# StoneDB 讀寫分離實踐方案

在 StoneDB 1.0 版本中，InnoDB 引擎處理 OLTP 的事務型業務，Tianmu 引擎處理 OLAP 的分析型業務。因此，需要在主從複製環境的基礎上做讀寫分離，所有的寫操作和部分讀操作走 InnoDB 引擎，所有的分析類查詢走 Tianmu 引擎。讀寫分離方案既可以使用第三方中介軟體，也可以在業務前端實現。本文介紹的是較為常用的中介軟體 ProxySQL。

伺服器配置說明

| **IP**        | **Memory** | **CPU** | **OS version**           |
| ------------- | ---------- | ------- | ------------------------ |
| 192.168.30.40 | 8G         | 8C      | CentOS Linux release 7.9 |
| 192.168.30.41 | 8G         | 8C      | CentOS Linux release 7.9 |
| 192.168.30.42 | 8G         | 8C      | CentOS Linux release 7.9 |
| 192.168.30.46 | 16G        | 16C     | CentOS Linux release 7.9 |

注：主從環境中的各個伺服器的配置一般情況下建議是一致的，但由於 StoneDB 不管重放 binlog，還是用於 OLAP 場景的查詢，都是較消耗系統資源的，建議 StoneDB 配置略高於 MySQL。

主從環境說明

| **IP**        | **DATABASE** | **ROLE** | **DB version** |
| ------------- | ------------ | -------- | -------------- |
| 192.168.30.40 | MySQL        | master   | MySQL 5.7      |
| 192.168.30.41 | /            | ProxySQL | /              |
| 192.168.30.42 | MySQL        | slave    | MySQL 5.7      |
| 192.168.30.46 | StoneDB      | slave    | StoneDB 5.7    |

注：MySQL 與 StoneDB 的版本建議保持一致。

架構圖說明 ![file](https://oscimg.oschina.net/oscnet/up-709219065c702cc000665221becdc93f2ac.png) 推薦採用一主兩從的架構，上層的 ProxySQL 用於讀寫分離：

1）master（192.168.30.40）使用 InnoDB 引擎，可讀寫，提供 OLTP 場景的讀寫業務； 2）slave1（192.168.30.42）使用 InnoDB 引擎，只讀，同時作為 standby，當 master 發生當機時，可切換至 slave1，保證業務正常執行； 3）slave2（192.168.30.46）使用 Tianmu 引擎，只讀，提供 OLAP 場景的讀業務。

# 1、作業系統環境檢查

作業系統環境檢查的步驟在四個節點均需要執行。

## 1.1 關閉防火牆

```shell
# systemctl stop firewalld 
# systemctl disable firewalld
```

## 1.2 關閉 SELINUX

```shell
# vim /etc/selinux/config
SELINUX = disabled
```

## 1.3 設定 Swap 分割槽

修改 vm.swappiness 的值為 1，表示儘量不使用 Swap。

```shell
# vi /etc/sysctl.conf
vm.swappiness = 1
```

## 1.4 修改作業系統的限制

```shell
# ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 1031433
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 65535
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 10240
cpu time               (seconds, -t) unlimited
max user processes              (-u) 1024
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

修改作業系統的軟硬限制
# vim /etc/security/limits.conf
* soft nofile 65535
* hard nofile 65535
mysql soft nproc 1028056
mysql hard nproc 1028056
```

## 1.5 建立使用者

```shell
# groupadd mysql
# useradd -g mysql mysql
# passwd mysql
```

ProxySQL 節點無需建立，以上步驟執行完之後，重啟作業系統。

# 2、部署 MySQL

在 master 節點和 slave1 節點安裝 MySQL。

## 2.1 下載安裝包

從官網下載 MySQL 5.7 的安裝包。

## 2.2 解除安裝 mariadb

```shell
# rpm -qa|grep mariadb
mariadb-5.5.56-2.el7.x86_64
mariadb-server-5.5.56-2.el7.x86_64
mariadb-libs-5.5.56-2.el7.x86_64
# yum remove mariadb*
# rpm -qa|grep mariadb
```

## 2.3 上傳 tar 包並解壓

```shell
# tar -zxvf mysql-5.7.36-linux-glibc2.12-x86_64.tar.gz -C /usr/local/
# cd /usr/local/
# mv mysql-5.7.36-linux-glibc2.12-x86_64 mysql
```

