Re: [arch-general] pacman seems to leak ftp connections
On Wed, 18 Aug 2010 00:54:26 -0700 Mike Rosset wrote: > > After playing around i a throwaway-chroot, the problem seems to be > > libfetch >=2.30. I just modified the PKGBUILD to different versions > > (without replacing or rebuilding pacman at all). > > > > Libfetch 2.26 fetches files without a problem, 2.30+ fails after > > downloading 5 files while MaxInstances in proftpd is set to 8. If I > > set MaxInstances to 3, downloading fails outright (also only for > > 2.30+), so something there seems to consume 3 connections before > > actually downloading something at all. > > > > I'd try to break it down further, but NetBSDs CVS server isn't > > talking to me at the moment. > > Ok maybe upate the bug with these results, so they have more > information. I've updated the bug-report with the above text as well as my results of a bisection of libfetch. Looking at the patch, the change in libfetch seems sensible and I suspect that something higher up the chain is calling it in a wrong way. As far as I can tell, it is possible, that pacman never called libfetch in The Right Way (TM), but this only got exposed, after libfetch stopped closing connections unconditionally. Let's hope that some of my stumbling around is actually helpfull :)
Re: [arch-general] pacman seems to leak ftp connections
Excerpts from Alexander Duscheleit's message of 2010-08-18 04:07:23 +0200: > Hi, > > since I upgraded to pacman 3.4.0 I notice a strange behavior in the way > pacman integrates with my local mirror server. First, pacman opens a new > ftp connection for every download, which spams the logs a lot. Second, > pacman doesn't seem to close those connections either at all, or at > least not in a timely fashion. This results in pacman not being able to > download more than a hand full of packages before my ftp won't let it > connect anymore. The server-log says: > > Aug 18 00:42:38 titan proftpd[4666]: titan.huntemann.uni-oldenburg.de - > MaxInstances (30) reached, new connection denied > > over and over while pacman switches to the next mirror for every > download. > > The pacman frontend clyde exhibits the same behavior, so I suspect the > culprit is somewhere in libalpm. Pacman prior to 3.4.0 did not show > this behavior and all downloads worked fine. > > Greetings, > Alex Hmm, this could be the reason for the behavior I experience recently. Every time I update a couple of packages it fails to download all of them. If I try again and again it works. I thought it was due to improperly synced mirrors, but it happens far too frequently. Just now it downloaded 4 packages. In the subsequent run four more, and so on. -- Philipp -- "Wir stehen selbst enttäuscht und sehn betroffen / Den Vorhang zu und alle Fragen offen." Bertolt Brecht, Der gute Mensch von Sezuan
Re: [arch-general] pacman seems to leak ftp connections
> After playing around i a throwaway-chroot, the problem seems to be > libfetch >=2.30. I just modified the PKGBUILD to different versions > (without replacing or rebuilding pacman at all). > > Libfetch 2.26 fetches files without a problem, 2.30+ fails after > downloading 5 files while MaxInstances in proftpd is set to 8. If I set > MaxInstances to 3, downloading fails outright (also only for 2.30+), so > something there seems to consume 3 connections before actually > downloading something at all. > > I'd try to break it down further, but NetBSDs CVS server isn't talking > to me at the moment. Ok maybe upate the bug with these results, so they have more information.
Re: [arch-general] pacman seems to leak ftp connections
On Wed, 18 Aug 2010 00:06:44 -0700
mike rosset wrote:
> > How would I best go about researching this? I have all the
> > components right here, and it's easy enough to trigger, but I have
> > no experience whatsoever in debugging libraries or C code in
> > general.
> >
> > I could try and set up a chroot to bisect pacman /
> > lib{fetch,archive,alpm} but I have no clue how good or bad random
> > pacman versions interact with the rest of the system.
>
> What I did to replicate this was create a chroot ie
>
> sudo mkdir -p archtest/var/lib/pacman
>
> and then test with a large group something like this
>
> sudo pacman -Sy gnome --cachedir
> $(pwd)/archtest/var/cache/pacman/pkg/ -r ./archtest/
>
> if you need to download again you can just purge chroot cachedir.
