4. Setup MySQL Replication

Owned by Neha Jain
Last updated: Jun 18, 2018 by Mohammadreza Pasandideh
5 min read

Common

These instructions apply to Beijing and newer releases.

Setup Steps

We are using MySQL Master-Master replication strategy to set up replication across two kubernetes clusters (aka sites). The setup is done through below manual steps.

 1. Verify MySQL server-id is different in both sites.

#Login to master db pod on site 1 and site 2 ubuntu@k8s-s1-master:~$ kubectl exec -it sdnc-dbhost-0 -n onap bash Defaulting container name to sdnc-db-container. Use 'kubectl describe pod/sdnc-dbhost-0' to see all of the containers in this pod. root@sdnc-dbhost-0:/#   #Verify server-id on site 1 root@sdnc-dbhost-0:/# cd /etc/mysql/conf.d root@sdnc-dbhost-0:/etc/mysql/conf.d# cat server-id.cnf [mysqld] server-id=100 #Verify server-id on site 2 root@sdnc-dbhost-0:/# cd /etc/mysql/conf.d root@sdnc-dbhost-0:/etc/mysql/conf.d# cat server-id.cnf [mysqld] server-id=200



  2. If MySQL site-id for site 1 and site 2, resulting from step 1, are not different, proceed with the below step to make them unique.

You can skip this step if the server-ids are verified to be unique in step #1. This step is only to be followed on site 2 (i.e. secondary site).

#Set server-id to a different number (e.g. 200) in the secondary site. #Assuming the current value for server-id on site 2 is 100, we aim to change it to 200. Login to master DB pod on the Secondary site and change it. ubuntu@k8s-s2-master:~$ kubectl exec -it sdnc-dbhost-0 -n onap bash root@sdnc-dbhost-0:/# sed -i 's/100/200/g' /etc/mysql/conf.d/server-id.cnf root@sdnc-dbhost-0:/etc/mysql/conf.d# service mysql restart [info] Stopping MySQL Community Server 5.7.21. ...........command terminated with exit code 137 ubuntu@k8s-s1-master:~$   #verify root@sdnc-dbhost-0:/# cd /etc/mysql/conf.d root@sdnc-dbhost-0:/etc/mysql/conf.d# cat server-id.cnf [mysqld] server-id=200



3. Verify NodePort Service Port Number on each site.

#verify nodeport service exists ubuntu@k8s-s1-master:~$ kubectl get svc -n onap | grep mysql mysql-nodeport NodePort 10.107.197.242 <none> 3306:30231/TCP,3307:30232/TCP 29s ubuntu@k8s-s1-master:~$ #verify the endpoints are assigned for the service #make a note of Node Port Number to use in step#5 ubuntu@k8s-s1-master:~$ kubectl describe svc mysql-nodeport -n onap Name: mysql-nodeport Namespace: onap Labels: statefulset.kubernetes.io/pod-name=sdnc-dbhost-0 Annotations: <none> Selector: statefulset.kubernetes.io/pod-name=sdnc-dbhost-0 Type: NodePort IP: 10.107.197.242 Port: sdnc-dbhost-0-port-3306 3306/TCP TargetPort: 3306/TCP NodePort: sdnc-dbhost-0-port-3306 30231/TCP Endpoints: 10.44.0.3:3306 Port: sdnc-dbhost-0-port-3307 3307/TCP TargetPort: 3307/TCP NodePort: sdnc-dbhost-0-port-3307 30232/TCP Endpoints: 10.44.0.3:3307 Session Affinity: None External Traffic Policy: Cluster Events: <none> ubuntu@k8s-s1-master:~$



4. Setup Master-Master Replication. 

On site 2 (Secondary site):


On site 1 (Primary site):



Verify replication status on both sites.

It should look like below: