服务器评测
兄弟们是否用LINUX 的时候觉得firefox 打开网站的时候显示正在解析主机。ie是正在连接主机。。有什么让我们第一次连接这个让点以后。第二次花更少点时间来解析这个域名呢。可能有些说历史记录可以。但我认为历史记录不过是记录网页的内容。域名的应该不会被缓存下来。。我以cent os 平台为例。这里介绍一个软件包叫 dnsmasq 可能通用yum 安装
1: yum -y install dnsmasq
2: hash
3: 修改/etc/dnsmasq.conf
把listen_address= 前面的#号去掉，然后再=后面加上本机环回地址127.0.0.1
或者在配置文件底部增加一行
listen-address=127.0.0.1
修改/etc/resolv.conf 文件
把第一DNS SERVER 改成 nameserver 127.0.0.1
4: 然后启动dnsmasq 服务
/etc/rc.d/init.d/dnsmasq start
chkconfig dnsmasq on
现在我把安装dnsmasq 前解析域名的时间和安装dnsmasq 后解析域名所用的时间贴出来。
安装dnsmasq 前:
ig baidu.com
; <<>> DiG 9.2.4 <<>> baidu.com
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 61569
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;baidu.com. IN A
;; ANSWER SECTION:
baidu.com. 466 IN A 202.108.22.46
baidu.com. 466 IN A 220.181.38.84
;; Query time: 40 msec
;; SERVER: 202.96.134.133#53(202.96.134.133)
;; WHEN: Wed Aug 29 21:43:31 2007
;; MSG SIZE rcvd: 59
第二次查询
[root@abc ~]# dig baidu.com
; <<>> DiG 9.2.4 <<>> baidu.com
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 58802
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;baidu.com. IN A
;; ANSWER SECTION:
baidu.com. 465 IN A 202.108.22.46
baidu.com. 465 IN A 220.181.38.84
;; Query time: 39 msec
;; SERVER: 202.96.134.133#53(202.96.134.133)
;; WHEN: Wed Aug 29 21:43:32 2007
;; MSG SIZE rcvd: 59
第三次查询
[root@abc ~]# dig baidu.com
; <<>> DiG 9.2.4 <<>> baidu.com
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 30773
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;baidu.com. IN A
;; ANSWER SECTION:
baidu.com. 464 IN A 220.181.38.84
baidu.com. 464 IN A 202.108.22.46
;; Query time: 31 msec
;; SERVER: 202.96.134.133#53(202.96.134.133)
;; WHEN: Wed Aug 29 21:43:33 2007
;; MSG SIZE rcvd: 59
第四次
[root@abc ~]# dig baidu.com
; <<>> DiG 9.2.4 <<>> baidu.com
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 48642
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;baidu.com. IN A
;; ANSWER SECTION:
baidu.com. 463 IN A 202.108.22.46
baidu.com. 463 IN A 220.181.38.84
;; Query time: 43 msec
;; SERVER: 202.96.134.133#53(202.96.134.133)
;; WHEN: Wed Aug 29 21:43:34 2007
;; MSG SIZE rcvd: 59
发现次是30-50 msec 之间
那么看安装dnsmasq 之后的查询速度
; <<>> DiG 9.2.4 <<>> baidu.com
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 10817
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;baidu.com. IN A
;; ANSWER SECTION:
baidu.com. 6164 IN A 202.108.22.46
baidu.com. 6164 IN A 220.181.38.84
;; Query time: 2 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Wed Aug 29 22:01:05 2007
;; MSG SIZE rcvd: 59
把dnsmasq 服务关掉后查询域名的速度
[root@abc ~]# service dnsmasq stop
Shutting down Lightweight caching nameserver (dnsmasq): [ OK ]
[root@abc ~]# dig baidu.com
; <<>> DiG 9.2.4 <<>> baidu.com
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51018
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;baidu.com. IN A
;; ANSWER SECTION:
baidu.com. 6122 IN A 220.181.38.84
baidu.com. 6122 IN A 202.108.22.46
;; Query time: 51 msec
;; SERVER: 202.96.134.133#53(202.96.134.133)
;; WHEN: Wed Aug 29 22:01:47 2007
;; MSG SIZE rcvd: 59
