When an update becomes available for a package installed on your cluster, the Ark console will display an alert symbol in the UP column of the Details panel for the cluster, and in the UP column of the DNSNAME table adjacent to the node that requires an update (see Figure 13.10):Figure 13.10 – The DNSNAME table.The overall cluster status (displayed in the top section of the Clusters tab) is based on the values of the nodes within the cluster.
• If all of the nodes within the cluster are up-to-date, the UP column displays a green checkmark.
• If one or more nodes require a non-critical update, the UP column displays a yellow alert symbol.
• If one or more nodes require a critical update, the UP column for the cluster displays a red error symbol.
• If one or more nodes have an unknown package status, the UP column for the cluster displays a grey checkmark.You can use the Upgrade icon (located on the Clusters tab) to perform a yum update on each node within the cluster. Note that if the yum update command fails during the upgrade process, EDB Ark will terminate the process and yum update will not be run on any remaining nodes, leaving the cluster partially upgraded.The yum update command will update all installed packages to the most recent version available of the same release (i.e., if you are running a 9.2 server, yum will update your database server to the most recent version of 9.2).The upgrade does not facilitate upgrading the server to a newer major release of Postgres. For example, to migrate between server version 9.3 and 9.4, you must perform a manual upgrade. For more information about performing a major version upgrade, please see Section 13.5.1, Performing a Major Version Upgrade.Before performing the upgrade, EDB Ark will perform a backup. During the upgrade process, all clients will be disconnected from the server. The upgraded server will retain the IP address used by the original server. When the upgrade has completed, clients may once again connect.After performing a yum update, the node will be rebooted, initiating any kernel updates required. When the update completes, EDB Ark will send an email notification that contains a list of the updated packages.If one or more nodes in your cluster are currently displaying an unknown status, EDB Ark will display the error message shown in Figure 13.11. You must correct the problem that is causing the unknown status before EDB Ark can perform an automatic upgrade.You can use the Postgres pg_dump and pg_restore utilities to upgrade a running cluster to a new major version of Postgres. To upgrade, use the pg_dump utility to make a copy your database, create a cluster that is running the upgraded version of Postgres, and then use pg_restore to install the database into the new cluster.
2. Invoke pg_dump, backing up the old cluster.
3. Create a new cluster, selecting the new major version for the database server in the Create a New Server Cluster dialog.
4. Perform a pg_restore on the new master using the backup created with pg_dump.For detailed information about using pg_dump and pg_restore to move an existing database into a new cluster, see Section 13.2.