在騰訊云上面搭建的mysql使用開發(fā)的電腦上navicat進(jìn)行訪問時(shí)總是特別的慢，原來是Mysql會(huì)對(duì)請(qǐng)求的地址進(jìn)行域名解析，開發(fā)的電腦并沒有域名，所以會(huì)導(dǎo)致特別的慢，使用以下進(jìn)行解決

[mysqld]
skip-name-resolve
skip-grant-tables

官方的解釋

How MySQL
uses DNS When a new thread connects to mysqld, mysqld will
spawn a new thread to handle the request. This thread will first check
if the hostname is in the hostname cache. If not the thread will call
gethostbyaddr_r() and gethostbyname_r() to resolve the hostname. If
the operating system doesn't support the above thread-safe calls, the
thread will lock a mutex and call gethostbyaddr() and gethostbyname()
instead. Note that in this case no other thread can resolve other
hostnames that is not in the hostname cache until the first thread is
ready. You can disable DNS host lookup by starting mysqld with
–skip-name-resolve. In this case you can however only use IP names in
the MySQL privilege tables. If you have a very slow DNS and many
hosts, you can get more performance by either disabling DNS lookop
with –skip-name-resolve or by increasing the HOST_CACHE_SIZE define
(default: 128) and recompile mysqld. You can disable the hostname
cache with –skip-host-cache. You can clear the hostname cache with
FLUSH HOSTS or mysqladmin flush-hosts. If you don't want to allow
connections over TCP/IP, you can do this by starting mysqld with
–skip-networking.

根據(jù)文檔說明，如果你的mysql主機(jī)查詢DNS很慢或是有很多客戶端主機(jī)時(shí)會(huì)導(dǎo)致連接很慢，由于我們的開發(fā)機(jī)器是不能夠連接外網(wǎng)的，所以DNS解析是不可能完成的，從而也就明白了為什么連接那么慢了。同時(shí)，請(qǐng)注意在增加該配置參數(shù)后，mysql的授權(quán)表中的host字段就不能夠使用域名而只能夠使用 ip地址了，因?yàn)檫@是禁止了域名解析的結(jié)果。

總結(jié)

以上所述是小編給大家介紹的MySql使用skip-name-resolve解決外網(wǎng)鏈接客戶端過慢問題，希望對(duì)大家有所幫助，如果大家有任何疑問請(qǐng)給我留言，小編會(huì)及時(shí)回復(fù)大家的。在此也非常感謝大家對(duì)腳本之家網(wǎng)站的支持！

最新評(píng)論