Page 3 - Contents; Preface; vii; Introduction; Object Implementation Bene
Contents Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii 1 Introduction Reliable Transaction Router . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–1 RTR Continuous Computing Concepts . . . . . . . . . . . . . . . . . ...
Page 5 - The following lines arrive at the client from RTR after the; Figures; xi
4–3 Commands and system response at client. . . . . . . . . . . . . . . . 4–14 4–4 The following lines arrive at the client from RTR after the user enters commands at the server. . . . . . . . . . . . . . . . . . . . 4–15 4–5 Creating a Facility with the C++ API . . . . . . . . . . . . . . . . . . 4...
Page 6 - Tables; viii
4–6 RTR Service Provider . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–17 5–1 RTR System Management Environment . . . . . . . . . . . . . . . . 5–4 5–2 RTR Runtime Environment . . . . . . . . . . . . . . . . . . . . . . . . . . 5–7 Tables 1 RTR Documents . . . . . . . . . . . . . ....
Page 7 - Purpose of this Document
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, Introducti...
Page 8 - Related Documentation; Table 1 RTR Documents; Document; For the system manager:
Related Documentation Table 1 describes RTR documents and groups them by audience. Table 1 RTR Documents Document Content For all users: HP Reliable Transaction Router Release Notes 1 Describes new features, corrections, restrictions, and known problems for RTR. HP Reliable Transaction Router Gettin...
Page 9 - Reader’s Comments
Table 1 (Cont.) RTR Documents Document Content HP Reliable Transaction Router JRTR Getting Started 2 Provides an overview of the object-oriented JRTR Toolkit including installation, con fi guration and Java programming concepts, with links to additional online documentation. HP Reliable Transaction ...
Page 10 - Conventions; Convention; New term; User input; Terms and titles; FE; Reading Path
Conventions This manual adopts the following conventions: Convention Description New term New terms are shown in bold when introduced and de fi ned. All RTR terms are de fi ned in the glossary at the end of this document. User input User input and programming examples are shown in a monospaced font....
Page 11 - Figure 1 RTR Reading Path
Figure 1 RTR Reading Path VM-0818A-AI System Manager Application Programmer = Tutorial (Online Only) If C+ + If Java If C GettingStarted C ApplicationProgrammer’sReferenceManual ApplicationDesignGuide JRTRGettingStarted SystemManager’sManual InstallationGuide RTR Help (Online Only) C++FoundationClas...
Page 13 - Introduction; Reliable Transaction Router; Failure tolerance; Introduction 1–1
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 Route...
Page 14 - HP Reliable Transaction Router Software Product Description; fl; –2 Introduction
Reliable Transaction Router Interoperability You use the architecture of RTR to ensure high availability and transaction completion. RTR supports applications that run on different hardware and different operating systems. RTR applications can be designed to work with several database products inclu...
Page 15 - RTR Continuous Computing Concepts; Introduction 1–3
Reliable Transaction Router processing system using RTR requires analysis, planning, and considered execution. RTR Continuous Computing Concepts RTR provides a continuous computing environment that is particularly valuable in fi nancial transactions, for example in banking, stock trading, or passeng...
Page 16 - RTR Terminology; –4 Introduction
RTR Continuous Computing Concepts • DurableFor more details on transactional ACID properties, see the brief discussion later in this document in the section Transaction Integrity and refer to the HP Reliable Transaction Router Application Design Guide . RTR Terminology In addition to the terms previ...
Page 17 - processes; client; applet; Figure 1–1 Client Symbol; Client
RTR Terminology • Standby server• Transactional shadowing• RTR journal• Partition• Key range• XA RTR Application An RTR application is user-written software that executes within the con fi nes of several distributed processes . The RTR application may perform user interface, business, and server log...
Page 18 - server; server application; Figure 1–2 Server Symbol; Server; channel; nodes; –6 Introduction
RTR Terminology Server A server is always a server application , one that reacts to a client’s units of work and carries them through to completion. This may involve updating persistent storage such as a database fi le, toggling a switch on a device, or performing another prede fi ned task. In the c...
Page 19 - frontend; facility; Introduction 1–7
RTR Terminology Roles A node that runs client applications is called a frontend (FE), or is said to have the frontend role. A node that runs server applications is called a backend (BE). Additionally, the transaction router (TR) contains no application software but acts as a traf fi c cop between fr...
