tag_set?(tag_set)
  tag_set.keys.all? do |k|
    tags[k] && tags[k] == tag_set[k]
  end
end
next_connection_id() click to toggle source

@api private

# File lib/mongo/server.rb, line 680
def next_connection_id
  @connection_id_gen.next_id
end
pool() click to toggle source

Get the connection pool for this server.

@example Get the connection pool for the server.

server.pool

@return [ Mongo::Server::ConnectionPool ] The connection pool.

@since 2.0.0

# File lib/mongo/server.rb, line 424
def pool
  if unknown?
    raise Error::ServerNotUsable, address
  end

  @pool_lock.synchronize do
    opts = connected? ? options : options.merge(populator_io: false)
    @pool ||= ConnectionPool.new(self, opts).tap do |pool|
      pool.ready
    end
  end
end
pool_internal() click to toggle source

Internal driver method to retrieve the connection pool for this server.

Unlike pool, pool_internal will not create a pool if one does not already exist.

@return [ Server::ConnectionPool | nil ] The connection pool, if one exists.

@api private

# File lib/mongo/server.rb, line 445
def pool_internal
  @pool_lock.synchronize do
    @pool
  end
end
publish_opening_event() click to toggle source

Publishes the server opening event.

@api private

# File lib/mongo/server.rb, line 340
def publish_opening_event
  publish_sdam_event(
    Monitoring::SERVER_OPENING,
    Monitoring::Event::ServerOpening.new(address, cluster.topology)
  )
end
reconnect!() click to toggle source

Restart the server monitor.

@example Restart the server monitor.

server.reconnect!

@return [ true ] Always true.

@since 2.1.0

# File lib/mongo/server.rb, line 475
def reconnect!
  if options[:monitoring_io] != false
    monitor.restart!
  end
  @connected = true
end
retry_reads?() click to toggle source

Whether the server supports modern read retries.

@api private

# File lib/mongo/server.rb, line 543
def retry_reads?
  !!(features.sessions_enabled? && logical_session_timeout)
end
retry_writes?() click to toggle source

Will writes sent to this server be retried.

@example Will writes be retried.

server.retry_writes?

@return [ true, false ] If writes will be retried.

@note Retryable writes are only available on server versions 3.6+ and with

sharded clusters or replica sets.

@note Some of the conditions in this method automatically return false for

for load balanced topologies. The conditions in this method should
always be true, since load-balanced topologies are only available on
MongoDB 5.0+, and not for standalone topologies. Therefore, we can
assume that retry writes are enabled.

@since 2.5.0

# File lib/mongo/server.rb, line 564
def retry_writes?
  !!(features.sessions_enabled? && logical_session_timeout && !standalone?) || load_balancer?
end
start_monitoring() click to toggle source

Start monitoring the server.

Used internally by the driver to add a server to a cluster while delaying monitoring until the server is in the cluster.

@api private

# File lib/mongo/server.rb, line 330
def start_monitoring
  publish_opening_event
  if options[:monitoring_io] != false
    monitor.run!
  end
end
status() click to toggle source

@return [ String ] String representing server status (e.g. PRIMARY).

@api private

# File lib/mongo/server.rb, line 362
def status
  case
  when load_balancer?
    'LB'
  when primary?
    'PRIMARY'
  when secondary?
    'SECONDARY'
  when standalone?
    'STANDALONE'
  when arbiter?
    'ARBITER'
  when ghost?
    'GHOST'
  when other?
    'OTHER'
  when mongos?
    'MONGOS'
  when unknown?
    'UNKNOWN'
  else
    # Since the summary method is often used for debugging, do not raise
    # an exception in case none of the expected types matched
    nil
  end
end
summary() click to toggle source

@note This method is experimental and subject to change.

@api experimental @since 2.7.0

# File lib/mongo/server.rb, line 393
def summary
  status = self.status || ''
  if replica_set_name
    status += " replica_set=#{replica_set_name}"
  end

  unless monitor&.running?
    status += " NO-MONITORING"
  end

  if @pool
    status += " pool=#{@pool.summary}"
  end

  address_bit = if address
    "#{address.host}:#{address.port}"
  else
    'nil'
  end

  "#<Server address=#{address_bit} #{status}>"
end
unknown!(options = {}) click to toggle source

Marks server unknown and publishes the associated SDAM event (server description changed).

If the generation is passed in options, the server will only be marked unknown if the passed generation is no older than the current generation of the server’s connection pool.

@param [ Hash ] options Options.

@option options [ Integer ] :generation Connection pool generation of

the connection that was used for the operation that produced the error.

@option options [ true | false ] :keep_connection_pool Usually when the

new server description is unknown, the connection pool on the
respective server is cleared. Set this option to true to keep the
existing connection pool (required when handling not master errors
on 4.2+ servers).

@option options [ TopologyVersion ] :topology_version Topology version

of the error response that is causing the server to be marked unknown.

@option options [ true | false ] :stop_push_monitor Whether to stop

the PushMonitor associated with the server, if any.

@option options [ Object ] :service_id Discard state for the specified

service id only.

@since 2.4.0, SDAM events are sent as of version 2.7.0

# File lib/mongo/server.rb, line 592
def unknown!(options = {})
  pool = pool_internal

  if load_balancer?
    # When the client is in load-balanced topology, servers (the one and
    # only that can be) starts out as a load balancer and stays as a
    # load balancer indefinitely. As such it is not marked unknown.
    #
    # However, this method also clears connection pool for the server
    # when the latter is marked unknown, and this part needs to happen
    # when the server is a load balancer.
    #
    # It is possible for a load balancer server to not have a service id,
    # for example if there haven't been any successful connections yet to
    # this server, but the server can still be marked unknown if one
    # of such connections failed midway through its establishment.
    if service_id = options[:service_id]
      pool&.disconnect!(service_id: service_id)
    end
    return
  end

  if options[:generation] && options[:generation] < pool&.generation
    return
  end

  if options[:topology_version] && description.topology_version &&
    !options[:topology_version].gt?(description.topology_version)
  then
    return
  end

  if options[:stop_push_monitor]
    monitor&.stop_push_monitor!
  end

  # SDAM flow will update description on the server without in-place
  # mutations and invoke SDAM transitions as needed.
  config = {}
  if options[:service_id]
    config['serviceId'] = options[:service_id]
  end
  if options[:topology_version]
    config['topologyVersion'] = options[:topology_version]
  end
  new_description = Description.new(address, config,
    load_balancer: load_balancer?,
    force_load_balancer: options[:connect] == :load_balanced,
  )
  cluster.run_sdam_flow(description, new_description, options)
end
update_description(description) click to toggle source

@api private

# File lib/mongo/server.rb, line 645
def update_description(description)
  pool = pool_internal
  if pool && !description.unknown?
    pool.ready
  end
  @description = description
end
update_last_scan() click to toggle source

@api private

# File lib/mongo/server.rb, line 685
def update_last_scan
  @last_scan = Time.now
  @last_scan_monotime = Utils.monotonic_time
end
with_connection(connection_global_id: nil, &block) click to toggle source

Execute a block of code with a connection, that is checked out of the server’s pool and then checked back in.

@example Send a message with the connection.

server.with_connection do |connection|
  connection.dispatch([ command ])
end

@return [ Object ] The result of the block execution.

@since 2.3.0

# File lib/mongo/server.rb, line 493
def with_connection(connection_global_id: nil, &block)
  pool.with_connection(connection_global_id: connection_global_id, &block)
end