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<推荐> 本文的完美排版/最后更新修正版本：http://www.noobu.com/0510_apache_mysql_sysctl_tweak.html <推荐> sH_B*cr3  
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人们常说，服务器的负载能力，很大程度上取决于系统管理员的配置和优化能力。这个是对的，相同的硬件、不同的软件配置，会造成截然不同的效果。下面我将给大家介绍一下如何优化 sysctrl, Apache 以及 MySQL 。请注意，所有配置均为取决于个人，请根据自己的实际情况做调整。 (p v6V2i  
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配置Sysctl hEhvA6f,  
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编辑此文件： 2'U+QK@  
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nano -w /etc/sysctl.conf =wquFA!c  
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如果该文件为空，则输入以下内容，否则请根据情况自己做调整： 9s2N!bx  
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# Controls source route verification @+&QNI06S  
# Default should work for all interfaces =bh.V@*  
net.ipv4.conf.default.rp_filter = 1 -F&*>?I  
# net.ipv4.conf.all.rp_filter = 1 ' }T6dS  
# net.ipv4.conf.lo.rp_filter = 1 Sp\ 7  
# net.ipv4.conf.eth0.rp_filter = 1 eUEO~M2&U{  
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# Disables IP source routing j6#RV@ p`  
# Default should work for all interfaces ~@ML>z7  
net.ipv4.conf.default.accept_source_route = 0 q%hxU.h  
# net.ipv4.conf.all.accept_source_route = 0 cwBf((~  
# net.ipv4.conf.lo.accept_source_route = 0 |P`:NAf2  
# net.ipv4.conf.eth0.accept_source_route = 0 f{ER]U  
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# Controls the System Request debugging functionality of the kernel U`)o$4Bq  
kernel.sysrq = 0 ,Vr'F  
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# Controls whether core dumps will append the PID to the core filename. xZ(f_Oy  
# Useful for debugging multi-threaded applications. \iM  
kernel.core_uses_pid = 1 /d-
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# Increase maximum amount of memory allocated to shm RqE|h6/  
# Only uncomment if needed! <
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# kernel.shmmax = 67108864 a534@U4,  
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# Disable ICMP Redirect Acceptance 5&N55?G6  
# Default should work for all interfaces e9@7GaL`"S  
net.ipv4.conf.default.accept_redirects = 0 ,+hH|$  
# net.ipv4.conf.all.accept_redirects = 0 uIb,n 5  
# net.ipv4.conf.lo.accept_redirects = 0 |)W N%#v  
# net.ipv4.conf.eth0.accept_redirects = 0 WPu{ ]<pl  
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# Enable Log Spoofed Packets, Source Routed Packets, Redirect Packets FEzjP$  
# Default should work for all interfaces rj> _L  
net.ipv4.conf.default.log_martians = 1 =vc8u&L2
 
# net.ipv4.conf.all.log_martians = 1 xhmrep6+<  
# net.ipv4.conf.lo.log_martians = 1 !Ey=  
# net.ipv4.conf.eth0.log_martians = 1 i9Tq h  
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# Decrease the time default value for tcp_fin_timeout connection a/v!W@Zz}  
net.ipv4.tcp_fin_timeout = 25 gvLzE&V}  
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# Decrease the time default value for tcp_keepalive_time connection q}'ww  
net.ipv4.tcp_keepalive_time = 1200 Spqbr@j  
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# Turn on the tcp_window_scaling 4,)EG1  
net.ipv4.tcp_window_scaling = 1 -)Zp"  
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# Turn on the tcp_sack iT2
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net.ipv4.tcp_sack = 1 }\$CU N  
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# tcp_fack should be on because of sack &h<\jqN/  
net.ipv4.tcp_fack = 1 hq|I%>y  
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# Turn on the tcp_timestamps =euMOs  
net.ipv4.tcp_timestamps = 1 \Aq$h:<  
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# Enable TCP SYN Cookie Protection Q*54!^l+_r  
net.ipv4.tcp_syncookies = 1 ;#XF.l,u  
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# Enable ignoring broadcasts request K3.z>.F'h  
net.ipv4.icmp_echo_ignore_broadcasts = 1 'TO/i:{\  
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# Enable bad error message Protection aHkt K/  
net.ipv4.icmp_ignore_bogus_error_responses = 1 U7xKu75G1  
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# Make more local ports available UWW'[gEP1  
# net.ipv4.ip_local_port_range = 1024 65000 _5/3RN  
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# Set TCP Re-Ordering value in kernel to ‘5′ 4hWFgk  
net.ipv4.tcp_reordering = 5 h3(B7n7  
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# Lower syn retry rates F$HL\y  
net.ipv4.tcp_synack_retries = 2 ]htx9ds=  
net.ipv4.tcp_syn_retries = 3 D6:"k 2  
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# Set Max SYN Backlog to ‘2048′ )%bY2 pk  
net.ipv4.tcp_max_syn_backlog = 2048 zJTSg  
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# Various Settings ,S7M4ajVZB  
net.core.netdev_max_backlog = 1024 j12khp?  
