list of letters
This site contains terms and definitions from many IBM software and hardware products as well as general computing terms.
See high availability.
See High Availability Control Workstation.
See high availability disaster recovery.
HADR log spooling
The ability for the log replay process on the HADR standby database to read transaction logs from disk and the log receive buffer, instead of from only the log receive buffer. This ability prevents transactions on the primary database from being blocked when replay on the standby database is relatively slow during a primary database load spike.
See hardware abstraction layer.
See high availability large database.
See HALDB online reorganization.
To round off a number by adjusting the last significant digit. When the number to the right of the last significant digit is 5 or greater, add 1 to the digit. For example, 2.475 half-adjusted to two decimal places becomes 2.48, but 2.474 becomes 2.47.
half-duplex (HD, HDX)
Describing a communications connection over which only one device at a time can transmit data. See also duplex.
- A session-layer component consisting of the combination of data flow control and transmission control components comprising one end of a session. See also primary end of a session, secondary end of a session, session connector.
- In SNA, one of the locations in a logical connection in a network.
A storage location whose address is evenly divisible by 2. See also word boundary.
- In WebSphere MQ, the identifier or token by which a program accesses an MQM object.
- A variable that represents an internal structure within a software system.
- In DB2 ODBC, a variable that refers to a data structure and associated resources.
- In the Java EE specification, an object that identifies an enterprise bean. A client may serialize the handle, and then later deserialize it to obtain a reference to the enterprise bean. (Sun)
- In application programming interfaces, a variable that represents an object, an instance of an application using some function, or a processing session.
- The portion of a message that contains control information.
- A character string that is created by an extender that is used to represent an image, an audio, or a video object in a table. A handle is stored for an object in a user table and in administrative support tables. In this way, an extender can link the handle that is stored in a user table with information about the object that is stored in the administrative support tables.
- In the AIX operating system, a data structure that is a temporary local identifier for an object. Allocating a handle creates it. Binding a handle makes it identify an object at a specific location.
- A character string that represents an object, and is used to retrieve the object.
- A pointer used by the condition manager as it traverses the stack. The handle cursor points to the condition handler currently being invoked in the stack frame, whether it is a user-written condition handler or a condition handler specific to a high level language.
- A pointer that keeps track of the current exception handler.
A condition that either a user-written condition handler or the high-level language-specific condition handler has processed and for which the condition handler has specified that execution should continue. See also unhandled condition.
- A function that is registered by the application programmer to be called by the system or by the application when certain events occur in the system or application.
- In the CICS Front End Programming Interface (FEPI), a transaction initiated to handle specified events.
- In web services, a mechanism for processing service content and extending the function of a JAX-RPC runtime system.
- An optional way of controlling the data source and adapters. The handler is responsible for handling requests that come from its associated graphic component that affect back-end data. See also equipment component, network component.
- A software routine that controls a program's reaction to specific external events, such as an interrupt handler.
- The exchange of predetermined signals when a connection is established between two data set devices.
- In Transport Layer Security (TLS), the initial setup of a TLS connection.
- The exchange of messages at the start of a Secure Sockets Layer session that allows the client to authenticate the server using public key techniques (and, optionally, for the server to authenticate the client) and then allows the client and server to cooperate in creating symmetric keys for encryption, decryption, and detection of tampering.
The Korean alphabet that consists of fourteen consonants and ten vowels. See also Jamo.
Term used in Taiwan for Chinese characters. See also Traditional Chinese.
A set of rules that is defined for an HA group that dictate whether zero (0), or more members are activated. The policy is associated with a specific HA group by matching the policy match criteria with the group name.
hard CPU shares
An attribute that defines the relative share of CPU resources on a host or LPAR that the WLM dispatcher allows a particular service class to use but not exceed, even if additional CPU resources are available.
See hard error.
- A named connection between an object and its parent directory. An object may have multiple named connections between itself and one or more parent directories.
- In a file system, an actual path to an existing object. A hard link is established by creating a directory entry. A hard link cannot cross file systems.
hard page segment
A page segment that is declared in the Map Page Segment structured field and loaded in the printer before printing begins. This resource can be reused during the job without being reloaded in the printer. Hard page segments can be controlled by a page segment list in a page definition. See also soft page segment.
A firm request for items from a storeroom that is defined by the need for the items within a specific time frame. A hard reservation reduces the available balance of items. Hard reservations are prioritized and cannot be superseded by other reservation types. See also soft reservation.
