When I use the command line mongo environment and run show dbs it returns this message.

Fri Mar 09 16:22:14 decode failed. probably invalid utf-8 string [Ç]
Fri Mar 09 16:22:14 why: TypeError: malformed UTF-8 character sequence at o
ffset 0
Fri Mar 09 16:22:14 Error: invalid utf8 shell/utils.js:1108

So I used the web interface to look closer at the data when I did list databases (http://10.1.50.21:15002/listDatabases?text=1) it returns the normal databases correctly, then there are 1462 entries that look like this:

{ "name" : "*", "sizeOnDisk" : 1, "empty" : true }

,

{ "name" : "1", "sizeOnDisk" : 1, "empty" : true }

,

{ "name" : "10", "sizeOnDisk" : 1, "empty" : true }

,

{ "name" : "2", "sizeOnDisk" : 1, "empty" : true }

,

{ "name" : "3", "sizeOnDisk" : 1, "empty" : true }

,

{ "name" : "4", "sizeOnDisk" : 1, "empty" : true }

,

{ "name" : "4images", "sizeOnDisk" : 1, "empty" : true }

,

{ "name" : "5", "sizeOnDisk" : 1, "empty" : true }

,

{ "name" : "6", "sizeOnDisk" : 1, "empty" : true }

,

{ "name" : "7", "sizeOnDisk" : 1, "empty" : true }

,

{ "name" : "8", "sizeOnDisk" : 1, "empty" : true }

,

{ "name" : "9", "sizeOnDisk" : 1, "empty" : true }

,

I don't know if something in our code messed up and created these or if something internal in mongo did it.

When I do a use admin then > db.databases.find(). It returns a list that is only the real databases.

We've got replica sets and sharding. The list appears the same on all shard.

Any Ideas what is going on and how to fix it? This is a production system and is running fine so far, but this definitely worries me.