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Compaq Reliable Transaction Router manual Concurrent servers Callout servers

Models: Reliable Transaction Router

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RTR Server Types

Standby server

Standby in a cluster

•Concurrent servers

•Callout servers

These are described in the next few paragraphs. You specify server types to your application in RTR API calls.

RTR server types help to provide continuous availability and a secure transactional environment.

The standby server remains idle while the RTR primary backend server performs its work, accepting transactions and updating the database. When the primary server fails, the standby server takes over, recovers any in-progress transactions, updates the database, and communicates with clients until the primary server returns. There can be many instances of a standby server. Activation of the standby server is transparent to the user.

A typical standby conﬁguration is shown in Figure 1–12, Standby Server Conﬁguration. Both physical servers running the RTR backend software are assumed by RTR to connect to the same database. The primary server is typically in use, and the standby server can be either idle or used for other applications, or data partitions, or facilities. When the primary server becomes unavailable, the standby server takes over and completes transactions as shown by the dashed line. Primary server failure could be caused by server process failure or backend (node) failure.

The intended and most common use of a standby server is in a cluster environment. In a non- cluster environment, seamless failover of standbys is not guaranteed.

Standby servers are ``spare'' servers which automatically take over from the main backend if it fails. This takeover is transparent to the application.

Figure 1–15 shows a simple standby conﬁguration. The two backend nodes are members of a cluster environment, and are both able to access the database.

For any one key range, the main or primary server (Server) runs on one node while the standby server (Standby) runs on the other node. The standby server process is running, but RTR does not pass any transactions to it. Should the primary node fail, RTR starts passing transactions to (Standby). Note that

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Compaq Reliable Transaction Router manual Concurrent servers Callout servers

Contents

January Revision/Update Information This is a new manualReliable Transaction Router Getting Started Compaq Computer Corporation Houston, TexasUNIX and The Open Group are trademarks of The Open Group This document was prepared using VAX DOCUMENT, Version2001 Compaq Computer Corporation Contents IntroductionArchitectural Concepts 5 The RTR Environment 3 Reliability Features4 RTR Interfaces Glossary Index ExamplesFigures TablesPage Document Structure PrefacePurpose of this Document Related Documentation RTR CommandsRouter Installation For all usersConventions Reading PathReaders Comments New termApplication Programmer Figure 1 RTR Reading PathSystem Manager If V2 toIntroduction Reliable Transaction RouterRTR Continuous Computing Concepts RTR Terminology Figure 1-1 Client Symbol Figure 1-2 Server Symbol Channel RTR conﬁguration RolesFE TR Figure 1-3 Roles SymbolsFigure 1-4 Facility Symbol Figure 1-5 Components in the RTR Environment Nontransactional messaging Transaction ID Transaction Controller 1-8 IntroductionFigure 1-6 Two-Tier Client/Server Environment Figure 1-7 Three-Tier Client/Server Environment1-10 Introduction Figure 1-8 Browser Applet ConﬁgurationWeb Server Process RTR Client Application Figure 1-9 RTR with Browser, Single Node, and Database Figure 1-10 RTR Deployed on Two NodesFigure 1-11 RTR Deployed on Three Nodes 1-12 IntroductionFigure 1-12 Standby Server Conﬁguration Transactional shadowing RTR JournalFigure 1-13 Transactional Shadowing Conﬁguration RTR Server Types Concurrent servers Callout servers Figure 1-15 Standby Servers Transactional shadow serverFigure 1-16 Shadow Servers Figure 1-17 Concurrent Servers User Accounts Facility Figure 1-18 A Callout ServerFigure 1-19 Bank Partitioning Example TR A partition can also have multiple standby servers RTR Networking Capabilities RouterPage Architectural Concepts The Three-Layer ModelFigure 2-1 The Three Layer Model ZKO-GS011-99AIFlexibility and Growth RTR Facilities Bridge the GapBroadcasts Transaction Integrity Flexibility and GrowthThe Partitioned Data Model Object-Oriented ProgrammingFigure 2-2 Partitioned Data Model ZKO-GS012-99AIObjects Table 2-1 Functional and Object-Oriented Programming ComparedMessages Class Relationships Example 2-1 Objects-Deﬁned SamplePolymorphism Object Implementation Beneﬁts XA Support Programmers Reference Manual and the RTR Application Design GuideReliability Features ServersRecovery Failover and RecoveryRecovery Scenarios Router FailoverBackend Recovery Router Recovery Frontend Recovery Page RTR Interfaces RTR Management Station RTR Management Station RTR CREATE FACILITY DESIGN/ALLROLES=NODEA $ RTRRTR SHOW JOURNAL RTR SHOW FACILITYRTR RTRRECEIVEMESSAGE/TIME=0 RTR RTRRECEIVEMESSAGE/CHAN=SRTR show transaction $ RTR RTR START RTRenters commands at the server RTR RTRRECEIVEMESSAGE/CHANNEL=C/timRTR RTRSTARTTX/CHAN=C RTR show transactionInterface Application Programming InterfacesBrowser Object-OrientedApplication Programming Interfaces Figure 4-1 RTR Browser Interfaceinterface, see the RTR C Application Programmers Reference RTR CExample of object creation in an RTR server program Manual and the RTR Application Design GuideExample of an open channel call in an RTR client program The RTR Environment The RTR System Management EnvironmentHandles all transactions and recovery Page Transaction Monitoring RTRManagement RTR Monitor pictures or the RTR Monitor let you view theManagement The RTR Runtime EnvironmentPartition Figure 5-2 RTR Runtime Environment RTR Release Notes RTR Installation GuideWhats Next? RTR Migration Guide ifPage applet GlossaryACID applicationcallout server branchbroadcast channeldata marshalling common classesconcurrent server data objectendian frontend message properties primaryprocess property classesRTR conﬁguration rollbackrouter RTR environmenttransaction shadowstandby transaction controllertransactional shadowing two-phase committransactional message Index Index-1Index-2