ProxySQL

proxysql的作用

1.读写分离，server可以进行分读组和写组

2.动态指定某一个sql进行cache

3.故障切换，依赖于他的配置动态加载，但是不能自动选主，需要依赖keepalived和MHA

4.配置动态更新

5.一个节点可以跑很多proxysql

6.percona公司的proxy

proxysql端口

监控的端口号：6633

管理端口号：6032

安装下载

[root@Darren1 tmp]# wget https://GitHub.com/sysown/proxysql/releases/download/v1.4.0/proxysql-1.4.0-1-Centos67.x86_64.rpm

[root@Darren1 tmp]# rpm -ivh proxysql-1.4.0-1-centos67.x86_64.rpm

[root@Darren1 tmp]# /etc/init.d/proxysql start

[root@Darren1 tmp]# ps -ef |grep proxy       

root      50769      1  0 05:19 ?        00:00:00 proxysql -c /etc/proxysql.cnf -D /var/lib/proxysql   

root      50770  50769  3 05:19 ?        00:00:00 proxysql -c /etc/proxysql.cnf -D /var/lib/proxysql

root      50798  50261  0 05:20 pts/3    00:00:00 grep proxy

#登陆：

[root@Darren1 proxysql]# Mysql -u admin -padmin -h 127.0.0.1 -P6032 --prompt='Admin> '

Admin> show databases;

+-----+---------+-------------------------------+

| seq | name    | file                          |

+-----+---------+-------------------------------+

| 0   | main    |                               |

| 2   | disk    | /var/lib/proxysql/proxysql.db |

| 3   | stats   |                               |

| 4   | monitor |                               |

+-----+---------+-------------------------------+

多层配置系统

（1）允许自动更新配置

（2）大部分配置无需重启，在运行状态配置生效

（3）允许回滚错误的配置

三层结构图：

[1] LOAD mysql USERS FROM MEMORY / LOAD MYSQL USERS TO RUNTIME

loads MySQL users from the in-memory database to the runtime data structures

[2] SAVE MYSQL USERS TO MEMORY / SAVE MYSQL USERS FROM RUNTIME

persists the MySQL users from the runtime data structures to the in-memory database

[3] LOAD MYSQL USERS TO MEMORY / LOAD MYSQL USERS FROM DISK

loads MySQL users from the on-disk database to the in-memory database

[4] SAVE MYSQL USERS FROM MEMORY / SAVE MYSQL USERS TO DISK

persists the MySQL users from the in-memory database to the on-disk database

[5] LOAD MYSQL USERS FROM CONFIG

loads from the configuration file the users into the in-memory database

适用于表：

  mysql_users mysql_servers

  mysql_query_rules  

  mysql_variables  

  admin_variables

scheduler计划任务

scheduler是类似cron的任务调度计划，允许运行自定义脚本。

主要有两个表：

admin@127.0.0.1 [main]>SHOW TABLES LIKE '%scheduler%';

+-------------------+

| tables            |

+-------------------+

| scheduler         |

| runtime_scheduler |

+-------------------+

scheduler ：可以用来设置调度计划

runtime_scheduler：只读，不能配置修改

admin@127.0.0.1 [main]> SHOW CREATE TABLE scheduler\G

*************************** 1. row ***************************

       table: scheduler

Create Table: CREATE TABLE scheduler (

    id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,

    active INT CHECK (active IN (0,1)) NOT NULL DEFAULT 1,

    interval_ms INTEGER CHECK (interval_ms>=100 AND interval_ms<=100000000) NOT NULL,

    filename VARCHAR NOT NULL,

    arg1 VARCHAR,

    arg2 VARCHAR,

    arg3 VARCHAR,

    arg4 VARCHAR,

    arg5 VARCHAR,

    comment VARCHAR NOT NULL DEFAULT '')

In details:

id : unique identifier of the scheduler job

active : if set to 1, the job is active. Otherwise is not

interval_ms : how often (in millisecond) the job will be started. Minimum interval_ms is 100 milliseconds

filename : full path of the executable to be executed

arg1 to arg5 : arguments (maximum 5) that can be passed to the job

comment : an free fORM text field to annotate the purpose of the job

用户配置 Users Configuration

定义一个新的用户：

admin@127.0.0.1 [main]>INSERT INTO mysql_users(username,passWord) VALUES ('user1','password1');