A resource declared in the appropriate Map structured field and loaded in the printer the first time it is referenced. It can be reused during the job without being reloaded to the printer. See also soft resource.
See required space.
The physical components of a computer system. See also software.
hardware abstraction layer (HAL)
In operating systems such as Windows NT, a layer in which assembly language code is isolated. A hardware abstraction layer functions similarly to an application programming interface (API) and is used by programmers to write device-independent applications.
A set of parameters used to configure hardware before an operating system installation. It includes RAID settings, BIOS update information, BIOS settings, and custom hardware configuration parameters.
- A system that controls managed systems, including the management of logical partitions and use of Capacity Upgrade on Demand. Using service applications, the HMC communicates with managed systems to detect and consolidate information, which is then sent to IBM for analysis. See also Capacity Upgrade on Demand, free pool, managed system.
- An integrated platform management interface through which data center personnel configure, control, and monitor System z hardware and software resources and manage System z hardware resources. The HMC communicates with each central processor complex (CPC) through the Support Element (SE). See also alternate Hardware Management Console, primary Hardware Management Console.
Hardware Management Console Application (HWMCA)
A user-customized, object-oriented graphical user interface (GUI) that provides a single point of control for the system's hardware elements. The HWMCA provides aggregated and individual real-time system status using colors; consolidated hardware messages support; consolidated services support; and hardware commands targeted at a single system, multiple systems, or a group of systems.
A monitor that collects and displays events and statistical data both for hardware and for software applications to identify failing resources in a network. For problem determination, it also provides probable cause information and recommended actions. See also session monitor.
hardware service manager (HSM)
A tool for displaying and working with system hardware from both a logical and a packaging viewpoint, for debugging input/output processors (IOPs) and devices, and for fixing failing and missing hardware.
A grouping of physical ports on a switch in a fabric. It can be implemented in the following configurations: one to one, one to many, and many to many. See also fabric.
The process of establishing the use of a single term for a concept. During harmonizaiton, terms that represent concepts and that are used across products or domains are examined and a single common term for the concept is established.
has components relationship
The type of relationship that indicates dedicated containment, such as a parent-child relationship among components in which the child components cannot be shared with other components. See also federates relationship, fixes relationship.
- In computer security, a number generated from a string of text that is used to ensure that transmitted messages arrived intact.
- A cryptographic irreversible data value, generated by the hashing algorithm, that is used to compare two values without the values being disclosed. See also hashing algorithm.
- An alphanumeric string that is generated from another value in order to aid in the searching and comparing of values within the entity database.
hashed message authentication code (HMAC)
A mechanism for message authentication using cryptographic hash functions. See also HOTP.
- A method of transforming a search key into an address for the purpose of storing and retrieving items of data.
- A method by which a large number of memory records are stored and can then be efficiently searched. This is accomplished through the use of a tailored index that organizes the memory records. This arrangement of records is called a hash table.
- The process of encoding a character string as a fixed-length bit string for comparison. The encoding may not necessarily be unique.
The algorithm used by the anonymizer to anonymize a hash value into a cryptographic irreversible data value. The algorithm is configured in the Configuration Console and stored in the anonymizer.dat configuration file. See also anonymizer, hash.
hash overflow index
A DB2 index used to track data rows that do not fit into the fixed hash space, and therefore, reside in the hash overflow space. DB2 accesses the hash overflow index to fetch rows from the hash overflow area.
- A table of information that is accessed by way of a shortened search key (the hash value). The use of a hash table minimizes average search time.
- The arrangement of memory records.
- A data structure that divides all elements into (preferably) equal-sized categories, or buckets, to allow quick access to the elements. The hash function determines which bucket an element belongs in.
In mobile computing, a protocol that groups tweets with other tweets about the same topic. For example, prefacing a tweet with "#Bills" groups a tweet in the Buffalo Bills subject group. See also social network.
A number that is generated from a string of text. The hash value (or simply hash), is substantially smaller than the text itself and is generated by a formula in such a way that is extremely unlikely that some other text will produce the same hash value. Hashes are used in security systems to ensure that transmitted messages have not been tampered with and also are used to access data records.
See high availability solution.
See Houston Automatic Spooling Program.
See Host Access Transformation Services.
An application that presents a Web-enabled version of a host application to users. A HATS application is created in HATS Studio from a HATS project and deployed to WebSphere Application Server and/or interacts with other host applications or e-business applications to present combined information to an end user.
