nginx & php5-fpm exited on signal 7 (SIGBUS) / 502 Gateway Timeout

[degoya]

i've got the problem when i load a page multiple times (i.E. 10 Tabs with autoreload) only some of the pages load others get 502.
it doesn't depend on the content of the page. when i open the same page in all tabs it's the same situation. about 3 out of 10 get 502 errors.
The 502 Error comes direct when i force the autoload for all pages so there is no timeout causing the error i think.
I reconized that this only happens when the modx cms cache is cleared a needs a rebuild on pageload. if the page is cached i don't get any 502 errors anymore. Btw. i'm running the modxcms.

I've installed the server after the Perfect Webserver Setup from howtoforge.
Running ispconfig3 on a Debian 7 OpenVZ machine with 24GB Ram 12 Cores and tested on a physical machine 32GB Ram 8 Cores same result.

**Installed modx cms 2.3.3 on:**

PHP 5.4.39-0+deb7u2 (fpm-fcgi) (built: Mar 25 2015 08:35:25)
nginx/1.6.2 & mysql

**Settings in ISPCONFIG Backend:**

    PHP-FPM Process Manager = ondemand
    PHP-FPM pm.max_children = 5000
    PHP-FPM pm.process_idle_timeout = 100
    PHP-FPM pm.max_requests = 5000


**error.log**

     2015/03/26 00:09:16 [error] 27345#0: *231 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 178.203.23.132, ser$

     2015/03/26 00:09:16 [error] 27345#0: *229 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 178.203.23.132, ser$

     2015/03/26 00:09:16 [error] 27345#0: *234 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 178.203.23.132, ser$


**PHP fpm log:**

    [25-Mar-2015 23:54:30.875237] DEBUG: pid 28694, fpm_pctl_perform_idle_server_maintenance(), line 362: [pool web91] currently 0 active children, 6 spare children
    [25-Mar-2015 23:54:30.875247] DEBUG: pid 28694, fpm_pctl_perform_idle_server_maintenance(), line 379: [pool web32] currently 0 active children, 2 spare children, 2 running children. Spawning rate 1
    [25-Mar-2015 23:54:30.875257] DEBUG: pid 28694, fpm_pctl_perform_idle_server_maintenance(), line 379: [pool apps] currently 0 active children, 2 spare children,
    2 running children. Spawning rate 1
    [25-Mar-2015 23:54:31.398167] DEBUG: pid 28694, fpm_event_loop(), line 419: event module triggered 1 events
    [25-Mar-2015 23:54:31.487717] DEBUG: pid 28694, fpm_got_signal(), line 76: received SIGCHLD
    [25-Mar-2015 23:54:31.487757] WARNING: pid 28694, fpm_children_bury(), line 252: [pool web91] child 28735 exited on signal 7 (SIGBUS) after 57.721563 seconds from start
    [25-Mar-2015 23:54:31.490246] NOTICE: pid 28694, fpm_children_make(), line 421: [pool web91] child 28783 started
    [25-Mar-2015 23:54:31.490269] DEBUG: pid 28694, fpm_event_loop(), line 419: event module triggered 1 events
    [25-Mar-2015 23:54:31.587862] DEBUG: pid 28694, fpm_got_signal(), line 76: received SIGCHLD
    [25-Mar-2015 23:54:31.587906] WARNING: pid 28694, fpm_children_bury(), line 252: [pool web91] child 28740 exited on signal 7 (SIGBUS) after 47.234370 seconds from start
    [25-Mar-2015 23:54:31.590430] NOTICE: pid 28694, fpm_children_make(), line 421: [pool web91] child 28784 started
    [25-Mar-2015 23:54:31.590460] WARNING: pid 28694, fpm_children_bury(), line 252: [pool web91] child 28741 exited on signal 7 (SIGBUS) after 42.284682 seconds from start


**core dump**
Core was generated by `php-fpm: pool web92 '.
Program terminated with signal 7, Bus error.
#0 lex_scan (zendlval=0x7ffe8db73b98) at /tmp/buildd/php5-5.4.39/Zend/zend_language_scanner.c:2265
2265 /tmp/buildd/php5-5.4.39/Zend/zend_language_scanner.c: No such file or directory.
(gdb) bt
#0 lex_scan (zendlval=0x7ffe8db73b98) at /tmp/buildd/php5-5.4.39/Zend/zend_language_scanner.c:2265
#1 0x0000000000690a20 in zendlex (zendlval=0x7ffe8db73b90) at /tmp/buildd/php5-5.4.39/Zend/zend_compile.c:6545
#2 0x000000000066b406 in zendparse () at /tmp/buildd/php5-5.4.39/Zend/zend_language_parser.c:3473
#3 0x00000000006708a3 in compile_file (file_handle=<incomplete type>, type=2) at Zend/zend_language_scanner.l:585
#4 0x00007f938e1f28bf in ?? () from /usr/lib/php5/20100525/apc.so
#5 0x000000000052170a in phar_compile_file (file_handle=<incomplete type>, type=32766) at /tmp/buildd/php5-5.4.39/ext/phar/phar.c:3411
#6 0x0000000000670a50 in compile_filename (type=2, filename=0x18cd5b0) at Zend/zend_language_scanner.l:628
#7 0x00000000006eb053 in ZEND_INCLUDE_OR_EVAL_SPEC_VAR_HANDLER (execute_data=0x7f9392527f20) at /tmp/buildd/php5-5.4.39/Zend/zend_vm_execute.h:11466
#8 0x00000000007082f7 in execute (op_array=0x15c11f0) at /tmp/buildd/php5-5.4.39/Zend/zend_vm_execute.h:410
#9 0x00000000006a719c in zend_execute_scripts (type=-1839889456, retval=0x300000008, file_count=32659) at /tmp/buildd/php5-5.4.39/Zend/zend.c:1329
#10 0x0000000000646b33 in php_execute_script (primary_file=0x2f32396265772f31) at /tmp/buildd/php5-5.4.39/main/main.c:2502
#11 0x000000000043251a in main (argc=0, argv=0xe20c60) at /tmp/buildd/php5-5.4.39/sapi/fpm/fpm/fpm_main.c:1938


**nginx.conf**

      tcp_nopush on;
      tcp_nodelay on;
      types_hash_max_size 2048;
    server_name_in_redirect off;
      include /etc/nginx/mime.types;
      default_type application/octet-stream;
      server_tokens  off;
      sendfile  on;
      keepalive_timeout  65;
      charset utf-8;
      client_max_body_size 64m;
      client_body_buffer_size 128k;
      client_body_timeout 300s;
      large_client_header_buffers 4 16k;
      server_names_hash_bucket_size 512;
      server_names_hash_max_size 2048;
      fastcgi_buffers 256 16k;
      fastcgi_buffer_size 128k;
      fastcgi_read_timeout 5m;
      fastcgi_max_temp_file_size 0;


**php-fpm.conf**

    emergency_restart_threshold = 60
    emergency_restart_interval = 1m
    process_control_timeout = 60s
    rlimit_files = 65536
    rlimit_core = unlimited


anybody got a idea or hint how to solve that problem?