创建一个由hostgroup，schema的用户：

admin@127.0.0.1 [main]>INSERT INTO mysql_users(username,password,default_hostgroup,default_schema) VALUES ('user2','password2',10,'sbtest1');

修改user2用户的最大连接数为100个：

admin@127.0.0.1 [main]>UPDATE mysql_users SET max_connections=100 WHERE username='user2';

修改事务持久化：

admin@127.0.0.1 [main]> UPDATE mysql_users SET transaction_persistent=1 WHERE username='user2';

密码hash加密：

admin@127.0.0.1 [main]>load mysql users to runtime;

admin@127.0.0.1 [main]>save mysql users from runtime;

admin@127.0.0.1 [main]>save mysql users to disk;

服务配置 （server configuration ）

1、往mysql_servers表中添加server时就为其划分好hostgroup_id（例如0表示写组，1表示读组）

2、往mysql_servers表中添加server时不区分hostgroup_id（例如全部设为0），然后通过mysql_replication_hostgroups表中的值，根据proxysql检测到的各server的read_only变量值来自动为后端server设置hostgroup_id

    强烈推荐用第一种方式： 因为第一种是完全由我们控制的;而第二种假如我们误将读server的read_only属性设置为0，则proxysql会将其重新分配到写组，这绝对是不期望的。

（1）添加一个新的服务：

admin@127.0.0.1 [main]>insert into mysql_servers(hostgroup_id,hostname,max_connections) values(0,'192.168.91.23',1000);

admin@127.0.0.1 [main]>insert into mysql_servers(hostgroup_id,hostname,max_connections) values(1,'192.168.91.22',1000);

admin@127.0.0.1 [(none)]>select * from mysql_servers;

+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+

| hostgroup_id | hostname      | port | status | weight | compression | max_connections | max_replication_lag | use_ssl | max_latency_ms | comment |

+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+

| 0            | 192.168.91.23 | 3306 | ONLINE | 1      | 0           | 1000            | 0                   | 0       | 0              |         |

| 1            | 192.168.91.22 | 3306 | ONLINE | 1      | 0           | 1000            | 0                   | 0       | 0              |         |

+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+

（2）修改限制连接数max_connections ：

admin@127.0.0.1 [main]>UPDATE mysql_servers SET max_connections=10 WHERE hostname='192.168.91.23';

（3）修改权重值weight：

例如：一主两从的环境，设置不同的权重：

Admin> SELECT hostgroup_id,hostname,weight,max_replication_lag FROM mysql_servers;

+--------------+------------+--------+---------------------+

| hostgroup_id | hostname   | weight | max_replication_lag |

+--------------+------------+--------+---------------------+

| 0            | 172.16.0.1 | 1000   | 30                  |

| 1            | 172.16.0.2 | 1000   | 30                  |

| 1            | 172.16.0.3 | 1000   | 30                  |

| 1            | 172.16.0.1 | 1      | 30                  |

+--------------+------------+--------+---------------------+

上面的情况，如果有读事物，99.95%将会发送给172.16.0.2和172.16.0.3主机上，0.05%会发送到172.16.0.1主机上，如果172.16.0.2和172.16.0.3变得不可用了，则所有的读会有172.16.0.1承担

（4）修改复制延时最大值max_replication_lag ：

admin@127.0.0.1 [main]>UPDATE mysql_servers SET max_replication_lag=30 WHERE hostname='192.168.91.23';

（5）打开压缩，把compression设置为非0

admin@127.0.0.1 [main]>UPDATE mysql_servers SET compression=2 WHERE hostname='192.168.91.23';      

（6）优雅的关闭一个服务：

把状态改变成 status = offline_soft. 

admin@127.0.0.1 [main]>UPDATE mysql_servers SET status='OFFLINE_SOFT' WHERE hostname='192.168.91.23';

