WIXLIB

Arcati Mainframe Yearbook 2022GlossaryBatchAn accumulation of data brought together for processingor transmission, usually unattended. Less formally,the processing of such data, as opposed to onlineprocessing where a user is present to respondinteractively.BCDBinary-Coded Decimal. A binary-coded notation inwhich each of the decimal digits is represented bya binary numeral. This differs from the pure binarynotation, where the entire number is represented as asingle binary numeral.BCSThe Basic Catalog Structure and the VVDS are the twoparts of the ICF catalog. The BCS contains dataset andalias names and volume serial numbers.BCUA Balanced Configuration Unit comprises processormemory, I/O, storage, and DB2 resources. It is thesmallest combination of these that work togetherefficiently. As more work is added to the system,so more BCUs can be added. This avoids any onecomponent being too big in terms of the others.BDAMBasic Direct Access Method allows programmers toaccess specific blocks of data on DASD.BenchmarkAn agreed workload used as a standard against whichto compare the performance of different hardware/software. For a benchmark to be useful it needs to bea public standard.Big DataThe SNA/APPN command used to activate an LU-LUsession following the successful completion of the SNA/APPN session initiation processing.Big SQLThis allows users to access Hadoop-based datausing familiar SQL statements. It utilizes InfoSphereBigInsights.Bimodal ITGartner’s management of IT model where one strandis very conservative and unwilling to change and theother strand embraces rapid application developmentand is tightly linked to business needs.124BINDThe SNA/APPN command used to activate an LU-LUsession following the successful completion of the SNA/APPN session initiation processing.BIOSBasic Input/Output System. The I/O component of asimple operating system defining the interface betweenthe operating system and the outside world.BitcoinsBitcoins originated in a 2008 concept paper by SatoshiNakamoto. Bitcoins are a virtual currency that are‘mined’ by solving complex algorithms and are usuallystored in a digital wallet. Bitcoin exchanges arecompletely private, which makes them popular withcriminals! Many legitimate companies offer productsfor sale using bitcoins.BLOBBinary Large OBject. A generic term for a file containingsome kind of binary data (text, image, document,sound, etc). Typically, BLOBs can be transferred andmanipulated across a wide range of platforms.BlockA string of data elements, such as characters, words,or physical records, that are recorded or transmittedas a unit.BlockchainA blockchain is a distributed database that maintainsa continuously growing list of ordered records.Blockchains are secure by design and an example ofa distributed computing system. Once recorded, thedata in a block cannot be altered retroactively.BluemixBluemix is an open-standards, cloud-based platform forbuilding, managing, and running all types of apps, forWeb, mobile, big data, and smart devices. It includesJava, mobile back-end development, and applicationmonitoring, all provided as-a-service in the cloud.BMSBasic Mapping Support. An interface between CICSand an application to control the movement andpresentation of datastreams to and from a dumbterminal. BMS allows data to be displayed withoutallowing for display-dependent formatting characters. Arcati Ltd, 2022

Arcati Mainframe Yearbook 2022GlossaryBooleanAn operation that follows the rules of Boolean algebra.BootTo prepare a computer system for operation by loadingan operating system.BPAMBasic Partitioned Access Method is a low-level accessmethod used to access Partitioned DataSets (PDSs).BreachThis is where a cyberattack has gained access toa network and the mainframe, giving unauthorisedaccess to data and backups to hackers.BSAMBasic Sequential Access Method, along with QSAM, isan access method used to access sequential datasets.BusGeneric term in data communications to describe awiring topology (such as that used in Ethernet) in whichdevices are connected along a single linear medium.BYODBring your own device is the policy many companiesare adopting to allow employees to bring their ownmobile devices (laptops, tablets, and smartphones) totheir workplace, and to use those devices to accessprivileged company information and applications.BYOIBring Your Own Identity is the growing practice of takinga validated identity with you and so not needing toremember different user-ids and passwords for differentenvironments. There are security issues.ByteA string of 8 bits that represents one EBCDIC character.The IBM mainframe architecture is organized aroundthe concept of the byte.CA programming language developed at Bell Labs in1972, so named because its predecessor was namedB. Unix was written in C. Arcati Limited, 2022C/C An optional, separately priced feature of z/OS, availablewith or without Debug Tool. The C/C IBM Open ClassLibrary is included with z/OS, but is only enabled whenC/C is licensed.CacheHigh-speed buffer between a fast device and a slowdevice. In large IBM systems cacheing may takeplace in the CPU (in main or expanded storage), thecontroller, device head-of-string, or the device itself(eg in a track buffer). It is used to reduce access time.Capacity on DemandProcessors can be purchased with extra capacityalready on-board but not functioning. When extracapacity is required at a site, it is turned on. This isnon-disruptive and customers don’t pay for the extracapacity until they start using it.CatalogA dataset that contains information about otherdatasets, eg type, location, size, format. The z/OSmaster catalog usually also contains entries for usercatalogs.CCLCommunication Controller for Linux (CCL) on zSeriesruns the Network Control Program (NCP) softwareproduct in Linux, enabling users to get rid of their legacy3745 communication controllers running NCP-basedSNA workloads to zSeries servers.CDSConfiguration DataSet.CGICommon Gateway Interface. A mechanism usedby HTTP servers to invoke arbitrary programs foradditional processing of certain requests; typically,those involving database access.Change managementThe methodology for planning and controlling softwarechanges.125

