Answers relative to AMP 7.5.5
1. Can we get current and historical logs of data usage by particular user on particular date or so..
Yes. For current data (user is currently online using wifi), run a quick search for the user's username or mac address (can be partial). The result will be the user's Client Detail page which will give useful data like current association time, current APs of association, signal quality and usage graphs, and more. Historical association history for that user is also on the Client Detail page. If user is not currently online, you can try using a Full Search of All Clients (note: username and role for active clients is in regular font, while historic not currently active clients are italicized).
2. Also can we track physical location of user current and historical ( in graphical format after importing the floor plans ).
Yes. If you already have VisualRF floor plans uploaded with APs accurately placed, then when you view the Client Detail page, there should be a thumbnail of the user's last known location. Further, if you navigate into VisualRF to the floor plan where the client is located currently (they have to be currently on to use the feature), you can select the client, expand Display from the drop down, and choose up to 24 hours for playback. 24 hours is the upper limit. If you want to see custom hours in the 24 hour period, you can do so from the advanced tab of the same Display dropdown.
3. Can we send automatic mail logs after device failure ??
Yes. If you go to System -> Triggers. You can create a trigger for Down Device alerts. When configuring the alert, there's an option at the bottom of the trigger config for emailing alerts. This requires AMP Setup -> Mail relay setting set, plus from the command line having a mail relay host (kb.airwave.com - search for 'mail relay').