Mysql 性能指标查看 简单的几个可以查看mysql性能指标的方法 根据数值结合业务做优化方案

QPS(每秒Query量)

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

TPS(每秒事务量)

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

key Buffer 命中率

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%

InnoDB Buffer命中率

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

Query Cache命中率

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

Table Cache状态量

mysql> show global  status like 'open%';
比较 open_tables  与 opend_tables 值

Thread Cache 命中率

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

锁定状态

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

复制延时量

mysql > show slave status
查看延时时间

Tmp Table 状况(临时表状况)

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，可能是排序句子过多或者是连接句子不够优化

Binlog Cache 使用状况

mysql > show status like 'Binlog_cache%';
如果Binlog_cache_disk_use值不为0 ，可能需要调大 binlog_cache_size大小

Innodb_log_waits 量

mysql > show status like 'innodb_log_waits';
Innodb_log_waits值不等于0的话，表明 innodb log  buffer 因为空间不足而等待