HATS EJB project
A project that contains enterprise beans made from Integration Objects that other applications can call to get host data. A HATS EJB project does not present transformed screens from a host application.
HATS/WebFacing enabled project
A project that can be linked with a HATS project for the purpose of creating combined applications with full access to both WebFacing and HATS customization capabilities. See also linked HATS/WebFacing project.
See host bus adapter.
See heuristic commit.
See host channel adapter.
See hardware configuration definition.
See Host Command Facility.
See 3270 Host Connection Program.
See host command processor.
See host command processor emulation.
See hardcopy task.
See hierarchical direct access method.
See high-density bipolar of order 3.
See hard disk drive.
See High-level Data Link Control.
See Handheld Device Markup Language.
See hierarchic direct organization.
See host-discovered resource.
See Host Ethernet Adapter.
- System-defined control information that precedes user data.
- In disk management, the 8-byte portion of the 520-byte disk sector used by the operating system for control and access information.
- See include statement.
- See message header.
- Text that is formatted to be in the top margin of printed pages in a document. See also footer.
- The portion of a message that contains control information.
See include file.
- A record that contains information, such as customer name and customer address, that is common to detail records. See also detail record.
- In RPG, output records that are printed at the top of a report and include report titles, column headings, or any other data needed to identify the information in the report.
- A record at the beginning of a file that details the sizes, locations, and other information that follows in the file.
Pertains to a program or application that can run without a graphical user interface or, in some cases, without any user interface at all. Headless operation is often used for network servers or embedded systems.
An autonomic manager that constantly monitors defined health policies. When a specified health policy condition does not exist in the environment, the health controller verifies that configured actions correct the error.
A measure of some aspect of the health of an object. Threshold-based health indicators identify whether the behavior of an object is within ranges of normal, warning, and alarm. State-based health indicators identify whether the state of an object is normal or non-normal. See also health monitor alert.
health information technology (HIT)
A technology, which includes a variety of integrated data sources, that is capable of capturing, analyzing, storing, and appropriately sharing information about an individual patient and patient populations.
An instance-level monitor that creates alerts based on a health indicator exceeding a threshold or being in non-normal state. The monitor sends notifications to the notification log and also sends emails and pages to contacts on its notification list.
health monitor alert
An alert that is generated by the health monitor and is based on the type of health indicator. See also health indicator.
- A logical grouping of memory that fulfills the needs of a particular component. For example, the utility heap memory is used by DB2 utilities such as backup, restore, and load.
- An object that provides dynamic storage for a procedure. The object is part of the activation group and is deleted when the activation group is deleted.
- A collection of dynamically allocated variables.
- An area of storage that is allocated with a lifetime unrelated to the execution of the current routine. The heap consists of the initial heap segment and zero or more increments.
- In Java programming, a block of memory that the Java virtual machine (JVM) uses at run time to store Java objects. Java heap memory is managed by a garbage collector, which automatically de-allocates Java objects that are no longer in use.
An area of contiguous storage that is allocated upon request from the user application. Heap elements are always allocated within a single heap segment. See also heap segment.
A storage pool used by the storage manager to improve the performance of heap storage allocation. The use of heap pools can improve the performance of an application, especially multi-threaded applications.
A contiguous area of storage obtained directly from the operating system. The Language Environment storage management scheme subdivides heap segments into individual heap elements. If the initial heap segment becomes full, Language Environment obtains a second segment, or increment, from the operating system. See also heap element.
An area of storage used for allocation of storage that has a lifetime that is not related to the execution of the current routine. The heap consists of the initial heap segment and zero or more increments.
A signal that one entity sends to another to convey that it is still active. See also call home, heartbeat call-home record, Remote Technical Assistance and Information Network.
heartbeat call-home record
Machine operating and service information sent to a service machine. These records might include such information as feature code information and the logical-configuration information for a product. See also heartbeat.
A pulse that is passed from a sending message channel agent (MCA) to a receiving MCA when there are no messages to send. The pulse unblocks the receiving MCA, which would otherwise remain in a wait state until a message arrived or the disconnect interval expired.
The state of a connection that results in the connection being maintained after the next commit operation. This is the initial state of connections. See also released state.
See DCN Local-Network Protocol.
