Hi All 
I'm attempting to figure out why only some filers and not others are having periods of no graph statistics within Performance Monitor 
I've done some troubleshooting and what I've determined is when a filer's statistics are not being displayed within graphs, the "dfm host diag" command will return this error for the filer:
XML (https port 443) Timeout. Could not read API response.
Whereas working filers (displaying statistics in the graphs) always succeed with:
XML (https port 443) Passed (0 ms)
There are periods of time when trouble filers actually have working graphs too and during these times, the "dfm host diag" command will return Passed (x ms) responses for XML check. So the Timeout error does coincide with when the Performance Monitor graphs aren't working.
During the periods of no statistics for particular filer, the "dfm perf data list" command shows the Newest Record as being quite out of date aswell (So the statistics aren't reaching DFM). I believe (currently) that the issue is some filers are not responding to API calls in a timely manner.
So with that explanation/analysis in mind, I have the following questions:
- Is it possible to determine on the filer directly that it has reached some sort of API limit (I'm not seeing anything in messages).
- Is there anything on the filer that I can tune to allow more API calls or improve performance?
FYI: DFM option "snapDeltaMonitorEnabled" has been disabled (To reduce API activity caused by DFM).
This is all 7-Mode.
Thanks in advance! 
Andrew.