Revert "Backport(v1.16): Fix fluent#4396: Add timeout to establish_connection to prevent infinite loop (fluent#5104) (fluent#5137)"

This reverts commit 18fe509.

Author: Watson1978

lib/fluent/plugin/out_forward.rb

@@ -610,17 +610,7 @@ def verify_connection
       end
 
       def establish_connection(sock, ri)
-        start_time = Fluent::Clock.now
-        timeout = @sender.hard_timeout
-
         while ri.state != :established
-          # Check for timeout to prevent infinite loop
-          if Fluent::Clock.now - start_time > timeout
-            @log.warn "handshake timeout after #{timeout}s", host: @host, port: @port
-            disable!
-            break
-          end
-
           begin
             # TODO: On Ruby 2.2 or earlier, read_nonblock doesn't work expectedly.
             # We need rewrite around here using new socket/server plugin helper.

test/plugin/test_out_forward.rb

@@ -1347,27 +1347,4 @@ def plugin_id_for_test?
       end
     end
   end
-
-  test 'establish_connection_timeout' do
-    @d = d = create_driver(%[
-      hard_timeout 1
-      <server>
-        host #{TARGET_HOST}
-        port #{@target_port}
-      </server>
-    ])
-
-    node = d.instance.nodes.first
-    mock_sock = flexmock('socket')
-    mock_sock.should_receive(:read_nonblock).with(512).and_return('').at_least.once
-
-    ri = Fluent::Plugin::ForwardOutput::ConnectionManager::RequestInfo.new(:helo)
-
-    assert_true node.available?
-    node.establish_connection(mock_sock, ri)
-    assert_false node.available?
-
-    logs = d.logs
-    assert{ logs.any?{|log| log.include?('handshake timeout after 1.0s') } }
-  end
 end