Date: Wed, 03 Apr 2013 11:00:26 -0700 From: Alfred Perlstein <alfred@ixsystems.com> To: Adrian Chadd <adrian@freebsd.org> Cc: arch@freebsd.org, Gleb Smirnoff <glebius@freebsd.org> Subject: Re: [CFR][CFT] counter(9): new API for faster and raceless counters Message-ID: <515C6E3A.9020300@ixsystems.com> In-Reply-To: <CAJ-VmokM=BUO=i2roCivjHc5RW8azhaFqsXM%2B9G_jU7sbkHGTg@mail.gmail.com> References: <20130401115128.GZ76816@FreeBSD.org> <20130402232606.GC1810@garage.freebsd.pl> <20130403002846.GB15334@onelab2.iet.unipi.it> <20130403100401.GA1349@garage.freebsd.pl> <515C68B5.2010006@ixsystems.com> <CAJ-VmokM=BUO=i2roCivjHc5RW8azhaFqsXM%2B9G_jU7sbkHGTg@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On 4/3/13 10:45 AM, Adrian Chadd wrote: > On 3 April 2013 10:36, Alfred Perlstein <alfred@ixsystems.com> wrote: >> Hey folks, sorry for the top post here, but I just came into this thread. >> >> Here at iXsystems we've just developed a set of scripts to scrape the >> various FreeBSD user land utilities (sysctl, netstat, nfsstat, vmstat, etc, >> etc) and put them into graphs based on time. > Cool! > >> The goal is to be able to line up all these metrics with whatever benchmark >> we are currently running and be able to see what may be causing issues. >> >> Potentially you should be able to scroll through the graphs and see things >> like "ran out of mbufs @time", "vm system began paging at @time", "buffer >> deaemon went nuts @time" >> >> Then we can take the information back and leverage it to make tuning >> decisions, or potentially change kernel algorithms. >> >> The only problem we have is that every user land tool has its own format, so >> along with my team we have written some shell to coerce the output from the >> various programs into pseudo-CSV (key/value pair) which can then be post >> processed by tools to convert to CSV which can then be put into something >> like open office, or put through an R program to graph it. >> >> I'm hoping to have something shortly. >> >> What I was hoping to do over the next few days was discuss with people how >> we can (or should we even) fix the user land statistics tools to output >> machine readable output that can be easily parsed. >> >> Example: netstat -m (hard to parse) versus 'vmstat -z | grep mbuf' easy to >> parse. >> >> The idea of outputting xml is good, CSV is OK, however CSV is problematic as >> in the case of sysctl, if new nodes appear, then we can't begin to emit >> them, we must either ignore them, or abort, or log them to auxiliary files. >> Anything that makes life easier is good. >> >> I should be able to share our scripts within the next couple of days. > that's quite shiny. > > It'd be really nice if we could come up with a consistent statistics > display, summary and export library. > > That way we could write tools that used a given data fetch/display API > and then we could have optional "things" that implement various export > methods. > > For example, I'm packing up Sam Leffler's "libstatfoo" for inclusion > into -HEAD, primarily so the tools that use it (wlanstats, mwlstats, > athstats and all the other ath stats programs I'm using) can use it. > > But once I've converted the stats tool over to that, I can do a few cute things: > > * the library has a generic way to list all of the supported > statistics fields - you register the statistic names with the library, > then you can create arbitrary format strings with the information; > * the library handles "now" versus "time series" data display itself - > you just need to populate the statistic structure with the relevant > stats and then call the right function to display things; > * I plan on extending it to spit out CSV output as a generic feature, > so I can start doing things like importing the output of those tools > direct into rrdtool/etc without any intermediary parsing scripts; > * .. and if I then add new stats fields, the (requested) output of the > script won't change, so tools won't break. > > Very cool. One thing to note, the CSV format: COLNAME1,COLNAME2,COLNAME3 DATA1,DATA2,DATA3 is vulnerable to problems where a new column will spring into being due to loading of a kernel module/driver/something. Imo it's better to look at XML or some other pseudo-CSV like: COLNAME1:DATA1,COLNAME2:DATA2,COLNAME3:DATA3 so that we are OK with columns springing into existence or leaving. -Alfred
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?515C6E3A.9020300>