Page 20 - Figure 1–4 Facility Symbol; General Ledger Facility; –8 Introduction
RTR Terminology Figure 1–4 Facility Symbol VM-0822A-AI A facility name is mapped to speci fi c physical nodes and their roles using the CREATE FACILITY command.Figure 1–5 shows the logical relationship between client application, server application, frontends (FEs), routers (TRs), and backends (BEs)...
Page 21 - transaction; Introduction 1–9
RTR Terminology Clients send messages to servers to ask that a piece of work be done. Such requests may be bundled together into transactions. An RTR transaction consists of one or more messages that have been grouped together by a client application, so that the work done as a result of each messag...
Page 22 - transaction ID; tier
RTR Terminology With transactional 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 tr...
Page 23 - Figure 1–6 Two-Tier Client/Server Environment
RTR Terminology Figure 1–6 Two-Tier Client/Server Environment Application Presentation and Business Logic (ODBC Model) Database Server Data Manager software VM-0824A-AI Figure 1–7 Three-Tier Client/Server Environment Presentation/User Interface Database Server Application Server/ Business Logic Data...
Page 24 - Figure 1–8 Browser Applet Configuration; RTR Frontend; Applet
RTR Terminology connection to the current router is maintained until the current router fails or connections to it are lost.All RTR software components can reside on a single node but are typically deployed on different nodes to achieve modularity, scalability, and redundancy for availability. Durin...
Page 25 - Figure 1–9 RTR with Browser, Single Node, and Database
RTR Terminology For example, you could use an underutilized system as a standby server in certain con fi gurations. As you modularize your application and distribute its components on frontends and backends, you can identify usage bottlenecks, add new nodes, and provide redundancy to increase availa...
Page 26 - Figure 1–11 RTR Deployed on Three Nodes; Database; standby server
RTR Terminology In this example, the frontend with the client application resides on one node, and the router with the server application reside a node that has both the router and backend roles. This is a typical con fi guration where routers are placed on backends rather than on frontends. A furth...
Page 27 - Figure 1–12 Standby Server Configuration; Primary Server; shadow server
RTR Terminology The standby server is usually placed on a node other than the node where the primary server runs, and should be, to avoid being a single point of failure. Network capability, clustering or disk-sharing technology, and appropriate software must be available on both primary and standby...
Page 28 - Figure 1–13 Transactional Shadowing Configuration; RTR journal
RTR Terminology Figure 1–13 Transactional Shadowing Configuration VM-0831A-AI TR FE Database Database BE Server application BE Server application Primary Server Shadow Server RTR Journal In the RTR environment, one data store (database or data fi le) is elected the primary, and a second data store i...
Page 29 - Note; RTR Server Types
RTR Terminology Note Transactional shadowing shadows only transactions controlled by RTR. For full redundancy to assure maximum availability, a con fi guration could employ disk shadowing in clusters at separate sites coupled with transactional shadowing across sites. Disk shadowing used in speci fi...
Page 31 - Figure 1–14 Standby Servers
RTR Server Types Note that 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...
Page 32 - Figure 1–15 Shadow Servers
RTR Server Types Transactional shadowing is done by partition. A transactional shadow con fi guration can have only two members of the shadow set.Shadow servers are servers on separate backends that handle the same transactions in parallel on identical copies of the database.Figure 1–15 shows a simp...
Page 33 - concurrent server; Partitioned Disks
RTR Server Types Concurrent server The concurrent server is an additional instance of a server application running on the same node. RTR delivers transactions to a free server from the pool of concurrent servers. If one server fails, the transaction in process is replayed to another server in the co...
Page 34 - callout server; User Accounts Facility
RTR Server Types Callout server The callout server enables message authentication on transaction requests made in a given facility, and could be used, for example, to provide audit trail logging. A callout server can run on either backend or router nodes. A callout server receives a copy of all mess...
Page 35 - partition; key range
RTR Server Types Authentication RTR callout servers provide facility-based processing for authentication. For example, a callout server can enable veri fi cation checks to be carried out on all requests in a given facility.Callout servers run on backend or router nodes. They receive a copy of every ...
Page 36 - Figure 1–18 Bank Partitioning Example; Accounts; HP Reliable
RTR Server Types Figure 1–18 Bank Partitioning Example VM-0837A-AI TR BE Server application BE Server application BE Server application BE Server application BE Server application Accounts 1-19,999 Accounts 20,000- 39,999 Accounts 40,000- 69,999 Accounts 70,000- 89,999 Accounts 90,000- 99,999 You ca...