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# Increase the maximum number of skb-heads to be cached ''wF%q  
net.core.hot_list_length = 256 f/]g@/`  
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# Increase the tcp-time-wait buckets pool size B#K 2?Et!t  
net.ipv4.tcp_max_tw_buckets = 360000 $jNp-5+Q;  
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# This will increase the amount of memory available for socket input/output queues 4&^BcWqA*f  
net.core.rmem_default = 65535 jl~ ?I*Gr  
net.core.rmem_max = 8388608 |T^c(RpOE  
net.ipv4.tcp_rmem = 4096 87380 8388608 w|WehNGr  
net.core.wmem_default = 65535 1U;p+k5c  
net.core.wmem_max = 8388608 gv,8Wo  
net.ipv4.tcp_wmem = 4096 65535 8388608 K\`>'C2_V  
net.ipv4.tcp_mem = 8388608 8388608 8388608 isR|K9qf^  
net.core.optmem_max = 40960 h$~\to$C  
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如果希望屏蔽别人 ping 你的主机，则加入以下代码： #DFfySH)A  
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# Disable ping requests q:/<^|  
net.ipv4.icmp_echo_ignore_all = 1 Au-h#YV  
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编辑完成后，请执行以下命令使变动立即生效： -*T<^G;rK  
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/sbin/sysctl -p [|!A3o  
/sbin/sysctl -w net.ipv4.route.flush=1 "bC1dl<  
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MySQL优化 B<" `<oG@|  
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编辑MySQL的配置文件： =,XCjiBeC  
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nano /etc/my.cnf z5@XFaQ  
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输入以下内容： L;V8c  
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connect_timeout=15 5]O{tS j  
interactive_timeout=100 $PJ==N  
join_buffer_size=1M M+ [ho]  
key_buffer=128M vr;`h/  
max_allowed_packet=16M ,X!6|l8  
max_connections=500 G+dq */  
max_connect_errors=10 wfo,r 7  
myisam_sort_buffer_size=64M v3r3$(Hr  
read_buffer_size=1M =E9\fRGU  
read_rnd_buffer_size=768K +byOThuE  
sort_buffer_size=1M bYsX?0T!p  
table_cache=1024 t/;2rIx>  
thread_cache_size=100 C8m9H8Qm  
thread_concurrency=4 >jt2vU@t.  
wait_timeout=300 o]1BWwtY&  
query_cache_size=32M .!3e$mhV  
query_cache_limit=1M Qu|CXUk  
query_cache_type=1 ZDW9H6ux  
skip-innodb :8`A  
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请注意，以上配置适用于512M~1024M内存，如内存更大的话请自行做调整。给项目增加内存会加快速度，但是使用过多的内存而导致启用swap的话，会极大的导致系统效率下降。其中 thread_concurrency 这项配置，单CPU的话请设置为2，双CPU的话请设置为4。  yXU.PSG*  
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Apache优化 -`faXFW'  
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以下优化适用于 Apache 1.3 系列，如果你用的是 2.0 系列的话，请自行做调整和判断。 6*Z7JiQ0  
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确认 Apache 的配置文件位置并开始编辑： C~2!@<y  
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locate httpd.conf u IXA{89  
nano -w /path/to/httpd.conf |u>V> PN  
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httpd.conf的文件有许多内容，笔者就拿出需要做优化的： i%o%bib#  
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KeepAlive On #aX#gh}1  
MaxKeepAliveRequests 1000 KtaoOe  
KeepAliveTimeout 3 ]zYIblpde  
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MinSpareServers 8 Ovx *  
MaxSpareServers 13 '@Uu/~;h  
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MaxRequestsPerChild 50 l0'Yq%Nf  
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将 KeepAliveTimeout 设定到较小的数字将有助于减少服务器上的无用等待链接，一定程度上能增加服务器负载。 Milp"L?B%  
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另外，下面这条不算优化，但是是Apache安全相关： :WRD<D_4  
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ServerSignature Off ~+{*KPiD  
ServerTokens ProductOnly yhgGvyD
 
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将 ServerSignature 关闭，并增加 ServerTokens ProductOnly 可以使常人无法检测到Apache的实际版本号，有助于Apache的安全。 fK:4jl-r  
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以上所做的这些优化在某种程度上会增强服务器的负载性能。但请注意，最佳的配置是实践出来的。