A protocol governing a group of database servers, of which at least one is a gateway participant. A heterogeneous commit ensures the all-or-nothing basis of distributed transactions in a heterogeneous environment.
Heterogeneous Workload Management
A core capability of the IBM Autonomic Computing Initiative that addresses the need to definitively determine the cause of a bottleneck in a complex system, including response time measurement and transaction processing.
The inconsistency in data between one or more participants that results when a heuristic decision to resolve an indoubt LUW at one or more participants differs from the decision that is recorded at the coordinator.
- A decision to force a commit or rollback of a logical unit of work in part of a transaction program network that is using the two-phase commit protocol. A heuristic decision is made when a system or communication failure prevents the logical unit of work from being completed.
- A decision made by a user to commit or roll back a transaction on a DB2 database.
- A decision that forces indoubt resolution at a participant by means other than automatic resynchronization between coordinator and participant.
In REXX, any sequence of zero or more hexadecimal digits (0-9, a-f, or A-F), optionally separated by blanks, delimited by apostrophes or quotation marks, and immediately followed by the symbol x or X.
See hierarchical file system.
HFS data set
See hierarchical file system data set.
See System/370 Host Interface Adapter.
See hierarchical indexed direct access method.
An address that is mapped to another address. The method of mapping that is used does not allow external systems to initiate communications with hidden addresses unless port numbers are specified.
hidden data node
A child of a collapsed parent node, not represented by a row in a Gantt or schedule chart. See also displayed data node.
A fully functional widget that transforms business data so that another widget can use this data. A hidden widget is not displayed on a page, unless all widgets are displayed. When a hidden widget is made visible, the widget has a dashed frame.
In AFP Utilities, a function on the screen view used to display elements hidden by other elements that were specified after the hidden elements and in the same or approximate position as the hidden elements.
Pertaining to data that is organized on computer systems using a hierarchy of containers, often called folders (directories) and files. In this scheme, folders can contain other folders and files. The successive containment of folders within folders creates the levels of organization, which is the hierarchy.
hierarchical direct access method (HDAM)
A database access method using algorithmic addressability to records in a hierarchic direct organization. A choice of OSAM or VSAM ESDS is available as a base for HDAM.
- A system for organizing files in a hierarchy, as in a UNIX system.
- A part of the i5/OS operating system that includes the application programming interfaces and the underlying file system support. HFS enables an application written in a high-level language to create, store, retrieve, and manipulate data on a storage device. The view of the data to the user is a hierarchical directory structure similar to DOS.
hierarchical file system data set (HFS data set)
A data set that contains a particular type of file system that is compliant with the Portable Operating System Interface (POSIX). An HFS data set is a collection of files and directories organized in a hierarchical structure that can be accessed using z/OS UNIX System Services (z/OS UNIX).
hierarchical indexed direct access method (HIDAM)
A database access method used for indexed access to records in a hierarchic direct organization. It provides indexed access to the root segments and pointer access to subordinate segments.
hierarchical sequential access method (HSAM)
An IMS HS organization that is used for sequential storage and access of segments on tape or direct access storage. BSAM and QSAM are used as the basis for HSAM.
hierarchical storage management (HSM)
A function that automatically distributes and manages data on disk, tape, or both by regarding devices of these types and potentially others as levels in a storage hierarchy that range from fast, expensive devices to slower, cheaper, and possibly removable devices. The objectives are to minimize access time to data and maximize available media capacity. See also hierarchical storage management client, recall, storage hierarchy.
hierarchical storage management client (HSM client)
A client program that works with the server to provide hierarchical storage management (HSM) for a system. See also hierarchical storage management, management class.
hierarchic direct organization (HD organization)
The physical storage organization in which database segments that represent a physical database record are related by direct address pointers in the segment's prefix.
- In COBOL, a set of entries that includes all subordinate entries to the next equal- or higher-level number.
- A type of container that is a hierarchical collection and classification of data. Hierarchies are made up of categories and items. Types of hierarchies include category hierarchies and organization hierarchies. See also category, container.
- In publish/subscribe messaging topology, a local queue manager connected to a parent queue manager.
- The tree-like arrangement of segments in a database, beginning with the root segment and proceeding down to dependent segments.
- The organization of a set of entities into a tree structure, with each entity (except the root) having one or more parent entities and an arbitrary number of child entities.
- A defined relationship among a set of attributes that are grouped by levels in the dimension of a cube model.
- A structure that has a predetermined ordering from high to low.
