附錄：對某次跟蹤狀況的詳細分析

　　本附錄描述了運行在Linux上的Apache 1.3系統(tǒng)調(diào)用的跟蹤情況。運行時（run-time）配置文件中除了必要的缺省選項外還增加了：

　　　　
　　　　AllowOverride none
　　　　Options FollowSymLinks
　　　　

　　被請求的文件是一個6K的靜態(tài)網(wǎng)頁，其中不包含特殊內(nèi)容。對于非靜態(tài)或者伴隨有內(nèi)容協(xié)商的請求，跟蹤結(jié)果將有明顯的不同（一些情況下會十分晦澀）。我們將首先列出完整的跟蹤結(jié)果，然后逐條進行分析。（它是由strace跟蹤程序生成的，其他類似的程序包括truss、ktrace和par）

accept(15, {sin_family=AF_INET, sin_port=htons(22283), sin_addr=inet_addr("127.0.0.1")}, [16]) = 3
flock(18, LOCK_UN) = 0
sigaction(SIGUSR1, {SIG_IGN}, {0x8059954, [], SA_INTERRUPT}) = 0
getsockname(3, {sin_family=AF_INET, sin_port=htons(8080), sin_addr=inet_addr("127.0.0.1")}, [16]) = 0
setsockopt(3, IPPROTO_TCP1, [1], 4) = 0
read(3, "GET /6k HTTP/1.0\r\nUser-Agent: "..., 4096) = 60
sigaction(SIGUSR1, {SIG_IGN}, {SIG_IGN}) = 0
time(NULL) = 873959960
gettimeofday({873959960, 404935}, NULL) = 0
stat("/home/dgaudet/ap/apachen/htdocs/6k", {st_mode=S_IFREG|0644, st_size=6144, ...}) = 0
open("/home/dgaudet/ap/apachen/htdocs/6k", O_RDONLY) = 4
mmap(0, 6144, PROT_READ, MAP_PRIVATE, 4, 0) = 0x400ee000
writev(3, [{"HTTP/1.1 200 OK\r\nDate: Thu, 11"..., 245}, {"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 6144}], 2) = 6389
close(4) = 0
time(NULL) = 873959960
write(17, "127.0.0.1 - - [10/Sep/1997:23:39"..., 71) = 71
gettimeofday({873959960, 417742}, NULL) = 0
times({tms_utime=5, tms_stime=0, tms_cutime=0, tms_cstime=0}) = 446747
shutdown(3, 1 /* send */) = 0
oldselect(4, [3], NULL, [3], {2, 0}) = 1 (in [3], left {2, 0})
read(3, "", 2048) = 0
close(3) = 0
sigaction(SIGUSR1, {0x8059954, [], SA_INTERRUPT}, {SIG_IGN}) = 0
munmap(0x400ee000, 6144) = 0
flock(18, LOCK_EX) = 0