Meteor 1.3 to 1.5 - Server CPU Usage up 250%

I have a meteor application which I updated from 1.3 to 1.5; Server side CPU usage has jumped by 250%; see Server Data

The application receives UDP messages (10 per second) and forwards then to other servers (20 per second). The app keeps the last 1000 messages in a small MongoDB, which I can look at logging into the client.

Are there any changes that would explain this performance hit???

Thanks for any insights. Kerry Woodbury, MatrixPD

stupid question, but have you tried restarting the server?

Yes, restarted the server several times. Looking at different nodes versions this week.

Node 4.8.3 is the supported version for Meteor 1.5