## 2.4 建立目錄

```shell
# mkdir -p /mysql/data/
# mkdir -p /mysql/log
# chown -R mysql:mysql /mysql/
```

## 2.5 配置引數檔案 my.cnf

### master

```shell
# vim /etc/my.cnf
[client]
port    = 3306
socket  = /mysql/data/mysql.sock

[mysqld]
port      = 3306
basedir   = /usr/local/mysql
datadir   = /mysql/data
socket    = /mysql/data/mysql.sock
pid_file  = /mysql/data/mysqld.pid
log_error = /mysql/log/mysqld.log
log_bin   = /mysql/log/mybinlog
server_id = 40
character_set_server = utf8mb4
collation_server = utf8mb4_general_ci
max_connections = 1000
binlog_format = row
default_storage_engine = innodb
read_only=0

innodb_buffer_pool_size = 4096000000
innodb_log_file_size = 1024000000
innodb_log_files_in_group = 3
innodb_io_capacity = 4000
innodb_io_capacity_max = 8000

#開啟GTID模式
gtid_mode = on
enforce_gtid_consistency = 1

#並行複製
binlog_transaction_dependency_tracking = WRITESET
transaction_write_set_extraction = XXHASH64
```

### slave1

```shell
# vim /etc/my.cnf
[client]
port    = 3306
socket  = /mysql/data/mysql.sock

[mysqld]
port      = 3306
basedir   = /usr/local/mysql
datadir   = /mysql/data
socket    = /mysql/data/mysql.sock
pid_file  = /mysql/data/mysqld.pid
log_error = /mysql/log/mysqld.log
log_bin   = /mysql/log/mybinlog
server_id = 42
character_set_server = utf8mb4
collation_server = utf8mb4_general_ci
max_connections = 1000
binlog_format = row
default_storage_engine = innodb
read_only=1

innodb_buffer_pool_size = 4096000000
innodb_log_file_size = 1024000000
innodb_log_files_in_group = 3
innodb_io_capacity = 4000
innodb_io_capacity_max = 8000

#開啟GTID模式
gtid_mode = on
enforce_gtid_consistency = 1

#並行複製
slave_parallel_type = LOGICAL_CLOCK
slave_parallel_workers = 4
```

## 2.6 初始化例項

```shell
/usr/local/mysql/bin/mysqld --defaults-file=/etc/my.cnf --initialize --user=mysql
```

## 2.7 啟動例項

```shell
/usr/local/mysql/bin/mysqld_safe --defaults-file=/etc/my.cnf --user=mysql &
```

注：管理員使用者的臨時密碼在 mysqld.log 中，第一次登陸後需要修改管理員使用者的密碼。

# 3、部署 StoneDB

## 3.1 下載安裝包

從官網下載 StoneDB 5.7 的安裝包。

## 3.2 上傳 tar 包並解壓

```shell
# cd /
# tar -zxvf stonedb-ce-5.7-v1.0.0.el7.x86_64.tar.gz
```

使用者可根據安裝規範將安裝包上傳至伺服器，解壓出來的目錄是 stonedb57，示例中的安裝路徑是 /stonedb57。

## 3.3 檢查依賴檔案

```shell
# cd /stonedb57/install/bin
# ldd mysqld
# ldd mysql
```

如果檢查返回有關鍵字 "not found"，說明缺少檔案，需要安裝對應的依賴包。例如：

libsnappy.so.1 => not found

在 Ubuntu 上使用命令 "sudo apt search libsnappy" 檢查，說明需要安裝 libsnappy-dev。在 RedHat 或者 CentOS 上使用命令 "yum search all snappy" 檢查，說明需要安裝 snappy-devel、snappy。

## 3.4 建立目錄

```shell
mkdir -p /stonedb57/install/data
mkdir -p /stonedb57/install/binlog
mkdir -p /stonedb57/install/log
mkdir -p /stonedb57/install/tmp
mkdir -p /stonedb57/install/redolog
mkdir -p /stonedb57/install/undolog
chown -R mysql:mysql /stonedb57
```

