I did a typo in my configuration file, instead server;host I wrote server:host (notice the :).
As the : is used a separator in datafile I did get warning about "unknown variable" but nothing clearly saying I did a mistake, neither why nothing get output even rrd data file get created.
I suggest either:
- to check a : appear in host definition and deny it with a clear message in log
- to escape : in datafile if this letter is allowed.
But the problem must not be ignore (It took to me one hour to find the issue...)
The problem appeared on 1.3.4 version which is not in trac version list.