Arcati Mainframe Yearbook 2022GlossaryChannelA specialized computer used in the IBM mainframearchitecture to control transfers between devices andthe processor unit. The channel offloads some of theprocessing associated with I/O from the main CPU.Channel adapterHardware unit to attach a channel to a processor.Channel attachedDevices that are directly attached to the processor bycable rather than over a communications link.ChannelsCICS TS 3.1 introduced a replacement for sizerestricted COMMAREAs – they are channels andcontainers. Any number of containers can be passedbetween programs and they are grouped together inchannels.CLISTControl language used to manage interactiveapplications in the z/OS TSO environment. Largelysuperseded by REXX.Cloud computingA new name for something similar to client/servercomputing. A user launches a browser and clicks a link.Somewhere else an application launches and work isdone. The mainframe seems to have always workedin this way. Organizations like Microsoft, Amazon, andGoogle are trying to become big players in this ‘new’paradigm.Cloud PaksIBM Cloud Paks are AI-powered software that comewith pre-integrated data, automation, and securitycapabilities. They help create hybrid cloud platforms.CHPIDCHannel Path IDentifier. A single byte binary value usedto uniquely identify each channel path on an eServerzSeries and previous mainframe systems.CMOSComplementary Metal Oxide Semiconductor. A chiptechnology used widely by IBM in its processors,superseding the water-cooled ECL chips on themainframe.CICSCustomer Information Control System. Generalpurpose TP monitor for terminal-oriented and intersystem transaction processing in z/OS and VSE/ESAenvironments. Now with added SOA.CMSConversational (originally Cambridge – the lab whereit was built) Monitor System. Operating system runningunder VM, and providing timesharing and programdevelopment facilities.CICS ExplorerThis is a system management tool for CICS systemsthat’s based on the Eclipse platform.COBOLProgramming language, very widely used forcommercial applications on the mainframe. Somesources suggest that CICS and COBOL account for85% of all transactions processed.CICSplexA CICS complex (CICSplex) is a group of intercommunicating CICS systems.CICSPlex System Manager (CPSM)This provides system management as well asautomation and workload management.CKDCount Key Data is a way to format disk drive usingcylinder number, track number, and physical record.Client/serverGeneric term for systems (also known as server/requester) in which one machine provides a range ofservices to one or more other machines.126Communication ServerIBM’s all inclusive, multi-platform, software bundle thatprovides a plethora of terminal emulation, Web-to-host,and networking capabilities.CompileThe translation of a high-level programming language(source program) into a machine language program(an executable program).CompilerA program that translates high-level programminglanguages into machine language programs. Arcati Ltd, 2022