Page 37 - Figure 1–19 Standby with Partitioning
RTR Server Types easily. The system manager can change the key range with a command, for example, in an overnight operation, or you can plan to do this during scheduled maintenance.A partition can also have multiple standby servers. Standby ServerConfigurations A node can be con fi gured as a primar...
Page 38 - RTR Networking Capabilities; Depending on operating system, RTR uses TCP/IP or DECnet
RTR Networking Capabilities RTR Networking Capabilities Depending on operating system, RTR uses TCP/IP or DECnet as underlying transports for the virtual network (RTR facilities) and can be deployed in both local area and wide area networks. PATHWORKS 32 is required for DECnet con fi gurations on Wi...
Page 39 - Architectural Concepts; The Three-Tier Architecture; Architectural Concepts 2–1
2 Architectural Concepts This chapter introduces concepts on basic transaction processing and RTR architecture. The Three-Tier Architecture RTR is based on a three-tier physical architecture consisting of frontend (FE) roles, backend (BE) roles and router (TR) roles. The roles are shown in Figure 2–...
Page 40 - Figure 2–1 The Multitier Model; –2 Architectural Concepts
The Three-Tier Architecture Figure 2–1 The Multitier Model VM-0839A-AI TR FE Terminals Frontends Routers Backends Database BE Server application BE Server application Client application TR FE Client application FE Client application FE Client application BE Server application Client application proc...
Page 41 - RTR Facilities Bridge the Gap; HP Reliable Transaction Router System Manager’s; Architectural Concepts 2–3
The Three-Tier Architecture • Allows performance or geographic expansion while protecting the investments made in existing hardware and application software The router tier contains no application software unless running callout servers. This tier reduces the number of logical network links required...
Page 42 - Broadcasts; –4 Architectural Concepts
Broadcasts Broadcasts Sometimes an application has a requirement to send unsolicited messages to multiple recipients.An example of such an application is a commodity trading system, where the clients submit orders and also need to be informed of the latest price changes.The RTR broadcast capability ...
Page 43 - Flexibility and Growth; Transaction Integrity; Architectural Concepts 2–5
Flexibility and Growth RTR also allows parallel execution. This means that different parts of a single transaction can be processed in parallel by multiple servers.RTR provides a comprehensive set of monitoring tools to help you evaluate the volume of traf fi c passing through the system. These tool...
Page 44 - The Partitioned Data Model; HP Reliable Transaction Router; Object-Oriented Programming; –6 Architectural Concepts
The Partitioned Data Model The Partitioned Data Model One goal in designing for high transaction throughput is reducing the time that users must wait for shared resources.While many elements of a transaction processing system can be duplicated, one resource that must be shared is the database. Users...
Page 45 - Figure 2–2 Partitioned Data Model; Architectural Concepts 2–7
Object-Oriented Programming Figure 2–2 Partitioned Data Model VM-0840A-AI TR FE Terminals Frontends Routers Backends Database BE Server application BE Server application Client application TR FE Client application FE Client application FE Client application BE Server application Partition 1 Partitio...
Page 46 - Table 2–1 Functional and Object-Oriented Programming; Functional Programming; Objects; HP; –8 Architectural Concepts
Object-Oriented Programming Table 2–1 Functional and Object-Oriented Programming Compared Functional Programming Object-Oriented Programming A program consists of data structures and algorithms. A program consists of a team of cooperating objects. The basic programming unit is the function, that whe...
Page 47 - Example 2–1 Objects-Defined Sample; Messages; Architectural Concepts 2–9
Object-Oriented Programming Example 2–1 Objects-Defined Sample Dog.h:class Dog{ ...};main.cpp:#include "Dog.h"main(){ Dog King;Dog Fifi; } Messages Objects communicate by sending messages. This is done by calling an object’s methods.Some principal categories of messages are:• Constructors: C...
Page 48 - Polymorphism; –10 Architectural Concepts
Object-Oriented Programming Polymorphism Polymorphism is the ability of objects, inherited from a common base or parent class, to respond differently to the same message. This is done by de fi ning different implementations of the same method name within the individual child class de fi nitions. For...
Page 49 - Java Support; Architectural Concepts 2–11
Java Support Java Support RTR clients and servers can be Java applications that obtain the bene fi ts of high availability, fault tolerance and scalability provided by RTR. RTR clients and servers employing Java technology use standard Java and J2EE interfaces for transaction management, data input/...
Page 51 - Reliability Features; similar; Reliability Features 3–1
3 Reliability Features This chapter addresses:• RTR server types• Failover and recovery• Recovery scenarios RTR Server Types Reliability in RTR is enhanced by the use of: • Concurrent servers• Standby servers• Shadow servers• Callout servers• Router failoverNote that, conceptually, servers can be co...
