In multiple-slave node structure, there is one master node and several slave nodes to improve the service availability of CUBRID.
Because replication log copy process and replication log reflection process are running at all nodes in the CUBRID HA group, a load of copying replication log occurs. Therefore, all nodes in the CUBRID HA group have high network and disk usage.
Because there are many nodes with HA enabled, read and write services never fail as long as a single node is alive.
In the multiple-slave node structure, the node becoming a master node when failover occurs is determined by the order specified in ha_node_list. If the value of ha_node_list is node1:node2:node3 and the master node is node1, node2 will become a new master node when node1 fails.
You can configure each node in the basic structure of HA as shown below:
For the databases.txt file of a broker node, it is necessary to configure the list of hosts configured as HA in db-host according to their priority. The following is an example of the databases.txt file:
#db-name vol-path db-host log-path
testdb1 /home/cubrid/DB/testdb1 nodeA:nodeB:nodeC /home/cubrid/DB/testdb1/log
The data in the CUBRID HA group may lose integrity when there are multiple failures in this structure.
In addition, if the mode of replication log copy process is ASYNC, the data in the CUBRID HA group may lose integrity.
If the data in the CUBRID HA group loses integrity for any of the reasons above, you can fix it by using Rebuilding Replications.