Monitor Application Events

require 'mongo'
# Creates a subscriber for command monitoring
subscriber = Mongo::Monitoring::CommandLogSubscriber.new
# Globally subscribes to command monitoring events
Mongo::Monitoring::Global.subscribe(Mongo::Monitoring::COMMAND, subscriber)
# Replace with your connection string and connect to your client
uri = '<connection string>'
client = Mongo::Client.new(uri)
# Subscribes to command monitoring events at the client level
client.subscribe( Mongo::Monitoring::COMMAND, subscriber)

require 'mongo'
subscriber = Mongo::Monitoring::ServerOpeningLogSubscriber.new
# Globally subscribes to ServerOpening events by using the SERVER_OPENING monitoring topic
Mongo::Monitoring::Global.subscribe(Mongo::Monitoring::SERVER_OPENING, subscriber)
# Replace with your connection string and connect to your client
uri = '<connection string>'
client = Mongo::Client.new(uri)
# Subscribes to ServerOpening events at the client level by using the SERVER_OPENING monitoring topic
client.subscribe(Mongo::Monitoring::SERVER_OPENING, subscriber)

class SDAMLogSubscriber
  include Mongo::Loggable
  def succeeded(event)
    log_debug(format_event(event))
  end
  private
  def logger
    Mongo::Logger.logger
  end
  def format_message(message)
    format("SDAM | %s", message)
  end
end
  
class TopologyOpeningLogSubscriber < SDAMLogSubscriber
  private
  def format_event(event)
    "Topology type '#{event.topology.display_name}' initializing."
  end
end
class ServerOpeningLogSubscriber < SDAMLogSubscriber
  private
  def format_event(event)
    "Server #{event.address} initializing."
  end
end
class ServerDescriptionChangedLogSubscriber < SDAMLogSubscriber
  private
  def format_event(event)
    "Server description for #{event.address} changed from " +
    "'#{event.previous_description.server_type}' to '#{event.new_description.server_type}'."
  end
end
class TopologyChangedLogSubscriber < SDAMLogSubscriber
  private
  def format_event(event)
    if event.previous_topology != event.new_topology
      "Topology type '#{event.previous_topology.display_name}' changed to " +
      "type '#{event.new_topology.display_name}'."
    else
      "There was a change in the members of the '#{event.new_topology.display_name}' " +
      "topology."
    end
  end
end
class ServerClosedLogSubscriber < SDAMLogSubscriber
  private
  def format_event(event)
    "Server #{event.address} connection closed."
  end
end
class TopologyClosedLogSubscriber < SDAMLogSubscriber
  private
  def format_event(event)
    "Topology type '#{event.topology.display_name}' closed."
  end
end

topology_opening_subscriber = TopologyOpeningLogSubscriber.new
server_opening_subscriber = ServerOpeningLogSubscriber.new
server_description_changed_subscriber = ServerDescriptionChangedLogSubscriber.new
topology_changed_subscriber = TopologyChangedLogSubscriber.new
server_closed_subscriber = ServerClosedLogSubscriber.new
topology_closed_subscriber = TopologyClosedLogSubscriber.new
Mongo::Monitoring::Global.subscribe(Mongo::Monitoring::TOPOLOGY_OPENING,
  topology_opening_subscriber)
Mongo::Monitoring::Global.subscribe(Mongo::Monitoring::SERVER_OPENING,
  server_opening_subscriber)
Mongo::Monitoring::Global.subscribe(Mongo::Monitoring::SERVER_DESCRIPTION_CHANGED,
  server_description_changed_subscriber)
Mongo::Monitoring::Global.subscribe(Mongo::Monitoring::TOPOLOGY_CHANGED,
  topology_changed_subscriber)
Mongo::Monitoring::Global.subscribe(Mongo::Monitoring::SERVER_CLOSED,
  server_closed_subscriber)
Mongo::Monitoring::Global.subscribe(Mongo::Monitoring::TOPOLOGY_CLOSED,
  topology_closed_subscriber)

topology_opening_subscriber = TopologyOpeningLogSubscriber.new
server_opening_subscriber = ServerOpeningLogSubscriber.new
server_description_changed_subscriber = ServerDescriptionChangedLogSubscriber.new
topology_changed_subscriber = TopologyChangedLogSubscriber.new
server_closed_subscriber = ServerClosedLogSubscriber.new
topology_closed_subscriber = TopologyClosedLogSubscriber.new
sdam_proc = Proc.new do |client|
  client.subscribe(Mongo::Monitoring::TOPOLOGY_OPENING,
    topology_opening_subscriber)
  client.subscribe(Mongo::Monitoring::SERVER_OPENING,
    server_opening_subscriber)
  client.subscribe(Mongo::Monitoring::SERVER_DESCRIPTION_CHANGED,
    server_description_changed_subscriber)
  client.subscribe(Mongo::Monitoring::TOPOLOGY_CHANGED,
    topology_changed_subscriber)
  client.subscribe(Mongo::Monitoring::SERVER_CLOSED,
    server_closed_subscriber)
  client.subscribe(Mongo::Monitoring::TOPOLOGY_CLOSED,
    topology_closed_subscriber)
end
client = Mongo::Client.new(['127.0.0.1:27017'], database: 'test',
  sdam_proc: sdam_proc)

require 'mongo'
# Creates a subscriber for connection pool monitoring
subscriber = Mongo::Monitoring::CmapLogSubscriber.new
# Globally subscribes to connection pool monitoring events
Mongo::Monitoring::Global.subscribe(Mongo::Monitoring::CONNECTION_POOL, subscriber)
# Replace with your connection string and connect to your client
uri = '<connection string>'
client = Mongo::Client.new(uri)
# Subscribes to connection pool monitoring events at the client level
client.subscribe(Mongo::Monitoring::CONNECTION_POOL, subscriber)