Excessive changes to Server Description

Question

I have a 3.4 replica set that is used by the Rails application (4.2.7) with Mongoid5 (5.1.6)

We receive an excessive “server changed message” message to our logging system that does not indicate a change at all (see below). The platform works fine, except for these registration messages. I searched the Internet and cannot find anything about what this may mean. Here is an example of messages that appear every 10 seconds.

D, [2016-12-14T07:49:53.882124 #20003] DEBUG -- : MONGODB | Server description for mongo2:27017 changed from 'secondary' to 'secondary'. D, [2016-12-14T07:49:53.892663 #20003] DEBUG -- : MONGODB | Server description for mongo1:27017 changed from 'primary' to 'primary'. D, [2016-12-14T07:50:03.875711 #20003] DEBUG -- : MONGODB | Server description for mongo3:27017 changed from 'secondary' to 'secondary'. D, [2016-12-14T07:50:03.884555 #20003] DEBUG -- : MONGODB | Server description for mongo2:27017 changed from 'secondary' to 'secondary'. D, [2016-12-14T07:50:03.894815 #20003] DEBUG -- : MONGODB | Server description for mongo1:27017 changed from 'primary' to 'primary'. D, [2016-12-14T07:50:13.878723 #20003] DEBUG -- : MONGODB | Server description for mongo3:27017 changed from 'secondary' to 'secondary'. D, [2016-12-14T07:50:13.886576 #20003] DEBUG -- : MONGODB | Server description for mongo2:27017 changed from 'secondary' to 'secondary'. D, [2016-12-14T07:50:13.900932 #20003] DEBUG -- : MONGODB | Server description for mongo1:27017 changed from 'primary' to 'primary'. D, [2016-12-14T07:50:23.881659 #20003] DEBUG -- : MONGODB | Server description for mongo3:27017 changed from 'secondary' to 'secondary'. D, [2016-12-14T07:50:23.888644 #20003] DEBUG -- : MONGODB | Server description for mongo2:27017 changed from 'secondary' to 'secondary'. D, [2016-12-14T07:50:23.903119 #20003] DEBUG -- : MONGODB | Server description for mongo1:27017 changed from 'primary' to 'primary'. D, [2016-12-14T07:50:33.884056 #20003] DEBUG -- : MONGODB | Server description for mongo3:27017 changed from 'secondary' to 'secondary'. D, [2016-12-14T07:50:33.890432 #20003] DEBUG -- : MONGODB | Server description for mongo2:27017 changed from 'secondary' to 'secondary'. D, [2016-12-14T07:50:33.905094 #20003] DEBUG -- : MONGODB | Server description for mongo1:27017 changed from 'primary' to 'primary'. 

Does anyone have any thoughts on what this might be?

Thanks.