ProxySQL快速入门

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准备

以CentOS 7.x下载为例：ProxySQL v2.4.5 x86_64 for RedHat & CentOS 7

• yum install -y proxysql-2.4.5-1-centos7.x86_64.rpm 安装
• systemctl start proxysql 启动

两种配置方式：

1. Admin interface
2. /etc/proxysql.cnf

Admin interface

进入控制台：mysql -u admin -padmin -h 127.0.0.1 -P6032 --prompt='Admin> '
初始化用户名密码均为 admin

note: If your MySQL client version is version 8.04 or higher add --default-auth=mysql_native_password to the above command to connect to the admin interface.

/etc/proxysql.cnf

• admin_variables: contains global variables that control the functionality of the admin interface.
• mysql_variables: contains global variables that control the functionality for handling the incoming MySQL traffic.
• mysql_servers: contains rows for the mysql_servers table from the admin interface. Basically, these define the backend servers towards which the incoming MySQL traffic is routed. Rows are encoded as per the .cfg file format, here is an example:

mysql_servers =
(
  {
    address="127.0.0.1"
    port=3306
    hostgroup=0
    max_connections=200
  }
)

• mysql_users: contains rows for the mysql_users table from the admin interface. Basically, these define the users which can connect to the proxy, and the users with which the proxy can connect to the backend servers. Rows are encoded as per the .cfg file format, here is an example:

mysql_users:
(
  {
    username = "root"
    password = "root"
    default_hostgroup = 0
    max_connections=1000
    default_schema="information_schema"
    active = 1
  }
)

• mysql_query_rules: contains rows for the mysql_query_rules table from the admin interface. Basically, these define the rules used to classify and route the incoming MySQL traffic, according to various criteria (patterns matched, user used to run the query, etc.). Rows are encoded as per the .cfg file format, here is an example (Note: the example is a very generic query routing rule and it is recommended to create specific rules for queries rather than using a generic rule such as this):

mysql_query_rules:
(
  {
    rule_id=1
    active=1
    match_pattern="^SELECT .* FOR UPDATE$"
    destination_hostgroup=0
    apply=1
  },
  {
    rule_id=2
    active=1
    match_pattern="^SELECT"
    destination_hostgroup=1
    apply=1
  }
)

• top-level configuration item: datadir, as a string, to point to the data dir.

基本配置

添加mysql服务器

Admin> SELECT * FROM mysql_servers;
+--------------+-----------+------+--------+--------+-------------+-----------------+---------------------+
| hostgroup_id | hostname  | port | status | weight | compression | max_connections | max_replication_lag |
+--------------+-----------+------+--------+--------+-------------+-----------------+---------------------+
| 1            | 10.10.0.1 | 3306 | ONLINE | 1      | 0           | 1000            | 0                   |
| 1            | 10.10.0.1 | 3306 | ONLINE | 1      | 0           | 1000            | 0                   |
| 1            | 10.10.0.1 | 3306 | ONLINE | 1      | 0           | 1000            | 0                   |
+--------------+-----------+------+--------+--------+-------------+-----------------+---------------------+

note: proxysql通过MySQL的read_only = 1配置判断是否是读写，primary数据库读写，slave只读，则 set global read_only = 1

监控

1. To create the user in MySQL connect to the PRIMARY and execute:

mysql> UPDATE global_variables SET variable_value='monitor' WHERE variable_name='mysql-monitor_username';
Query OK, 1 row affected (0.00 sec)

2. add the credentials of the monitor user to ProxySQL

ProxySQL Admin> UPDATE global_variables SET variable_value='monitor' WHERE variable_name='mysql-monitor_username';
Query OK, 1 row affected (0.00 sec)

ProxySQL Admin> UPDATE global_variables SET variable_value='monitor' WHERE variable_name='mysql-monitor_password';
Query OK, 1 row affected (0.00 sec)

3. configure the various monitoring intervals

ProxySQL Admin> UPDATE global_variables SET variable_value='2000' WHERE variable_name IN ('mysql-monitor_connect_interval','mysql-monitor_ping_interval','mysql-monitor_read_only_interval');
Query OK, 3 rows affected (0.00 sec)

