[Varnish] #1488: Panic at high volume of requests

[Varnish]

#1488: Panic at high volume of requests
--------------------------+--------------------
 Reporter:  mattrobenolt  |       Type:  defect
   Status:  new           |   Priority:  normal
Milestone:                |  Component:  build
  Version:  4.0.0         |   Severity:  normal
 Keywords:  panic         |
--------------------------+--------------------
 Caused Varnish to panic when benchmarking with ~30k+ rps.

 {{{
 varnish> panic.show
 200
 Last panic at: Fri, 25 Apr 2014 23:12:11 GMT
 Assert error in WRW_Write(), cache/cache_wrw.c line 255:
   Condition((wrk) != NULL) not true.
 thread = (cache-worker)
 ident = Linux,3.13.0-24-generic,x86_64,-smalloc,-smalloc,-hcritbit,epoll
 Backtrace:
   0x4325b5: /usr/sbin/varnishd() [0x4325b5]
   0x4484da: /usr/sbin/varnishd(WRW_Write+0x12a) [0x4484da]
   0x438046: /usr/sbin/varnishd() [0x438046]
   0x438655: /usr/sbin/varnishd() [0x438655]
   0x438e58: /usr/sbin/varnishd(V1D_Deliver+0x4f8) [0x438e58]
   0x435b77: /usr/sbin/varnishd(CNT_Request+0x3b7) [0x435b77]
   0x42cccb: /usr/sbin/varnishd(HTTP1_Session+0x3eb) [0x42cccb]
   0x439f78: /usr/sbin/varnishd() [0x439f78]
   0x434ab4: /usr/sbin/varnishd(Pool_Work_Thread+0xb4) [0x434ab4]
   0x4477e8: /usr/sbin/varnishd() [0x4477e8]
 req = 0x7f99f0072ad0 {
   sp = 0x7f99f0028670, vxid = 1075054490,  step = R_STP_DELIVER,
   req_body = R_BODY_NONE,
   restarts = 0, esi_level = 0
   sp = 0x7f99f0028670 {
     fd = 475, vxid = 9207815,
     client = 127.0.0.1 32303,
     step = S_STP_WORKING,
   },
   ws = 0x7f99f0072c60 {
     id = "req",
     {s,f,r,e} = {0x7f99f0074aa0,+384,(nil),+57392},
   },
   http[req] = {
     ws = 0x7f99f0072c60[req]
       "GET",
       "/embed/comments/090849",
       "HTTP/1.1",
       "Host: 127.0.0.1:6081",
       "X-Forwarded-For: 127.0.0.1, 127.0.0.1",
       "Accept-Encoding: gzip",
   },
   http[resp] = {
     ws = 0x7f99f0072c60[req]
       "HTTP/1.1",
       "200",
       "OK",
       "Cache-Control: max-age=3600",
       "Content-Encoding: gzip",
       "Content-Type: text/html",
       "Grace: max-age=3600",
       "X-Accel-Expires: 15",
       "Date: Fri, 25 Apr 2014 23:12:09 GMT",
       "X-Varnish: 1312666 11600334",
       "Age: 0",
       "Via: 1.1 varnish (v4)",
       "X-Served-By: test-shield-1.dal01",
       "X-Cache: HIT",
       "X-Cache-Hits: 10",
       "Transfer-Encoding: chunked",
       "Connection: keep-alive",
       "Accept-Ranges: bytes",
   },
   vcl = {
     srcname = {
       "input",
       "Builtin",
       "includes/x-forwarded-for.vcl",
       "includes/recv-common.vcl",
       "includes/surrogate-control.vcl",
       "includes/grace.vcl",
       "includes/health-synthetic.vcl",
       "includes/x-served-by.vcl",
     },
   },
   obj (REQ) = 0x7f9b60269e40 {
     vxid = 2159083982,
     http[obj] = {
       ws = 0x7f9b0c010f40[obj]
         "HTTP/1.1",
         "200",
         "OK",
         "Cache-Control: max-age=3600",
         "Content-Encoding: gzip",
         "Content-Type: text/html",
         "Grace: max-age=3600",
         "X-Accel-Expires: 15",
         "Date: Fri, 25 Apr 2014 23:12:09 GMT",
     },
     len = 15210,
     store = {
       15210 {
         1f 8b 08 00 00 09 6e 88 00 ff ec 7d 79 77 1b c7 |......n....}yw..|
         b1 ef ff fe 14 6d e4 9e e7 dc fb b0 cc be e0 52 |.....m.........R|
         d4 a3 64 2d 94 65 4b 91 18 2b 4e 94 a3 33 98 69 |..d-.eK..+N..3.i|
         00 63 ce 82 cc 42 0a ce c9 77 7f bf ea 1e 2c c4 |.c...B...w....,.|
         [15146 more]
       },
     },
   },
 },
 }}}

 I'll be happy to supply any other information you may need. Not sure what
 else is relevant beyond this panic.

-- 
Ticket URL: <https://www.varnish-cache.org/trac/ticket/1488>
Varnish <https://varnish-cache.org/>
The Varnish HTTP Accelerator