Class: Mongo::Server::Monitor

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Includes:
Loggable
Defined in:
lib/mongo/server/monitor.rb,
lib/mongo/server/monitor/connection.rb

Overview

This object is responsible for keeping server status up to date, running in a separate thread as to not disrupt other operations.

Since:

  • 2.0.0

Defined Under Namespace

Classes: Connection

Constant Summary collapse

HEARTBEAT_FREQUENCY =

The default time for a server to refresh its status is 10 seconds.

Since:

  • 2.0.0

10.freeze
MIN_SCAN_FREQUENCY =

The minimum time between forced server scans. Is minHeartbeatFrequencyMS in the SDAM spec.

Since:

  • 2.0.0

0.5.freeze
RTT_WEIGHT_FACTOR =

The weighting factor (alpha) for calculating the average moving round trip time.

Since:

  • 2.0.0

0.2.freeze

Constants included from Loggable

Loggable::PREFIX

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Loggable

#log_debug, #log_error, #log_fatal, #log_info, #log_warn, #logger

Constructor Details

#initialize(address, listeners, options = {}) ⇒ Monitor

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Note:

Monitor must never be directly instantiated outside of a Server.

Create the new server monitor.

Examples:

Create the server monitor.

Mongo::Server::Monitor.new(address, listeners)

Parameters:

  • address (Address) —

    The address to monitor.

  • listeners (Event::Listeners) —

    The event listeners.

  • options (Hash) (defaults to: {}) —

    The options.

Since:

  • 2.0.0



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# File 'lib/mongo/server/monitor.rb', line 116

def initialize(address, listeners, options = {})
  @description = Description.new(address, {})
  @inspector = Description::Inspector.new(listeners)
  @options = options.freeze
  @connection = Connection.new(address, options)
  @last_round_trip_time = nil
  @last_scan = nil
  @mutex = Mutex.new
end

Instance Attribute Details

#connection ⇒ Mongo::Connection (readonly)

Returns connection The connection to use.

Returns:

  • (Mongo::Connection) —

    connection The connection to use.

Since:

  • 2.0.0



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# File 'lib/mongo/server/monitor.rb', line 45

def connection
  @connection
end

#description ⇒ Server::Description (readonly)

Returns description The server description the monitor refreshes.

Returns:

Since:

  • 2.0.0



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# File 'lib/mongo/server/monitor.rb', line 49

def description
  @description
end

#inspector ⇒ Description::Inspector (readonly)

Returns inspector The description inspector.

Returns:

Since:

  • 2.0.0



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# File 'lib/mongo/server/monitor.rb', line 52

def inspector
  @inspector
end

#last_scan ⇒ Time (readonly)

Returns last_scan The time of the last server scan.

Returns:

  • (Time) —

    last_scan The time of the last server scan.

Since:

  • 2.4.0



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# File 'lib/mongo/server/monitor.rb', line 60

def last_scan
  @last_scan
end

#options ⇒ Hash (readonly)

Returns options The server options.

Returns:

  • (Hash) —

    options The server options.

Since:

  • 2.0.0



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# File 'lib/mongo/server/monitor.rb', line 55

def options
  @options
end

Instance Method Details

#heartbeat_frequency ⇒ Integer

Get the refresh interval for the server. This will be defined via an option or will default to 5.

Examples:

Get the refresh interval.

server.heartbeat_frequency

Returns:

  • (Integer) —

    The heartbeat frequency, in seconds.

Since:

  • 2.0.0



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# File 'lib/mongo/server/monitor.rb', line 98

def heartbeat_frequency
  @heartbeat_frequency ||= options[:heartbeat_frequency] || HEARTBEAT_FREQUENCY
end

#restart! ⇒ Thread

Restarts the server monitor unless the current thread is alive.

Examples:

Restart the monitor.

monitor.restart!

Returns:

  • (Thread) —

    The thread the monitor runs on.

Since:

  • 2.1.0



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# File 'lib/mongo/server/monitor.rb', line 165

def restart!
  @thread.alive? ? @thread : run!
end

#run! ⇒ Thread

Runs the server monitor. Refreshing happens on a separate thread per server.

Examples:

Run the monitor.

monitor.run

Returns:

  • (Thread) —

    The thread the monitor runs on.

Since:

  • 2.0.0



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# File 'lib/mongo/server/monitor.rb', line 135

def run!
  @thread = Thread.new(heartbeat_frequency) do |i|
    loop do
      sleep(i)
      scan!
    end
  end
end

#scan! ⇒ Description

Note:

If the system clock is set to a time in the past, this method can sleep for a very long time.

Perform a check of the server with throttling, and update the server’s description.

If the server was checked less than MIN_SCAN_FREQUENCY seconds ago, sleep until MIN_SCAN_FREQUENCY seconds have passed since the last check. Then perform the check which involves running isMaster on the server being monitored and updating the server description as a result.

Examples:

Run a scan.

monitor.scan!

Returns:

Since:

  • 2.0.0



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# File 'lib/mongo/server/monitor.rb', line 84

def scan!
  throttle_scan_frequency!
  @description = inspector.run(description, *ismaster)
end

#stop! ⇒ Boolean

Stops the server monitor. Kills the thread so it doesn’t continue taking memory and sending commands to the connection.

Examples:

Stop the monitor.

monitor.stop!

Returns:

  • (Boolean) —

    Is the Thread stopped?

Since:

  • 2.0.0



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# File 'lib/mongo/server/monitor.rb', line 153

def stop!
  connection.disconnect! && @thread.kill && @thread.stop?
end