feat: add mariadb replica guide

docs/linux/mysql-replication.md

@@ -0,0 +1,151 @@
+# MySQL / MariaDB replication
+This is tested on MariaDB 11.
+
+## Prepare source server/database
+
+### Prepare mysql for replication
+
+```shell
+vim /etc/mysql/conf.d/mysqld.cnf
+
+[mysqld]
+server-id = 1
+log-bin = /var/log/mysql/mysql-bin.log
+binlog-format = ROW
+binlog-do-db = databeast
+bind-address = 0.0.0.0
+gtid_strict_mode = 1
+log_slave_updates = 1
+```
+
+Restart mysql: `systemctl restart mysql`
+
+### Create replication user
+
+```shell
+DROP USER IF EXISTS 'replicator'@'replica.example.com';
+CREATE USER 'replicator'@'replica.example.com' IDENTIFIED BY 'supersecure';
+GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'replicator'@'replica.example.com';
+FLUSH PRIVILEGES;
+```
+
+### Create database dump
+
+```shell
+mariadb-dump -u root -psupersecuresource --single-transaction --gtid --master-data=1 --databases databeast > /tmp/databeast.sql
+```
+
+Or feel lucky with pipes... Execute this from the replica host.
+
+```shell
+mysql -u root -p -e "CREATE DATABASE IF NOT EXISTS databeast;"
+mariadb-dump -h source.example.com -u root -p --single-transaction --databases databeast | pv | mysql -u root -p
+```
+
+## Configure replicate
+
+### Prepare mysql for replication
+
+```shell
+vim /etc/mysql/conf.d/mysqld.cnf
+
+[mysqld]
+server-id = 2
+read-only = 1
+relay-log = /var/log/mysql/mysql-relay-bin
+log-bin = /var/log/mysql/mysql-bin.log
+binlog-format = ROW
+bind-address = 0.0.0.0
+gtid_strict_mode = 1
+log_slave_updates = 1
+```
+
+Restart mysql: `systemctl restart mysql`
+
+### Copy database dump
+
+```shell
+scp -O source.example.com:/tmp/databeast.sql /tmp/databeast.sql
+```
+
+### Import database dump
+
+```shell
+mysql -u root -p -e "CREATE DATABASE IF NOT EXISTS databeast;"
+mysql -u root -p < /tmp/databeast.sql
+```
+
+### Activate replication
+
+```shell
+STOP REPLICA;
+RESET REPLICA;
+CHANGE REPLICATION SOURCE TO
+  SOURCE_HOST='source.example.com',
+  SOURCE_USER='replicator',
+  SOURCE_PASSWORD='supersecure',
+  SOURCE_USE_GTID=slave_pos;
+START REPLICA;
+```
+
+## Monitor replication
+
+```shell
+SHOW REPLICA STATUS\G
+*************************** 1. row ***************************
+                Slave_IO_State: Waiting for master to send event
+                   Master_Host: source.example.com
+                   Master_User: replicator
+                   Master_Port: 3306
+                 Connect_Retry: 60
+               Master_Log_File: mysql-bin.000020
+           Read_Master_Log_Pos: 10338204
+                Relay_Log_File: mysql-relay-bin.000002
+                 Relay_Log_Pos: 10321516
+         Relay_Master_Log_File: mysql-bin.000020
+              Slave_IO_Running: Yes
+             Slave_SQL_Running: Yes
+               Replicate_Do_DB:
+           Replicate_Ignore_DB:
+            Replicate_Do_Table:
+        Replicate_Ignore_Table:
+       Replicate_Wild_Do_Table:
+   Replicate_Wild_Ignore_Table:
+                    Last_Errno: 0
+                    Last_Error:
+                  Skip_Counter: 0
+           Exec_Master_Log_Pos: 10338204
+               Relay_Log_Space: 10321825
+               Until_Condition: None
+                Until_Log_File:
+                 Until_Log_Pos: 0
+            Master_SSL_Allowed: Yes
+            Master_SSL_CA_File:
+            Master_SSL_CA_Path:
+               Master_SSL_Cert:
+             Master_SSL_Cipher:
+                Master_SSL_Key:
+         Seconds_Behind_Master: 0
+ Master_SSL_Verify_Server_Cert: Yes
+                 Last_IO_Errno: 0
+                 Last_IO_Error:
+                Last_SQL_Errno: 0
+                Last_SQL_Error:
+   Replicate_Ignore_Server_Ids:
+              Master_Server_Id: 1
+                Master_SSL_Crl:
+            Master_SSL_Crlpath:
+                    Using_Gtid: Slave_Pos
+                   Gtid_IO_Pos: 0-1-581756
+       Replicate_Do_Domain_Ids:
+   Replicate_Ignore_Domain_Ids:
+                 Parallel_Mode: optimistic
+                     SQL_Delay: 0
+           SQL_Remaining_Delay: NULL
+       Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
+              Slave_DDL_Groups: 0
+Slave_Non_Transactional_Groups: 0
+    Slave_Transactional_Groups: 28339
+          Replicate_Rewrite_DB:
+1 row in set (0.001 sec)
+```