The monitor page does not give good awareness with respect to what is actually happening with scans. It would be interesting to know the following.
- Number of seeks done on server side
- Number of entries read on the server side
- Number of entries returned on the servers die
A filtering iterator may do a lot of seeks and drop a lot of data, but this is not really shown in anyway on the monitor page. If we displayed the info above, then a user could see the filter seeking, reading and not returning data. Currently only the amount of data returned by iterators is displayed, not the amount of data read by iterators.
Also the current monitor page displays scan session, which corresponds to a user starting a scan on a tablet server. It does give the user a info about how many seeks the iterators that are running as part of that scan session are doing.