《Mysql學習MySQL數據庫遠程連接很慢的解決方案》要點：
本文介紹了Mysql學習MySQL數據庫遠程連接很慢的解決方案，希望對您有用。如果有疑問，可以聯系我們。
MYSQL必讀有次同事提出開發使用的MySQL數據庫連接很慢,因為我們的MySQL開發數據庫是單獨一臺機器部署的,所以認為可能是網絡連接問題導致的.
MYSQL必讀在進行 ping和route后發現網絡通信都是正常的,而且在MySQL機器上進行本地連接發現是很快的,所以網絡問題基本上被排除了.以前也遇到過一次這樣的問題,可后來就不知怎么突然好了,這次又遭遇這樣的問題,所以想看看是不是MySQL的配置問題.在查詢MySQL相關文檔和網絡搜索后,發現了一個配置似乎可以解決這樣的問題,就是在MySQL的配置文件中增加如下配置參數：
MYSQL必讀
[mysqld]
skip-name-resolve
MYSQL必讀在Linux下配置文件是/etc/my.cnf,在windows下配置文件是MySQL安裝目錄下的my.ini文件.注意該配置是加在 [mysqld]下面,在更改配置并保存后,然后重啟mysql并遠程連接測試,一切恢復如初.該參數的官方解釋信息如下：
MYSQL必讀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.
MYSQL必讀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.
MYSQL必讀You can disable DNS host lookup by starting mysqld with Cskip-name-resolve. In this case you can however only use IP names in the MySQL privilege tables.
MYSQL必讀If you have a very slow DNS and many hosts, you can get more performance by either disabling DNS lookop with Cskip-name-resolve or by increasing the HOST_CACHE_SIZE define (default: 128) and recompile mysqld.
MYSQL必讀You can disable the hostname cache with Cskip-host-cache. You can clear the hostname cache with FLUSH HOSTS or mysqladmin flush-hosts.
MYSQL必讀If you don't want to allow connections over TCP/IP, you can do this by starting mysqld with Cskip-networking.
MYSQL必讀根據文檔說明,如果你的mysql主機查詢DNS很慢或是有很多客戶端主機時會導致連接很慢,由于我們的開發機器是不能夠連接外網的,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, 請注意在增加該配置參數后,mysql的授權表中的host字段就不能夠使用域名而只能夠使用 ip地址了 ,因為這是禁止了域名解析的結果.
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