为什么此代码显示在我的日志中？也无法理解它的作用
2019-04-12 06:50:03.069924 W [12624:11358480 loggable.rb:84] Mongoid -- MONGODB | Unsupported client option 'roles'. It will be ignored.
2019-04-12 06:50:03.070662 D [12624:11358480] Mongoid -- MONGODB | EVENT: #<TopologyOpening topology=Unknown[]>
2019-04-12 06:50:03.070707 D [12624:11358480] Mongoid -- MONGODB | Topology type 'unknown' initializing.
2019-04-12 06:50:03.071311 D [12624:11358480] Mongoid -- MONGODB | EVENT: #<TopologyChanged prev=Unknown[] new=Unknown[127.0.0.1:27017]>
2019-04-12 06:50:03.071353 D [12624:11358480] Mongoid -- MONGODB | Topology type 'Unknown' changed to type 'Unknown'.
2019-04-12 06:50:03.071414 D [12624:11358480] Mongoid -- MONGODB | EVENT: #<ServerOpening address=127.0.0.1:27017 topology=Unknown[127.0.0.1:27017]>
2019-04-12 06:50:03.071437 D [12624:11358480] Mongoid -- MONGODB | Server 127.0.0.1:27017 initializing.
2019-04-12 06:50:03.075527 D [12624:50819140] Mongoid -- MONGODB | EVENT: #<ServerDescriptionChanged address=127.0.0.1:27017 topology=Single[127.0.0.1:27017] prev=#<Mongo::Server:Description:0x50840560 config={} average_round_trip_time=> new=#<Mongo::Server:Description:0x50768640 config={"ismaster"=>true, "maxBsonObjectSize"=>16777216, "maxMessageSizeBytes"=>48000000, "maxWriteBatchSize"=>100000, "localTime"=>2019-04-12 06:50:03 UTC, "logicalSessionTimeoutMinutes"=>30, "minWireVersion"=>0, "maxWireVersion"=>6, "readOnly"=>false, "ok"=>1.0} average_round_trip_time=0.002720725>>
2019-04-12 06:50:03.075622 D [12624:50819140] Mongoid -- MONGODB | Server description for 127.0.0.1:27017 changed from 'unknown' to 'standalone'.
2019-04-12 06:50:03.075693 D [12624:50819140] Mongoid -- MONGODB | EVENT: #<TopologyChanged prev=Unknown[127.0.0.1:27017] new=Single[127.0.0.1:27017]>
2019-04-12 06:50:03.075715 D [12624:50819140] Mongoid -- MONGODB | Topology type 'Unknown' changed to type 'Single'.
这是来自Ruby MongoDB驱动程序的调试级别输出，涉及服务器发现和监视（https://github.com/mongodb/specifications/blob/master/source/server-discovery-and-monitoring/server-discovery-and-monitoring.rst）。
这些消息不应出现在信息的日志级别或更高级别。驱动程序文档说明了如何更改日志级别：https://docs.mongodb.com/ruby-driver/master/tutorials/ruby-driver-create-client/#logging