（7）删除一个服务delete即可

在proxysql连接msyql server

[root@Darren1 ~]# mysql -u admin -padmin -h 127.0.0.1 -P6032

#配置DB主机:

admin@127.0.0.1 [main]>insert into mysql_servers(hostgroup_id,hostname) values(0,'192.168.91.23');

admin@127.0.0.1 [main]>insert into mysql_servers(hostgroup_id,hostname) values(1,'192.168.91.22');

admin@127.0.0.1 [(none)]>select * from mysql_servers;

+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+

| hostgroup_id | hostname      | port | status | weight | compression | max_connections | max_replication_lag | use_ssl | max_latency_ms | comment |

+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+

| 0            | 192.168.91.23 | 3306 | ONLINE | 1      | 0           | 1000            | 0                   | 0       | 0              |         |

| 1            | 192.168.91.22 | 3306 | ONLINE | 1      | 0           | 1000            | 0                   | 0       | 0              |         |

+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+

#在mysql主库上创建监控用户：

root@localhost [(none)]>create user monitor@'192.168.91.%' identified by 'monitor';

root@localhost [(none)]>grant all on *.* to monitor@'192.168.91.%';

#在proxysql中配置监控用户和密码：

admin@127.0.0.1 [(none)]>UPDATE global_variables SET variable_value='monitor' WHERE variable_name='mysql-monitor_username';

admin@127.0.0.1 [(none)]>UPDATE global_variables SET variable_value='monitor' WHERE variable_name='mysql-monitor_password';

#配置监控时间间隔：如mysql-monitor_connect_interval、  mysql-monitor_ping_interval、  mysql-monitor_read_only_interval：

admin@127.0.0.1 [(none)]>UPDATE global_variables SET variable_value='2000' WHERE variable_name IN ('mysql-monitor_connect_interval','mysql-monitor_ping_interval','mysql-monitor_read_only_interval');

admin@127.0.0.1 [(none)]>select * from global_variables where variable_name like 'mysql-monitor_%';

+-----------------------------------------------------+----------------+

| variable_name                                       | variable_value |

+-----------------------------------------------------+----------------+

| mysql-monitor_enabled                               | true           |

| mysql-monitor_connect_timeout                       | 600            |

| mysql-monitor_ping_max_failures                     | 3              |

| mysql-monitor_ping_timeout                          | 1000           |

| mysql-monitor_replication_lag_interval              | 10000          |

| mysql-monitor_replication_lag_timeout               | 1000           |

| mysql-monitor_groupreplication_healthcheck_interval | 5000           |

| mysql-monitor_groupreplication_healthcheck_timeout  | 800            |

| mysql-monitor_username                              | monitor        |

| mysql-monitor_password                              | monitor        |

| mysql-monitor_query_interval                        | 60000          |

| mysql-monitor_query_timeout                         | 100            |

| mysql-monitor_slave_lag_when_null                   | 60             |

| mysql-monitor_wait_timeout                          | true           |

| mysql-monitor_writer_is_also_reader                 | true           |

| mysql-monitor_history                               | 600000         |

| mysql-monitor_connect_interval                      | 2000           |

| mysql-monitor_ping_interval                         | 2000           |

| mysql-monitor_read_only_interval                    | 2000           |

| mysql-monitor_read_only_timeout                     | 500            |

+-----------------------------------------------------+----------------+

admin@127.0.0.1 [(none)]>LOAD MYSQL VARIABLES TO RUNTIME;

admin@127.0.0.1 [(none)]>SAVE MYSQL VARIABLES TO DISK;

admin@127.0.0.1 [(none)]>show tables from monitor;

+------------------------------------+

| tables                             |

+------------------------------------+

| mysql_server_connect               |

| mysql_server_connect_log           |

| mysql_server_group_replication_log |

| mysql_server_ping                  |

| mysql_server_ping_log              |

| mysql_server_read_only_log         |

| mysql_server_replication_lag_log   |

+------------------------------------+

admin@127.0.0.1 [(none)]>SELECT * FROM monitor.mysql_server_connect_log ORDER BY time_start_us DESC LIMIT 10;

+---------------+------+------------------+-------------------------+---------------+

| hostname      | port | time_start_us    | connect_success_time_us | connect_error |

