[Orca-dev] Re: too many open files issue -> found it

[Blair Zajac]

Yes, Orca finding the number of file descriptors could be done
pretty easily.  The problem is managing this number.  Orca manages
this when opening RRD files, but it'll take more modifications to
do this with the HTML files.  Probably the easiest way is to have
Orca::HTMLFile store the HTML to write in memory and then write it
to disk when the subroutine calling the object has DESTROYED the
object.  This wouldn't be too hard to do, but it would increase the
memory usage.

Maybe a smart thing would be to have Orca::HTMLFile see how many
open fds there are and then decide in the moment if it should cache
the HTML and write it later in one go or open the file now and
write to it continuously as the caller writes to it.

Blair

Adrian Bhatt wrote:
> 
> I am using perl 5.005_03 that comes with solaris8. It
> turns out that the perl binary I am using will only
> open up 256 files. I determined this with
> 
> #!/usr/bin/perl
> 
> use FileHandle;
> 
> for ($i=0;$i<2048;$i++){
>         $fd[$i] = new FileHandle;
>         $fd[$i] -> open(">$i") or die "stopped at: $i:
> $!\n";
> }
> 
> When I ran this same script on a version of 5.6.1 that
> I compiled it would run all the way up to the ulimit.
> 
> Would there be an easy way to check this limit in perl
> and manage file descripters appropiatly?
> 
> Bob
> 
> --- Blair Zajac <blair at gps.caltech.edu> wrote:
> > Hello,
> >
> > The way to limit the number of open files that Orca
> > uses is to edit
> > lib/Orca/OpenFileHash.pm and find the 100 and lower
> > this.  Try this
> > and see what happens.  Which version of Orca are you
> > using?
> >
> > If this doesn't work, then can you try running Orca
> > with just one
> > host instead of 6 and put the HTML pages up for
> > viewing so I can
> > take a look at them.
> >
> > At this point, put the scripts up on your site with
> > some example
> > plots, that's the best way.
> >
> > Regards,
> > Blair
> >
> > Adrian Bhatt wrote:
> > >
> > > I searched the archives and some some discussion
> > to
> > > having issues of too many open files. Most of
> > those
> > > issues were solved by increase the file descripter
> > > limit from something like 64 to 128 or 256. We
> > started
> > > our file descripter limit at 512. All was working
> > > really well. Last night at the request of certain
> > data
> > > from the business we added some plots detailing
> > some
> > > more information about different file system
> > usage. So
> > > I set up the plots at let orca munge through all
> > the
> > > data, to my dismay I came back an hour later to
> > find
> > > error messages like the ones below. So I did some
> > math
> > > and figured that at 6 servers, the normal plots,
> > as
> > > well as a plot for each file system (40 per box)
> > that
> > > the number of files (html/png/meta) that orca
> > would be
> > > creating was reaching into the thousands. So I
> > > increased the file descripter limit to 1024. Still
> > no
> > > good. Then to 2048. Still no good. Then to 4096.
> > When
> > > it failed at this point I began thinking something
> > is
> > > wrong. I started looking through the code mostly
> > at
> > > HTMLFile.pm then how it was called. I am a little
> > > confused about how you open files then how they
> > get
> > > closed, but that is probally because I only spent
> > > about 20 minutes looking through it. Is it
> > possible
> > > there is some sort of leak that under X condition
> > it
> > > doesn't close some file handle right away? If so
> > were
> > > should I start looking for such a leak?
> > >
> > > We have also created some scripts which create
> > data
> > > files for various peices of equipment to feed into
> > > orca. Is there a place to publish such scripts or
> > > should I publish them on my site and send a link
> > to
> > > the user list? Just wondering how to give back to
> > the
> > > community.
> > >
> > > Thanks again for any help. It would be greatly
> > > appreciated.
> > >
> > > Bob
> > >
> > > /opt/orca/bin/orca: warning: cannot create
> > > Orca::HTMLFile object: cannot open
> > >
> >
> `/opt/orca/data/e10k/html/o_mntC_per_mkt_per_app_per_dqmgr_p,o_mntU_per_mkt_per_app_per_dqmgr_p,o_mntA_per_mkt_per_app_per_dqmgr_p-monthly.html.htm'
> > > for writing: Too many open files.
> > >
> > > /opt/orca/bin/orca: warning: cannot create
> > > Orca::HTMLFile object: cannot open
> > >
> >
> `/opt/orca/data/e10k/html/o_mntC_per_mkt_per_app_per_dqmgr_p,o_mntU_per_mkt_per_app_per_dqmgr_p,o_mntA_per_mkt_per_app_per_dqmgr_p-quarterly.html.htm'
> > > for writing: Too many open files.
> > >
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