摘要：
mysqladmin是 MySQL一个重要的客户端，最常见的是使用它来关闭数据库，除此，该命令还可以了解MySQL运行状态、进程信息、进程杀死等。本文介绍一下如何使用 mysqladmin extended-status(因为没有"歧义"，所以可以使用ext代替)了解MySQL的运行状态。
1. 使用-r/-i参数
使用mysqladmin extended-status命令可以获得所有MySQL性能指标，即show global status的输出，不过，因为多数这些指标都是累计值，如果想了解当前的状态，则需要进行一次差值计算，这就是mysqladmin extended-status的一个额外功能，非常实用。默认的，使用extended-status，看到也是累计值，但是，加上参数 -r(--relative)，就可以看到各个指标的差值，配合参数-i(--sleep)就可以指定刷新的频率，那么就有如下命令：
mysqladmin --no-defaults -uroot -r -i 1 -p123456 extended-status +---------------------------------------+----------+ | Variable_name | Value | +---------------------------------------+----------+ | Aborted_clients | 0 | | Aborted_connects | 0 | | Binlog_cache_disk_use | 0 | | Binlog_cache_use | 0 | | Bytes_received | 35 | | Bytes_sent | 7372 | …………………… | Threads_running | 0 | | Uptime | 1 | | Uptime_since_flush_status | 1 | +---------------------------------------+----------+
2. 配合grep使用
配合grep使用，我们就有：
mysqladmin --no-defaults -uroot -p123456 -r -i 1 extended-status |grep "Questions\|Queries\|Innodb_rows\|Com_select \|Com_insert \|Com_update \|Com_delete " | Com_delete | 0 | | Com_insert | 0 | | Com_select | 0 | | Com_update | 0 | | Innodb_rows_deleted | 0 | | Innodb_rows_inserted | 0 | | Innodb_rows_read | 0 | | Innodb_rows_updated | 0 | | Queries | 113 | | Questions | 113 |
3. 配合简单的awk使用
使用awk，同时输出时间信息：
mysqladmin --no-defaults -uroot -p123456 -P3306 -r -i 1 ext |awk -F"|" ‘{\ if($2 ~ /Variable_name/){ print " <------------- " strftime("%H:%M:%S") " ------------->"; } if($2 ~ /Questions|Queries|Innodb_rows|Com_select |Com_insert |Com_update |Com_delete |Innodb_buffer_pool_read_requests/) print $2 $3;}‘ <------------- 11:37:27 -------------> Com_delete 0 Com_insert 0 Com_select 0 Com_update 0 Innodb_buffer_pool_read_requests 6549 Innodb_rows_deleted 0 Innodb_rows_inserted 0 Innodb_rows_read 0 Innodb_rows_updated 0 Queries 131 Questions 131 <------------- 11:37:28 -------------> Com_delete 0 Com_insert 0 Com_select 0 Com_update 0 Innodb_buffer_pool_read_requests 0 Innodb_rows_deleted 0 Innodb_rows_inserted 0 Innodb_rows_read 0 Innodb_rows_updated 0 Queries 1 Questions 1
4. 配合复杂一点的awk
反正也不简单了，那就更复杂一点，这样让输出结果更友好点，因为awk不支持动态变量，所以代码看起来比较复杂：
mysqladmin --no-defaults -uroot -p123456 -r -i 1 ext |gawk -F"|" "BEGIN{ count=0; }"‘{ if($2 ~ /Variable_name/ && ++count == 1){\ print "----------|---------|--- MySQL Command Status --|----- Innodb row operation ----|-- Buffer Pool Read --"; print "---Time---|---QPS---|select insert update delete| read inserted updated deleted| logical physical";}else if ($2 ~ /Queries/){queries=$3;}else if ($2 ~ /Com_select /){com_select=$3;}else if ($2 ~ /Com_insert /){com_insert=$3;}else if ($2 ~ /Com_update /){com_update=$3;}else if ($2 ~ /Com_delete /){com_delete=$3;}else if ($2 ~ /Innodb_rows_read/){innodb_rows_read=$3;}else if ($2 ~ /Innodb_rows_deleted/){innodb_rows_deleted=$3;}else if ($2 ~ /Innodb_rows_inserted/){innodb_rows_inserted=$3;}else if ($2 ~ /Innodb_rows_updated/){innodb_rows_updated=$3;}else if ($2 ~ /Innodb_buffer_pool_read_requests/){innodb_lor=$3;}else if ($2 ~ /Innodb_buffer_pool_reads/){innodb_phr=$3;}else if ($2 ~ /Uptime / && count >= 2){ printf(" %s |%9d",strftime("%H:%M:%S"),queries); printf("|%6d %6d %6d %6d",com_select,com_insert,com_update,com_delete); printf("|%6d %8d %7d %7d",innodb_rows_read,innodb_rows_inserted,innodb_rows_updated,innodb_rows_deleted); printf("|%10d %11d\n",innodb_lor,innodb_phr);}}‘ ----------|---------|--- MySQL Command Status --|----- Innodb row operation ----|-- Buffer Pool Read -- ---Time---|---QPS---|select insert update delete| read inserted updated deleted| logical physical 11:39:51 | 1| 0 0 0 0| 0 0 0 0| 0 0 11:39:52 | 1| 0 0 0 0| 0 0 0 0| 0 0 11:39:53 | 1| 0 0 0 0| 0 0 0 0| 0 0 11:39:54 | 1| 0 0 0 0| 0 0 0 0| 0 0 11:39:55 | 1| 0 0 0 0| 0 0 0 0| 0 0 11:39:56 | 1| 0 0 0 0| 0 0 0 0| 0 0 ………… …………
这里注意，要是awk是mawk的话，会出现：function strftime never defined ，所以要用gawk。
本文来自：http://www.orczhou.com/index.php/2014/03/some-tricky-about-mysqladmin-extended-status/