[Pkg-varnish-devel] Bug#815812: varnish: Assert error in vbf_stp_startfetch(), cache/cache_fetch.c line 360

[Grégoire BRENON]

Source: varnish
Version: 4.0.2-1
Severity: important

Dear Maintainer,


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Our varnish server dies periodically (about each ten minutes) with this error, unabling it to
actually keep much in cache for a decent amount of time (max ~150M for like 30m). The server was
running just fine with the same configuration on varnish 4.0.3-2 from varnish's repository :
https://repo.varnish-cache.org/debian. This was on Debian wheezy.

We then tried to upgrade to jessie and found there was an official package for varnish 4, so
we created two virtual machines with Debian jessie. One got the 4.0.3-2 from varnish-cache.org,
the other got Debian's official 4.0.2-1. The latter experienced the error I'm reporting while
the former just kept on just fine (still using exactly the same configuration).

By downgrading the 'good' one to 4.0.2-1, the problem arises on it too ! Upgrading back to
4.0.3-1 solves the issue.

Here is what I could recover from panic.show :

Last panic at: Wed, 24 Feb 2016 16:19:03 GMT
Assert error in vbf_stp_startfetch(), cache/cache_fetch.c line 360:
  Condition((bo->do_esi) == 0) not true.
thread = (cache-worker)
ident = Linux,3.16.0-4-amd64,x86_64,-smalloc,-smalloc,-hcritbit,epoll
Backtrace:
  0x4330a8: /usr/sbin/varnishd() [0x4330a8]
  0x42112d: /usr/sbin/varnishd() [0x42112d]
  0x435cdc: /usr/sbin/varnishd(Pool_Work_Thread+0x39c) [0x435cdc]
  0x44912c: /usr/sbin/varnishd() [0x44912c]
  0x7f9f13a450a4: /lib/x86_64-linux-gnu/libpthread.so.0(+0x80a4) [0x7f9f13a450a4]
  0x7f9f1377a87d: /lib/x86_64-linux-gnu/libc.so.6(clone+0x6d) [0x7f9f1377a87d]
  busyobj = 0x7f9f01dac020 {
    ws = 0x7f9f01dac0e0 {
      id = "bo",
      {s,f,r,e} = {0x7f9f01dae008,+23624,(nil),+57368},
    },
  refcnt = 2
  retries = 1
  failed = 0
  state = 1
    is_do_esi
    is_do_stream
    is_do_pass
    is_uncacheable
    bodystatus = 2 (chunked),
    },
    http[bereq] = {
      ws = 0x7f9f01dac0e0[bo]
        "GET",
        "/p03024452",
        "HTTP/1.1",
        "Host: www.*******.com",
        "Cookie: PHPSESSID=***************; r_mode=***************; SVID=4",
        "Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
        "From: googlebot(at)googlebot.com",
        "User-Agent: Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)",
        "X-Forwarded-Proto: http",
        "X-Forwarded-For: 66.249.64.108",
        "Accept-Encoding: gzip",
        "X-Varnish: 295287",
        "X-Varnish: 33133",
    },
    http[beresp] = {
      ws = 0x7f9f01dac0e0[bo]
        "HTTP/1.1",
        "302",
        "Moved Temporarily",
        "Server: nginx",
        "Date: Wed, 24 Feb 2016 16:19:03 GMT",
        "Content-Type: text/html;charset=utf-8",
        "Transfer-Encoding: chunked",
        "Expires: Thu, 19 Nov 1981 08:52:00 GMT",
        "Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0",
        "Pragma: no-cache",
        "Set-Cookie: r_mode=***************; expires=Sun, 24-Apr-2016 16:19:03 GMT; Max-Age=5184000; path=/; domain=.********.com",
        "Location: http://www.********.com/p03024452/someGreatPage.html",
        "Accept-Ranges: none",
    },
    ws = 0x7f9f01dac270 { BAD_MAGIC(0x00000000) },
    },
  objcore (FETCH) = 0x7f9f0286a980 {
    refcnt = 2
    flags = 0x102
    objhead = 0x7f9f12c18240
  }
  }

I'm surprised how similar to bug #815713 this looks while still not being the same as far as I know.


-- System Information:
Debian Release: 8.3
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.16.0-4-amd64 (SMP w/4 CPU cores)
Locale: LANG=fr_FR.UTF-8
Shell: /bin/bash
Init: systemd (via /run/systemd/system)