ProxySQL Admin> SELECT * FROM global_variables WHERE variable_name LIKE 'mysql-monitor_%';
+----------------------------------------+---------------------------------------------------+
| variable_name                          | variable_value                                    |
+----------------------------------------+---------------------------------------------------+
| mysql-monitor_history                  | 600000                                            |
| mysql-monitor_connect_interval         | 2000                                              |
| mysql-monitor_connect_timeout          | 200                                               |
| mysql-monitor_ping_interval            | 2000                                              |
| mysql-monitor_ping_timeout             | 100                                               |
| mysql-monitor_read_only_interval       | 2000                                              |
| mysql-monitor_read_only_timeout        | 100                                               |
| mysql-monitor_replication_lag_interval | 10000                                             |
| mysql-monitor_replication_lag_timeout  | 1000                                              |
| mysql-monitor_username                 | monitor                                           |
| mysql-monitor_password                 | monitor                                           |
| mysql-monitor_query_variables          | SELECT * FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES |
| mysql-monitor_query_status             | SELECT * FROM INFORMATION_SCHEMA.GLOBAL_STATUS    |
| mysql-monitor_query_interval           | 60000                                             |
| mysql-monitor_query_timeout            | 100                                               |
| mysql-monitor_timer_cached             | true                                              |
| mysql-monitor_writer_is_also_reader    | true                                              |
+----------------------------------------+---------------------------------------------------+
17 rows in set (0.00 sec)

4. Apply changes: LOAD MYSQL VARIABLES TO RUNTIME . Persist the configuration changes SAVE MYSQL VARIABLES TO DISK .

Admin> LOAD MYSQL VARIABLES TO RUNTIME;
Query OK, 0 rows affected (0.00 sec)

Admin> SAVE MYSQL VARIABLES TO DISK;
Query OK, 54 rows affected (0.02 sec)

健康检查

健康检查的库monitor

ProxySQL Admin> SHOW TABLES FROM monitor;
+----------------------------------+
| tables                           |
+----------------------------------+
| mysql_server_connect             |
| mysql_server_connect_log         |
| mysql_server_ping                |
| mysql_server_ping_log            |
| mysql_server_read_only_log       |
| mysql_server_replication_lag_log |
+----------------------------------+
6 rows in set (0.00 sec)

ProxySQL Admin> SELECT * FROM monitor.mysql_server_connect_log ORDER BY time_start_us DESC LIMIT 3;
+-----------+------+------------------+----------------------+---------------+
| hostname  | port | time_start_us    | connect_success_time | connect_error |
+-----------+------+------------------+----------------------+---------------+
| 10.10.0.1 | 3306 | 1456968814253432 | 562                  | NULL          |
| 10.10.0.2 | 3306 | 1456968814253432 | 309                  | NULL          |
| 10.10.0.3 | 3306 | 1456968814253432 | 154                  | NULL          |
+-----------+------+------------------+----------------------+---------------+
3 rows in set (0.00 sec)

ProxySQL Admin> SELECT * FROM monitor.mysql_server_ping_log ORDER BY time_start_us DESC LIMIT 3;
+-----------+------+------------------+-------------------+------------+
| hostname  | port | time_start_us    | ping_success_time | ping_error |
+-----------+------+------------------+-------------------+------------+
| 10.10.0.1 | 3306 | 1456968828686787 | 124               | NULL       |
| 10.10.0.2 | 3306 | 1456968828686787 | 62                | NULL       |
| 10.10.0.3 | 3306 | 1456968828686787 | 57                | NULL       |
+-----------+------+------------------+-------------------+------------+
3 rows in set (0.01 sec)

复制hostgroups

ProxySQL通过监控mysql server的read_only配置来观察 replication topology. hostgroups可在表mysql_replication_hostgroups中定义，插入时必须定义a pair of READER and WRITER hostgroups

Admin> SHOW CREATE TABLE mysql_replication_hostgroupsG
*************************** 1. row ***************************
       table: mysql_replication_hostgroups
Create Table: CREATE TABLE mysql_replication_hostgroups (
writer_hostgroup INT CHECK (writer_hostgroup>=0) NOT NULL PRIMARY KEY,
reader_hostgroup INT NOT NULL CHECK (reader_hostgroup<>writer_hostgroup AND reader_hostgroup>0),
check_type VARCHAR CHECK (LOWER(check_type) IN ('read_only','innodb_read_only','super_read_only','read_only|innodb_read_only','read_only&innodb_read_only')) NOT NULL DEFAULT 'read_only',
comment VARCHAR,
UNIQUE (reader_hostgroup))
1 row in set (0.00 sec)