+---------------+------+------------------+-------------------------+---------------+

| 192.168.91.23 | 3306 | 1495445436268761 | 1894                    | NULL          |

| 192.168.91.22 | 3306 | 1495445436267947 | 3301                    | NULL          |

| 192.168.91.23 | 3306 | 1495445434267631 | 601                     | NULL          |

| 192.168.91.22 | 3306 | 1495445434266684 | 1898                    | NULL          |

| 192.168.91.23 | 3306 | 1495445432267286 | 527                     | NULL          |

| 192.168.91.22 | 3306 | 1495445432266457 | 1646                    | NULL          |

+---------------+------+------------------+-------------------------+---------------+

admin@127.0.0.1 [(none)]>SELECT * FROM monitor.mysql_server_ping_log ORDER BY time_start_us DESC LIMIT 10;

+---------------+------+------------------+----------------------+------------+

| hostname      | port | time_start_us    | ping_success_time_us | ping_error |

+---------------+------+------------------+----------------------+------------+

| 192.168.91.23 | 3306 | 1495445542307107 | 147                  | NULL       |

| 192.168.91.22 | 3306 | 1495445542306299 | 504                  | NULL       |

| 192.168.91.23 | 3306 | 1495445540306625 | 173                  | NULL       |

| 192.168.91.22 | 3306 | 1495445540305786 | 596                  | NULL       |

| 192.168.91.23 | 3306 | 1495445538305981 | 165                  | NULL       |

+---------------+------+------------------+----------------------+------------+

admin@127.0.0.1 [(none)]>LOAD MYSQL ServerS TO RUNTIME;

MySQL replication hostgroups

对应表 mysql_replication_hostgroups

表的作用：配置写组（比如1）和读组（比如2），ProxySQL会根据read_only参数把主机分配到对应的读组合写组中

如read_only=0 ,分配到hostgroup 1

如read_only=1 , 分配到 hostgroup 2

admin@127.0.0.1 [(none)]>INSERT INTO mysql_replication_hostgroups(writer_hostgroup,reader_hostgroup) VALUES (1,2);

admin@127.0.0.1 [(none)]>select * from  mysql_replication_hostgroups;

+------------------+------------------+---------+

| writer_hostgroup | reader_hostgroup | comment |

+------------------+------------------+---------+

| 1                | 2                | NULL    |

+------------------+------------------+---------+

#现在192.168.91.22是read_only=0,所以hostgroup_id=1：

admin@127.0.0.1 [(none)]>SELECT * FROM mysql_servers;

+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+

| hostgroup_id | hostname      | port | status | weight | compression | max_connections | max_replication_lag | use_ssl | max_latency_ms | comment |

+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+

| 0            | 192.168.91.23 | 3306 | ONLINE | 1      | 0           | 1000            | 0                   | 0       | 0              |         |

| 1            | 192.168.91.22 | 3306 | ONLINE | 1      | 0           | 1000            | 0                   | 0       | 0              |         |

+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+

admin@127.0.0.1 [(none)]>load mysql servers to runtime;

root@localhost [(none)]>set global read_only=1;

admin@127.0.0.1 [(none)]>SELECT * FROM monitor.mysql_server_read_only_log ORDER BY time_start_us DESC LIMIT 10;

+---------------+------+------------------+-----------------+-----------+-------+

| hostname      | port | time_start_us    | success_time_us | read_only | error |

+---------------+------+------------------+-----------------+-----------+-------+

| 192.168.91.22 | 3306 | 1495449784913364 | 10240           | 1         | NULL  |

| 192.168.91.22 | 3306 | 1495449782913147 | 3161            | 1         | NULL  |

| 192.168.91.22 | 3306 | 1495449780912973 | 5600            | 1         | NULL  |

| 192.168.91.22 | 3306 | 1495449778913003 | 8661            | 1         | NULL  |  |

+---------------+------+------------------+-----------------+-----------+-------+

#现在192.168.91.22是read_only=1,所以被分配到hostgroup_id=2：

admin@127.0.0.1 [(none)]>select * from mysql_servers;

+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+

| hostgroup_id | hostname      | port | status | weight | compression | max_connections | max_replication_lag | use_ssl | max_latency_ms | comment |

