Merge branch 'master' into remove-deprecated-monkey-patch-methods

README.md

@@ -19,9 +19,9 @@ Compatibility
 
 Mongoid supports and is tested against:
 
-- MRI 2.7 - 3.1
+- MRI 2.7 - 3.2
 - JRuby 9.4
-- MongoDB server 3.6 - 6.0
+- MongoDB server 3.6 - 7.0
 
 Issues
 ------

docs/reference/configuration.txt

@@ -863,58 +863,57 @@ as the following example shows:
 Usage with Forking Servers
 ==========================
 
-When using Mongoid with a forking web server such as Puma, Unicorn or
-Passenger, it is recommended to not perform any operations on Mongoid models
-in the parent process prior to the fork.
-
-When a process forks, Ruby threads are not transferred to the child processes
-and the Ruby driver Client objects lose their background monitoring. The
-application will typically seem to work just fine until the deployment
-state changes (for example due to network errors, a maintenance event) at
-which point the application is likely to start getting ``NoServerAvailable``
-exception when performing MongoDB operations.
-
-If the parent process needs to perform operations on the MongoDB database,
-reset all clients in the workers after they forked. How to do so depends
-on the web server being used.
-
-If the parent process does not need to perform operations on the MongoDB
-database after child processes are forked, close the clients in the parent
-prior to forking children. If the parent process performs operations on a Mongo
-client and does not close it, the parent process will continue consuming a
-connection slot in the cluster and will continue monitoring the cluster for
-as long as the parent remains alive.
-
-.. note::
-
-  The close/reconnect pattern described here should be used with Ruby driver
-  version 2.6.2 or higher. Previous driver versions did not recreate
-  monitoring threads when reconnecting.
+When using Mongoid with a forking web server such as Puma, or any application
+that otherwise forks to spawn child processes, special considerations apply.
+
+If possible, we recommend to not perform any MongoDB operations in the parent
+process prior to forking, which will avoid any forking-related pitfalls.
+
+A detailed technical explanation of how the Mongo Ruby Driver handles forking
+is given in the `driver's "Usage with Forking Servers" documentation
+<https://www.mongodb.com/docs/ruby-driver/current/reference/create-client/#usage-with-forking-servers>`.
+In a nutshell, to avoid various connection errors such as ``Mongo::Error::SocketError``
+and ``Mongo::Error::NoServerAvailable``, you must do the following:
+
+1. Disconnect MongoDB clients in the parent Ruby process immediately *before*
+   forking using ``Mongoid.disconnect_clients``. This ensures the parent and child
+   process do not accidentally reuse the same sockets and have I/O conflicts.
+   Note that ``Mongoid.disconnect_clients`` does not disrupt any in-flight
+   MongoDB operations, and will automatically reconnect when you perform new
+   operations.
+2. Reconnect your MongoDB clients in the child Ruby process immediately *after*
+   forking using ``Mongoid.reconnect_clients``. This is required to respawn
+   the driver's monitoring threads in the child process.
+
+Most web servers provide hooks that can be used by applications to
+perform actions when the worker processes are forked. The following
+are configuration examples for several common Ruby web servers.
 
 Puma
 ----
 
 Use the ``on_worker_boot`` hook to reconnect clients in the workers and
-the ``before_fork`` hook to close clients in the parent process
-(`Puma documentation <https://puma.io/puma/>`_):
+the ``before_fork`` and ``on_refork`` hooks to close clients in the
+parent process (`Puma documentation <https://puma.io/puma/#clustered-mode>`_).
 
 .. code-block:: ruby
 
-  on_worker_boot do
-    if defined?(Mongoid)
-      Mongoid::Clients.clients.each do |name, client|
-        client.close
-        client.reconnect
-      end
-    else
-      raise "Mongoid is not loaded. You may have forgotten to enable app preloading."
-    end
-  end
+  # config/puma.rb
 
+  # Runs in the Puma master process before it forks a child worker.
   before_fork do
-    if defined?(Mongoid)
-      Mongoid.disconnect_clients
-    end
+    Mongoid.disconnect_clients
+  end
+
+  # Required when using Puma's fork_worker option. Runs in the
+  # child worker 0 process before it forks grandchild workers.
+  on_refork do
+    Mongoid.disconnect_clients
+  end
+
+  # Runs in each Puma child process after it forks from its parent.
+  on_worker_boot do
+    Mongoid.reconnect_clients
   end
 
 Unicorn
@@ -926,21 +925,14 @@ the ``before_fork`` hook to close clients in the parent process
 
 .. code-block:: ruby
 
-  after_fork do |server, worker|
-    if defined?(Mongoid)
-      Mongoid::Clients.clients.each do |name, client|
-        client.close
-        client.reconnect
-      end
-    else
-      raise "Mongoid is not loaded. You may have forgotten to enable app preloading."
-    end
+  # config/unicorn.rb
+
+  before_fork do |_server, _worker|
+    Mongoid.disconnect_clients
   end
 
-  before_fork do |server, worker|
-    if defined?(Mongoid)
-      Mongoid.disconnect_clients
-    end
+  after_fork do |_server, _worker|
+    Mongoid.reconnect_clients
   end
 
 Passenger
@@ -956,12 +948,7 @@ before the workers are forked.
 
   if defined?(PhusionPassenger)
     PhusionPassenger.on_event(:starting_worker_process) do |forked|
-      if forked
-        Mongoid::Clients.clients.each do |name, client|
-          client.close
-          client.reconnect
-        end
-      end
+      Mongoid.reconnect_clients if forked
     end
   end
 

lib/mongoid.rb

@@ -100,6 +100,16 @@ def disconnect_clients
     Clients.disconnect
   end
 
+  # Reconnect all active clients.
+  #
+  # @example Reconnect all active clients.
+  #   Mongoid.reconnect_clients
+  #
+  # @return [ true ] True.
+  def reconnect_clients
+    Clients.reconnect
+  end
+
   # Convenience method for getting a named client.
   #
   # @example Get a named client.

lib/mongoid/clients.rb

@@ -47,9 +47,19 @@ def default
       #
       # @return [ true ] True.
       def disconnect
-        clients.values.each do |client|
-          client.close
-        end
+        clients.each_value(&:close)
+        true
+      end
+
+      # Reconnect all active clients.
+      #
+      # @example Reconnect all active clients.
+      #   Mongoid::Clients.reconnect
+      #
+      # @return [ true ] True.
+      def reconnect
+        clients.each_value(&:reconnect)
+        true
       end
 
       # Get a stored client with the provided name. If no client exists

lib/mongoid/config.rb

@@ -376,10 +376,14 @@ def time_zone
     #   config.running_with_passenger?
     #
     # @return [ true | false ] If the app is deployed on Passenger.
+    #
+    # @deprecated
     def running_with_passenger?
       @running_with_passenger ||= defined?(PhusionPassenger)
     end
 
+    Mongoid.deprecate(self, :running_with_passenger?)
+
     private
 
     def set_log_levels

lib/mongoid/config/defaults.rb

@@ -25,6 +25,8 @@ def load_defaults(version)
         when "8.1"
           self.immutable_ids = false
           self.legacy_persistence_context_behavior = true
+          self.around_callbacks_for_embeds = true
+          self.prevent_multiple_calls_of_embedded_callbacks = false
 
           load_defaults "9.0"
         when "9.0"