我最近设置了Unbound for DNS缓存,以及
Linux Mint 18.1上的DNScrypt.它工作,但我注意到页面只在很短的时间内缓存：
>首次查询google.com – 48ms(域未缓存)
> google.com的第二个查询(紧接着之后) – 0ms(域缓存)
> google.com的第三次查询(在〜分钟后) – 46ms(域未缓存)
这是预期的行为,还是我需要设置不同的东西来缓存页面更长的时间？这是我的Unbound配置(/etc/unbound/unbound.conf)：
#
Unbound configuration file for Debian.
#
# See the unbound.conf(5) man page.
#
# See /usr/share/doc/unbound/examples/unbound.conf for a commented
# reference config file.age
#
# The following line includes additional configuration files from the
# /etc/unbound/unbound.conf.d directory.
include: "/etc/unbound/unbound.conf.d/*.conf"
server:
verbosity: 1
num-threads: 4
outgoing-range: 8192
so-rcvbuf: 4m
so-sndbuf: 4m
so-reuseport: yes
msg-cache-size: 50m
msg-cache-slabs: 16
num-queries-per-thread: 4096
rrset-cache-size: 100m
rrset-cache-slabs: 16
infra-cache-slabs: 16
do-ip4: yes
do-ip6: no
do-udp: yes
do-tcp: yes
do-daemonize: yes
hide-identity: yes
hide-version: yes
harden-short-bufsize: yes
harden-large-queries: yes
harden-glue: yes
harden-dnssec-stripped: yes
harden-below-nxdomain: yes
harden-referral-path: yes
logfile: "/etc/unbound/unbound.log"
use-caps-for-id: yes
do-not-query-localhost: no
prefetch: no
forward-zone:
name: "."
forward-addr: 127.0.0.1@40
解决方法
未绑定将(或至少应该)将结果缓存在
TTL中为您请求的记录指定的时间.
这正是我在一个运行未绑定的系统上观察到的.初始请求需要14ms,后续请求需要0ms,当TTL到期时,下一个请求需要14ms.
初始请求显示300秒TTL并需要18ms
;; ANSWER SECTION: google.com. 300 IN A 172.217.20.46 ;; Query time: 18 msec ;; SERVER: 10.34.20.1#53(10.34.20.1) ;; WHEN: Sun Feb 12 20:39:30 2017 ;; MSG SIZE rcvd: 44
后续请求 – TTL正在倒计时并需要0ms
;; ANSWER SECTION: google.com. 196 IN A 172.217.20.46 ;; Query time: 0 msec ;; SERVER: 10.34.20.1#53(10.34.20.1) ;; WHEN: Sun Feb 12 20:41:14 2017 ;; MSG SIZE rcvd: 44
TTL已过期,因此另一个上游请求为23ms
;; ANSWER SECTION: google.com. 300 IN A 172.217.20.46 ;; Query time: 23 msec ;; SERVER: 10.34.20.1#53(10.34.20.1) ;; WHEN: Sun Feb 12 20:44:37 2017 ;; MSG SIZE rcvd: 44