Admin> INSERT INTO mysql_replication_hostgroups (writer_hostgroup,reader_hostgroup,comment) VALUES (1,2,'cluster1');
Query OK, 1 row affected (0.00 sec)
// 生效
Admin> LOAD MYSQL SERVERS TO RUNTIME;
Query OK, 0 rows affected (0.00 sec)

The read_only check results are logged to the mysql_servers_read_only_log table in the monitor database:

Admin> SELECT * FROM monitor.mysql_server_read_only_log ORDER BY time_start_us DESC LIMIT 3;
+-----------+-------+------------------+--------------+-----------+-------+
| hostname  | port  | time_start_us    | success_time | read_only | error |
+-----------+-------+------------------+--------------+-----------+-------+
| 10.10.0.1 | 3306  | 1456969634783579 | 762          | 0         | NULL  |
| 10.10.0.2 | 3306  | 1456969634783579 | 378          | 1         | NULL  |
| 10.10.0.3 | 3306  | 1456969634783579 | 317          | 1         | NULL  |
+-----------+-------+------------------+--------------+-----------+-------+
3 rows in set (0.01 sec)

持久化配置：

Admin> SAVE MYSQL SERVERS TO DISK;
Query OK, 0 rows affected (0.01 sec)

Admin> SAVE MYSQL VARIABLES TO DISK;
Query OK, 54 rows affected (0.00 sec)

MySQL Users

配置完 mysql_servers之后要配置mysql_users

Admin> SHOW CREATE TABLE mysql_usersG
*************************** 1. row ***************************
       table: mysql_users
Create Table: CREATE TABLE mysql_users (
username VARCHAR NOT NULL,
password VARCHAR,
active INT CHECK (active IN (0,1)) NOT NULL DEFAULT 1,
use_ssl INT CHECK (use_ssl IN (0,1)) NOT NULL DEFAULT 0,
default_hostgroup INT NOT NULL DEFAULT 0,
default_schema VARCHAR,
schema_locked INT CHECK (schema_locked IN (0,1)) NOT NULL DEFAULT 0,
transaction_persistent INT CHECK (transaction_persistent IN (0,1)) NOT NULL DEFAULT 0,
fast_forward INT CHECK (fast_forward IN (0,1)) NOT NULL DEFAULT 0,
backend INT CHECK (backend IN (0,1)) NOT NULL DEFAULT 1,
frontend INT CHECK (frontend IN (0,1)) NOT NULL DEFAULT 1,
max_connections INT CHECK (max_connections >=0) NOT NULL DEFAULT 10000,
PRIMARY KEY (username, backend),
UNIQUE (username, frontend))
1 row in set (0.00 sec)

Admin> INSERT INTO mysql_users(username,password,default_hostgroup) VALUES ('root','',1);
Query OK, 1 row affected (0.00 sec)

Admin> INSERT INTO mysql_users(username,password,default_hostgroup) VALUES ('stnduser','stnduser',1);
Query OK, 1 row affected (0.00 sec)

Admin> SELECT * FROM mysql_users;                                                                                                                      
+----------+----------+--------+---------+-------------------+----------------+---------------+------------------------+--------------+---------+----------+-----------------+
| username | password | active | use_ssl | default_hostgroup | default_schema | schema_locked | transaction_persistent | fast_forward | backend | frontend | max_connections |
+----------+----------+--------+---------+-------------------+----------------+---------------+------------------------+--------------+---------+----------+-----------------+
| root     |          | 1      | 0       | 1                 | NULL           | 0             | 0                      | 0            | 1       | 1        | 10000           |
| stnduser | stnduser | 1      | 0       | 1                 | NULL           | 0             | 0                      | 0            | 1       | 1        | 10000           |
+----------+----------+--------+---------+-------------------+----------------+---------------+------------------------+--------------+---------+----------+-----------------+
2 rows in set (0.00 sec)

ProxySQL Admin> LOAD MYSQL USERS TO RUNTIME;
Query OK, 0 rows affected (0.00 sec)
ProxySQL Admin> SAVE MYSQL USERS TO DISK;
Query OK, 0 rows affected (0.01 sec)

测试

sysbench --report-interval=5 --num-threads=4 --num-requests=0 --max-time=20 --test=tests/db/oltp.lua --mysql-user='stnduser' --mysql-password='stnduser' --oltp-table-size=10000 --mysql-host=127.0.0.1 --mysql-port=6033 run

[ output omitted ]

Note: For older versions of sysbench, report-interval should be removed and --db-ps-mode=disable added.