Arcati Mainframe Yearbook 2022GlossaryComposite applicationsA composite application is an application built bycombining multiple services. This tends to meantaking part of a really useful mainframe applicationand combining it with some other code so that themainframe application becomes available over the WebCPCCentral Processor Complex.CompressionGeneric term for a method of reducing the amount ofspace needed to store data, by encoding the data. Thisis achieved through the elimination of empty fields,gaps, redundancies, and unnecessary data to shortenthe length of records or blocks.CRMCustomer Relationship Management refers to theway organizations manage their relationships withcustomers – including finding, marketing to, selling to,and servicing these customers.ConnectorOne way of integrating CICS applications as Webservices is to use connectors on the mainframe anduse native interfaces to permit tight integration with thetarget application.ContainersCICS TS 3.1 introduced a replacement for sizerestricted COMMAREAs – they are channels andcontainers. Any number of containers can be passedbetween programs and they are grouped together inchannels. Channels are deleted when no programsare using them.Control PointSNA/APPN/HPR functionality that performsauthorization, directory services and configurationmanagement.CORBACommon Object Request Broker Architecture. Set ofstandards for distributed object management from theObject Management Group (OMG).CouplingGeneric term used to mean connecting of processorstogether into a more or less tightly-knit computingcomplex. Used specifically by IBM to mean theconnection of multiple eServer zSeries processors ina Sysplex.Coupling FacilityHardware from IBM, where common tables can beshared in a Sysplex, for high-speed cacheing, updatelocking of shared data, list processing and workloadbalancing between multiple processors. Arcati Limited, 2022CPUCentral Processing Unit. Processor. The part of acomputer that executes instructions.CTGCICS Transaction Gateway provides J2EE standardsbased access to CICS applications, which means it’san easy way to make existing CICS applications partof a Service-Oriented Architecture (SOA).CTCChannel-To-Channel connections would link twomainframes and provide high-speed communication.CyberattackBad actors trying to and often successfully gainingaccess to a network and the mainframe, then exfiltratingoften confidential data.CyberSecurity Mesh Architecture (CSMA)An integrated approach to securing IT assetsregardless of their location. It redefines the perimetersof cybersecurity to the identity of a person or a thing.Gartner predicts that this will reduce the financialimplications of cyber incidents by 90% in less thantwo years.CylinderThe tracks, in an assembly of magnetic disks, thatcan be accessed without repositioning the accessmechanism.DASDDirect Access Storage Device. IBMspeak for disk.DATDynamic Address Translation. The process by whichvirtual addresses are converted into real addressesduring instruction execution.127

Arcati Mainframe Yearbook 2022GlossaryData dictionaryA data dictionary (DD) is a database containinginformation about the way items of data are used.Typically a DD contains details of data names, datausage, data structures, data models, and so on.Db2ZAIIBM Db2 AI for z/OS empowers the optimizer in theDb2 for z/OS engine to determine the best-performingquery access paths, based on a site’s workloadcharacteristics.Data lakeA data lake is a repository of data stored in its naturalformat. This could be in a Hadoop-based repository.DebugThe human problem determination process forsoftware. Literally, to remove bugs.Data miningThe practice of using a data warehouse for highlycomplex, ad hoc queries.DEDBData Entry DataBases are one of two types of IMS fastpath database. These databases do not have indexesand are stored in VSAM files.Data Privacy PassportsThese were introduced with the z15 mainframe. Theyenable users to protect and provision data, and revokeaccess to that data at any time. They not only work inthe z15 environment, but also across an enterprise’shybrid multi-cloud environment.Data sewerWhat happens to a data lake as more and more recordsare added.Data warehouseGeneral term for a collection of database, middleware,and query tools that allow fast, flexible access to nearoperational corporate data.DataOpsThis is an automated, process-oriented methodology,that’s used to improve the quality and reduce the cycletime of data analytics.DataPowerIBM WebSphere DataPower SOA Appliances is a familyof pre-built, pre-configured rack mountable networkdevices that accelerate Web services deploymentswhile extending SOA infrastructure.DatasetA unit of data storage and retrieval consisting of oneor more data records. Outside of the IBM mainframeenvironment, people call them files.DB2Database/2. Relational database management systemfirst announced for mainframe environments in 1983.Originally promoted as an end-user tool, but is nowIBM’s preferred DBMS for just about everything andruns on all platforms.128DefragmentationThe use of a software utility to improve accessand retrieval time by rewriting fragmented data tocontiguous sectors of a computer storage medium.Denial of ServiceAn insidious, carefully-orchestrated attack on computersystems or networks to overload their resources with abarrage of requests in the hope of discovering overloadinduced vulnerabilities within the targets or to justdisrupt the mission-critical activities of an enterprise.DeOSNo longer is DDoS (Distributed Denial of Service)our only worry, we need to think about Destruction OfService attacks.DeviceAny computer peripheral, such as tape or DASD, orany object that appears to be a peripheral.DevOpsPart DEVelopment and part OPerations, DevOpsis a philosophy emphasizing the collaboration andcommunication between software developers andother IT people, so that building, testing, and releasingsoftware, can happen rapidly, frequently, and morereliably.DevSecOpsDevSecOps is DevOps with security considerationintroduced earlier in the life cycle of applicationdevelopment in an attempt to minimize vulnerabilities. Arcati Ltd, 2022