## 3.5 配置引數檔案 my.cnf

```shell
# vim /stonedb57/install/my.cnf
[client]
port    = 3306
socket  = /stonedb57/install/tmp/mysql.sock

[mysqld]
port      = 3306
basedir   = /stonedb57/install/
datadir   = /stonedb57/install/data
socket    = /stonedb57/install/tmp/mysql.sock
pid_file  = /stonedb57/install/data/mysqld.pid
log_error = /stonedb57/install/log/mysqld.log
log_bin   = /stonedb57/install/binlog/binlog
server_id = 46
character_set_server = utf8mb4
collation_server = utf8mb4_general_ci
max_connections = 1000
binlog_format = row
default_storage_engine = tianmu
read_only=1

innodb_buffer_pool_size = 2048000000
innodb_log_file_size = 1024000000
innodb_log_files_in_group = 3
innodb_io_capacity = 4000
innodb_io_capacity_max = 8000
innodb_log_group_home_dir   = /stonedb57/install/redolog/
innodb_undo_directory       = /stonedb57/install/undolog/
innodb_undo_log_truncate    = 1
innodb_undo_tablespaces     = 3
innodb_undo_logs            = 128

#開啟GTID模式
gtid_mode = on
enforce_gtid_consistency = 1

#並行複製
slave_parallel_type = LOGICAL_CLOCK
slave_parallel_workers = 8  
```

## 3.6 初始化例項

```shell
/stonedb57/install/bin/mysqld --defaults-file=/stonedb57/install/my.cnf --initialize --user=mysql
```

## 3.7 啟動例項

```shell
/stonedb57/install/bin/mysqld_safe --defaults-file=/stonedb57/install/my.cnf --user=mysql &
```

注：管理員使用者的臨時密碼在 mysqld.log 中，第一次登陸後需要修改管理員使用者的密碼。

# 4、配置主從

## 4.1 建立複製使用者

```sql
create user 'repl'@'%' identified by 'mysql123';
grant replication slave on *.* to 'repl'@'%';
```

## 4.2 備份主庫

```shell
/usr/local/mysql/bin/mysqldump -uroot -pmysql123 --single-transaction --set-gtid-purged=on -B aa > /tmp/aa.sql
```

## 4.3 傳輸備份檔案

```shell
scp /tmp/aa.sql root@192.168.30.42:/tmp
scp /tmp/aa.sql root@192.168.30.43:/tmp
```

注：如果資料較大，建議使用 mydumper.

## 4.4 slave1 節點

```shell
/usr/local/mysql/bin/mysql -uroot -pmysql123 -S /mysqldb/data/mysql.sock
source /tmp/aa.sql
```

注：恢復前需要確保 gtid_executed 為空。

## 4.5 slave2 節點

在恢復前，需要修改儲存引擎，註釋鎖表語句。

```shell
sed -i 's/UNLOCK TABLES/-- UNLOCK TABLES/g' /tmp/aa.sql
sed -i 's/LOCK TABLES `/-- LOCK TABLES `/g' /tmp/aa.sql
sed -i 's/ENGINE=InnoDB/ENGINE=tianmu/g' /tmp/aa.sql

/stonedb57/install/bin/mysql -uroot -pmysql123 -S /stonedb57/install/tmp/mysql.sock
source /tmp/aa.sql
```

注：恢復前需要確保 gtid_executed 為空。

## 4.6 建立主從複製

### slave1 節點

```sql
CHANGE MASTER TO
MASTER_HOST='192.168.30.40',
MASTER_PORT=3306,
MASTER_USER='repl',
MASTER_PASSWORD='mysql123',
MASTER_AUTO_POSITION = 1;

start slave;
show slave status\G
```

### slave2 節點

```sql
CHANGE MASTER TO
MASTER_HOST='192.168.30.40',
MASTER_PORT=3306,
MASTER_USER='repl',
MASTER_PASSWORD='mysql123',
MASTER_AUTO_POSITION = 1;

start slave;
show slave status\G
```

# 5、配置 ProxySQL

## 5.1 安裝 ProxySQL

```shell
# mkdir -p /home/ProxySQL
# cd /home/ProxySQL
# yum install proxysql-2.2.0-1-centos7.x86_64.rpm
# rpm -qa|grep proxysql
# rpm -ql proxysql
```

注：/etc/proxysql.cnf 為 ProxySQL 的配置檔案。

## 5.2 啟動 ProxySQL

```shell
# systemctl start proxysql
# netstat -lntp|grep proxysql
tcp        0      0 0.0.0.0:6032            0.0.0.0:*               LISTEN      17957/proxysql      
tcp        0      0 0.0.0.0:6033            0.0.0.0:*               LISTEN      17957/proxysql 
```

