apache rewrite在per-server和per-dir两种模式下的效率对比

待我称王封你为后i 2022-07-16 14:07 160阅读 0赞

虽说rewrite不难，但有些细节可能不是每个人都清楚，比如说rewrite在per-server和per-dir两种配置下的效率，下面我们通过开启日志来判断到底哪个效率好，在实验前请下做

好相关配置，并编辑适当的测试文件a.html，b.html，每次测试后通过tail -f /usr/local/apache2/logs/rewrite.log来实时监控发生了什么。

先看per-server配置：

01 <VirtualHost \*:80>  
02     ServerName \_default\_  
03  
04     RewriteEngine on  
05  
06     RewriteLog /usr/local/apache2/logs/rewrite.log  
07     RewriteLogLevel 9  
08  
09     \# RewriteRule ^/a.html$ /usr/local/apache2/htdocs/b.html \[L\]  
10     \# RewriteRule ^/a.html$ /b.html \[L\]  
11 </VirtualHost>

规则：RewriteRule ^/a.html$ /usr/local/apache2/htdocs/b.html

日志：

init rewrite engine with requested uri /a.html  
applying pattern '^/a.html$' to uri '/a.html'  
rewrite '/a.html' -> '/usr/local/apache2/htdocs/b.html'  
local path result: /usr/local/apache2/htdocs/b.html  
go-ahead with /usr/local/apache2/htdocs/b.html \[OK\]

规则：RewriteRule ^/a.html$ /b.html

日志：

init rewrite engine with requested uri /a.html  
applying pattern '^/a.html$' to uri '/a.html'  
rewrite '/a.html' -> '/b.html'  
local path result: /b.html  
prefixed with document\_root to /usr/local/apache2/htdocs/b.html  
go-ahead with /usr/local/apache2/htdocs/b.html \[OK\]

再看per-dir配置：

01 <Directory "/usr/local/apache2/htdocs">  
02     RewriteEngine on  
03  
04     RewriteLog /usr/local/apache2/logs/rewrite.log  
05     RewriteLogLevel 9  
06  
07     \# RewriteRule ^a.html$ /usr/local/apache2/htdocs/b.html \[L\]  
08     \# RewriteRule ^a.html$ /b.html \[L\]  
09     \# RewriteRule ^a.html$ b.html \[L\]  
10 </Directory>

规则：RewriteRule ^a.html$ /usr/local/apache2/htdocs/b.html

日志：

strip per-dir prefix: /usr/local/apache2/htdocs/a.html -> a.html  
applying pattern '^a.html$' to uri 'a.html'  
rewrite 'a.html' -> '/usr/local/apache2/htdocs/b.html'  
strip document\_root prefix: /usr/local/apache2/htdocs/b.html -> /b.html  
internal redirect with /b.html \[INTERNAL REDIRECT\]  
strip per-dir prefix: /usr/local/apache2/htdocs/b.html -> b.html  
applying pattern '^a.html$' to uri 'b.html'  
pass through /usr/local/apache2/htdocs/b.html

规则：RewriteRule ^a.html$ /b.html

日志：

strip per-dir prefix: /usr/local/apache2/htdocs/a.html -> a.html  
applying pattern '^a.html$' to uri 'a.html'  
rewrite 'a.html' -> '/b.html'  
internal redirect with /b.html \[INTERNAL REDIRECT\]  
strip per-dir prefix: /usr/local/apache2/htdocs/b.html -> b.html  
applying pattern '^a.html$' to uri 'b.html'  
pass through /usr/local/apache2/htdocs/b.html

即便简单通过日志的行数，我们也能看到per-server的效率高于per-dir，仔细查看日志，会发现当在per-dir配置下使用rewrite 时，系统会发生一次“INTERNAL REDIRECT”，所

以以后写rewrite时，除非必要，否则不要使用pre-dir配置，而应尽可能使用per-server配置，至于是使用 file路径，还是url路径，差别不大，不过url路径的看上去更短些，也

更好维护一些。