> after that I'm not sure how best to debug libfetch possibly using
> netstat, lsof and strace?
After playing around i a throwaway-chroot, the problem seems to be
libfetch >=2.30. I just modified the PKGBUILD to different versions
(without replacing or rebuilding pacman at all).
Libfetch 2.26 fetches files without a problem, 2.30+ fails after
downloading 5 files while MaxInstances in proftpd is set to 8. If I set
MaxInstances to 3, downloading fails outright (also only for 2.30+), so
something there seems to consume 3 connections before actually
downloading something at all.
I'd try to break it down further, but NetBSDs CVS server isn't talking
to me at the moment.
Re: [arch-general] pacman seems to leak ftp connections
> How would I best go about researching this? I have all the components
> right here, and it's easy enough to trigger, but I have no experience
> whatsoever in debugging libraries or C code in general.
>
> I could try and set up a chroot to bisect pacman /
> lib{fetch,archive,alpm} but I have no clue how good or bad random
> pacman versions interact with the rest of the system.
What I did to replicate this was create a chroot ie
sudo mkdir -p archtest/var/lib/pacman
and then test with a large group something like this
sudo pacman -Sy gnome --cachedir
$(pwd)/archtest/var/cache/pacman/pkg/ -r ./archtest/
if you need to download again you can just purge chroot cachedir.
after that I'm not sure how best to debug libfetch possibly using
netstat, lsof and strace?
Re: [arch-general] pacman seems to leak ftp connections
On Wed, 18 Aug 2010 14:21:01 +1000
"Allan McRae" wrote:
> On 18/08/10 12:07, Alexander Duscheleit wrote:
> > Hi,
> >
> > since I upgraded to pacman 3.4.0 I notice a strange behavior in the
> > way pacman integrates with my local mirror server. First, pacman
> > opens a new ftp connection for every download, which spams the logs
> > a lot. Second, pacman doesn't seem to close those connections
> > either at all, or at least not in a timely fashion. This results in
> > pacman not being able to download more than a hand full of packages
> > before my ftp won't let it connect anymore. The server-log says:
> >
> > Aug 18 00:42:38 titan proftpd[4666]:
> > titan.huntemann.uni-oldenburg.de - MaxInstances (30) reached, new
> > connection denied
> >
> > over and over while pacman switches to the next mirror for every
> > download.
> >
> > The pacman frontend clyde exhibits the same behavior, so I suspect
> > the culprit is somewhere in libalpm. Pacman prior to 3.4.0 did not
> > show this behavior and all downloads worked fine.
> >
>
> This bug has been reported: http://bugs.archlinux.org/task/20371
Great, seems I should remember to actually set the right project in
FS :(
>
> However, no-one appears to have investigated whether this was
> libarchive's fault or libalpm's.
How would I best go about researching this? I have all the components
right here, and it's easy enough to trigger, but I have no experience
whatsoever in debugging libraries or C code in general.
I could try and set up a chroot to bisect pacman /
lib{fetch,archive,alpm} but I have no clue how good or bad random
pacman versions interact with the rest of the system.
Re: [arch-general] pacman seems to leak ftp connections
On 18/08/10 12:07, Alexander Duscheleit wrote: Hi, since I upgraded to pacman 3.4.0 I notice a strange behavior in the way pacman integrates with my local mirror server. First, pacman opens a new ftp connection for every download, which spams the logs a lot. Second, pacman doesn't seem to close those connections either at all, or at least not in a timely fashion. This results in pacman not being able to download more than a hand full of packages before my ftp won't let it connect anymore. The server-log says: Aug 18 00:42:38 titan proftpd[4666]: titan.huntemann.uni-oldenburg.de - MaxInstances (30) reached, new connection denied over and over while pacman switches to the next mirror for every download. The pacman frontend clyde exhibits the same behavior, so I suspect the culprit is somewhere in libalpm. Pacman prior to 3.4.0 did not show this behavior and all downloads worked fine. This bug has been reported: http://bugs.archlinux.org/task/20371 However, no-one appears to have investigated whether this was libarchive's fault or libalpm's. Allan