注：6032 是管理埠，6033 是服務埠。

## 5.3 管理員登入 ProxySQL

```shell
# mysql -uadmin -padmin -h127.0.0.1 -P6032 --prompt='ProxySQL>'
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.5.30 (ProxySQL Admin Module)

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

注：ProxySQL 的使用者名稱和密碼預設都是 admin，加引數 prompt 是為了便於區分環境。

## 5.4 建立 ProxySQL 所需使用者

在 master 上建立 ProxySQL 的監控使用者和對外訪問使用者，其中監控使用者只需要有 replication client 許可權即可。

```sql
###監控使用者
create user 'monitor'@'%' identified by 'MySQL_123';
grant replication client on *.* to 'monitor'@'%';

###對外訪問使用者（用於連線ProxySQL）
create user 'proxysql'@'%' identified by 'MySQL_123';
grant select,delete,update,insert on *.* to 'proxysql'@'%';
```

## 5.5 配置 ProxySQL 主從分組資訊

### 1）建立分組

表 mysql_replication_hostgroups 的欄位 writer_hostgroup、reader_hostgroup 分別代表寫組和讀組，都要大於 0 且不能相同，該環境中定義寫組為 10，讀組為 20。

ProxySQL 會根據 read_only 的取值將 server 進行分組，read_only=0 為 master，被分到編號為 10 的寫組，read_only=1 為 slave，被分到編號為 20 的讀組。

```sql
###建立分組
insert into mysql_replication_hostgroups(writer_hostgroup,reader_hostgroup,comment) values(10,20,'proxy');
load mysql servers to runtime;
save mysql servers to disk;

### 2）新增主從節點

```sql
insert into mysql_servers(hostgroup_id,hostname,port) values(10,'192.168.30.40',3306);
insert into mysql_servers(hostgroup_id,hostname,port) values(20,'192.168.30.46',3306);
load mysql servers to runtime;
save mysql servers to disk;

###檢視狀態
ProxySQL>select * from mysql_servers;
+--------------+---------------+------+-----------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+
| hostgroup_id | hostname      | port | gtid_port | status | weight | compression | max_connections | max_replication_lag | use_ssl | max_latency_ms | comment |
+--------------+---------------+------+-----------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+
| 20           | 192.168.30.40 | 3306 | 0         | ONLINE | 1      | 0           | 1000            | 0                   | 0       | 0              |         |
| 20           | 192.168.30.46 | 3306 | 0         | ONLINE | 1      | 0           | 1000            | 0                   | 0       | 0              |         |
+--------------+---------------+------+-----------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------+
2 rows in set (0.00 sec)
```

