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15 result(s) for Redundancy

• OPC-10000-4 – OPC Unified Architecture - Part 4: Services
  3.1.10 Redundancy
  Redundancy presence of duplicate components enabling the continued operation after a failure of an OPC UA component Note 1 to entry: This may apply to Server s, Clients or networks
• OPC-10000-1 – OPC Unified Architecture - Part 1: Overview and Concepts
  5.4 Redundancy
  Redundancy OPC UA provides the data structures and services by which Redundancy may be achieved in a standardized manner. Redundancy may be used for high availability, fault tolerance and load ... balancing. OPC 10000-4 formally defines Client , Server and Network Redundancy . Whether and what Redundancy is supported by an OPC UA Application is defined by its Profiles . Profiles are described
• OPC-10000-4 – OPC Unified Architecture - Part 4: Services
  3.1.11 RedundantServerSet
  entry: A RedundantServerSet is a group of Servers that are configured to provide Redundancy . These Servers have requirements related to the address space and provide Failovers
• OPC-10000-4 – OPC Unified Architecture - Part 4: Services
  6.6.1 Redundancy overview
  Redundancy overview OPC UA enables Servers, Clients and networks to be redundant. OPC UA provides the data structures and Services by which Redundancy may be achieved in a standardized manner ... Server Redundancy allows Clients to have multiple sources from which to obtain the same data. Server Redundancy can be achieved in multiple manners, some of which require Client interaction, others
• OPC-10000-4 – OPC Unified Architecture - Part 4: Services
  6.6.2.1 General
  General There are two general modes of Server Redundancy , transparent and non-transparent. In transparent Redundancy the Failover of Server responsibilities from one Server to another is transparent ... perform any actions to continue to send or receive data. In non-transparent Redundancy the Failover from one Server to another and actions to continue to send or receive data
• OPC-10000-4 – OPC Unified Architecture - Part 4: Services
  6.6.2.2 RedundantServerSet Requirements
  that Clients shall be prepared for lost continuation points. Servers in Transparent and HotAndMirrored Redundancy sets shall synchronize continuation points and they may do so in other modes
• OPC-10000-4 – OPC Unified Architecture - Part 4: Services
  6.6.2.3.1 Client behaviour
  have an identical ServerUri and an identical EndpointUrl . Figure 26 shows a typical transparent Redundancy setup. Figure 26 - Transparent Redundancy setup example For transparent Redundancy , OPC UA provides data structures ... with a ServerId contained in the information provided in the TransparentRedundancyType Object . In transparent Redundancy , a Client is not able to control which physical Server it actually connects to. Failover
• OPC-10000-4 – OPC Unified Architecture - Part 4: Services
  6.6.2.4.1 Overview
  Overview For non-transparent Redundancy , OPC UA provides the data structures to allow the Client to identify what Servers are available in the RedundantServerSet and also Server information which tells ... discovery including the registration with a GlobalDiscoveryServer . Figure 27 shows a typical non-transparent Redundancy setup. Figure 27 - Non-Transparent Redundancy setup For non-transparent Redundancy , the Servers will have
• OPC-10000-4 – OPC Unified Architecture - Part 4: Services
  6.6.2.4.5.1 General
  defines a list of Client actions for initial connections and Failovers . Table 107 - Redundancy Failover actions Failover mode and Client options Cold Warm Hot (a) Hot (b) HotAndMirrored On initial ... Server using a lesser Failover mode, i.e. for a Server that provides Hot Redundancy , a Client might connect and choose to treat it as if the Server was running
• OPC-10000-4 – OPC Unified Architecture - Part 4: Services
  6.6.2.4.5.5 HotAndMirrored
  Figure 32 - HotAndMirrored Failover This Failover mode is similar to the transparent Redundancy . The advantage is that the Client has full control over selecting the Server . The disadvantage is that
• OPC-10000-4 – OPC Unified Architecture - Part 4: Services
  6.6.2.5 Hiding Failover with a Server Proxy
  Hiding Failover with a Server Proxy A vendor can use the non-transparent Redundancy features to create a Server proxy running on the Client machine to provide transparent Redundancy ... into the Client and to enable simpler Clients to take advantage of non-transparent Redundancy . The Server proxy simply duplicates Subscriptions and modifications to Subscriptions , by passing the calls
• OPC-10000-4 – OPC Unified Architecture - Part 4: Services
  6.6.3 Client Redundancy
  Client Redundancy Client Redundancy is supported in OPC UA by the TransferSubscriptions Service and by exposing Client information in the Server diagnostic information. Since Subscription lifetime is not tied
• OPC-10000-4 – OPC Unified Architecture - Part 4: Services
  6.6.4.1 Overview
  Redundant networks can be used with OPC UA in either transparent or non-transparent Redundancy . Network Redundancy can be combined with Server and Client Redundancy
• OPC-10000-4 – OPC Unified Architecture - Part 4: Services
  6.6.4.2 Transparent
  network path and Failover are transparent to the Client and the Server . Transparent network Redundancy is illustrated in Figure 34 . Figure 34 - Transparent network Redundancy Examples: A physical appliance/device such
• OPC-10000-4 – OPC Unified Architecture - Part 4: Services
  6.6.4.3 Non-Transparent
  created with another Endpoint . Sessions and Subscriptions can be reused. Non-transparent network Redundancy is illustrated in Figure 35 . Figure 35 - Non-transparent network Redundancy The information about the different