* Re: httpd 502s [was: trying to figure out 100% CPU usage in nntpd...]
@ 2019-09-13 3:12 5% ` Eric Wong
0 siblings, 0 replies; 2+ results
From: Eric Wong @ 2019-09-13 3:12 UTC (permalink / raw)
To: Konstantin Ryabitsev; +Cc: meta
Konstantin Ryabitsev <konstantin@linuxfoundation.org> wrote:
> On Thu, Sep 12, 2019 at 08:35:03AM +0000, Eric Wong wrote:
> > Eric Wong <e@80x24.org> wrote:
> > > One more thing, are you running any extra middlewares in the
> > > .psgi file? Thanks.
>
> No, it's just vanilla what comes with the source.
OK, and Perl 5.16.3 from CentOS 7? (4:5.16.3-294.el7_6 RPM)
> > That's probably not it, I suspected the non-fileno path was
> > being hit, but I just tested a debug change on top of
> > b7cfd5aeff4b6b316b61b327af9c144776d77225 (branch: "unlink")
> > ("tmpfile: support O_APPEND and use it in DS::tmpio")
> > to fake the presence of a middleware wrapping psgi.input.
>
> I sent you a dump of lsof -p of all 4 processes after about 20 minutes
> of running. For another data point, the daemon was running in
> SELinux-permissive mode, to make sure unlinks aren't failing because of
> any permission errors.
It looks like there's a Perl reference leak (cycle) of some
sort holding on to FDs, since you have lots of input files and
pipes, yet only one established IPv4 connection. And the inodes
encoded into the filenames don't point to the connected socket,
even....
However, I'm not able to reproduce it on my CentOS 7 VM which
has nginx 1.12.2. I don't think nginx is a factor in this
since public-inbox-httpd is clearly not holding TCP sockets
open, even.
Not at all familiar with SELinux, but I'm just using the
defaults CentOS comes with and running both nginx +
public-inbox-httpd as a regular user.
That "if (0..." GitHTTPBackend patch definitely isn't needed
for testing anymore and only makes FD exhaustion happen sooner.
> Let me know if you would like any further info.
If there's a reference leak somewhere, this could also be part
of the high memory use you showed us a few months ago. Dunno
if you had many FDs back then.
I could see about adding explicit close() calls in a few
places, but that would make a corresponding memory leak
harder-to-notice, even.
I pushed out two patches to the "unlink" branch which may be
able to reproduce the issue on your end (I see nothing out of
the ordinary on my slow CentOS 7 VM or Debian machines/VMs)
* [PATCH] t/httpd-corner: check for leaking FDs and pipes
* [RFC] t/git-http-backend: add MANY_CLONE test
# no pipes should be present in -httpd with -W0
prove -lv t/httpd-corner.t
# unrelated note: there's 4 pipes from -W1 (the default),
# but I think 2 can be closed, actually...
GIANT_GIT_DIR=/path/to/git.git MANY_CLONE=1 prove -lv t/git-http-backend.t
If those updated test cases can't reproduce the problem,
can you reproduce this on erol or any other machines?
perhaps with a different Perl?
Thanks.
^ permalink raw reply [relevance 5%]
* [PATCH] t/httpd-corner: check for leaking FDs and pipes
@ 2019-09-13 1:50 7% Eric Wong
0 siblings, 0 replies; 2+ results
From: Eric Wong @ 2019-09-13 1:50 UTC (permalink / raw)
To: meta
-W0 (no workers) should not create any pipes on its own,
and we shouldn't have any deleted FDs if no clients are
connected.
This can find if leaks which may be triggered by PublicInbox::HTTP
(and not Qspawn or GitHTTPBackend).
---
t/httpd-corner.t | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/t/httpd-corner.t b/t/httpd-corner.t
index c72bc9c6..af838628 100644
--- a/t/httpd-corner.t
+++ b/t/httpd-corner.t
@@ -526,6 +526,14 @@ SKIP: {
defined(my $x = getsockopt($sock, SOL_SOCKET, $var)) or die;
is($x, $accf_arg, 'SO_ACCEPTFILTER unchanged if previously set');
};
+SKIP: {
+ use PublicInbox::Spawn qw(which);
+ skip 'only testing lsof(8) output on Linux', 1 if $^O ne 'linux';
+ skip 'no lsof in PATH', 1 unless which('lsof');
+ my @lsof = `lsof -p $pid`;
+ is_deeply([grep(/\bdeleted\b/, @lsof)], [], 'no lingering deleted inputs');
+ is_deeply([grep(/\bpipe\b/, @lsof)], [], 'no extra pipes with -W0');
+};
done_testing();
^ permalink raw reply related [relevance 7%]
Results 1-2 of 2 | reverse | options above
-- pct% links below jump to the message on this page, permalinks otherwise --
2019-09-10 8:38 trying to figure out 100% CPU usage in nntpd Konstantin Ryabitsev
2019-09-10 18:12 ` Eric Wong
2019-09-11 2:22 ` httpd 502s [was: trying to figure out 100% CPU usage in nntpd...] Eric Wong
2019-09-11 10:24 ` Konstantin Ryabitsev
2019-09-11 17:12 ` Eric Wong
2019-09-11 17:36 ` Konstantin Ryabitsev
2019-09-12 0:05 ` Eric Wong
2019-09-12 2:49 ` Eric Wong
2019-09-12 8:35 ` Eric Wong
2019-09-12 11:37 ` Konstantin Ryabitsev
2019-09-13 3:12 5% ` Eric Wong
2019-09-13 1:50 7% [PATCH] t/httpd-corner: check for leaking FDs and pipes Eric Wong
Code repositories for project(s) associated with this public inbox
https://80x24.org/public-inbox.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).