- A particular view of a business dimension. A hierarchy contains the definition of related reference data that is organized into a tree structure of members related as parents and children.
- The ability of IT services to withstand all outages and continue providing processing capability according to some predefined service level. Covered outages include both planned events, such as maintenance and backups, and unplanned events, such as software failures, hardware failures, power failures, and disasters. See also fault tolerance, high availability solution.
- Pertaining to a clustered system that is reconfigured when node or daemon failures occur so that workloads can be redistributed to the remaining nodes in the cluster. See also application tier.
high-availability data replication
A synchronous method of data replication that is used to maintain a backup copy of the entire database server that applications can access quickly in the event of a catastrophic failure.
high availability disaster recovery (HADR)
A disaster recovery solution that uses log shipping and provides data to a standby system if a partial or complete site failure occurs on a primary system. See also asynchronous mode, log shipping, Q replication, standard database, standby database, super asynchronous mode.
high availability solution (HA solution)
A combination of hardware, software, and services that fully automates the recovery process and does not disrupt user activity. HA solutions must provide an immediate recovery point with a fast recovery time. See also high availability.
high-density bipolar of order 3 (HDB3)
An E1 line coding method in which each block of four successive zeros is replaced by 000V or B00V, so that the number of B pulses between consecutive V pulses is odd. Therefore, successive V pulses are of alternate polarity so that no dc component is introduced. Note: B represents an inserted pulse conforming to the alternate mark inversion rule and V represents an AMI violation. HDB3 is similar to B8ZS used with T1.
The conceptual level of control or processing logic existing in the hierarchical structure of a station that is above the link layer and upon which the performance of data link functions are dependent (for example: device control, buffer allocation, station management).
See higher layer.
high-level language application programming interface (HLLAPI)
A programming interface that usually operates in conjunction with an emulator, such as 3270 emulation, and allows interaction using 3270 data stream between a host and a remote application program.
high-performance file system (HPFS)
In PC operating systems, an installable file system that uses high-speed buffer storage, known as a cache, to provide fast access to large disk volumes. The file system also supports the coexistence of multiple, active file systems on a single personal computer, with the capability of multiple and different storage devices.
high-performance optical file system (HPOFS)
An IBM-developed media-format architecture that is available when initializing optical media. This media format is required for Write Once Read Many (WORM) media, and it is the default media format when initializing erasable optical media.
high private area
Part of the CICS address space, consisting of the local system queue area (LSQA), the scheduler work area (SWA), and subpools 229 and 230. The area at the high end of the CICS address space is not specifically used by CICS, but contains information and control blocks that are needed by the operating system to support the region and its requirements. See also local system queue area.
high-speed link (HSL)
A hardware connectivity architecture that links system processors to system I/O buses and other systems. See also remote input/output.
high-speed link loop
The system-to-expansion-unit connectivity technology that is required to implement switchable independent disk pools residing on an expansion unit. The servers and expansion units in a cluster that uses resilient devices on an external expansion unit must be on an HSL loop that is connected with HSL cables.
high-speed link ring (HSL ring)
A logical ring of HSL connections originating from the HSL controller of a processor unit, sequentially connecting I/O or other processor units and ending back at the HSL controller where the ring originated.
high watermark setup (HWS)
A method to allocate a minimum number of unique device types that fulfill the requirements for each job step. Devices used in one step can be released and used again in later steps.
Any of the set of numerals used in many Arabic countries instead of, or in addition to, the Arabic numerals. Hindi numeral shapes are ?????????, which correspond to the Arabic numeral shapes of 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9, respectively. See also Arabic numeral, Chinese numeral, number, Roman numeral.
An extension to both the queued sequential access method (QSAM) and the Virtual Storage Access Method (VSAM) designed to improve performance. Hiperbatch uses the Data Lookaside Facility to provide an alternate fast-path method of making data available to many batch jobs.
A System z hardware feature that provides high performance internal communications between logical partitions (LPARs) within the same central processor complex (CPC) without the use of any additional or external hardware equipment such as a channel adapter.
A high-performance, virtual-storage space of up to 2 gigabytes (GB). Unlike an address space, a hiperspace contains only user data and does not contain system control blocks or common areas; code does not execute in a hiperspace. Unlike a data space, data in a hiperspace cannot be referenced directly; data must be moved to an address space in blocks of 4 KB before being processed.
hiperspace memory file
A type of file that is stored in a single buffer in an address space, with the rest of the data being kept in a hiperspace. In contrast, for regular files, all the file data is stored in a single address space.
