[Beowulf] stace_analyzer.pl can't work.

Joe Landman landman at scalableinformatics.com
Tue Sep 16 08:38:27 EDT 2008


Jeff Layton wrote:
> 
> I've never used Mercurial or any other "real" programming tool for 
> tracking changes, but go for it! It forces me to learn it.

Common ones these days are Mercurial and git.  I prefer the former, it 
is understandable by mere mortals.

> I like the idea of a DB, but I'm a bit worried that this will get out of 
> hand. It's a simple tool to do a quick analysis (although I have bigger 
> plans in mind). I haven't looked at SQLite in a few years. Is it still 
> an in-memory DB or does it allow you to dump the DB to a file (or two).

On disk very simple database.  Nothing even remotely complex about it. 
Slowly (and surely) many projects that have been using bdb (or more 
correctly *db) are migrating to it.  We have been using it for a while 
for lots of little things.  Works quite well, painless to set up (you 
don't).

> 
> BTW - thanks for the patch. I like the second option of ignoring any 
> return codes that are negative. Easy change.

should read

	...  if ($junk < 0);



> 
> Thanks!
> 
> Jeff
> 
> 
> ----- Original Message ----
> From: Joe Landman <landman at scalableinformatics.com>
> To: Jeff Layton <laytonjb at att.net>
> Cc: Mark Hahn <hahn at mcmaster.ca>; Eric.L <eric.l.2046 at gmail.com>; 
> beowulf at beowulf.org
> Sent: Tuesday, September 16, 2008 8:13:10 AM
> Subject: Re: [Beowulf] stace_analyzer.pl can't work.
> 
> A quick patchy-patchy for 310
> 
> 
> 
> --- strace_analyzer.pl <http://strace_analyzer.pl>    2008-09-16 
> 07:57:34.000000000 -0400
> +++ strace_analyzer_new.pl <http://strace_analyzer_new.pl>    2008-09-16 
> 08:01:45.000000000 -0400
> @@ -307,7 +307,7 @@
>             $junk =~ s/[^0-9]//g;
> 
>             # Keep track of total number bytes read
> -          $ReadBytesTotal += $junk;
> +          $ReadBytesTotal += $junk if ($junk != -1);
> 
>             # Clean up write unit
>             ($junk1, $junk2)=split(/\,/,$cmd_unit);
> 
> 
> There may be other error return codes which are negative, so if you want
> to filter those as well, use "(if $junk < 0)" rather than the above.
> 
> As for the rest of the code structure, writing this parser isn't all
> that hard, and for those with smaller memories but bigger disks (and a
> desired to analyze large straces), we could use the DBIx::SimplePerl
> module.  Jeff is already putting his arrays together as hashes, and that
> module makes it real easy to dump a hash data structure directly into a
> database, say a SQLite3 database.  Which, curiously, could make a bit of
> the code easier to deal with/write/debug.
> 
> The issue you have to worry about in dealing with huge streams of data,
> is running out of ram.  This happens.  Many "common" techniques fail
> when data gets very large (compared to something like ram).  We had to
> solve a large upload/download problem for a customer who decided to use
> a web server for multi gigabyte file upload/download form in an
> application.  The common solution was to pull everything in to ram and
> massage it from there.  This failed rather quickly.
> 
> I don't personally have large amounts of "free" time, but I could likely
> help out a bit with this.  Jeff, do you want me to create something on
> our mercurial server for this?  Or do you have it in SVN/CVS somewhere?
> 
> Joe
> 
> 
> -- 
> Joseph Landman, Ph.D
> Founder and CEO
> Scalable Informatics LLC,
> email: landman at scalableinformatics.com 
> <mailto:landman at scalableinformatics.com>
> web  : http://www.scalableinformatics.com
>         http://jackrabbit.scalableinformatics.com
> phone: +1 734 786 8423 x121
> fax  : +1 866 888 3112
> cell : +1 734 612 4615


-- 
Joseph Landman, Ph.D
Founder and CEO
Scalable Informatics LLC,
email: landman at scalableinformatics.com
web  : http://www.scalableinformatics.com
        http://jackrabbit.scalableinformatics.com
phone: +1 734 786 8423 x121
fax  : +1 866 888 3112
cell : +1 734 612 4615
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