I have already gone through that link, still gdb was not catching core dump...
Log snippet:
2014/10/30 13:54:07 [debug] 16259#0: *2 http static fd: 11
2014/10/30 13:54:07 [debug] 16259#0: *2 http set discard body
2014/10/30 13:54:07 [debug] 16259#0: *2 HTTP/1.1 200 OK^M
Server: nginx/1.7.6^M
Date: Thu, 30 Oct 2014 08:24:07 GMT^M
Content-Type: text/html^M
Content-Length: 1249^M
Last-Modified: Thu, 28 Aug 2014 12:20:24 GMT^M
Connection: keep-alive^M
ETag: "53ff1e88-4e1"^M
Access-Control-Allow-Origin: *^M
Access-Control-Allow-Methods: GET, OPTIONS, POST^M
Access-Control-Allow-Headers: origin, authorization, accept^M
Accept-Ranges: bytes^M
2014/10/30 13:54:07 [debug] 16259#0: *2 write new buf t:1 f:0 00000000025B6B50, pos 00000000025B6B50, size: 381 file: 0, size: 0
2014/10/30 13:54:07 [debug] 16259#0: *2 http write filter: l:0 f:0 s:381
2014/10/30 13:54:07 [debug] 16259#0: *2 http output filter "/grafana_prod.html?"
2014/10/30 13:54:07 [debug] 16259#0: *2 http copy filter: "/grafana_prod.html?"
2014/10/30 13:54:07 [debug] 16259#0: *2 http postpone filter "/grafana_prod.html?" 00007FFFD64F0CB0
2014/10/30 13:54:07 [debug] 16259#0: *2 write old buf t:1 f:0 00000000025B6B50, pos 00000000025B6B50, size: 381 file: 0, size: 0
2014/10/30 13:54:07 [debug] 16259#0: *2 write new buf t:0 f:1 0000000000000000, pos 0000000000000000, size: 0 file: 0, size: 1249
2014/10/30 13:54:07 [debug] 16259#0: *2 http write filter: l:1 f:0 s:1630
2014/10/30 13:54:07 [debug] 16259#0: *2 http write filter limit 0
2014/10/30 13:54:07 [debug] 16259#0: *2 writev: 381
2014/10/30 13:54:07 [debug] 16259#0: *2 sendfile: @0 1249
2014/10/30 13:54:07 [debug] 16259#0: *2 sendfile: 1249, @0 1249:1249
2014/10/30 13:54:07 [debug] 16259#0: *2 http write filter 0000000000000000
2014/10/30 13:54:07 [debug] 16259#0: *2 http copy filter: 0 "/grafana_prod.html?"
2014/10/30 13:54:07 [debug] 16259#0: *2 http finalize request: 0, "/grafana_prod.html?" a:1, c:1
2014/10/30 13:54:07 [debug] 16259#0: *2 set http keepalive handler
2014/10/30 13:54:07 [debug] 16259#0: *2 http close request
2014/10/30 13:54:07 [debug] 16259#0: *2 http log handler
2014/10/30 13:54:07 [debug] 16259#0: *2 run cleanup: 00000000025BF6A0
2014/10/30 13:54:07 [debug] 16259#0: *2 file cleanup: fd:11
2014/10/30 13:54:07 [debug] 16259#0: *2 free: 00000000025BE6C0, unused: 8
2014/10/30 13:54:07 [debug] 16259#0: *2 free: 00000000025B6980, unused: 2899
2014/10/30 13:54:07 [debug] 16259#0: *2 free: 00000000025C8610
2014/10/30 13:54:07 [debug] 16259#0: *2 free: 00000000025C8610
2014/10/30 13:54:07 [debug] 16259#0: *2 free: 00000000025B2640, unused: 0
2014/10/30 13:54:07 [debug] 16259#0: *2 free: 00000000025C8500, unused: 120
2014/10/30 13:54:07 [debug] 16259#0: timer delta: 1
2014/10/30 13:54:07 [debug] 16259#0: worker cycle
2014/10/30 13:54:07 [debug] 16259#0: epoll timer: -1
2014/10/30 13:54:17 [debug] 16392#0: bind() 0.0.0.0:80 #6
2014/10/30 13:54:17 [debug] 16392#0: bind() 0.0.0.0:8090 #7
2014/10/30 13:54:17 [notice] 16392#0: OS: Linux 2.6.32-358.18.1.el6.x86_64
2014/10/30 13:54:17 [notice] 16392#0: getrlimit(RLIMIT_NOFILE): 8192:8192
2014/10/30 13:54:17 [debug] 16393#0: write: 8, 00007FFF049D4300, 6, 0
2014/10/30 13:54:17 [debug] 16393#0: write: 8, 00007FFF049D4300, 6, 0
2014/10/30 13:54:17 [debug] 16393#0: setproctitle: "nginx: master process /idap/activeRelease/nginx/sbin/nginx -c /idap/activeRelease/conf/nginx/idap_gp_nginx.conf"
2014/10/30 13:54:17 [notice] 16393#0: start worker processes
2014/10/30 13:54:17 [debug] 16393#0: channel 3:8
2014/10/30 13:54:17 [notice] 16393#0: start worker process 16394
2014/10/30 13:54:17 [debug] 16393#0: sigsuspend
2014/10/30 13:54:17 [debug] 16394#0: malloc: 0000000000D03EB0:6144
2014/10/30 13:54:17 [debug] 16394#0: malloc: 00007F9DCDD3E010:212992
2014/10/30 13:54:17 [debug] 16394#0: malloc: 0000000000D223C0:106496
2014/10/30 13:54:17 [debug] 16394#0: malloc: 0000000000D3C3D0:106496
2014/10/30 13:54:17 [debug] 16394#0: epoll add event: fd:6 op:1 ev:00002001
2014/10/30 13:54:17 [debug] 16394#0: epoll add event: fd:7 op:1 ev:00002001
2014/10/30 13:54:17 [debug] 16394#0: epoll add event: fd:8 op:1 ev:00002001
2014/10/30 13:54:17 [debug] 16394#0: setproctitle: "nginx: worker process"
2014/10/30 13:54:17 [debug] 16394#0: worker cycle
