Class: ActiveReplicas::Rails4::ProcessLocalConnectionHandler

Inherits:
Object
  • Object
show all
Defined in:
lib/active_replicas/rails4/process_local_connection_handler.rb

Overview

Provisioned for each process by ConnectionHandler. Each process owns its own pools of connections to primary and replica databases. Proxying connection pools are then provisioned for each thread.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(proxy_configuration) ⇒ ProcessLocalConnectionHandler

Returns a new instance of ProcessLocalConnectionHandler.



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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 14

def initialize(proxy_configuration)
  @proxy_configuration = proxy_configuration
  initialize_pools

  # Each thread gets its own `ProxyingConnectionPool`.
  @reserved_proxies = Concurrent::Map.new

  extend MonitorMixin
end

Instance Attribute Details

#primary_pool ⇒ Object (readonly)

Returns the value of attribute primary_pool.



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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 12

def primary_pool
  @primary_pool
end

#proxy_configuration ⇒ Object (readonly)

Returns the value of attribute proxy_configuration.



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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 11

def proxy_configuration
  @proxy_configuration
end

#replica_pools ⇒ Object (readonly)

Returns the value of attribute replica_pools.



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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 12

def replica_pools
  @replica_pools
end

Instance Method Details

#active_connections? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 50

def active_connections?
  connection_pool_list.any?(&:active_connection?)
end

#clear_active_connections! ⇒ Object 



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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 54

def clear_active_connections!
  synchronize do
    connection_pool_list.each(&:release_connection)
    clear_current_proxy
  end
end

#clear_all_connections! ⇒ Object 



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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 68

def clear_all_connections!
  synchronize do
    connection_pool_list.each(&:disconnect!)
    clear_proxies!
  end
end

#clear_current_proxy ⇒ Object

Remove the current reserved ProxyingConnectionPool from the pool.



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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 113

def clear_current_proxy
  @reserved_proxies.delete current_thread_id
end

#clear_proxies! ⇒ Object

Clear all reserved ProxyingConnectionPool instances from the pool.



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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 118

def clear_proxies!
  @reserved_proxies.clear
end

#clear_reloadable_connections! ⇒ Object 



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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 61

def clear_reloadable_connections!
  synchronize do
    connection_pool_list.each(&:clear_reloadable_connections!)
    clear_proxies!
  end
end

#connected?(klass) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 85

def connected?(klass)
  pool = retrieve_connection_pool klass
  pool && pool.connected?
end

#connection_pool_list ⇒ Object

Returns a list of all the connection pools owned by this handler.



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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 25

def connection_pool_list
  [@primary_pool] + @replica_pools.values
end

#current_proxy ⇒ Object

Returns the ThreadLocalConnectionHandler for this thread.



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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 106

def current_proxy
  @reserved_proxies[current_thread_id] || synchronize do
    @reserved_proxies[current_thread_id] ||= ProxyingConnectionPool.new(self)
  end
end

#current_thread_id ⇒ Object 



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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 122

def current_thread_id
  Thread.current.object_id
end

#establish_connection(owner, spec) ⇒ Object 



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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 29

def establish_connection(owner, spec)
  prefix = '[ActiveReplicas::Rails4::ConnectionHandler#establish_connection]'
  details = "#{spec.config.inspect} (owner: #{owner.inspect})"

  synchronize do
    if @proxy_configuration[:primary] == spec.config
      ActiveRecord::Base.logger&.warn "#{prefix} Ignoring new spec as it matches existing primary spec: #{details}"
    else
      ActiveRecord::Base.logger&.warn "#{prefix} Overwriting connection spec: #{details}"
      ActiveRecord::Base.logger&.info "#{prefix} Called from:\n" + Kernel.caller.map {|t| "  #{t}" }.join("\n")
      @proxy_configuration = { primary: spec.config }
    end

    clear_all_connections!
    initialize_pools

    # Rails returns a connection pool.
    retrieve_connection_pool owner
  end
end

#remove_connection(owner_klass) ⇒ Object 



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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 90

def remove_connection(owner_klass)
  if proxy = clear_current_proxy
    proxy.automatic_reconnect = false
    proxy.disconnect!
    proxy.spec.config
  end
end

#retrieve_connection(klass) ⇒ Object

Cribbed from:

https://github.com/rails/rails/blob/4-2-stable/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb#L568

Raises:

  • (ConnectionNotEstablished) 


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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 77

def retrieve_connection(klass)
  pool = retrieve_connection_pool klass
  raise ConnectionNotEstablished, "No connection pool for #{klass}" unless pool
  conn = pool.connection
  raise ConnectionNotEstablished, "No connection for #{klass} in connection pool" unless conn
  conn
end

#retrieve_connection_pool(klass) ⇒ Object 



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# File 'lib/active_replicas/rails4/process_local_connection_handler.rb', line 98

def retrieve_connection_pool(klass)
  current_proxy
end