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| Both sides previous revision Previous revision Next revision | Previous revision | ||
| mysql8_innodb_cluster [2024/06/22 14:59] – [Templates] andonovj | mysql8_innodb_cluster [2024/06/25 13:40] (current) – andonovj | ||
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| Line 2: | Line 2: | ||
| Innodb CLuster is a modern solution to provide group replication for MySQL. In this configuration, | Innodb CLuster is a modern solution to provide group replication for MySQL. In this configuration, | ||
| - | {{: | + | {{: |
| Of course our IPs will look different because I am waaaay too lazy to care for proper pictures. | Of course our IPs will look different because I am waaaay too lazy to care for proper pictures. | ||
| Line 37: | Line 37: | ||
| - name: Stop firewall | - name: Stop firewall | ||
| - | | + | service: |
| + | name: firewalld | ||
| + | state: stopped | ||
| </ | </ | ||
| Line 65: | Line 67: | ||
| shell: | | shell: | | ||
| temporal_password=`awk '/A temporary password is generated for/ {a=$0} END{ print a }' / | temporal_password=`awk '/A temporary password is generated for/ {a=$0} END{ print a }' / | ||
| + | mysql -uroot -p${temporal_password} -e "SET GLOBAL super_read_only = 0; SET GLOBAL read_only = 0; " --connect-expired-password | ||
| mysql -uroot -p${temporal_password} -e "ALTER USER ' | mysql -uroot -p${temporal_password} -e "ALTER USER ' | ||
| echo " | echo " | ||
| Line 80: | Line 83: | ||
| name: mysqld | name: mysqld | ||
| state: stopped | state: stopped | ||
| - | |||
| - | - name: Template the my.cnf | ||
| - | template: | ||
| - | dest: "/ | ||
| - | src: templates/ | ||
| - | owner: " | ||
| - | group: " | ||
| - | mode: ' | ||
| - name: Define the primary host (e.g. first host in the group) | - name: Define the primary host (e.g. first host in the group) | ||
| Line 96: | Line 91: | ||
| set_fact: | set_fact: | ||
| secondary_nodes: | secondary_nodes: | ||
| + | |||
| + | - name: Get secondary hosts | ||
| + | debug: | ||
| + | var: secondary_nodes | ||
| - name: Start MySQL | - name: Start MySQL | ||
| Line 120: | Line 119: | ||
| - name: Bootstrap the cluster (new deployment) | - name: Bootstrap the cluster (new deployment) | ||
| command: mysqlsh -f / | command: mysqlsh -f / | ||
| + | |||
| + | - name: Wait to start | ||
| + | wait_for: | ||
| + | timeout: 5 | ||
| - name: Add the other instances | - name: Add the other instances | ||
| command: mysqlsh -f / | command: mysqlsh -f / | ||
| - | when: inventory_hostname | + | when: inventory_hostname |
| </ | </ | ||
| Line 130: | Line 133: | ||
| < | < | ||
| + | | ||
| + | | ||
| { | { | ||
| " | " | ||
| Line 196: | Line 201: | ||
| # | # | ||
| - | var cluster_user_password = "{{ cluster_user_password }}" | + | var cluster_user_password = "{{ cluster_user_password }}"; |
| - | var clusterName = "{{ cluster_name }}" | + | var clusterName = "{{ cluster_name }}"; |
| - | var secondary_nodes = "{{ secondary_nodes }}" | + | var secondary_nodes = "{{ secondary_nodes }}"; |
| + | var root_password = "{{ root_password }}"; | ||
| + | var cluster_user = "{{ cluster_user }}"; | ||
| - | var mysql = require(' | + | var mysql = require(' |
| - | try { | + | try{ |
| - | var session = mysql.getClassicSession(' | + | dba.configureInstance(' |
| - | | + | password: `${root_password}`, |
| - | | + | |
| + | interactive: | ||
| + | clusterAdmin: | ||
| + | clusterAdminPassword: | ||
| + | }); | ||
| } catch(e){ | } catch(e){ | ||
| - | print(' | + | print(' |
| } | } | ||
| Line 217: | Line 228: | ||
| var secondary_nodes = secondary_nodes.replaceAll(" | var secondary_nodes = secondary_nodes.replaceAll(" | ||
| - | var mysql = require(' | + | var mysql = require(' |
| try { | try { | ||
| Line 230: | Line 241: | ||
| } | } | ||
| </ | </ | ||
| + | |||
| + | |||
| + | =====Management===== | ||
| + | It is all cool and stuff, but let's go through several scenarios with our cluster: | ||
| + | |||
| + | 1. Loss of a member | ||
| + | 2. Backup | ||
| + | 3. Recovery | ||
| + | |||
| + | |||
| + | First thing first, what we do if the connection between the primary and the secondary fails, well we have to rejoin, let's see how. | ||
| + | |||
| + | |||
| + | ====Loss of a member==== | ||
| + | To do that, we will simulate a stop of the service, someone stopped our service :-). | ||
| + | |||
| + | < | ||
| + | [root@mysql-cluster-b ~]# service mysqld stop | ||
| + | Redirecting to / | ||
| + | [root@mysql-cluster-b ~]# | ||
| + | </ | ||
| + | |||
| + | Since our cluster can tolerate one failure, after that, it cannot tolerate anymore: | ||
| + | |||
| + | |||
| + | |||
| + | < | ||
| + | | ||
| + | | ||
| + | { | ||
| + | " | ||
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| + | }, | ||
| + | " | ||
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| + | " | ||
| + | " | ||
| + | " | ||
| + | " | ||
| + | **" | ||
| + | " | ||
| + | }, | ||
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| + | } | ||
| + | }, | ||
| + | " | ||
| + | }, | ||
| + | " | ||
| + | } | ||
| + | </ | ||
| + | |||
| + | We see that the node is down. So let's try to simulate a restoration of the connection: | ||
| + | |||
| + | < | ||
| + | [root@mysql-cluster-b ~]# service mysqld start | ||
| + | Redirecting to / | ||
| + | [root@mysql-cluster-b ~]# | ||
| + | </ | ||
| + | |||
| + | Now we can check again: | ||
| + | |||
| + | < | ||
| + | { | ||
| + | " | ||
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| + | } | ||
| + | }, | ||
| + | " | ||
| + | }, | ||
| + | " | ||
| + | } | ||
| + | </ | ||
| + | |||
| + | Now we see that it is working, if for some reason it doesn' | ||
| + | < | ||
| + | Cluster.rejoinInstance(instance) | ||
| + | cluster.rescan() | ||
| + | </ | ||
| + | |||
| + | It is important that if the UUID was changed, we have to remove the instance from the metadata before adding it: | ||
| + | |||
| + | < | ||
| + | cluster.removeInstance(" | ||
| + | cluster.rescan() | ||
| + | </ | ||
| + | |||
| + | |||
| + | ====Backup==== | ||
| + | |||
| + | |||
| + | ====Restore==== | ||