/ 3.2. Initial Cluster Setup
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Initial Cluster Setup

After having installed the HA packages, you can configure the initial cluster setup with YaST. This includes the communication channels between the nodes, security aspects like using encrypted communication and starting OpenAIS as service.

For the communication channels, you need to define a bind network address (bindnetaddr), a multicast address (mcastaddr) and a multicast port (mcastport). The bindnetaddr is the network address to bind to. To ease sharing configuration files across the cluster, OpenAIS uses network interface netmask to mask only the address bits that are used for routing the network. The mcastaddr can be a IPv4 or IPv6 multicast address. The mcastport is the UDP port specified for mcastaddr.

The nodes in the cluster will know each other from using the same multicast address and the same port number. For different clusters, use a different multicast address.

Procedure 3.1. Configuring the Cluster

  1. Start YaST and select Miscellaneous+Cluster or run yast2 cluster on a command line to start the initial cluster configuration dialog.

  2. In the Communication Channel category, configure the channels used for communication between the cluster nodes. This information is written to the /etc/ais/openais.conf configuration file.

    Define the Bind Network Address, the Multicast Address and the Multicast Port to use for all cluster nodes.

  3. Specify a unique Node ID for every cluster node. It is recommended to start at 1.

  4. In the Security category, define the authentication settings for the cluster. If Enable Security Authentication is activated, HMAC/SHA1 authentication is used for communication between the cluster nodes.

    This authentication method requires a shared secret, which is used to protect and authenticate messages. The authentication key (password) you specify will be used on all nodes in the cluster. For a newly created cluster, click Generate Auth Key File to create an authentication key that is written to /etc/ais/authkey.

  5. In the Service category, choose whether you want to start OpenAIS on this cluster server each time it is booted.

    If you select Off, you must start OpenAIS manually each time this cluster server is booted. To start OpenAIS manually, use the rcopenais start command.

    To start OpenAIS immediately, click Start OpenAIS Now.

  6. If all options are set according to your wishes, click Finish. YaST then automatically also adjusts the firewall settings and opens the UDP port used for multicast.

  7. After the initial configuration is done, you need to transfer the configuration to the other nodes in the cluster. The easiest way to do so is to copy the /etc/ais/openais.conf file to the other nodes in the cluster. As each node needs to have a unique node ID, make sure to adjust the node ID accordingly after copying the file.

  8. If you want to use encrypted communication, also copy the /etc/ais/authkey to the other nodes in the cluster.

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