MYSQL常用的性能指标

QPS = Questions(or Queries) / seconds
mysql > show  global status like 'Question%';

TPS = (Com_commit + Com_rollback) / seconds
mysql > show global status like'Com_commit';
mysql > show global status like'Com_rollback';

mysql>show  global  status  like   'key%';
key_buffer_read_hits = (1-key_reads /key_read_requests) * 100%
key_buffer_write_hits = (1-key_writes /key_write_requests) * 100%

mysql> show status like'innodb_buffer_pool_read%';
innodb_buffer_read_hits = (1 -innodb_buffer_pool_reads / innodb_buffer_pool_read_requests) * 100%

mysql> show status like 'Qcache%';
Query_cache_hits = (Qcahce_hits /(Qcache_hits + Qcache_inserts )) * 100%;

mysql> show global  status like 'open%';

mysql> show global status like'Thread%';
mysql> show global status like'Connections';
Thread_cache_hits = (1 - Threads_created /connections ) * 100%

mysql> show global  status like '%lock%';
Table_locks_waited/Table_locks_immediate=0.3%  如果这个比值比较大的话，说明表锁造成的阻塞比较严重
Innodb_row_lock_waits innodb行锁，太大可能是间隙锁造成的

mysql > show slave status

mysql > show status like 'Create_tmp%';
Created_tmp_disk_tables/Created_tmp_tables比值最好不要超过10%，如果Created_tmp_tables值比较大，

mysql > show status like'Binlog_cache%';

mysql > show status like'innodb_log_waits';

mysql> mysql -e "show global statuslike 'Open_files';
mysql> mysql -e "show global statuslike 'Open_tables';

         编辑/etc/my.cnf，在[mysqld]域中添加：
         slow_query_log= 1   # 开启慢查询
         slow_query_log_file=/data/mysql/slow.log   # 慢查询日志路径
         long_query_time= 1        # 慢查询的时长

  show global variables like 'general_log';

    set global general_log=on;