Page 52 - Failover and Recovery; Router Failover; –2 Reliability Features
RTR Server Types When there is concern that your database is a single point of failure, add a shadow server, if possible at a different physical location. • Standby servers provide a node that can take over processing on a data partition when the primary server or node fails.When there is concern th...
Page 53 - Recovery Scenarios; Reliability Features 3–3
Failover and Recovery BackendRestartRecovery Transactions in the process of being committed at the time of a failure are recovered from RTR’s disk journal. Recovery could be with a concurrent server, a standby server, or a restarted server created when the failed backend restarts.Correct ordering of...
Page 54 - –4 Reliability Features
Recovery Scenarios FrontendRecovery If a frontend is lost:• All transactions committed but not completed on the frontend node at the time of failure will be completed. • All transactions started but not committed on the frontend node at the time of failure will be aborted. 3–4 Reliability Features
Page 55 - RTR Interfaces; RTR Interfaces 4–1
4 RTR Interfaces RTR provides interfaces for system management (the management interfaces) and for development of transaction processing and management applications (the programming or application development interfaces). ManagementInterfaces The management interfaces are:• The RTR Administrator, a ...
Page 56 - Figure 4–1 RTR Administrator; HP Reliable Transaction Router System; –2 RTR Interfaces
RTR Interfaces Figure 4–1 RTR Administrator vm-1152A-AI The RTR CLI contains all RTR system manager commands and calls to all RTR C API routines such as rtr_open_channel or rtr_create_facility . You can use either the RTR Manager or the RTR CLI to manage your RTR con fi guration. You can also use th...
Page 57 - Figure 4–2 RTR Command Line Interface; RTR Interfaces 4–3
RTR Interfaces Figure 4–2 RTR Command Line Interface VM-1103a-AI ProgrammingInterfaces RTR provides several programming or application development interfaces for design and implementation of transaction processing programs. They include the following:• The object-oriented RTR Java interface You can ...
Page 58 - –4 RTR Interfaces
RTR Interfaces • An interface that enables use of an X/Open Distributed Transaction Processing-conformant resource managerThis interface, invoked through the RTR management interfaces, enables RTR applications to be used with X/Open-compliant resource managers such as Oracle8. • The OpenVMS API cont...
Page 59 - Table 4–1 RTR Development Interfaces and their Use; RTR Interfaces 4–5
RTR Interfaces Many books are available to assist the developer with both design and development, including:• J. Gray, A. Reuter, Transaction Processing: Concepts and Techniques , Morgan Kaufmann, San Mateo, CA, 1992 • Philip A. Bernstein, Eric Newcomer, Principles of Transaction Processing , Morgan...
Page 60 - RTR Management; RTR Manager; –6 RTR Interfaces
RTR Management RTR Management You can manage RTR from several locations: • from a node on which RTR is running• from a remote node from which you send RTR commands to a node running RTR • from a web browser that can be on or access a node running RTR RTRAdministrator With the RTR Administrator, you ...
Page 61 - Figure 4–3 RTR Manager; RTR Explorer; RTR Interfaces 4–7
RTR Management Figure 4–3 RTR Manager VM-1158A-AI http://nodename nodename nodename RTR Explorer Figure 4–4 shows a sample screen of the RTR Explorer with several de fi ned facilities. The RTR Explorer lets the system manager or administrator view the entire RTR con fi guration by facility and by no...
Page 62 - Figure 4–4 RTR Explorer: View of All Facilities; the state of the facility. Information for each node includes its; –8 RTR Interfaces
RTR Management Figure 4–4 RTR Explorer: View of All Facilities vm-1155A-AI Information available for each facility includes the facility name, the alerts associated with nodes participating in the facility, and the state of the facility. Information for each node includes its name, role, cluster nam...
Page 63 - Figure 4–5 RTR Explorer: View of One Facility; Design Facility; RTR Interfaces 4–9
RTR Management Figure 4–5 RTR Explorer: View of One Facility VM-1151A-AI http://nodename Mode: Navigation Design Facility nodename nodename nodename Generated by nodename with 8 seconds old information Nodes can monitor themselves for alerts. Each alert can be set at progressive levels of severity –...
Page 64 - unique; user
RTR Management or group of nodes. If there are no fl ags, the node or group is operating normally. RTR CommandLine Interface The command line interface (CLI) to the RTR API enables the programmer to write short RTR applications from the RTR command line. This can be useful for testing short program ...