See High-Performance Parallel Interface.
One of the two common Japanese phonetic alphabets (the other is katakana). The symbols are cursive or curvilinear in style. Hiragana syllables are typically used in the representation of native Japanese words and grammatical particles. See also Kanji, Katakana.
- In Performance Tools, a bar graph used in the performance advisor to display the variations over time of one type of data in a performance data collection.
- In the GDDM function, a chart in which each value of the dependent variable corresponds to a range of values of the independent variable (represented by the width of the associated bar). For example, such a chart might display the number of people in various age ranges.
A technique for summarizing data distribution that divides the range of possible values in a data set into intervals, such that each interval contains approximately the same percentage of the values. A set of statistics are collected for each interval.
A set of files that contain information about Infoprint Server print jobs that are no longer on the JES spool. These print jobs finished processing or were deleted from the JES spool. Infoprint Central can display information about print jobs in the historical inventory.
A row in a history table. See also history table.
- Metadata in a versioned object base (VOB) that consists of event records for objects in that VOB.
- The recorded changes to modules and objects, which can be viewed on module and object properties sheets.
- A summary of the system activities, such as system and job information, device status, system operator messages, and a record of program temporary fix (PTF) activity on the system. The history log is identified by the name QHST, and the system-recognized identifier for the object type is *MSGQ.
- A file that keeps a record of activities for a workflow.
A table that is used by the database manager to store historical versions of rows from the associated system-period temporal table. See also historical row, system-period temporal table.
See health information technology.
An object that associates an index to every pixel. Pixels with the same index behave the same way in interactions. This approach enables pure client-side interaction capabilities in JViews Web applications without requiring roundtripping to the servers. Highlighting and tooltips are typical interactions that can be performed using hitmap technology.
The collection of all region information for a hitmap. See also region.
See hierarchical loop.
See high-level language.
See high-level language pointer.
See high-level qualifier.
See home location register.
See Hardware Management Console.
- A method of stopping the normal disposition of a record, usually because of court cases or investigations.
- A function that protects a cell against breakback.
A special type of cursor which is not closed at the end of a transaction. The database server still closes all other cursors, and it still releases all locks, but the hold cursor remains open until it is explicitly closed.
The default non-working days calendar for all job streams. A holidays calendar must be created and named "holidays", otherwise the default non-working days are considered to be all Saturdays and Sundays. See also calendar, non-working days calendar.
A field at the beginning of a track that contains information that identifies the physical track and its association with a cylinder. See also track.
- The area of storage that z/OS currently recognizes as dispatched.
- The address space in which MVS initially dispatches a work unit. When MVS initially dispatches a work unit, the home address space, the primary address space, and the secondary address space are the same. During execution of the work unit, the home address space remains the same, but the primary and secondary address spaces can change.
See local cell.
In enterprise beans, an interface that defines zero or more create and remove methods for a session bean or zero or more create, finder, and remove methods for an entity bean. See also remote interface.
- In DFSMSrmm, the location to which DFSMSrmm normally returns a volume when the volume is no longer retained by vital records processing.
- In Backup, Recovery, and Media Services, the storage location where available media is stored awaiting reuse. Typically, this is the on-site tape inventory.
- The node from which an application developer compiles and runs a program. The home node can be any workstation on the LAN.
- The highest priority node for a resource group. The home node is the first node that is listed in the default node list for any nonconcurrent resource group.
- The initial web page that is returned by a website when a user specifies the URL for the website. Essentially, the home page is the entry point for accessing the contents of the website.
- The top-level web page of a portal.
- The position (farthest left) to which the print head moves after the printer is turned on and the Stop or Reset button is pressed.
- The first item in a list or the first line of help information.
- In System i Access, the first position of the first input field on the display.
In CDE, a choice at logout to designate a particular session, other than the one you are currently in, as the one you will automatically return to at the next login. See also current session.
A four-dimensional method of representing three-dimensional space. A point (x, y, z, w) in homogeneous coordinates is used to represent a point (X, Y, Z) in three-dimensional space by taking X=x/w, Y=y/w, and Z=z/w.
Hong Kong S.A.R. of China
See Hong Kong S.A.R. of the PRC.
- A location in a compiled program where the compiler has inserted an instruction that allows programmers to interrupt the program (by setting breakpoints) for debugging purposes.