ProxySQL Statistics, the foundation for Query Rules

ProxySQL 在库stats 中提供了实时的数据。

ProxySQL Admin> SHOW TABLES FROM stats;
+--------------------------------+
| tables                         |
+--------------------------------+
| stats_mysql_query_rules        |
| stats_mysql_commands_counters  |
| stats_mysql_processlist        |
| stats_mysql_connection_pool    |
| stats_mysql_query_digest       |
| stats_mysql_query_digest_reset |
| stats_mysql_global             |
+--------------------------------+
7 rows in set (0.00 sec)

stats_mysql_connection_pool

ProxySQL Admin> SELECT * FROM stats.stats_mysql_connection_pool;
+-----------+-----------+----------+--------------+----------+----------+--------+---------+---------+-----------------+-----------------+
| hostgroup | srv_host  | srv_port | status       | ConnUsed | ConnFree | ConnOK | ConnERR | Queries | Bytes_data_sent | Bytes_data_recv |
+-----------+-----------+----------+--------------+----------+----------+--------+---------+---------+-----------------+-----------------+
| 1         | 10.10.0.1 | 3306     | ONLINE       | 0        | 4        | 5      | 0       | 144982  | 7865186         | 278734683       |
| 2         | 10.10.0.1 | 3306     | ONLINE       | 0        | 0        | 0      | 0       | 0       | 0               | 0               |
| 2         | 10.10.0.2 | 3306     | ONLINE       | 0        | 0        | 0      | 0       | 0       | 0               | 0               |
| 2         | 10.10.0.3 | 3306     | ONLINE       | 0        | 0        | 0      | 0       | 0       | 0               | 0               |
+-----------+-----------+----------+--------------+----------+----------+--------+---------+---------+-----------------+-----------------+
4 rows in set (0.00 sec)

stats_mysql_commands_counters

ProxySQL Admin> SELECT * FROM stats_mysql_commands_counters WHERE Total_cnt;
+---------+---------------+-----------+-----------+-----------+---------+---------+----------+----------+-----------+-----------+--------+--------+---------+----------+
| 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 |
+---------+---------------+-----------+-----------+-----------+---------+---------+----------+----------+-----------+-----------+--------+--------+---------+----------+
| BEGIN   | 1921940       | 7249      | 4214      | 2106      | 570     | 340     | 14       | 5        | 0         | 0         | 0      | 0      | 0       | 0        |
| COMMIT  | 5986400       | 7249      | 119       | 3301      | 1912    | 1864    | 44       | 8        | 1         | 0         | 0      | 0      | 0       | 0        |
| DELETE  | 2428829       | 7249      | 325       | 5856      | 585     | 475     | 5        | 3        | 0         | 0         | 0      | 0      | 0       | 0        |
| INSERT  | 2260129       | 7249      | 356       | 5948      | 529     | 408     | 6        | 2        | 0         | 0         | 0      | 0      | 0       | 0        |
| SELECT  | 40461204      | 101490    | 12667     | 69530     | 11919   | 6943    | 268      | 149      | 13        | 1         | 0      | 0      | 0       | 0        |
| UPDATE  | 6635032       | 14498     | 333       | 11149     | 1597    | 1361    | 42       | 16       | 0         | 0         | 0      | 0      | 0       | 0        |
+---------+---------------+-----------+-----------+-----------+---------+---------+----------+----------+-----------+-----------+--------+--------+---------+----------+
6 rows in set (0.00 sec)

