观察你的系统
• MySQL
– 活动进程(Process list)
– 日志文件(slow log, alert log, general query log, binlog)
– Status variables（com_select, com_insert,.etc )
– InnoDB(物理读、逻辑读、innodb status)
– 参数配置
– Stack trace(plus source code)
• SQL
– 执行计划，explain
• OS
– 内存, SWAP, /proc/meminfo
– CPU, load, ps
– IO（磁盘、网络)
• Iostat
• Profile
– Oprofile
– gprof
