pcp
[Top] [All Lists]

Re: [pcp] RFC: allowing longer metric and instance names in MMV(5) forma

To: Ken McDonell <kenj@xxxxxxxxxxxxxxxx>
Subject: Re: [pcp] RFC: allowing longer metric and instance names in MMV(5) format
From: Nathan Scott <nathans@xxxxxxxxxx>
Date: Wed, 29 Jun 2016 19:48:20 -0400 (EDT)
Cc: Paul Smith <psmith@xxxxxxxxxx>, Ryan Doyle <rdoyle@xxxxxxxxxx>, Suyash <dextrous93@xxxxxxxxx>, Lukas Berk <lberk@xxxxxxxxxx>, pcp developers <pcp@xxxxxxxxxxx>
Delivered-to: pcp@xxxxxxxxxxx
In-reply-to: <012901d1d249$5be820c0$13b86240$@internode.on.net>
References: <236242739.2883373.1467174433044.JavaMail.zimbra@xxxxxxxxxx> <354261953.2889296.1467178515176.JavaMail.zimbra@xxxxxxxxxx> <012901d1d249$5be820c0$13b86240$@internode.on.net>
Reply-to: Nathan Scott <nathans@xxxxxxxxxx>
Thread-index: AQHXm0lvP9ch8R/hfZdqXTgxM6r06J/1WgngqlFyA/U=
Thread-topic: allowing longer metric and instance names in MMV(5) format

----- Original Message -----
> > -----Original Message-----
> > From: pcp-bounces@xxxxxxxxxxx [mailto:pcp-bounces@xxxxxxxxxxx] On Behalf Of
> > Nathan Scott
> > Sent: Wednesday, June 29, 2016 3:35 PM
> > To: Paul Smith <psmith@xxxxxxxxxx>; Ryan Doyle <rdoyle@xxxxxxxxxx>; Suyash
> > <dextrous93@xxxxxxxxx>; Lukas Berk <lberk@xxxxxxxxxx>
> > Cc: pcp developers <pcp@xxxxxxxxxxx>
> > Subject: [pcp] RFC: allowing longer metric and instance names in MMV(5)
> > format
> > 
> > ...
> 
> +1 ... good plan.
> 
> I've tweaked the patch a little to make the language more consistent
> (attached) and have a couple of observations ...
> 

Taa.

> 1. It does not appear that an Indoms2 section is needed (it was referred to
> but not defined).

Yeah, it is the same structure.  I was thinking it will be helpful as a new
TOC type though, so that it's easy for pmdammv to know whether an instance2 
or instance1 structure needs to be decoded.  *shrug*, OTOH, maybe we should
just mandate that v2 mmv file version cannot contain v1 metric/instance TOC
entries?  (currently v2 could have either/both - v1 is more compact, so I'd
be inclined to allow both still).

> 2. I don't recall what the "Unused padding (zero filled)" entries are for in
> the Instance and Metric entries, but could we (a) drop them from the
> Instance2 and Metric2 entries, and/or give them a better description in the
> man page (are they reserved for internal use, or some sort of backwards
> compatibility thing?)

My reading of it is that it was done to 64-bit align the fields following
afterward within those structures.  Guess we'd need to prod Max to confirm
though.

cheers.

--
Nathan

<Prev in Thread] Current Thread [Next in Thread>