stats_mysql_query_digest

ProxySQL Admin> 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 |
+-----------+--------------------+----------+--------------------+----------------------------------------------------------------------+------------+------------+------------+----------+----------+----------+
| 1         | sbtest             | stnduser | 0x13781C1DBF001A0C | SELECT c FROM sbtest1 WHERE id=?                                     | 72490      | 1456971810 | 1456971830 | 17732590 | 23       | 58935    |
| 1         | sbtest             | stnduser | 0x704822A0F7D3CD60 | SELECT DISTINCT c FROM sbtest1 WHERE id BETWEEN ? AND ?+? ORDER BY c | 7249       | 1456971810 | 1456971830 | 9629225  | 20       | 121604   |
| 1         | sbtest             | stnduser | 0xADF3DDF2877EEAAF | SELECT c FROM sbtest1 WHERE id BETWEEN ? AND ?+? ORDER BY c          | 7249       | 1456971810 | 1456971830 | 6650716  | 26       | 76159    |
| 1         | sbtest             | stnduser | 0x5DBEB0DD695FBF25 | COMMIT                                                               | 7249       | 1456971810 | 1456971830 | 5986400  | 64       | 59229    |
| 1         | sbtest             | stnduser | 0xCCB481C7C198E52B | UPDATE sbtest1 SET k=k+? WHERE id=?                                  | 7249       | 1456971810 | 1456971830 | 3948930  | 44       | 47860    |
| 1         | sbtest             | stnduser | 0x7DD56217AF7A5197 | SELECT c FROM sbtest1 WHERE id BETWEEN ? AND ?+?                     | 7249       | 1456971810 | 1456971830 | 3235986  | 22       | 24624    |
| 1         | sbtest             | stnduser | 0xE75DB8313E268CF3 | SELECT SUM(K) FROM sbtest1 WHERE id BETWEEN ? AND ?+?                | 7249       | 1456971810 | 1456971830 | 3211197  | 51       | 29569    |
| 1         | sbtest             | stnduser | 0x5A23CA36FB239BC9 | UPDATE sbtest1 SET c=? WHERE id=?                                    | 7249       | 1456971810 | 1456971830 | 2686102  | 23       | 27779    |
| 1         | sbtest             | stnduser | 0x55319B9EE365BEB5 | DELETE FROM sbtest1 WHERE id=?                                       | 7249       | 1456971810 | 1456971830 | 2428829  | 29       | 11676    |
| 1         | sbtest             | stnduser | 0x10634DACE52A0A02 | INSERT INTO sbtest1 (id, k, c, pad) VALUES (?, ?, ?, ?)              | 7249       | 1456971810 | 1456971830 | 2260129  | 61       | 13711    |
| 1         | sbtest             | stnduser | 0x4760CBDEFAD1519E | BEGIN                                                                | 7249       | 1456971810 | 1456971830 | 1921940  | 30       | 39871    |
| 1         | information_schema | stnduser | 0x9DD5A40E1C46AE52 | SELECT ?                                                             | 1          | 1456970758 | 1456970758 | 1217     | 1217     | 1217     |
| 1         | information_schema | stnduser | 0xA90D80E5831B091B | SELECT @@port                                                        | 1          | 1456970769 | 1456970769 | 273      | 273      | 273      |
| 1         | information_schema | stnduser | 0x52A2BA0B226CD90D | select @@version_comment limit ?                                     | 2          | 1456970758 | 1456970769 | 0        | 0        | 0        |
+-----------+--------------------+----------+--------------------+----------------------------------------------------------------------+------------+------------+------------+----------+----------+----------+
14 rows in set (0.00 sec)

