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Reliable Transaction Router
Getting Started
Order Number: AA-RLE1A-TE
January 2001
This document introduces Reliable Transaction Router and describes its
concepts for the system manager, system administrator, and applications
programmer.
Revision/Update Information: This is a new manual.
Software Version: Reliable Transaction Router Version 4.0
Compaq Computer Corporation
Houston, Texas
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© 2001 Compaq Computer Corporation Compaq, the Compaq logo, AlphaServer, TruCluster, VAX, and VMS Registered in U. S. Patent and Trademark Office. DECnet, OpenVMS, and PATHWORKS are trademarks of Compaq Information Technologies Group, L.P. Microsoft and Windows NT are trademarks of Microsoft Corporation. Intel is a trademark of Intel Corporation. UNIX and The Open Group are trademarks of The Open Group. All other product names mentioned herein may be trademarks or registered trademarks of their r
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Contents Preface ..................................................... vii 1 Introduction Reliable Transaction Router . . ........................... 1–1 RTR Continuous Computing Concepts . . ................... 1–2 RTR Terminology . . ................................... 1–3 RTR Server Types . ................................... 1–15 RTR Networking Capabilities ........................... 1–23 2 Architectural Concepts The Three-Layer Model ................................ 2–1 RTR Facilities Brid
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3 Reliability Features Servers . . ........................................... 3–1 Failover and Recovery ................................. 3–2 Router Failover ................................... 3–2 Recovery Scenarios . ................................... 3–2 Backend Recovery ................................. 3–3 Router Recovery .................................. 3–3 Frontend Recovery ................................ 3–3 4 RTR Interfaces RTR Management Station . . . ........................... 4
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Figures 1 RTR Reading Path ................................. x 1–1 Client Symbol . ................................... 1–4 1–2 Server Symbol . ................................... 1–5 1–3 Roles Symbols . ................................... 1–6 1–4 Facility Symbol ................................... 1–6 1–5 Components in the RTR Environment .................. 1–7 1–6 Two-Tier Client/Server Environment ................... 1–9 1–7 Three-Tier Client/Server Environment.................. 1–9 1–8 Browse
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Preface Purpose of this Document The goal of this document is to assist an experienced system manager, system administrator, or application programmer to understand the Reliable Transaction Router (RTR) product. Document Structure This document contains the following chapters: • Chapter 1, Introduction to RTR, provides information on RTR technology, basic RTR concepts, and RTR terminology. • Chapter 2, Architectural Concepts, introduces the RTR three-layer model and explains ths use of RTR funct
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Related Documentation Additional resources in the RTR documentation kit include: Document Content For all users: Reliable Transaction Describes new features, changes, and Router Release Notes known restrictions for RTR. RTR Commands Lists all RTR commands, their qualifiers and defaults. For the system manager: Reliable Transaction Describes how to install RTR on all Router Installation supported platforms. Guide Reliable Transaction Describes how to configure, manage, Router System and monitor RTR
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Reader’s Comments Compaq welcomes your comments on this guide. Please send your comments and suggestions by email to rtrdoc@compaq.com. Please include the document title, date from title page, order number, section and page numbers in your message. For product information, send email to rtr@compaq.com. Conventions This manual adopts the following conventions: Convention Description New term New terms are shown in bold when introduced and defined. All RTR terms are defined in the glossary at the en
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Cover SPD Release letter Notes Figure 1 RTR Reading Path Getting Started System Manager Application Programmer Application Installation Design Guide Guide If V2 to V3 If C++ C Application C++ System Migration Programmer's Manager's Foundation Guide Reference Classes Manual Manual Commands = Tutorial ZKO-GS015-99AI x
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1 Introduction This document introduces RTR and describes RTR concepts. It is intended for the system manager or administrator and for the application programmer who is developing an application that works with Reliable Transaction Router (RTR). Reliable Transaction Router Reliable Transaction Router (RTR) is failure-tolerant transactional messaging middleware used to implement large, distributed applications with client/server technologies. RTR helps ensure business continuity across multivendo
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RTR Continuous Computing Concepts RTR Continuous Computing Concepts RTR provides a continuous computing environment that is particularly valuable in financial transactions, for example in banking, stock trading, or passenger reservations systems. RTR satisfies many requirements of a continuous computing environment: • Reliability • Failure tolerance • Data and transaction integrity • Scalability • Ease of building and maintaining applications • Interoperability with multiple operating systems RTR
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RTR Terminology RTR Terminology The following terms are either unique to RTR or redefined when used in the RTR context. If you have learned any of these terms in other contexts, take the time to assimilate their meaning in the RTR environment. The terms are described in the following order: • Application • Client, client application • Server, server application • Channel • RTR configuration • Roles • Frontend • Router • Backend • Facility • Transaction • Transactional messaging • Nontransactional
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RTR Terminology An RTR application is user-written software that executes RTR Application within the confines of several distributed processes. The RTR application may perform user interface, business, and server logic tasks and is written in response to some business need. An RTR application can be written in any language, commonly C or C++, and includes calls to RTR. RTR applications are composed of two kinds of actors, client applications and server applications. An application process is show
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RTR Terminology Figure 1–2 Server Symbol RTR expects client and server applications to identify themselves Channel before they request RTR services. During the identification process, RTR provides a tag or handle that is used for subsequent interactions. This tag or handle is called an RTR channel.A channel is used by client and server applications to exchange units of work with the help of RTR. An application process can have one or more client or server channels. An RTR configuration consists of
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RTR Terminology Figure 1–3 Roles Symbols FE BE TR Facility The mapping between nodes and roles is done using a facility. An RTR facility is the user-defined name for a particular configuration whose definition provides the role-to-node map for a given application. Nodes can share several facilities. The role of a node is defined within the scope of a particular facility. The router is the only role that knows about all three roles. A router can run on the same physical node as the frontend or backen
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RTR Terminology Figure 1–5 Components in the RTR Environment User Accounts Facility FE TR BE Client Server application application General Ledger Facility LKG-11203-98WI disconnected before all parts of the transaction are done, then the transaction remains incomplete. Transaction A transaction is a piece of work or group of operations that must be executed together to perform a consistent transformation of data. This group of operations can be distributed across many nodes serving multiple data
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RTR Terminology messaging, RTR ensures that a transaction is ‘‘all or nothing’’— either fully completed or discarded; either both the checking account debit and the savings account credit are done, or the checking account debit is backed out and not recorded in the database. RTR transactions have the ACID properties. Nontransactional An application will also contain nontransactional tasks such messaging as writing diagnostic trace messages or sending a broadcast message about a change in a stock
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RTR Terminology Figure 1–6 Two-Tier Client/Server Environment DM Database Server Application Presentation and Business Logic (ODBC Model) LKG-11204-98WI Figure 1–7 Three-Tier Client/Server Environment DB Server Database Application Presentation/ Application Server/ Database Server User Interface Business Logic LKG-11205-98WI RTR provides a multicomponent software model where clients running on frontends, routers, and servers running on backends cooperate to provide reliable service and transact
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RTR Terminology All components can reside on a single node but are typically deployed on different nodes to achieve modularity, scalability, and redundancy for availability. With different systems, if one physical node goes down or off line, another router and backend node takes over. In a slightly different configuration, you could have an application that uses an external applet running on a browser that connects to a client running on the RTR frontend. Such a configuration is shown in Figure 1–