- An empty script in which code can be entered.
A unique number assigned to a specific trace point. All trace entries include the hook identifier of the originating trace point in the trace entry header. A hook ID is a 12-bit value. For user programs, the hook ID may be a value from 0x010 to 0x0FF. Hook identifiers are defined in the /usr/include/sys/trchkid.h file.
- The number of host-to-host connections in a route.
- In a gateway, an indication that the next string represents the hop count to the destination host or network.
A packet of data transferred from one system to another that describes context about some earlier processing. Transaction tracking has two types of hop data: origin data and previous hop data.
Pertaining to data that is tracked between applications in a domain. See also vertical.
- A workstation required by extended agents. It can be any Tivoli Workload Scheduler workstation except another extended agent.
- In performance profiling, a machine that owns processes that are being profiled. See also server.
- The controlling or highest-level system in a data communications configuration.
- In a cooperative processing environment, the system running the server program with which the CoOperative Development Environment/400 session communicates.
- A computer that is connected to a network and that provides an access point to that network. The host can be a client, a server, or both a client and server simultaneously. See also client, server.
- In TCP/IP, any system that has at least one IP address associated with it.
See IP address.
In CoOperative Development Environment/400, a command processed on a host system. It can be sent from the host emulation window or from the AD/Cycle CoOperative Development Environment session.
Host Command Facility (HCF)
A feature available on a System/370, 43xx, or 30xx host system that enables a user on the host system to use applications on a System i system or other systems as if they were using remotely attached 5250-type display stations.
host command processor emulation (HCP emulation)
A function of the Point-of-Sale Utility licensed program that allows the System i system to appear to the host command processor (HCP) in a point-of-sale system as if the System i system were the System/370 host system.
Host Ethernet Adapter (HEA)
A physical Ethernet adapter that is integrated directly into the GX+ bus on a managed system. HEAs offer high throughput, low latency, and virtualization support for Ethernet connections.
- The unique identification of a host within an address family on a network, but without the network identification. A host ID is not necessarily sufficient to establish communications with a host.
- In TCP/IP, that part of the Internet address that defines the host on the network. The length of the host ID depends on the type of network class (A, B, or C).
- A numeric identifier assigned to a group of host Fibre Channel ports for the purpose of logical unit number (LUN) mapping. For each host ID, there is a separate mapping of Small Computer System Interface (SCSI) IDs to volumes.
A root managed resource that provides manageability interfaces to the multiple indirect managed resources that are associated with it. For example, a messaging server, along with the queue managers and queues that are its indirect managed resources, is a hosting domain. See also direct managed resource, indirect managed resource.
A type of managed resource that acts as a container for a set of hosted managed resources throughout their lifetime. See also change manager, installable unit, smallest installable unit.
Either the primary or a secondary partition that is not a guest partition. The hosting partition has the real I/O devices that the virtual I/O device drivers in a guest partition connect to. The hosting partition also supplies the guest partition's DST console session, via a TELNET connection into the hosting partition. The guest partition's console is not part of the hosting partition's console. The host partition's console, the guest partition's console session and the guest partition's operating system's console are all different console sessions.
A set of buttons or links representing functions typically available from a host keyboard, such as function keys or the Enter key. See also application keypad.
See host name mapping file.
host-mixed encoding scheme
An encoding scheme that contains a mixture of single-byte EBCDIC code pages and double-byte host code pages. A 5026 encoding scheme, for example, is CP290 (single byte) and CP300 (double byte).
See host name.
- In Internet communication, the name given to a computer. The host name might be a fully qualified domain name such as mycomputer.city.company.com, or it might be a specific subname such as mycomputer. See also fully qualified domain name, IP address, network address.
- The network name for a network adapter on a physical machine in which the node is installed.
- A node that provides an application programming interface (API) and a common application interface.
- In SNA, a subarea node that contains a system services control point (SSCP), for example, an IBM System/390 computer with MVS and VTAM.
A logical object that represents a list of worldwide port names (WWPNs) and a list of iSCSI names that identify the interfaces that the host system uses to communicate with a device. iSCSI names can be either iSCSI qualified names (IQNs) or extended-unique identifiers (EUIs).
host print transform (HPT)
An i5/OS print function that converts an SNA character string (SCS) data stream into an ASCII data stream. The conversion enables consistent ASCII printing through hardware connections.