### 3）為 ProxySQL 建立監控使用者

```sql
###建立監控使用者（在ProxySQL建立）
set mysql-monitor_username='monitor';
set mysql-monitor_password='MySQL_123';
load mysql variables to runtime;
save mysql variables to disk;

###對連線使用者監控
ProxySQL>select * from monitor.mysql_server_connect_log;
+---------------+------+------------------+-------------------------+------------------------------------------------------------------------+
| hostname      | port | time_start_us    | connect_success_time_us | connect_error                                                          |
+---------------+------+------------------+-------------------------+------------------------------------------------------------------------+
| 192.168.30.40 | 3306 | 1664183920198998 | 0                       | Access denied for user 'monitor'@'192.168.30.41' (using password: YES) |
| 192.168.30.46 | 3306 | 1664183920926981 | 0                       | Access denied for user 'monitor'@'HAMI02' (using password: YES)        |
| 192.168.30.46 | 3306 | 1664183970671663 | 1616                    | NULL                                                                   |
| 192.168.30.40 | 3306 | 1664183971672625 | 2089                    | NULL                                                                   |
+---------------+------+------------------+-------------------------+------------------------------------------------------------------------+
4 rows in set (0.00 sec)

注：在沒有建立監控使用者前，會有很多的connect_error，這是因為沒有配置監控資訊時的錯誤，配置後如果connect_error的結果為NULL，則表示正常。

###對心跳資訊的監控
ProxySQL>select * from mysql_server_ping_log limit 10;
+---------------+------+------------------+----------------------+------------------------------------------------------------------------+
| hostname      | port | time_start_us    | ping_success_time_us | ping_error                                                             |
+---------------+------+------------------+----------------------+------------------------------------------------------------------------+
| 192.168.30.40 | 3306 | 1664183880229349 | 0                    | Access denied for user 'monitor'@'192.168.30.41' (using password: YES) |
| 192.168.30.46 | 3306 | 1664183880427787 | 0                    | Access denied for user 'monitor'@'HAMI02' (using password: YES)        |
| 192.168.30.40 | 3306 | 1664183890229405 | 0                    | Access denied for user 'monitor'@'192.168.30.41' (using password: YES) |
| 192.168.30.46 | 3306 | 1664183890336793 | 0                    | Access denied for user 'monitor'@'HAMI02' (using password: YES)        |
| 192.168.30.40 | 3306 | 1664183900229529 | 0                    | Access denied for user 'monitor'@'192.168.30.41' (using password: YES) |
| 192.168.30.46 | 3306 | 1664183900357491 | 0                    | Access denied for user 'monitor'@'HAMI02' (using password: YES)        |
| 192.168.30.46 | 3306 | 1664183910229710 | 0                    | Access denied for user 'monitor'@'HAMI02' (using password: YES)        |
| 192.168.30.40 | 3306 | 1664183910406115 | 0                    | Access denied for user 'monitor'@'192.168.30.41' (using password: YES) |
| 192.168.30.46 | 3306 | 1664183920229740 | 0                    | Access denied for user 'monitor'@'HAMI02' (using password: YES)        |
| 192.168.30.40 | 3306 | 1664183920346638 | 0                    | Access denied for user 'monitor'@'192.168.30.41' (using password: YES) |
+---------------+------+------------------+----------------------+------------------------------------------------------------------------+
10 rows in set (0.00 sec)

###對read_only值監控
ProxySQL>select * from mysql_server_read_only_log limit 10;
+---------------+------+------------------+-----------------+-----------+------------------------------------------------------------------------------------------------------------+
| hostname      | port | time_start_us    | success_time_us | read_only | error                                                                                                      |
+---------------+------+------------------+-----------------+-----------+------------------------------------------------------------------------------------------------------------+
| 192.168.30.46 | 3306 | 1664183876942878 | 0               | NULL      | timeout on creating new connection: Access denied for user 'monitor'@'HAMI02' (using password: YES)        |
| 192.168.30.40 | 3306 | 1664183876961694 | 0               | NULL      | timeout on creating new connection: Access denied for user 'monitor'@'192.168.30.41' (using password: YES) |
| 192.168.30.46 | 3306 | 1664183878441697 | 0               | NULL      | timeout on creating new connection: Access denied for user 'monitor'@'HAMI02' (using password: YES)        |
| 192.168.30.40 | 3306 | 1664183878461063 | 0               | NULL      | timeout on creating new connection: Access denied for user 'monitor'@'192.168.30.41' (using password: YES) |
| 192.168.30.46 | 3306 | 1664183879941587 | 0               | NULL      | timeout on creating new connection: Access denied for user 'monitor'@'HAMI02' (using password: YES)        |
| 192.168.30.40 | 3306 | 1664183879961993 | 0               | NULL      | timeout on creating new connection: Access denied for user 'monitor'@'192.168.30.41' (using password: YES) |
| 192.168.30.46 | 3306 | 1664183881441750 | 0               | NULL      | timeout on creating new connection: Access denied for user 'monitor'@'HAMI02' (using password: YES)        |
| 192.168.30.40 | 3306 | 1664183881461890 | 0               | NULL      | timeout on creating new connection: Access denied for user 'monitor'@'192.168.30.41' (using password: YES) |
| 192.168.30.40 | 3306 | 1664183882942044 | 0               | NULL      | timeout on creating new connection: Access denied for user 'monitor'@'192.168.30.41' (using password: YES) |
| 192.168.30.46 | 3306 | 1664183882958866 | 0               | NULL      | timeout on creating new connection: Access denied for user 'monitor'@'HAMI02' (using password: YES)        |
+---------------+------+------------------+-----------------+-----------+------------------------------------------------------------------------------------------------------------+
10 rows in set (0.00 sec)

注：monitor就會開始監控後端的read_only值，然後按照read_only的值將某些節點自動移到讀寫組。
```

