increase sess_workspace to fix assert error?

[Enno van Amerongen]

Dear List,


After deployment of a vmod we've written (that enables us to select a director by id in url), we've been experiencing assert errors.


Below are the stack traces, but to not waste your time, here's what I think it boils down to:


{ overflow#012    id = "sess",#012    {s,f,r,e} = {0x7fed76034c78,+16384,(nil),+16384},#012  }


4k as session workspace has worked fine for us for years, but our vmod sharding adds hundreds of directors (as opposed to 4), while the number of backends stayed the same (about 25).


So, my question is, do I just need to increase sess_workspace to fix this? If not, what else ;)


Regards,


Enno van Amerongen








Both stacktraces


Apr  2 18:43:32 obfuscated /var/www/varnish[12750]: Child (20498) Panic message: Assert error in vh_get_var_alloc(), vmod_var.c line 77:#012  Condition((v) != 0) not true.#012errno = 32 (Broken pipe)#012thread = (cache-worker)#012ident = Linux,2.6.32-5-amd64,x86_64,-smalloc,-smalloc,-hcritbit,epoll#012Backtrace:#012  0x439199: pan_backtrace+19#012  0x43946e: pan_ic+1ad#012  0x7fe137efe347: _end+7fe13786898f#012  0x7fe137efe862: _end+7fe137868eaa#012  0x7fecc5b93e73: _end+7fecc54fe4bb#012  0x7fecc5b939ea: _end+7fecc54fe032#012  0x7fecc5ba24f1: _end+7fecc550cb39#012  0x4417bd: VCL_recv_method+6d#012  0x41d8f5: cnt_recv+262#012  0x41e68d: CNT_Session+5cb#012sp = 0x7fed81293008 {#012  fd = 2849, id = 2849, xid = 918440385,#012  client = 10.1.1.1 51854,#012  step = STP_RECV,#012  handling = deliver,#012  err_code = 200, err_reason = (null),#012  restarts = 0, esi_level = 0#012  flags = #012  bodystatus = 4#012  ws = 0x7fed81293080 { overflow#012    id = "sess",#012    {s,f,r,e} = {0x7fed81293c78,+16384,(nil),+16384},#012  },#012  http[req] = {#012    ws = 0x7fed81293080[sess]#012      "GET",#012      "/f/146057654_2.jpg",#012      "HTTP/1.1",#012      "User-Agent: Opera/9.80 (Windows NT 6.1; WOW64) Presto/2.12.388 Version/12.14",#012      "Host: img.obfuscated.com",#012      "Accept: text/html, application/xml;q=0.9, application/xhtml+xml, image/png, image/webp, image/jpeg, image/gif, image/x-xbitmap, */*;q=0.1",#012      "Accept-Language: fr-FR,fr;q=0.9,en;q=0.8",#012      "Referer: http://obfuscated",#012      "Connection: Keep-Alive",#012  },#012  worker = 0x7feece7efaa0 {#012    ws = 0x7feece7efcd8 { #012      id = "wrk",#012      {s,f,r,e} = {0x7feece7dd9f0,+16,(nil),+65536},#012    },#012    },#012    vcl = {#012      srcname = {#012        "input",#012        "Default",#012        "/obfuscated/img_backends.vcl",#012        "/obfuscated/img_directors.vcl",#012


So we removed the vmod_var from our configuration as it wasn't really required anyway.


Then 13 minutes later, Varnish crashed again, now with a different, but similar assert error:


Apr  2 19:07:22 obfuscated /var/www/varnish[12750]: Child (18818) Panic message: Assert error in VRT_int_string(), cache_vrt.c line 324:#012  Condition((p = WS_Alloc(sp->http->ws, size)) != 0) not true.#012thread = (cache-worker)#012ident = Linux,2.6.32-5-amd64,x86_64,-smalloc,-smalloc,-hcritbit,epoll#012Backtrace:#012  0x439199: pan_backtrace+19#012  0x43946e: pan_ic+1ad#012  0x4435f7: VRT_int_string+88#012  0x7fe686b9ce1f: _end+7fe686507467#012  0x7fe686b9c99a: _end+7fe686506fe2#012  0x7fe686ba7424: _end+7fe686511a6c#012  0x4417bd: VCL_recv_method+6d#012  0x41d8f5: cnt_recv+262#012  0x41e68d: CNT_Session+5cb#012  0x43aa0a: wrk_thread_real+8cc#012sp = 0x7fed76034008 {#012  fd = 2357, id = 2357, xid = 2009537706,#012  client = 80.239.243.196 59852,#012  step = STP_RECV,#012  handling = deliver,#012  err_code = 200, err_reason = (null),#012  restarts = 0, esi_level = 0#012  flags = #012  bodystatus = 4#012  ws = 0x7fed76034080 { overflow#012    id = "sess",#012    {s,f,r,e} = {0x7fed76034c78,+16384,(nil),+16384},#012  },#012  http[req] = {#012    ws = 0x7fed76034080[sess]#012      "GET",#012      "/f/148682988.jpg",#012      "HTTP/1.1",#012      "User-Agent: Opera/9.80 (Android; Opera Mini/7.5.32193/29.3134; U; nl) Presto/2.8.119 Version/11.10",#012      "Host: img.obfuscated.com",#012      "Accept: text/html, application/xml;q=0.9, application/xhtml+xml, image/png, image/webp, image/jpeg, image/gif, image/x-xbitmap, */*;q=0.1",#012      "Accept-Language: nl,en;q=0.9",#012      "Referer: obfuscated",#012      "Connection: Keep-Alive",#012      "X-OperaMini-Phone: Android #",#012      "X-OperaMini-Phone-UA: Mozilla/5.0 (Linux; U; Android 2.2.2; nl-be; Stockholm Build/HuaweiU8180) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",#012      "x-forwarded-for: obfuscated",#012      "Device-Stock-UA: Mozilla/5.0 (Linux; U; Android 2.2.2; nl-be; Stockholm Build/HuaweiU8180) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",#012      "X
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