Solve the slow connection MySQL method

After the recent installation of MYSQL5 on a Linux server, the local use of client-side MySQL is very slow and the local program connection is very slow.
Workaround: Add skip-name-resolve under [mysqld] in the configuration file MY.CNF.

The reason is that the default installation of MySQL turns on DNS reverse parsing. If disabled, you cannot use the hostname in the MySQL authorization table, but only in IP format.

Attached: how MySQL uses DNS

When a new thread connects to Mysqld, Mysqld would spawn a new thread to handle the request. This thread would first check if the hostname is in the hostname cache. If not the thread would call Gethostbyaddr_r () and Gethostbyname_r () to resolve the hostname.

If the operating system doesn ' t support the above Thread-safe calls, the thread would lock a mutex and call gethostbyaddr () and gethostbyname () instead. Note that in this case no other thread can resolve other hostnames that's not in the hostname cache until the first Threa D 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 had a very slow DNS and many hosts, you can get to more performance by either disabling DNS lookup with--SKIP-NAME-R Esolve 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.

or add in Host

192.168.1.21 N-21

Solve the slow connection MySQL method