Arcati Mainframe Yearbook 2022GlossaryDFSMSData Facility Storage Management Subsystem. Anelement of z/OS and also available for z/VM, asDFSMS/VM. The idea is that you simply tell the systemabout your storage, back-up, performance, and otherrequirements of the data, and the system does the restfor you. Of course, it’s not really that simple.DFSMSdfpDFSMS Data Facility Product. A component of DFSMSthat provides functions for storage, data, program, anddevice management, in conjunction with distributeddata access. Enables the definition of the servicesto be assigned to new datasets. Handles catalogmanagement and access methods.DFSMSdssDFSMS DataSet Services. An optional, separatelypriced feature of DFSMS that handles device migration,copy, space management, and dump/restore. Italso converts existing data between non-SMS andSMS volumes, and provides an interface for storageadministrators (ISMF).Disruptive technologyHenry Ford said: “If I had asked people what theywanted, they would have said faster horses”. That’s anexample of a disruptive technology – something thatchanges the way people do things.DL/IData Language/I. The I is the Roman numeral One. Thedata manipulation language within IMS DB. DL/I is alsothe product name for IBM’s VSE/ESA implementationof IMS DB.DLSwWidely-used SNA/APPN(/NetBIOS)-over-TCP/IPtransport mechanism which, however, unlike EE, doesnot support SNA COS or routing.DMZA De-Militarized Zone is used in the on-going waragainst viruses and malware etc. Typically, onecomputer accepts incoming data and send outgoingdata. Behind it is a firewall, and behind that is theprotected LAN.DFSMShsmDFSMS Hierarchical Storage Manager. An optional,separately priced feature of DFSMS. It is a sophisticatedautomated system for both back-up and hierarchicalstorage management. It includes an ISPF interfacefor end users who wish to migrate, recall, back-up, orrecover individual datasets, or to override the defaultmigration and/or back-up parameters.DockerDocker is a software container platform. Everything youneed to make the software work is packaged into thiscontainer. It includes libraries and settings to run on anyplatform. This way, you get an efficient, lightweight, selfcontained system, plus the assurance that the softwarewill always run the same, no matter where it’s deployed.IBM has Docker Enterprise Edition for IBM Cloud.DFSMSrmmDFSMS Removable Media Manager. Its goal was tointegrate the system managed storage principles ofDFSMS into all removable media, most notably tapeand optical.DominoWeb server technology from Lotus (June 1996), whichallows browsers to interact with Notes and access Notesdatabases. Now closely integrated with WebSphere.Digital reinventionSuccessful digital reinvention follows a fundamentalrethink or reimagining of how an organization operatesand how it engages with its environment and customers.Digital Transformation (DX)Another way of describing the inevitable change intechnology that occurs in businesses that plan to stayin business. Arcati Limited, 2022DRaaSDisaster Recovery as a Service is the replication andhosting of physical or virtual servers by a third-party toprovide failover in the event of a catastrophe.EBCDICExtended Binary Coded Decimal Interchange Code.Coded 8-bit character set (giving 256 characters) usedby IBM mainframes.129

Arcati Mainframe Yearbook 2022Glossarye-businessUsed to refer to business transactions that use theInternet.ECIThe External Call Interface is used by CICS to allownon-CICS programs to invoke programs under CICS.EclipseEclipse is an Open Source IDE. IBM’s version is soldas WebSphere Studio Workbench. The Eclipse platformcomprises the platform run-time, the workspace, theworkbench, the Standard Widget Toolkit (SWT), theVersion and Configuration Management (VCM), andthe help system. Eclipse comes with a large numberof plug-ins. The user interface for Eclipse is known asthe workbench.Edge computingPutting some computing power at the furthest reachesof the network to control IoT devices, for exampleEEHPR-over-UDP/IP, created by committee and codifiedin RFC 2353 in 1998, which permits SNA/APPNnetworking, replete with native COS and routing, acrossIP networks.EJBEnterprise JavaBeans. A server-side, transactionoriented extension to the JavaBeans component modelspecification published by Sun. EJB are JavaBeans, buthave no user interface and are designed to run within aspecial EJB container. In principle, any properly codedEJB should run within any fully compliant EJB container.EnqueueThe z/OS expression (often abbreviated to ENQ) forrequesting resource serialization. ENQ can be used toput a user-named entry in the system resource queuein order to prevent another program using a seriallyusable resource.Enterprise Content Management (ECM)This refers to a way of organizing and storing anorganization’s documents, and other content, thatrelate to the organization’s processes. Nowadays,ECM can be used when talking about strategies,methods, and tools used throughout the life-cycle ofthe content. ECM also covers the capture, search,and networking of documents with digital archiving,document management, and workflow.130Enterprise ExtenderEnterprise Extender (EE) is a combination of SNAencapsulated in IP packets, so it can be thought of asa kind of protocol.EPIA CICS External Presentation Interface

Glossary of Terminology Definitions of some mainframe-related terms This glossary is intended as an aide memoire for experienced mainframers and a useful reference for those new to the z/OS world. If you would like to suggest any new entries for the next edition, please send them to mainframe@arcati.com (we will even list you as a contributor .