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From: Eric Wong <e@80x24.org>
To: meta@public-inbox.org
Subject: [PATCH 0/2] leak workarounds for Perl 5.16 on CentOS/RHEL 7
Date: Thu, 26 Sep 2019 01:50:36 +0000	[thread overview]
Message-ID: <20190926015038.29770-1-e@80x24.org> (raw)

After many hours of reviewing our code in PublicInbox::Qspawn,
PublicInbox::GitHTTPBackend, and PublicInbox::HTTP and finding
nothing but cleanups and documentation improvements; it seems
the leaks affecting lore is down to bugs in Perl 5.16.3.

After removing the warning for Deflater being missing in
d883d4a93b23be134038e28f421eafca70c3d838
("httpd: get rid of Deflater warning"), I missed that my
own CentOS 7 VM was missing that module so was unable to
reproduce the FD leaks :x

The first patch is a straightforward workaround that I was
able to test without Plack::Middleware::Deflater being installed.

The second patch stops loading Deflater in httpd on Perls
earlier than 5.18.  (But I haven't built or tested 5.18 myself).
Enabling gzip in varnish will be needed for 5.16 users.

Independently of this fix, I've long been considering replacing
Deflater with a buffer-to-gzip layer which would reduce memory
pressure from intermediate uncompressed strings.  This might
serve as impetus to move that idea along (and of course I'd
test it heavily under CentOS 7 :>).

Anybody using custom .psgi files on Perl 5.16.x will need to
make adjustments to disable the Deflater in that.

Eric Wong (2):
  ds: workaround a memory leak in Perl 5.16.x
  httpd: disable Deflater middleware by default on Perl <5.18

 lib/PublicInbox/DS.pm     | 9 ++++++---
 script/public-inbox-httpd | 8 +++++++-
 2 files changed, 13 insertions(+), 4 deletions(-)

-- 
EW


             reply	other threads:[~2019-09-26  1:50 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-26  1:50 Eric Wong [this message]
2019-09-26  1:50 ` [PATCH 1/2] ds: workaround a memory leak in Perl 5.16.x Eric Wong
2019-09-26  1:50 ` [PATCH 2/2] httpd: disable Deflater middleware by default on Perl <5.18 Eric Wong
2019-09-26 12:36 ` [PATCH 0/2] leak workarounds for Perl 5.16 on CentOS/RHEL 7 Konstantin Ryabitsev
2019-09-26 21:16   ` Eric Wong
2019-09-27 21:01 ` [PATCH 3/2] qspawn: workaround Perl 5.16.3 leak, re-enable Deflater Eric Wong

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