ooh a foolish fault!
But as seem as proxy mode,between two contiguous lines in the debug log,the time is 4-5 seconds,I dont know why?

eg:
2011/05/06 15:14:10 [debug] 86514#0: *101 http upstream request: "/general/mytable/intel_view/index.php?"
2011/05/06 15:14:10 [debug] 86514#0: *101 http upstream dummy handler
2011/05/06 15:14:10 [debug] 86514#0: timer delta: 100
2011/05/06 15:14:10 [debug] 86514#0: posted events 0000000000000000
2011/05/06 15:14:10 [debug] 86514#0: worker cycle
2011/05/06 15:14:10 [debug] 86514#0: kevent timer: 299900, changes: 0
2011/05/06 15:14:14 [debug] 86514#0: kevent events: 1
2011/05/06 15:14:14 [debug] 86514#0: kevent: 8: ft:-1 fl:0020 ff:00000000 d:5816 ud:0000000801102150
2011/05/06 15:14:14 [debug] 86514#0: *101 http upstream request: "/general/mytable/intel_view/index.php?"
2011/05/06 15:14:14 [debug] 86514#0: *101 http upstream process header
2011/05/06 15:14:14 [debug] 86514#0: *101 malloc: 0000000801302000:524288

the full log:
http://www.toofiles.com/zh/rawfilesdownload-documents-7z-nginx_log.html