A few weeks ago, I tried to use mod_file_cache which tested under our pressure test, however I met some strange behaviors. Now I can use ab to reproduce it. I'm using Apache2.2.0 on 4P Xeon(EM64T) and EL4U2 ( 2.6.9-22.ELsmp, 64bit). Apache configuration: <IfModule mod_file_cache.c> mmapfile /usr/local/apache2/htdocs/index.html #just cache one file </IfModule> ThreadLimit 600 <IfModule worker.c> StartServers 10 MaxClients 500000 ServerLimit 5000 MinSpareThreads 1000 MaxSpareThreads 2000 ThreadsPerChild 100 MaxRequestsPerChild 0 ListenBackLog 3000 </IfModule> MaxRequestsPerChild 0 Now I test with "/usr/local/apache2/bin/ab -n 100000 -c 10 localhost/index.html", during the tests, some threads segmentation fault. I used gdb to get the backtrace, however looks like these segmentation fault will happen in different places. Most are: #0 0x0000003d26e2e989 in kill () from /lib64/tls/libc.so.6 #1 <signal handler called> #2 0x00000000006fe818 in ?? () #3 0x000000000042d5fa in ap_rgetline_core (s=0x45007058, n=8192, read=0x45007060, r=0x2ac4e2fd28, fold=0, bb=0x2ac4e31248) at protocol.c:222 #4 0x000000000042dbd8 in ap_get_mime_headers_core (r=0x2ac4e2fd28, bb=0x2ac4e31248) at protocol.c:681 #5 0x000000000042e4b2 in ap_read_request (conn=0x6e86c0) at protocol.c:909 #6 0x0000000000462540 in ap_process_http_connection (c=0x6e86c0) at http_core.c:189 #7 0x0000000000440ac3 in ap_run_process_connection (c=0x6e86c0) at connection.c:43 #8 0x000000000046d877 in worker_thread (thd=0x63cea8, dummy=Variable "dummy" is not available. ) at worker.c:531 #9 0x0000003d279060aa in start_thread () from /lib64/tls/libpthread.so.0 #10 0x0000003d26ec5b43 in clone () from /lib64/tls/libc.so.6 #11 0x0000000000000000 in ?? () #0 0x0000003d26e2e989 in kill () from /lib64/tls/libc.so.6 #1 <signal handler called> #2 0x0000000000443668 in add_any_filter_handle (frec=0x5b61a8, ctx=0x0, r=0x7257e8, c=0x715990, r_filters=0x725a68, p_filters=0x725a78, c_filters=0x715a08) at util_filter.c:330 #3 0x000000000044390a in ap_add_input_filter_handle (f=Variable "f" is not available. ) at util_filter.c:415 #4 0x000000000042e639 in ap_read_request (conn=0x715990) at protocol.c:1022 #5 0x0000000000462540 in ap_process_http_connection (c=0x715990) at http_core.c:189 #6 0x0000000000440ac3 in ap_run_process_connection (c=0x715990) at connection.c:43 #7 0x000000000046d877 in worker_thread (thd=0x63d208, dummy=Variable "dummy" is not available. ) at worker.c:531 #8 0x0000003d279060aa in start_thread () from /lib64/tls/libpthread.so.0 #9 0x0000003d26ec5b43 in clone () from /lib64/tls/libc.so.6 #10 0x0000000000000000 in ?? () #0 0x0000003d26e2e989 in kill () from /lib64/tls/libc.so.6 #1 <signal handler called> #2 ap_invoke_filter_init (filters=0x2c) at config.c:312 #3 0x000000000043a6f3 in ap_invoke_handler (r=0x2ac4e02978) at config.c:344 #4 0x0000000000464bb0 in ap_process_request (r=0x2ac4e02978) at http_request.c:258 #5 0x00000000004625cd in ap_process_http_connection (c=0x7138b0) at http_core.c:171 #6 0x0000000000440ac3 in ap_run_process_connection (c=0x7138b0) at connection.c:43 #7 0x000000000046d877 in worker_thread (thd=0x63d598, dummy=Variable "dummy" is not available. ) at worker.c:531 #8 0x0000003d279060aa in start_thread () from /lib64/tls/libpthread.so.0 #9 0x0000003d26ec5b43 in clone () from /lib64/tls/libc.so.6 #10 0x0000000000000000 in ?? () Are these threads segmentation fault due to over pressure? I also tested cachefile directive and without mod_file_cache, both works OK. Any ideas? Should I submit a bug request? Thx, Xuekun
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