1.max_connect_errors默认为10,表示1个主机10次连接失败,将再也不能连接mysql服务器了,要等mysql admin执行flush hosts才可以进行连接。
2.connect_timeout 当网络有时候比较拥塞的时候,可能会高于这个数。 3.skip-name-resolve默认情况下mysql需要开启线程去请求客户端所用的域名,其中涉及到两个函数gethostbyaddr_r() and gethostbyname_r().通常这样会很慢,我们可以关闭mysqld不去反解dns。 If the operating system supports the thread-safe gethostbyaddr_r() and gethostbyname_r() calls, the thread uses them to perform host name resolution. If the operating system does not support the thread-safe calls, the thread locks a mutex and calls gethostbyaddr() and gethostbyname() instead. In this case, no other thread can resolve host names that are not in the host name cache until the first thread unlocks the mutex. You can disable DNS host name lookups by starting mysqld with the –skip-name-resolve option. However, in this case, you can use only IP numbers in the MySQL grant tables. If you have a very slow DNS and many hosts, you can get
more performance by either disabling DNS lookups with –skip-name-resolve
or by increasing the HOST_CACHE_SIZE define (default value: 128) and
recompiling mysqld. 4.interactive_timeout默认是28800,默认太大了,可以改个稍微小的参数比如10-120 5.max_connections最大的mysqld提供连接数,默认是150,一般正式生产服务器都不止这个数。可以根据实际情况进行修改 6.back_log默认值50,较小参考值100-200(内存要消耗点) 7.slave_net_timeoutMySQL
主从复制的时候,
当Master和Slave之间的网络中断,但是Master和Slave无法察觉的情况下(比如防火墙或者路由问题)。Slave会等待
slave_net_timeout设置的秒数后,才能认为网络出现故障,然后才会重连并且追赶这段时间主库的数据。 8.wait_timeout这个就不用说了,前面有篇《mysql的长连接》专门说了 |
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