Compaq Reliable Transaction Router manual Standby Servers

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RTR Server Types

one node can contain the primary servers for one key range and standby servers for another key range to balance the load across systems. This allows the nodes in a cluster environment to act as standby for other nodes without having idle hardware. When setting up a standby server, both servers must have access to the same journal.

Figure 1–15 Standby Servers

Terminals	Frontends (FE)
	FE

Client

FE

Client

FE

Client

Routers (TR)

Backends (BE) Database (DB)

BE

Server

BE

DB

Standby

TR

ZKO-GS013-99AI

Transactional shadow server

The transactional shadow server places all transactions recorded on the primary server on a second database. The transactional shadow server can be at the same site or at a different site, and must exist in a networked environment.

A transactional shadow server can also have standby servers for greater reliability. When one member of a shadow set fails, RTR remembers the transactions executed at the surviving site in a journal, and replays them when the failed site returns. Only after all journaled transactions are recovered does the recovering site receive new online transactions. Transactional shadowing is done by partition. A transactional shadow conﬁguration can have only two members of the shadow set.

Shadow servers are servers on separate backends which handle the same transactions in parallel on identical copies of the database.

Introduction 1–17

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Contents Reliable Transaction Router Getting Started Page Contents Reliability Features Figures Page Preface Purpose of this DocumentDocument Structure For all users Related DocumentationReaders Comments Reading PathSystem Manager Application Programmer If V2 to= Tutorial Reliable Transaction Router IntroductionRTR Continuous Computing Concepts RTR Continuous Computing ConceptsRTR Terminology RTR TerminologyClient Symbol Server Symbol Roles Symbols Components in the RTR Environment Nontransactional messaging Transaction ID Controller Database Server Application PresentationBusiness Logic Odbc Model RTR Frontend PC BrowserJournal Browser11 RTR Deployed on Three Nodes 12 Standby Server Conﬁguration 13 Transactional Shadowing Conﬁguration RTR Server Types RTR Server TypesStandby server Standby in a cluster 15 Standby Servers 16 Shadow Servers Server1 Server2 Server3 Server4 17 Concurrent ServersPartition a Transaction19 Bank Partitioning Example Standby Server Conﬁgurations Anonymous clients Tunnel RTR Networking Capabilities RTR Networking CapabilitiesPage Three-Layer Model Architectural ConceptsThree Layer Model Three-Layer ModelRTR Facilities Bridge the Gap RTR Facilities Bridge the GapBroadcasts Flexibility and GrowthFlexibility and Growth Transaction IntegrityPartitioned Data Model Object-Oriented ProgrammingPartitioned Data Model Partitioned Data Model Object-Oriented ProgrammingFunctional and Object-Oriented Programming Compared ObjectsExample 2-1 Objects-Deﬁned Sample Messages Class RelationshipsPolymorphism Object Implementation Beneﬁts XA Support XA SupportServers Reliability FeaturesFailover and Recovery Recovery ScenariosFailover and Recovery Recovery Scenarios Backend Recovery Router Recovery Frontend RecoveryPage RTR Interfaces RTR Management Station RTR Management Station RTR Create Facility DESIGN/ALLROLES=NODEA RTR RTRRECEIVEMESSAGE/TIME=0 RTR RTRSTARTTX/CHAN=C Interface Application Programming InterfacesRTR Browser Interface Application Programming InterfacesRTR C Example of an open channel call in an RTR client program RTR System Management Environment RTR EnvironmentRtrcomserv RTR System Management EnvironmentManagement Station Running Browser Software RTR System Management EnvironmentMonitoring RTR RTR Runtime Environment RTR Runtime Environment Client ApplicationOptional External Applet Not Running Whats Next? Whats Next?Page Glossary Channel BranchBroadcast Callout serverData object Common classesConcurrent server Data marshallingEvent driven Fault tolerantEndian EventKey range FrontendInquorate JournalMultithreaded MessageMessage handler MultichannelProperty classes PrimaryProcess PropertiesRTR environment RollbackRouter RTR conﬁgurationTransaction controller ShadowStandby TransactionTwo-phase commit Transactional messageTransactional shadowing Index-1 IndexIndex-2