### 4）為 ProxySQL 配置對外訪問使用者

```sql
insert into mysql_users(username,password,default_hostgroup) values('proxysql','MySQL_123',10);
insert into mysql_users(username,password,default_hostgroup) values('proxysql2','*0815E74A768849A6CCF0E9C1C5B940FB4D9F839E',20);
load mysql users to runtime;
save mysql users to disk;

ProxySQL>select * from mysql_users\G
*************************** 1. row ***************************
              username: proxysql
              password: MySQL_123
                active: 1
               use_ssl: 0
     default_hostgroup: 10
        default_schema: NULL
         schema_locked: 0
transaction_persistent: 1
          fast_forward: 0
               backend: 1
              frontend: 1
       max_connections: 10000
            attributes: 
               comment: 
*************************** 2. row ***************************
              username: proxysql2
              password: *0815E74A768849A6CCF0E9C1C5B940FB4D9F839E
                active: 1
               use_ssl: 0
     default_hostgroup: 20
        default_schema: NULL
         schema_locked: 0
transaction_persistent: 1
          fast_forward: 0
               backend: 1
              frontend: 1
       max_connections: 10000
            attributes: 
               comment: 
2 rows in set (0.00 sec)
```

mysql_users 表最主要的三個欄位 username、password、default_hostgroup 解釋。

username：前端連線 ProxySQL 的資料庫使用者

password：使用者對應的密碼，即可以是明文密碼，也可以是 hash 密碼，如果想使用 hash 密碼，可以先在某個節點上執行 select password ('password')，然後將加密結果複製到該欄位。

default_hostgroup：使用者預設的路由目標，例如：若使用者 proxysql2 是個只讀使用者，則該欄位值可以設定為 20，表示所有的 SQL 語句預設情況下將路由到 hostgroup_id=20 的組；若使用者不是隻讀使用者，則該欄位必須設定為 10，表示 DML 語句會路由到 hostgroup_id=10 的組，查詢語句即會路由到 hostgroup_id=10 的組，也會路由到 hostgroup_id=20 的組。

## 5.6 配置讀寫分離策略

ProxySQL 的路由規則配置比較靈活，可以基於使用者級別，資料庫級別等。由於 StoneDB 提供的是 OLAP 分析型查詢業務場景，建議將聚合類查詢、即席查詢、複雜查詢等分發到 StoneDB。由於只是測試，因此只配置了幾個簡單的路由規則。

與查詢規則有關的表有兩個：mysql_query_rules 和 mysql_query_rules_fast_routing，表 mysql_query_rules_fast_routing 是 mysql_query_rules 的擴充套件，並在以後評估快速路由策略和屬性（僅在 ProxySQL 1.4.7 + 中可用）。

