[Mongrel] Mongrel hangs in production. gdb stack included

Ezra Zygmuntowicz ezmobius at gmail.com
Wed Apr 30 14:52:55 EDT 2008


	Also are you 100% certain you are using the native C mysql-ruby  
bindings and not the built into rails pure ruby ones?

-Ezra



On Apr 30, 2008, at 6:28 AM, Erik Morton wrote:
> It happens at night usually so I haven't had a chance to run show  
> innodb status yet. I will say that once when it happened show  
> processlist still showed all of the expected connections.
>
> I have no large hooks. Just a call to MyObject.find(:all, :include  
> => :parent) that generates an SQL statement approximately  
> 2,000-3,000 characters long. My max_packet is set to 16mb
>
> Erik
> On Apr 30, 2008, at 8:50 AM, Dave Cheney wrote:
>> What does
>> mysql> show innodb status\G
>> mysql> show processlist;
>>
>> show during the hang, it may be a deadlock in the db. We had  
>> similar problems with large after_save hooks that would deadlock  
>> updating multiple tables.
>>
>> Cheers
>>
>> Dave
>>
>> On 30/04/2008, at 12:31 PM, Erik Morton wrote:
>>
>>> I am getting hanging Mongrels daily under light volume.
>>>
>>> Mongrel Web Server 1.1.4
>>> Apache 2.2 w/mod_proxy
>>> RedHat EL4 2.6.9-5.ELsmp #1 SMP Wed Jan 5 19:30:39 EST 2005 i686  
>>> i686 i386 GNU/Linux
>>> ruby 1.8.5 (2006-08-25) [i686-linux]
>>> fastthread (1.0.1)
>>> Mysql 5.0.45
>>>
>>> The mongrels are hanging with 0% CPU, their database connections  
>>> are still being reported as open by mysql. Attaching gdb to the  
>>> processes yields similar results (included below). I have no idea  
>>> about what the next steps are in figuring out what is going on --  
>>> short of upgrading to ruby 1.8.6!
>>>
>>> Help and pointers are much appreciated.
>>>
>>> (gdb) whe
>>> #0  0x0058b7a2 in _dl_sysinfo_int80 () from /lib/ld-linux.so.2
>>> #1  0x0065ec93 in __read_nocancel () from /lib/tls/libc.so.6
>>> #2  0x04ccc27f in vio_read (vio=0xfffffe00, buf=0xfffffe00  
>>> <Address 0xfffffe00 out of bounds>, size=-512) at viosocket.c:44
>>> #3  0x04ccc356 in vio_read_buff (vio=0x9088ae0,
>>>  buf=0xb5d471df "e Travel Plaza, located on I-90 eastbound between  
>>> Interchanges 48A (Pembroke) and 48 (Batavia), at milepost 397. The  
>>> renovation projects scheduled at Ulster and Pembroke travel  
>>> plazas, in addition to "..., size=4412) at viosocket.c:95
>>> #4  0x04ccd8f6 in my_real_read (net=0x913eb10, complen=0xbfed5e98)  
>>> at net.c:804
>>> #5  0x04ccdc30 in my_net_read (net=0x913eb10) at net.c:978
>>> #6  0x04cc6b78 in net_safe_read (mysql=0x913eb10) at client.c:596
>>> #7  0x04cc792f in cli_read_rows (mysql=0x913eb10,  
>>> mysql_fields=0xad6e1a0, fields=59) at client.c:1343
>>> #8  0x04cc9881 in mysql_store_result (mysql=0x913eb10) at client.c: 
>>> 2697
>>> #9  0x04ca299f in store_result (obj=3076071240) at mysql.c:677
>>> #10 0x0805bcb4 in rb_call0 (klass=3076091220, recv=3076071240,  
>>> id=27825, oid=4294966784, argc=1, argv=0xbfed6160,  
>>> body=0xb7596458, flags=0) at eval.c:5665
>>> #11 0x0805c017 in rb_call (klass=3076091220, recv=3076071240,  
