[OSM-dev] Volunteers needed now. OSM for Myanmar disaster relief.

[Brett Henderson]

Apache fails after renderd errors.  The apache crash isn't ideal but it 
sounds like the cause is actually renderd not apache.  I'll run a 
renderd trace but I guess I'll have to recompile it to reduce the number 
of threads first.

The renderd application provides this console output:
Rendering daemon
Got incoming connection, fd 5, number 1
Render fd(5) z(6), x(57), y(24)
DONE TILE 6 56-63 24-31
Problem reading sub tiles for metatile x(56) y(24) z(6), got -1
Connection 0, fd 5 closed, now 0 left

The apache strace output is:
Process 13081 attached - interrupt to quit
epoll_wait(14, {{EPOLLIN, {u32=3117611608, u64=13799930156540951128}}}, 
2, -1) = 1
accept(4, {sa_family=AF_INET6, sin6_port=htons(3681), 
inet_pton(AF_INET6, "::ffff:192.168.1.11", &sin6_addr), sin6_flowinfo=0, 
sin6_scope_id=0}, [28]) = 15
semop(3178504, 0x3b86f6, 1)             = 0
getsockname(15, {sa_family=AF_INET6, sin6_port=htons(80), 
inet_pton(AF_INET6, "::ffff:192.168.1.110", &sin6_addr), 
sin6_flowinfo=0, sin6_scope_id=0}, [28]) = 0
fcntl64(15, F_GETFL)                    = 0x2 (flags O_RDWR)
fcntl64(15, F_SETFL, O_RDWR|O_NONBLOCK) = 0
read(15, "GET /osm_tiles2/6/57/24.png HTTP"..., 8000) = 632
gettimeofday({1213109370, 443427}, NULL) = 0
open("/proc/loadavg", O_RDONLY)         = 16
read(16, "0.08 0.07 0.08 2/224 13095\n", 64) = 27
close(16)                               = 0
stat64("/home/www/html/direct/6/0/0/0/49/136.meta", 0xbf8320c0) = -1 
ENOENT (No such file or directory)
stat64("/home/www/html/direct/6/0/0/0/49/152.png", 0xbf8320c0) = -1 
ENOENT (No such file or directory)
futex(0x92a180, FUTEX_WAKE_PRIVATE, 2147483647) = 0
socket(PF_FILE, SOCK_STREAM, 0)         = 16
connect(16, {sa_family=AF_FILE, path="/tmp/osm-renderd"}, 110) = 0
send(16, "\1\0\0\0\1\0\0\0009\0\0\0\30\0\0\0\6\0\0\0", 20, 0) = 20
select(17, [16], NULL, NULL, {3, 0})    = 1 (in [16], left {2, 498000})
recv(16, "\1\0\0\0\3\0\0\0009\0\0\0\30\0\0\0\6\0\0\0", 20, 0) = 20
mmap2(NULL, 1052672, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 
-1, 0) = 0xb7d28000
open("/home/www/html/direct/6/0/0/0/49/136.meta", O_RDONLY) = -1 ENOENT 
(No such file or directory)
open("/home/www/html/direct/6/0/0/0/49/152.png", O_RDONLY) = -1 ENOENT 
(No such file or directory)
stat64("/home/www/html/direct/6/0/0/0/49/136.meta", 0xbf832060) = -1 
ENOENT (No such file or directory)
stat64("/home/www/html/direct/6/0/0/0/49/152.png", 0xbf832060) = -1 
ENOENT (No such file or directory)
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
chdir("/etc/httpd")                     = 0
rt_sigaction(SIGSEGV, {SIG_DFL}, {SIG_DFL}, 8) = 0
kill(13081, SIGSEGV)                    = 0
sigreturn()                             = ? (mask now [])
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
Process 13081 detached

Jon Burgess wrote:
> 2008/6/10 Brett Henderson <brett at bretth.com>:
>   
>> I've just found something, when attempting to render this URL.
>> http://localhost/osm_tiles2/6/57/24.png
>> I get errors in the apache error_log stating that a child exited with a
>> Segmentation fault.  That sounds ominous unless there's just some error
>> handling going awry.
>>
>>     
>
> Try restarting the web server. I've certainly seen segv's if you do
> multiple "make install" without restarting the server (reloading the
> config is not sufficient).
>
> If that fails then try either running strace to see where it gets too
> before diteing or try attaching GDB to one of the processes (it makes
> things easier if you limit the number of server processes to 1).
>
>