mysql_query_rules 表的幾個欄位解釋。

active：是否啟用這個規則，1 表示啟用，0 表示禁用

match_pattern：設定規則

destination_hostgroup：預設指定的分組

apply：真正執行應用規則

```sql
###建立規則
這裡我建立兩個規則：
1）把所有以select開頭的語句分配到編號為20的讀組中；
2）把select...for update語句分配到編號為10的寫組中，其他所有操作都會預設路由到寫組。
insert into mysql_query_rules(rule_id,active,match_pattern,destination_hostgroup,apply) values(1,1,'^select.*for update$',10,1);
insert into mysql_query_rules(rule_id,active,match_pattern,destination_hostgroup,apply) values(2,1,'^select',20,1);
insert into mysql_query_rules(rule_id,active,match_pattern,destination_hostgroup,apply) values(3,1,'^select*sum',20,1);
load mysql query rules to runtime;
save mysql query rules to disk;

###檢視規則
ProxySQL>select * from mysql_query_rules\G
*************************** 1. row ***************************
              rule_id: 1
               active: 1
             username: NULL
           schemaname: NULL
               flagIN: 0
          client_addr: NULL
           proxy_addr: NULL
           proxy_port: NULL
               digest: NULL
         match_digest: NULL
        match_pattern: ^select.*for update$
 negate_match_pattern: 0
         re_modifiers: CASELESS
              flagOUT: NULL
      replace_pattern: NULL
destination_hostgroup: 10
            cache_ttl: NULL
   cache_empty_result: NULL
        cache_timeout: NULL
            reconnect: NULL
              timeout: NULL
              retries: NULL
                delay: NULL
    next_query_flagIN: NULL
       mirror_flagOUT: NULL
     mirror_hostgroup: NULL
            error_msg: NULL
               OK_msg: NULL
          sticky_conn: NULL
            multiplex: NULL
  gtid_from_hostgroup: NULL
                  log: NULL
                apply: 1
           attributes: 
              comment: NULL
*************************** 2. row ***************************
              rule_id: 2
               active: 1
             username: NULL
           schemaname: NULL
               flagIN: 0
          client_addr: NULL
           proxy_addr: NULL
           proxy_port: NULL
               digest: NULL
         match_digest: NULL
        match_pattern: ^select
 negate_match_pattern: 0
         re_modifiers: CASELESS
              flagOUT: NULL
      replace_pattern: NULL
destination_hostgroup: 20
            cache_ttl: NULL
   cache_empty_result: NULL
        cache_timeout: NULL
            reconnect: NULL
              timeout: NULL
              retries: NULL
                delay: NULL
    next_query_flagIN: NULL
       mirror_flagOUT: NULL
     mirror_hostgroup: NULL
            error_msg: NULL
               OK_msg: NULL
          sticky_conn: NULL
            multiplex: NULL
  gtid_from_hostgroup: NULL
                  log: NULL
                apply: 1
           attributes: 
              comment: NULL
*************************** 3. row ***************************
              rule_id: 3
               active: 1
             username: NULL
           schemaname: NULL
               flagIN: 0
          client_addr: NULL
           proxy_addr: NULL
           proxy_port: NULL
               digest: NULL
         match_digest: NULL
        match_pattern: ^select*sum
 negate_match_pattern: 0
         re_modifiers: CASELESS
              flagOUT: NULL
      replace_pattern: NULL
destination_hostgroup: 20
            cache_ttl: NULL
   cache_empty_result: NULL
        cache_timeout: NULL
            reconnect: NULL
              timeout: NULL
              retries: NULL
                delay: NULL
    next_query_flagIN: NULL
       mirror_flagOUT: NULL
     mirror_hostgroup: NULL
            error_msg: NULL
               OK_msg: NULL
          sticky_conn: NULL
            multiplex: NULL
  gtid_from_hostgroup: NULL
                  log: NULL
                apply: 1
           attributes: 
              comment: NULL
3 rows in set (0.00 sec)
```

注：博主的環境都是搭建在[cnaaa伺服器](https://www.cnaaa.com/)上的，select...for update 規則的 rule_id 必須要小於普通的 select 規則的 rule_id，因為 ProxySQL 是根據 rule_id 的順序進行規則匹配的。

## 5.7 讀寫分離測試

### 1）讀操作

```sql
# mysql -uproxysql -pMySQL_123 -h127.0.0.1 -P6033
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 6
Server version: 5.5.30 (ProxySQL)

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

proxysql@HAMI02 17:21:  [(none)]> select sum(money) from aa.ttt;
+------------+
| sum(money) |
+------------+
|    88888.8 |
+------------+
1 row in set (0.01 sec)

proxysql@HAMI02 17:21:  [(none)]> select @@server_id;
+-------------+
| @@server_id |
+-------------+
|          46 |
+-------------+
1 row in set (0.00 sec)
```

### 2）寫操作

```sql
# mysql -uproxysql -pMySQL_123 -h127.0.0.1 -P6033
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 19
Server version: 5.5.30 (ProxySQL)

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

proxysql@HAMI02 19:53:  [(none)]> begin;
Query OK, 0 rows affected (0.00 sec)

proxysql@HAMI02 19:54:  [(none)]> insert into aa.t1 values(7);
Query OK, 1 row affected (0.00 sec)

proxysql@HAMI02 19:54:  [(none)]> select @@server_id;
+-------------+
| @@server_id |
+-------------+
|          40 |
+-------------+
1 row in set (0.00 sec)
```

# 6、建議項

1）建議設定為 GTID 模式，好處是從庫發生 crash 後，不需要去找位點，系統會自動拉起復制執行緒；

2）在從庫的並行 worker 相同的情況下，從庫 StoneDB 相比從庫 InnoDB 會消耗更多的 CPU 資源，如果未來上生產環境，建議 StoneDB 的配置略比 InnoDB 的配置高；

3）若從庫 StoneDB 的延遲較高，可臨時關閉引數 tianmu_enable_rowstore，待追上主庫後再開啟引數。關閉該引數帶來的風險是如果在同步過程中 StoneDB 發生重啟，重啟後會出現丟資料的情況；

4）建議將聚合類查詢、即席查詢、複雜查詢等分發到 StoneDB。

StoneDB 讀寫分離實踐方案

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