MySQL Query Rules

表mysql_query_rules记录了路由规则

Admin> SHOW CREATE TABLE mysql_query_rules\G
*************************** 1. row ***************************
       table: mysql_query_rules
Create Table: CREATE TABLE mysql_query_rules (
    rule_id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
    active INT CHECK (active IN (0,1)) NOT NULL DEFAULT 0,
    username VARCHAR,
    schemaname VARCHAR,
    flagIN INT CHECK (flagIN >= 0) NOT NULL DEFAULT 0,
    client_addr VARCHAR,
    proxy_addr VARCHAR,
    proxy_port INT,
    digest VARCHAR,
    match_digest VARCHAR,
    match_pattern VARCHAR,
    negate_match_pattern INT CHECK (negate_match_pattern IN (0,1)) NOT NULL DEFAULT 0,
    re_modifiers VARCHAR DEFAULT 'CASELESS',
    flagOUT INT CHECK (flagOUT >= 0),
    replace_pattern VARCHAR CHECK(CASE WHEN replace_pattern IS NULL THEN 1 WHEN replace_pattern IS NOT NULL AND match_pattern IS NOT NULL THEN 1 ELSE 0 END),
    destination_hostgroup INT DEFAULT NULL,
    cache_ttl INT CHECK(cache_ttl > 0),
    cache_empty_result INT CHECK (cache_empty_result IN (0,1)) DEFAULT NULL,
    cache_timeout INT CHECK(cache_timeout >= 0),
    reconnect INT CHECK (reconnect IN (0,1)) DEFAULT NULL,
    timeout INT UNSIGNED,
    retries INT CHECK (retries>=0 AND retries <=1000),
    delay INT UNSIGNED,
    next_query_flagIN INT UNSIGNED,
    mirror_flagOUT INT UNSIGNED,
    mirror_hostgroup INT UNSIGNED,
    error_msg VARCHAR,
    OK_msg VARCHAR,
    sticky_conn INT CHECK (sticky_conn IN (0,1)),
    multiplex INT CHECK (multiplex IN (0,1,2)),
    gtid_from_hostgroup INT UNSIGNED,
    log INT CHECK (log IN (0,1)),
    apply INT CHECK(apply IN (0,1)) NOT NULL DEFAULT 0,
    attributes VARCHAR CHECK (JSON_VALID(attributes) OR attributes = '') NOT NULL DEFAULT '',
    comment VARCHAR)
1 row in set (0.00 sec)

ProxySQL Admin> INSERT INTO mysql_query_rules (rule_id,active,username,match_digest,destination_hostgroup,apply) VALUES (10,1,'stnduser','^SELECT c FROM sbtest1 WHERE id=?,2,1);
Query OK, 1 row affected (0.00 sec)

ProxySQL Admin> INSERT INTO mysql_query_rules (rule_id,active,username,match_digest,destination_hostgroup,apply) VALUES (20,1,'stnduser','DISTINCT c FROM sbtest1',2,1);
Query OK, 1 row affected (0.00 sec)
// 生效
ProxySQL Admin> LOAD MYSQL QUERY RULES TO RUNTIME;
Query OK, 0 rows affected (0.00 sec)

注意：

• 路由规则由 rule_id
• 只有active=1的规则会被应用
• 支持正则匹配 ^,$ mark the beginning and the end of a pattern,in this case match_digestormatch_pattern should completely match the query
• apply=1 表示当前规则匹配上，后续规则不再匹配。

Query Caching

默认不缓存，可在表mysql_query_rules中设定cache_ttl字段（单位ms）

Query Rewrite

提供两种匹配机制：

• match_digest：match the regular expression against the digest of the query which strips SQL query data (e.g. SELECT c FROM sbtest1 WHERE id=? as represented in stats_mysql_query_digest.query_digest
• match_pattern：match the regular expression against the actual text of the query (e.g. SELECT c FROM sbtest1 WHERE id=2

ProxySQL读写分离

2个端口区分读写流量

例如：通过ProxySQL Admin来配置路由端口，假设已经配置好primary and replicas configured in the right hostgroups: MySQL writer in hostgroup 1, and MySQL readers in hostgroup 2.

1. 在mysql-interfaces配置两个端口并重启

SET mysql-interfaces='0.0.0.0:6401;0.0.0.0:6402';
## save it on disk and restart proxysql
SAVE MYSQL VARIABLES TO DISK;
PROXYSQL RESTART;

2. 添加路由for incoming port

INSERT INTO mysql_query_rules (rule_id,active,proxy_port,destination_hostgroup,apply)
VALUES (1,1,6401,1,1), (2,1,6402,2,1);
LOAD MYSQL QUERY RULES TO RUNTIME;
SAVE MYSQL QUERY RULES TO DISK; # if you want this change to be permanent

正则区分读写流量（生产环境不适用）

在mysql_query_rules表中插入时加入匹配规则

UPDATE mysql_users SET default_hostgroup=1; # by default, all goes to HG1
LOAD MYSQL USERS TO RUNTIME;
SAVE MYSQL USERS TO DISK; # if you want this change to be permanent
INSERT INTO mysql_query_rules (rule_id,active,match_digest,destination_hostgroup,apply)
VALUES
(1,1,'^SELECT.*FOR UPDATE$',1,1),
(2,1,'^SELECT',2,1);
LOAD MYSQL QUERY RULES TO RUNTIME;
SAVE MYSQL QUERY RULES TO DISK; # if you want this change to be permanent