>>> mid=27825, argc=1, argv=0xbfed6160, scope=0) at eval.c:6048
>>> #12 0x08058127 in rb_eval (self=3076059900, n=0x113c) at ruby.h:654
>>> #13 0x0805d99b in rb_yield_0 (val=6, self=3076059900, klass=0,  
>>> flags=0, avalue=0) at eval.c:4987
>>> #14 0x08058475 in rb_eval (self=3076059900, n=0x113c) at eval.c:3248
>>> #15 0x08058952 in rb_eval (self=3076059900, n=0x113c) at eval.c:3624
>>> #16 0x0805d99b in rb_yield_0 (val=6, self=3076059900, klass=0,  
>>> flags=0, avalue=0) at eval.c:4987
>>> #17 0x08058475 in rb_eval (self=3082341360, n=0x113c) at eval.c:3248
>>> #18 0x0805b9ce in rb_call0 (klass=3082341260, recv=3082341360,  
>>> id=53385, oid=4294966784, argc=0, argv=0x0, body=0xb7b931f8,  
>>> flags=0) at eval.c:5954
>>> #19 0x0805c017 in rb_call (klass=3082341260, recv=3082341360,  
>>> mid=53385, argc=0, argv=0x0, scope=0) at eval.c:6048
>>> #20 0x08058127 in rb_eval (self=3082341360, n=0x113c) at ruby.h:654
>>>
>>>
>>> (gdb) whe
>>> #0  0x0058b7a2 in _dl_sysinfo_int80 () from /lib/ld-linux.so.2
>>> #1  0x0065ec93 in __read_nocancel () from /lib/tls/libc.so.6
>>> #2  0x01d6d27f in vio_read (vio=0xfffffe00, buf=0xfffffe00  
>>> <Address 0xfffffe00 out of bounds>, size=-512) at viosocket.c:44
>>> #3  0x01d6d356 in vio_read_buff (vio=0x93e7c30,
>>>  buf=0xb6f00db4 "~\202\215^-?\213\201?QJ\237\203\201\230D?\232V 
>>> \201M8\233\224?\201\021-o\217[\200?#?\211\236\200?\203?? 
>>> 0\213\021wC?h\211\236j\234?\215\210F]̣\232\207\006Q\b\236\220\205? 
>>> Dv\231t\204?8\220\224 \203?-\214\216\236\202?$\026\210?\201?\203Y?u 
>>> \221?v???\217?jS??\215?]\206??\213?P?\235?\212\023DS\230? 
>>> \210 at 8\210\223d\206o-?\215?\204?$R\210z\202?\203\017??\230\236v?? 
>>> \026\226", size=503704)
>>>  at viosocket.c:95
>>> #4  0x01d6e8f6 in my_real_read (net=0x93e71a8, complen=0xbff9efa8)  
>>> at net.c:804
>>> #5  0x01d6ec30 in my_net_read (net=0x93e71a8) at net.c:978
>>> #6  0x01d67b78 in net_safe_read (mysql=0x93e71a8) at client.c:596
>>> #7  0x01d6892f in cli_read_rows (mysql=0x93e71a8,  
>>> mysql_fields=0xaec8f00, fields=51) at client.c:1343
>>> #8  0x01d6a881 in mysql_store_result (mysql=0x93e71a8) at client.c: 
>>> 2697
>>> #9  0x01d4399f in store_result (obj=3071130920) at mysql.c:677
>>> #10 0x0805bcb4 in rb_call0 (klass=3071150400, recv=3071130920,  
>>> id=27825, oid=4294966784, argc=1, argv=0xbff9f270,  
>>> body=0xb70e0058, flags=0) at eval.c:5665
>>> #11 0x0805c017 in rb_call (klass=3071150400, recv=3071130920,  
>>> mid=27825, argc=1, argv=0xbff9f270, scope=0) at eval.c:6048
>>> #12 0x08058127 in rb_eval (self=3071126200, n=0x7af98) at ruby.h:654
>>>
>>> _______________________________________________
>>> Mongrel-users mailing list
>>> Mongrel-users at rubyforge.org
>>> http://rubyforge.org/mailman/listinfo/mongrel-users
>>
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>
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- Ezra Zygmuntowicz
-- Founder & Software Architect
-- ezra at engineyard.com
-- EngineYard.com



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