Hi all,
here is a patch that provides two new features to the NCV graph backend. It answers to a request I did on August 2nd (subject: "Dynamic or Split NCV").
split-ncv : Lets you store an ever-changing set of data on a status column basis. Say, you want to keep track of who is accessing a database. It works by creating a rrd file per ncv line instead of packing a lot of DS in a single rrd file. I use it to keep track of tomcat session number per context, harddrive temperature, database connexions, and a whole bunch of other things, such a the repartition of loaded classes on a jvm (useful to find memory leaks).
trackmax : it lets you keep track of the maximum value of a dataset, along with the average. It's useful when the maximum is somehow as significant than the average over time. (say, to track a hard-limited ressource, such as telephone lines). I use it to keep track of the maximum number of busy X25 lines on a specific application. It only works for NCV at the time, but I may add it to other tests.
The patch includes the documentation for all this. It applies on today's snapshot and on october' all-in-one. It does not work with the plain release because of a nasty bug in do_ncv.c.
Well, here's the patch. Consider it beta, but yet it works on my production server. I strongly hope it will be included in the mainstream hobbit (I don't like maintaining local patches :)).
Regards,
-- Charles Goyard - cgoyard at cvf.fr - (+33) 1 45 38 01 31