以上的路由规则如下：

• all SELECT FOR UPDATE statements will be sent to HG1
• all other SELECT statements will be sent to HG2
• everything else will be sent to HG1 (the default)

regex和digest智能区分读写流量

• 配置所有流量至MySQL主节点
• 分析stats_mysql_query_digest去定位最耗时的SELECT语句
• 决定哪些语句可以读分离（可以忍受复制延迟，复制主机硬件支持）
• 配置mysql_query_rules将这些语句路由到副本

定位最耗时的语句

• 基于total execution time

Admin> SELECT digest,SUBSTR(digest_text,0,25),count_star,sum_time 
FROM stats_mysql_query_digest 
WHERE digest_text LIKE 'SELECT%' 
ORDER BY sum_time DESC LIMIT 5;
+--------------------+--------------------------+------------+---------------+
| digest             | SUBSTR(digest_text,0,25) | count_star | sum_time      |
+--------------------+--------------------------+------------+---------------+
| 0x037C3E6D996DAFE2 | SELECT a.ip_id as ip_id, | 2030026798 | 1479082636017 |
| 0xB081A85245DEA5B7 | SELECT a.ip_id as ip_id, | 2025902778 | 1206116187539 |
| 0x38BE36BDFFDBE638 | SELECT instance.name as  | 59343662   | 1096236803754 |
| 0xB4233552504E43B8 | SELECT ir.type as type,  | 1362897166 | 488971769571  |
| 0x4A131A16DCFFD6C6 | SELECT i.id as id, i.sta | 934402293  | 475253770301  |
+--------------------+--------------------------+------------+---------------+
5 rows in set (0.01 sec)

• 基于 query count

Admin> SELECT digest,SUBSTR(digest_text,0,25),count_star,sum_time 
FROM stats_mysql_query_digest 
WHERE digest_text LIKE 'SELECT%' 
ORDER BY count_star DESC LIMIT 5;
+--------------------+--------------------------+------------+---------------+
| digest             | SUBSTR(digest_text,0,25) | count_star | sum_time      |
+--------------------+--------------------------+------------+---------------+
| 0x037C3E6D996DAFE2 | SELECT a.ip_id as ip_id, | 2030040688 | 1479092529369 |
| 0xB081A85245DEA5B7 | SELECT a.ip_id as ip_id, | 2025916528 | 1206123010791 |
| 0x22E0A5C585C53EAD | SELECT id as instanceid, | 1551361254 | 426419508609  |
| 0x3DB4B9FA4B2CB36F | SELECT i.id as instancei | 1465274289 | 415565419867  |
| 0xB4233552504E43B8 | SELECT ir.type as type,  | 1362906755 | 488974931108  |
+--------------------+--------------------------+------------+---------------+
5 rows in set (0.00 sec)

• 基于max execution time

Admin> SELECT digest,SUBSTR(digest_text,0,25),count_star,sum_time,sum_time/count_star avg_time, min_time, max_time 
FROM stats_mysql_query_digest 
WHERE digest_text LIKE 'SELECT%' 
ORDER BY max_time DESC LIMIT 5;
+--------------------+--------------------------+------------+--------------+----------+----------+-----------+
| digest             | SUBSTR(digest_text,0,25) | count_star | sum_time     | avg_time | min_time | max_time  |
+--------------------+--------------------------+------------+--------------+----------+----------+-----------+
| 0x36CE5295726DB5B4 | SELECT COUNT(*) as total | 146390     | 185951894994 | 1270249  | 445      | 237344243 |
| 0xDA8C56B5644C0822 | SELECT COUNT(*) as total | 44130      | 24842335265  | 562935   | 494      | 231395575 |
| 0x8C1B0405E1AAB9DB | SELECT COUNT(*) as total | 1194       | 1356742749   | 1136300  | 624      | 216677507 |
| 0x6C03197B4A2C34BE | Select *, DateDiff(Date_ | 4796       | 748804483    | 156131   | 607      | 197881845 |
| 0x1DEFCE9DEF3BDF87 | SELECT DISTINCT i.extid  | 592196     | 40209254260  | 67898    | 416      | 118055372 |
+--------------------+--------------------------+------------+--------------+----------+----------+-----------+
5 rows in set (0.01 sec)

