Hi Logo,

I've not used this module myself, but is it possible you have your connection attributes named wrong? From the docs for MongoDB::MongoClient:

connect_timeout_ms

This attribute specifies the amount of time in milliseconds to wait fo
+r a new connection to a server.

The default is 10,000 ms.

If set to a negative value, connection operations will block indefinit
+ely until the server replies or until the operating system TCP/IP sta
+ck gives up (e.g. if the name can't resolve or there is no process li
+stening on the target host/port).

A zero value polls the socket during connection and is thus likely to 
+fail except when talking to a local process (and perhaps even then).

This may be set in a connection string with the 'connectTimeoutMS' opt
+ion.
[download]

So it looks like you can use 'connectTimeoutMS' in a connection string, but you have to use 'connect_timeout_ms' attribute directly.

Hope this helps!