Page 66 - Examples
RTR Management Examples Example 4–1 The user issues the following commands on the server application where RTR is running on the backend. $ RTRCopyright 1994, 2003 Hewlett-Packard Development Company, L.P.RTR> set mode/group%RTR-I-STACOMSRV, starting command server on node NODEA%RTR-I-GRPMODCHG, ...
Page 68 - Example 4–3 Commands and system response at client.
RTR Management Example 4–3 Commands and system response at client. $ RTRRTR> START RTR%RTR-S-RTRSTART, RTR started on node NODEA in group "username" RTR> RTR_OPEN_CHANNEL/CHANNEL=C/CLIENT/fac=DESIGN/partition=des_1%RTR-S-OK, normal successful completion RTR> RTR_RECEIVE_MESSAGE/CHAN...
Page 69 - commands at the server.
RTR Management Example 4–4 The following lines arrive at the client from RTR after the user enters commands at the server. %RTR-S-OK, normal successful completion channel name: C msgsb msgtype: rtr_mt_reply msglen: 25 usrhdl: 0 tid: 63b01d10,0,0,0,0,2e59,43ea2002 message offset bytes text 000000 41 ...
Page 70 - Application Programming Interfaces; JRTR Getting Started; RTR Clients
Application Programming Interfaces Application Programming Interfaces You write application programs and management applications with the RTR application programming interfaces. RTR JavaObject-OrientedInterface You can use Java and J2EE technology to write applications that use RTR. For additional i...
Page 71 - Figure 4–6 RTR Service Provider; // Get a datasource that has been configured by the administrator
Application Programming Interfaces Figure 4–6 RTR Service Provider JNDI VM-1181A-AI Service Provider DataSource Connection Pool JDBC Driver JRTR Server Application A database resource is represented by a datasource object. For the application to locate the datasource representing the database resour...
Page 74 - Example 4–5 Creating a Facility with the C++ API; delete pFacilityManager
Application Programming Interfaces Example 4–5 Creating a Facility with the C++ API // Use the C++ interface to create an RTR facilityRTRFacilityManager::CreateFacilityWithAllRoles_3(){bool bOverallResult = true;//Create facility manager, abort if creation fails RTRFacilityManager * pFacilityManager...
Page 75 - Example 4–6 Starting RTR with the C++ API
Application Programming Interfaces Example 4–6 Starting RTR with the C++ API //Start RTR. RTR rtr;rtr.Start(); Example 4–7 Creating a Facility with the C++ API //Create facility named "myFacility". RTRFacilityManager FacMgr;rtr_status_t sts = FacMgr.CreateFacility("myFacility", "...
Page 77 - The RTR Environment; The RTR System Management Environment; The RTR Environment 5–1
5 The RTR Environment The RTR environment has two parts:• System management environment• Runtime environment The RTR System Management Environment You manage your RTR environment from a management station, which can be on a node running RTR or on some other node. You can manage your RTR environment ...
Page 78 - –2 The RTR Environment
The RTR System Management Environment • Sends messages between nodes• Handles all transactions and recoveryRTRACP handles interprocess communication traf fi c, network traf fi c, and is the main repository of runtime information. ACP processes operate across all RTR roles and execute certain command...
Page 79 - Monitoring RTR; HP Reliable Transaction; The RTR Environment 5–3
The RTR System Management Environment The Command Server Process executes commands both locally and across nodes. Commands that can be executed at the RTR COMSERV include:• START RTR• CREATE/MODIFY JOURNAL• SHOW LINK/FACILITY/SERVER/CLIENT (ACP must be running) • Application programmer commands (for...
Page 80 - Figure 5–1 RTR System Management Environment; transaction state; –4 The RTR Environment
The RTR System Management Environment Figure 5–1 RTR System Management Environment VM-0841A-AI Management StationRunning Browser Software FE RTRACP RTRD RTR COMSERV RTR CLI TR RTRACP RTRD RTR COMSERV BE RTRACP RTRD RTR COMSERV RTR CLI TransactionManagement The RTR transaction is the heart of an RTR ...
Page 81 - The RTR Environment 5–5
The RTR System Management Environment Transaction journal state describes how a transaction progresses from the point of view of the RTR journal. The transaction journal state, not seen by frontends and routers, managed by the backend, is used by RTR for recovery replay of a transaction after a fail...
