Cloud functions can be activated provided that you have at least three cluster nodes, however, the fault-tolerance features will work only on 4 and more cluster nodes and a network storage configured.
More information about network storages can be found under How to connect storages.
To enable cloud functions, navigate to the Cluster settings → Cloud functions:
- License IP-address - enter the IP address that the license is bound to. That IP address will be automatically "recovered" on another cluster node in case of the failure.
- Cloud functions - select the checkbox to activate the cloud functions.
- Transport - how information is transmitted within the cluster:
- Multicast:
- Multicast address - corosync multicast address;
- Multicast port - corosync port. Possible value: current (mcastport) - to receive information and previous (mcastport - 1) to send it. If several clusters are running in one network, you need to set different values for every cluster;
- Time to live (TTL) - if the cluster is running on a routed network, the value must be larger than "1".
- Unicast:
- multicast port - corosync port. Possible value: current (mcastport) - to receive information and previous (mcastport - 1) to send it. If several clusters are running in one network, you need to set different values for every cluster;
- Multicast:
Enabling cloud functions will start corosync and corolistener on all of the cluster nodes. In the list of cluster nodes in VMmanager you will see the icon indicating that the node is included into the cluster. The /tmp/.lock.vmmgr.firstinit and /tmp/.lock.vmmgr.service files are created on the master node. The system starts the database replication and enables the needed systems (corosync, corolistener). The /tmp/.lock.vmmgr.firstinit file is deleted.