Comment 3 for bug 1734903

a potential "cheap" fix for this would be to do something like:

err := st.session.Ping()
if err != nil {
  // failed to talk to the database, try refreshing our connection
  st.session.Refresh()
}
return st.session.DB(jujuDB).C(txnLogC)

It might even be reasonable to do a Refresh more often, as if the txnlog watcher is restarting, we probably have reason to suspect the connection.