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Version: 2023.3

Glossary

Terms used in this guide are described in the following table.

TermDescription
Active-ActiveAll nodes in the cluster are active. A load balancing algorithm/policy determines the preferred node for a given session. This is a more scalable architecture. However, it is more complex to manage.
Active-PassiveA fully redundant instance of each node is present. The passive node is brought online when its associated primary node fails.
Active-StandbyOne node in the cluster is active. The other node is inactive until failover is triggered (warm standby).
AlwaysOn Availability GroupsA high-availability and disaster-recovery solution that provides an enterprise-level alternative to MSSQL database mirroring.
ARRActive Request Routing. This is an IIS server native load balancing solution.
ARR Server FarmA logical group of application servers where HTTP requests are routed based on HTTP inspection rules and load balance algorithm.
Availability databasesA failover environment for a discrete set of user databases (an availability group) that fail over together.
Availability replicaAn instantiation of an availability group that is hosted by a specific instance of SQL Server and that maintains a local copy of each availability database that belongs to the availability group.
Two types of availability replicas exist: a single primary replica and one to four secondary replicas. The server instances that host the availability replicas for a given availability group must reside on different nodes of a single Windows Server Failover Clustering (WSFC) cluster.
NLBNetwork Load Balancing. Use the NLB Manager to create and manage NLB clusters from a single computer.
SANStorage area network, dedicated network used to enhance storage devices. It is a high-speed network, providing a direct connection between servers and storage, including shared storage, clusters, and disaster-recovery devices.
SPOFSingle Point of Failure.
Warm UpgradeAn administrator is able to upgrade one node of the cluster to a new version of CloudShell (Quali Server) while the other node is active, then fall back to the new node and upgrade the standby without any downtime for the end user.
Windows load balancing managerWindows load balancing manager enables you to create and manage Network Load Balancing (NLB) clusters from a single computer. By centralizing NLB administration tasks, many common configuration errors are eliminated.
WSFCWindows Server Failover Clustering