This glossary includes only the terms used in this book. For a description of Adaptive Server and SQL terms, see the Adaptive Server Glossary.
A system that is set up as a two-node configuration where both nodes in the cluster include Adaptive Servers managing independent workloads, and are capable of taking over each other’s workload in the event of a failure.
A multi-node setup that involves a single Adaptive Server, a primary node on which the Adaptive Server primarily runs, and a set of secondary nodes that can host the Adaptive Server and its resources, if necessary.
A high-availability system consisting of one primary companion and one secondary companion. In an asymmetric system, only the primary companion can fail over. The secondary Adaptive Server is also known as a “hot standby.”
A collection of nodes in a high availability system. A cluster for the Adaptive Server high availability system consists of at least two nodes.
Each Adaptive Server in a primary availability system is a companion. One Adaptive Server is called a companion server and the other is called the secondary companion server.
A connection that has the failover property set fails over to the secondary companion
The planned event during which Adaptive Server is migrated back to, and restarted on, a primary companion, after failover has taken place. This involves moving the failed-over databases, devices, and client connections from the secondary companion to the restarted primary companion.
The mode of the primary companion after it has failed-over and is running on the secondary companion.
The process by which Adaptive Server migrates to another that which takes over the responsibility of managing the failed server. Failover may occur due to scheduled maintenance or a failure of Adaptive Server or the machine running Adaptive Server.
The mode during which two Adaptive Servers in a high availability system are functioning as independent servers and are configured to fail over during a scheduled maintenance or system failure.
The Adaptive Server whose databases and connections are migrated to the secondary Adaptive Server during failover.
Placeholder databases created on the secondary companion for every user database on the primary companion. Proxy databases reserve the database names so that during failover, all database names are unique on the system.
The mode of Adaptive Server while it is being configured for high availability. During this mode, Adaptive Server cannot fail over.
A system state where Adaptive Server can exist for an extended period of time, such as the day-to-day operation of Adaptive Server.
The mode of Adaptive Server after companion mode has been suspended. During this mode, Adaptive Server cannot fail over; it is working independently of the companion Adaptive Server.
A high availability system in which two independent Adaptive Servers act as failover servers for each other. That is, each Adaptive Server acts as both a primary and a secondary companion.