+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+

| 0            | 192.168.91.23 | 3306 | ONLINE | 1      | 0           | 1000            | 0                   | 0       | 0              |         |

| 2            | 192.168.91.22 | 3306 | ONLINE | 1      | 0           | 1000            | 0                   | 0       | 0              |         |

+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+

admin@127.0.0.1 [(none)]>SAVE MYSQL SERVERS TO DISK;

admin@127.0.0.1 [(none)]>save mysql variables to disk;

mysql_users

admin>INSERT INTO mysql_users(username,password,default_hostgroup) VALUES ('user1','147258',0);

admin>INSERT INTO mysql_users(username,password,default_hostgroup) VALUES ('user2','147258',1);

admin>INSERT INTO mysql_users(username,password,default_hostgroup) VALUES ('user3','147258',2);

admin@127.0.0.1 [(none)]>load mysql users to runtime;

admin@127.0.0.1 [(none)]>save mysql users to disk;

#需要在数据库层面创建对应的用户名和密码才能登陆操作数据库：

root@localhost [(none)]>create user user1@'%' identified by '147258';

root@localhost [(none)]>grant all on *.* to user1@'%';

mysql -u user1 -p147258 -h 127.0.0.1 -P6033

user1@127.0.0.1 [testdb]>select @@hostname;

+------------+

| @@hostname |

+------------+

| Darren1    |

+------------+

#可以用sysbench做测试：

[root@Darren1 ~]# sysbench --time=20 --threads=4  --mysql-host=localhost --mysql-user=user1 --mysql-password='147258' --mysql-port=6033  --mysql-db=sbtest --tables=4 --table_size=1000  /home/mysql/sysbench-1.0.3/src/lua/oltp_read_write.lua prepare

[root@Darren1 ~]# sysbench --time=20 --threads=4  --mysql-host=localhost --mysql-user=user1 --mysql-password='147258' --mysql-port=6033  --mysql-db=sbtest --tables=4 --table_size=1000  /home/mysql/sysbench-1.0.3/src/lua/oltp_read_write.lua run

ProxySQL Statistics

ProxySQL可以通过stats库收集大量统计信息

admin@127.0.0.1 [(none)]>show tables from stats;

+-----------------------------------+

| tables                            |

+-----------------------------------+

| global_variables                  |

| stats_mysql_commands_counters     |

| stats_mysql_connection_pool       |

| stats_mysql_connection_pool_reset |

| stats_mysql_global                |

| stats_mysql_processlist           |

| stats_mysql_query_digest          |

| stats_mysql_query_digest_reset    |

| stats_mysql_query_rules           |

| stats_mysql_users                 |

+-----------------------------------+

#stats.stats_mysql_connection_pool表：

admin@127.0.0.1 [(none)]>SELECT * FROM stats.stats_mysql_connection_pool;

+-----------+---------------+----------+--------+----------+----------+--------+---------+---------+-----------------+-----------------+------------+

| hostgroup | srv_host      | srv_port | status | ConnUsed | ConnFree | ConnOK | ConnERR | Queries | Bytes_data_sent | Bytes_data_recv | Latency_us |

+-----------+---------------+----------+--------+----------+----------+--------+---------+---------+-----------------+-----------------+------------+

| 0         | 192.168.91.23 | 3306     | ONLINE | 0        | 0        | 0      | 22      | 0       | 0               | 0               | 168        |

| 2         | 192.168.91.22 | 3306     | ONLINE | 0        | 0        | 0      | 0       | 0       | 0               | 0               | 926        |

| 1         | 192.168.91.22 | 3306     | ONLINE | 0        | 0        | 0      | 176     | 0       | 0               | 0               | 926        |

+-----------+---------------+----------+--------+----------+----------+--------+---------+---------+-----------------+-----------------+------------+

#stats_mysql_commands_counters表：

作用：

returns detailed information about the type of statements executed, and the distribution of execution time!