• 其他

Admin> SELECT digest,SUBSTR(digest_text,0,20),count_star,sum_time,sum_time/count_star avg_time, min_time, max_time 
FROM stats_mysql_query_digest 
WHERE digest_text LIKE 'SELECT%' AND min_time > 1000 
ORDER BY sum_time DESC LIMIT 5;

Admin> SELECT digest,SUBSTR(digest_text,0,25),count_star,sum_time,sum_time/count_star avg_time, ROUND(sum_time*100.00/(SELECT SUM(sum_time) 
FROM stats_mysql_query_digest),3) pct 
FROM stats_mysql_query_digest 
WHERE digest_text LIKE 'SELECT%' AND sum_time/count_star > 1000000 
ORDER BY sum_time DESC LIMIT 5;

Admin> SELECT digest,SUBSTR(digest_text,0,25),count_star,sum_time,sum_time/count_star avg_time, ROUND(sum_time*100.00/(SELECT SUM(sum_time) 
FROM stats_mysql_query_digest WHERE digest_text LIKE 'SELECT%'),3) pct 
FROM stats_mysql_query_digest WHERE digest_text LIKE 'SELECT%' AND sum_time/count_star > 15000
ORDER BY sum_time DESC LIMIT 5;

Sharding

• User based sharding
• Schema based sharding
• Data based sharding

User based sharding

在表mysql_users创建用户时，指定default_hostgroup即可，这种不需要指定query rules

INSERT INTO mysql_users
(username, password, active, default_hostgroup, comment)
VALUES
('accounts', 'shard0_pass', 1, 0, 'Routed to the accounts shard'),
('transactions', 'shard1_pass', 1, 1, 'Routed to the transactions shard'),
('logging', 'shard2_pass', 1, 2, 'Routed to the logging shard');

LOAD MYSQL USERS RULES TO RUNTIME;
SAVE MYSQL USERS RULES TO DISK;

建议在应用中保存应用到用户的映射：

+--------------+--------------+-------------+
| app_module   | shard_user   | shard_pass  |
+--------------+--------------+-------------+
| CRM          | accounts     | shard0_pass |
| OLTP         | transactions | shard1_pass |
| Log Manager  | logging      | shard1_pass |
+--------------+--------------+-------------+

Schema based sharding

在mysql_query_rules中指定destination_hostgroup：

INSERT INTO mysql_query_rules (rule_id, active, schemaname,
destination_hostgroup, apply)
VALUES
(1, 1, 'shard_0', 0, 1),
(2, 1, 'shard_1', 1, 1),
(3, 1, 'shard_2', 2, 1);

LOAD MYSQL QUERY RULES TO RUNTIME;
SAVE MYSQL QUERY RULES TO DISK;

Data based sharding

要点：

• 从一开始就要设计好应用，严格遵循query rules
• 基本上通过表mysql_query_rules中的match_digest和match_pattern实现
• sharding一般都是针对表去sharding而不是库

# 针对INSERT分片
INSERT INTO mysql_query_rules (rule_id, active, match_pattern, destination_hostgroup,
apply)
VALUES
(1, 1, 'loc_account_data \(loc_id, user, acc_id\) VALUES
\(20086020554955909836090724037181646035', 0, 1),
(2, 1, 'loc_account_data \(loc_id, user, acc_id\) VALUES
\(20086020554955909836090724037181646035’, 1, 1),
(3, 1, 'loc_account_data \(loc_id, user, acc_id\) VALUES
\(20086020554955909836090724037181646035’, 2, 1);

# 针对UPDATES / DELETES / SELECTS分片
INSERT INTO mysql_query_rules (rule_id, active, match_pattern, destination_hostgroup,
apply)
VALUES
(4, 1, 'loc_id = 20086020554955909836090724037181646035', 0, 1),
(5, 1, 'loc_id = 21503957780049285539986052866765125704', 1, 1),
(6, 1, 'loc_id = 75863560943999160082133817802533222835', 2, 1);

sharding considerations

• user 和 schema 分片简单好维护
• 针对每个分片都要考虑各自的规则，如读写分离
• 分片不知三种，以上只是最常见的