On Fri, Apr 16, 2010 at 02:38:28PM +0200, lars.kulseng@item.ntnu.no wrote:

I am monitoring wireless access points using NAV 3.5.4. Some of these access points only report "N/A" for Availability and response time.

This is a similar issue to bug #345783 submitted by Yours truly, but not identical, because here there is no data at all, while bug #345783 addressed an issue with certain time periods being empty. It may be related though...

I have looked in the rrd_file table, and there are entries for the relevant devices, as well as rrd files in the rrd folder.

Is this a bug or a seeding error?

Well, as we confirmed while discussing this on IRC, it's a bug in the pping (and servicemon) subsystems.

https://bugs.launchpad.net/nav/+bug/566574

In short: pping will not handle a case of reseeding, i.e. if you delete an IP device and seed it again using Seed DB, the reseeded device's availability statistics will be unavailable (!).

When the IP Device is deleted, so is NAV's knowledge of the corresponding RRD file used to log availability and ping roundtrip times. The RRD file itself is not deleted, however. pping will re-use this RRD file when the IP device is reseeded, but it will only add it to NAV's registry of RRD files if it had to create the RRD file from scratch.

A patch is in the works.