Page 82 - RTR Runtime Environment; –6 The RTR Environment
The RTR System Management Environment • Overriding the automatic recovery procedures of RTR with manual recovery procedures, for added fl exibility • Specifying retry limits for problem transactionsThe operator can selectively inspect transactions, modify states, or remove transactions from the jour...
Page 83 - Figure 5–2 RTR Runtime Environment; This concludes the material on RTR concepts and capabilities; The RTR Environment 5–7
What’s Next? Figure 5–2 RTR Runtime Environment LIBRTR/RTRDLL LIBRTR/RTRDLL VM-0842A-AI Optional External AppletNot Running RTR FE RTRACP RTRD RTR COMSERV RTR CLI TR RTRACP RTRD RTR COMSERV BE RTRACP RTRD RTR COMSERV RTR CLI Client application Server application LIBRTR/RTRDLL What’s Next? This concl...
Page 85 - Glossary; Glossary–1
Glossary ACID Transaction properties supported by RTR: atomicity, consistency, isolation, durability. For additional information, see the section on Transaction Integrity in Chapter 2. ACP The RTR Application Control Process. API Application programming interface. applet A small application designed...
Page 86 - Glossary–2
bank An establishment for the custody of money, which it pays out on a customer’s request. branch A subdivision of a bank; perhaps in another town. broadcast A nontransactional message. callout server A server process used for transactional authentication. CGI Common Gateway Interface channel A logi...
Page 87 - Glossary–3
commit sequence number (CSN) A sequence number assigned to an RTR commit group, established by the vote window, the time interval during which transaction response is returned from the backend to the router. All transactions in the commit group have the same CSN and lock the database. common classes...
Page 88 - Glossary–4
deadlock Deadly embrace, a situation that occurs when two transactions or parts of transactions con fl ict with each other, which could violate the consistency ACID property when committing them to the database. disk shadowing A process by which identical data are written to multiple disks to increa...
Page 89 - Glossary–5
facility The mapping between nodes and roles used by RTR and established when the facility is created. facility manager A C++ API management class that creates and deletes facilities. facility member A de fi ned entity within a facility. A facility member is a role and node combined. Can be a client...
Page 90 - Glossary–6
JNDI Java Naming and Directory Interface, an API providing such functions to applications written in the Java programming language. Connection pools and datasources are registered with a JNDI service. key range An attribute of a key segment, for example a range A to E or F to K. key segment An attri...
Page 91 - Glossary–7
multichannel An application that uses more than one channel. A server is usually multichannel. multithreaded An application that uses more than one thread of execution in a single process. MS DTC Microsoft DTC; see DTC. network partition A network partition, usually inadvertently, separates a networ...
Page 92 - Glossary–8
polymorphism The ability of objects inherited from a common parent class to respond differently to the same message. The object responds depending on where it is in the inheritance hierarchy. primary The state of the partition servicing the original data store or database. A primary has a secondary ...
Page 93 - Glossary–9
roles Roles are de fi ned for each node in an RTR con fi guration based on the requirements of a speci fi c facility. Roles are frontend, router, or backend. rollback When a transaction has been committed on the primary database but cannot be committed on its shadow, the committed transaction must b...
Page 97 - Index; Index–1
Index A ACID properties, 2–5Anonymous client, 1–25API, 4–1Applet, 1–12Application distributed, 2–5RTR, 1–5software, 2–3 Application logging, 3–2Authentication, 1–23, 3–2 B Backend, 2–1 loss, 3–3recovery, 3–3 BE, 2–1Broadcast, 2–4 C Callout server, 1–22, 1–23, 3–2 Callout server, 1–22Channel, 1–6Chec...
Page 98 - Index–2
I ID transaction, 1–10 J J2EE, 2–11Java, 2–11Journal RTR, 1–16 K Key range, 1–18, 1–23 L LAN, 1–26Link failure recovery, 3–3Load balance, 1–19Lock database, 2–6 Logging application, 3–2 M Messaging nontransactional, 1–10transactional, 1–9 Microsoft SQL Server, 2–11Monitoring RTR, 5–3 N Network wide ...
Page 99 - Index–3
Runtime environment, 5–6 S Security check, 1–23 Server, 1–6 callout, 1–22, 1–23, 3–2concurrent, 1–21, 3–1shadow, 1–15, 3–2spare, 1–18standby, 1–14, 1–18, 3–2standby con fi guration, 1–25 transactional shadow, 1–19types, 3–1 Serviceprovider, Glossary–10Shadow server, 1–15, 1–20, 3–2 Shadowing disk, 1...