#统计一些sql的操作：

admin@127.0.0.1 [(none)]>select * from stats_mysql_commands_counters;

+-------------------+---------------+-----------+-----------+-----------+---------+---------+----------+----------+-----------+-----------+--------+--------+---------+----------+

| Command           | Total_Time_us | Total_cnt | cnt_100us | cnt_500us | cnt_1ms | cnt_5ms | cnt_10ms | cnt_50ms | cnt_100ms | cnt_500ms | cnt_1s | cnt_5s | cnt_10s | cnt_INFs |

+-------------------+---------------+-----------+-----------+-----------+---------+---------+----------+----------+-----------+-----------+--------+--------+---------+----------+

| ALTER_TABLE       | 0             | 0         | 0         | 0         | 0       | 0       | 0        | 0        | 0         | 0         | 0      | 0      | 0       | 0        |

| ALTER_VIEW        | 0             | 0         | 0         | 0         | 0       | 0       | 0        | 0        | 0         | 0         | 0      | 0      | 0       | 0        |

| ANALYZE_TABLE     | 0             | 0         | 0         | 0         | 0       | 0       | 0        | 0        | 0         | 0         | 0      | 0      | 0       | 0        |

| BEGIN             | 0             | 0         | 0         | 0         | 0       | 0       | 0        | 0        | 0         | 0         | 0      | 0      | 0       | 0        |

| CALL              | 0             | 0         | 0         | 0         | 0       | 0       | 0        | 0        | 0         | 0         | 0      | 0      | 0       | 0        |

| CHANGE_MASTER     | 0             | 0         | 0         | 0         | 0       | 0       | 0        | 0        | 0         | 0         | 0      | 0      | 0       | 0        |

| COMMIT            | 0             | 0         | 0         | 0         | 0       | 0       | 0        | 0        | 0         | 0   

...........

#stats_mysql_query_digest查看执行过的查询操作

admin@127.0.0.1 [(none)]>SELECT * FROM stats_mysql_query_digest ORDER BY sum_time DESC;

+-----------+--------------------+----------+--------------------+-----------------------------------+------------+------------+------------+----------+----------+----------+

| hostgroup | schemaname         | username | digest             | digest_text                       | count_star | first_seen | last_seen  | sum_time | min_time | max_time |

+-----------+--------------------+----------+--------------------+-----------------------------------+------------+------------+------------+----------+----------+----------+

| 0         | information_schema | user1    | 0x1E092DAEFFBBF262 | select ?                          | 1          | 1495462584 | 1495462584 | 111316   | 111316   | 111316   |

| 0         | testdb             | user1    | 0x3765930C7143F468 | select * from t1                  | 1          | 1495462644 | 1495462644 | 101438   | 101438   | 101438   |

| 0         | information_schema | user1    | 0x99531AEFF718C501 | show tables                       | 2          | 1495462594 | 1495

.......

#查询表stats_mysql_query_digest_reset的作用就是把表stats_mysql_query_digest清空

admin@127.0.0.1 [(none)]>select * from stats_mysql_query_digest_reset;

admin@127.0.0.1 [(none)]>select * from stats_mysql_query_digest;

Empty set (0.00 sec)

路由规则（MySQL Query Rules）

表: mysql_query_rules

作用：控制读写分离

表中：apply=1 means that no further rules are checked if there is a match

#创建一个rule:表示SELECT * FROM t1$开头的SQL语句会通过hostgroup为0的主机执行：

admin@127.0.0.1 [(none)]>INSERT INTO mysql_query_rules (rule_id,active,username,match_digest,destination_hostgroup,apply) VALUES (10,1,'user1','^SELECT * FROM t1$',0,1);

admin@127.0.0.1 [(none)]>LOAD MYSQL QUERY RULES TO RUNTIME;

[root@Darren1 lua]# mysql -u user1 -p147258 -h 127.0.0.1 -P6033

user1@127.0.0.1 [testdb]>select * from t1;

#可以看到前面的select语句分配到hostgroup为0的服务器上：

admin@127.0.0.1 [(none)]>SELECT hostgroup hg, sum_time, count_star, digest_text FROM stats_mysql_query_digest ORDER BY sum_time DESC;

+----+----------+------------+------------------+

| hg | sum_time | count_star | digest_text      |

+----+----------+------------+------------------+

| 0  | 716      | 1          | select * from t1 |

+----+----------+------------+------------------+