<div dir="ltr"><div><div>Hello,<br>
    I would like to ask your for help for a really strange case that we have..<br>We have migrated from varnish 3.07 to varnish 4.03 few months ago. The last few days.<br>we have a strange problem.<br>Child died on request. The backends was unreachable at that time (we are using a hash director).<br></div>We did get a panic message like :<br><br>varnishd[30906]: Child (6755) Panic message:#012Assert error in VDI_GetFd(), cache/cache_dir.c line 111:#012  Condition((d) != NULL) not true.<br>#012thread = (cache-worker)#012version = varnish-4.0.3 revision b8c4a34#012ident = Linux,3.10.0-327.10.1.el7.x86_64,x86_64,-smalloc,-smalloc,-hcritbit,epoll#012<br>Backtrace:#012  0x7eff9489f6b3: /usr/sbin/varnishd(+0x3e6b3) [0x7eff9489f6b3]#012  0x7eff948813c4: /usr/sbin/varnishd(VDI_GetFd+0xe4)<br>[0x7eff948813c4]#012  0x7eff948a021b: /usr/sbin/varnishd(PipeRequest+0xcb) [0x7eff948a021b]#012  0x7eff948a432c: /usr/sbin/varnishd(CNT_Request+0xaec) [0x7eff948a432c]<br>#012  0x7eff94898f2b: /usr/sbin/varnishd(HTTP1_Session+0x7eb) [0x7eff94898f2b]#012  0x7eff948a8747: /usr/sbin/varnishd(+0x47747) [0x7eff948a8747]#012  <br>0x7eff948a9878: /usr/sbin/varnishd(SES_pool_accept_task+0x2b8) [0x7eff948a9878]#012  0x7eff948a291d: /usr/sbin/varnishd(Pool_Work_Thread+0x39d) [0x7eff948a291d]#012  <br>0x7eff948b7bc2: /usr/sbin/varnishd(+0x56bc2) [0x7eff948b7bc2]#012  0x7eff93029dc5: /lib64/libpthread.so.0(+0x7dc5) <br>[0x7eff93029dc5]#012req = 0x7eff64012020 {#012  sp = 0x7eff6281ae20, vxid = 1075806210,  step = R_STP_PIPE,#012  req_body = R_BODY_PRESENT,#012  restarts = 0, esi_level = 0,<br>#012  sp = 0x7eff6281ae20 {#012    fd = 122, vxid = 2064385,#012    client = 172.16.50.169 46012,#012    step<br>= S_STP_WORKING,#012  },#012  worker = 0x7eff36b90c50 {#012    ws = 0x7eff36b90e70 {#012      id = "wrk",#012      {s,f,r,e} = {0x7eff36b90450,0x7eff36b90450,(nil),+2048},#012    },<br>#012  VCL::method = 0x0,#012  VCL::return = pipe,#012  },#012  ws = 0x7eff640121b8 {#012    id = "req",#012    {s,f,r,e} = {0x7eff64014010,+1480,(nil),+57360},#012  },<br>#012  http[req] = {#012    ws<br>= 0x7eff640121b8[req]#012      "POST",#012      "/api/login",#012      "HTTP/1.1",#012      "Host: <a href="http://www.xxx.com">www.xxx.com</a>",#012<br>     "X-Real-IP: 188.73.254.105",#012      "X-Forwarded-Proto: https",<br>     #012      "Connection: close",#012      "Content-Length: 39",#012      "Accept-Encoding: gzip",#012      "CF-IPCountry: GR",#012      "CF-RAY: 28735bfd70642342-FRA",#012      <br>     "CF-Visitor: {"scheme":"https"}",#012      "accept: */*",#012      <br>     "accept-language: en-GR;q=1.0, el-GR;q=0.9",#012      "content-type: application/json",#012      <br>     "cookie: __cfduid=dbe3f7943ad953c0c32fed9c23d5ec53e1456395183; _ga=GA1.2.1866397751.1458056300; <br>     exauth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      <br>     "user-agent: xxx/com.bbb.ccc (37; OS Version 9.0.2 (Build 13A452))",#012<br>  "x-requested-with: XMLHttpRequest",#012      "CF-Connecting-IP: 188.73.254.105",#012      "X-Forwarded-For: 188.73.254.105,<br>188.73.254.105, 173.16.50.169",#012      "X-defHash: /login + <a href="http://www.xxx.com">www.xxx.com</a>",#012  },#012  vcl = {#012    <br>srcname = {#012      "input",#012      "Builtin",#012      "origins-xxx.vcl",#012      "origins-xxx.vcl",#012      "origins-others.vcl",#012      "origins-staging.vcl",#012<br>      "banlist.vcl",#012    },#012  },#012},<br> lin-varnish03 varnishd[30906]: Child cleanup complete<br> lin-varnish03 varnishd[30906]: child (13007) Started<br><br><br></div><div>Thanks in advance<br></div><div>Yiannis<br></div></div>