- A processor that controls a user application network.
- The primary or controlling computer in a multiple computer installation.
- An enterprise mainframe computer system that hosts 3270 applications. In the 3270 terminal service development tools, the developer uses the 3270 terminal service recorder to connect to the host system.
- See host.
- A computer, either mainframe (S/390 or zSeries) or open-system, that is connected to the ESS. S/390 or zSeries hosts are connected to the ESS through ESCON or FICON interfaces. Open-systems hosts are connected to the ESS by the Small Computer System Interface (SCSI) or the Fibre Channel interface.
host transit time
The average time (in seconds) that all transactions spend in the host. The time includes both VTAM and application time. It is also reported as an average for the transactions that originate at the logical unit for which data collection is occurring.
- A program data area that provides value to or receives value from a column in an SQL table.
- In an application program, a programming variable that is referred to by embedded SQL statements. The value of the host variable comes from the host program when a statement is executed or a cursor is opened. A host variable is a colon followed by a name (:name). See also parameter marker.
- In an application program, a variable that is referred to by embedded SQL statements. Host variables are programming variables in the application program and are the primary mechanism for transmitting data between tables in the database and application program work areas.
A volume that represents the volume functional role from an application point of view. The host volume can be connected to a host or server. It receives read, write, and update application I/O, depending on the site to which the application is writing.
- In a remote journal network, pertaining to the function of replicating an application's dependent data from one primary System i product to a backup System i product. If the primary system fails, processing can be performed on the backup system.
- For programs that are running or resident on a backup systems, a configuration in which a copy of the program is installed for backup purposes, started, and actively doing work such as applying journaled database transactions. See also cold backup, warm backup.
The process of adding new components to a running server without stopping and restarting the application server or application. See also dynamic reloading.
See monitored directory.
- A keystroke or a combination of keystrokes pressed simultaneously that activate or toggle a specific mode. For example on a bidirectional keyboard (such as an Arabic or a Hebrew one), pressing the keyboard combination Alt+Right Shift will change the keyboard group to the national (Arabic or Hebrew) one.
- A key sequence used to shift operations between different applications or between different functions of an application.
- To jump from a host session to an application on a workstation, or from the workstation to the host session.
- A graphical device that is used in topologies to highlight the part of an end-to-end transaction that has crossed specified thresholds and has a significant transaction time deviation.
- A memory location or synchronization resource for which multiple processors compete excessively. This competition can cause a disproportionately large performance degradation when one processor blocks the resource, preventing other processors from accessing it and forcing them to become idle.
- Text or a picture in a rich-text field that a user can click to perform an action, run a formula or script, or follow a link.
- An area of the display that, when clicked on, calls a macroinstruction.
hourly average data
An average of all response times detected by a policy over a one-hour period. See also instance data.
hover drill button
A button that facilitates the ability to drill down on members. Hover drill buttons can be permanently visible, or visible only when hovering with the mouse pointer over a member. It is also possible not to show hover drill buttons.
See high-performance file system.
See high-performance option.
See high-performance optical file system.
See High-Performance Routing.
See Rapid Transport Protocol connection.
See Rapid Transport Protocol connection.
See host print transform.
See high-performance transmission subsystem.
See human readable interpretation.
See hardware system area.
See hierarchical sequential access method.
See high-speed link.
See high-speed link ring.
See hierarchical storage management client.
See HSM complex.
See hierarchic sequential organization.
See high-speed sequential processing.
See Hypertext Markup Language.
See Harmonized Tariff Schedule.
See Hypertext Transfer Protocol.
A type of channel within a transport chain that provides client applications with persistent HTTP connections to remote hosts that are either blocked by firewalls or require an HTTP proxy server. An HTTP channel is used to exchange application data in the body of an HTTP request and an HTTP response that are sent to and received from a remote server.
See HTTP daemon.
See HyperText Transfer Protocol-Next Generation.
- A request sent to the site either during the Explore or Test stage of the scan.
- A transaction that a web browser initiates and that adheres to HTTP.
HTTP Server for i5/OS
A licensed program that enables a computer that uses the Hypertext Transfer Protocol (HTTP) to serve objects by responding to requests from other programs, such as browsers. The IBM HTTP Server for i5/OS, which supports the Secure Sockets Layer (SSL) protocol, provides secure communications between a server and an SSL-capable browser.
- A half-duplex device that sums all of its input and then broadcasts that sum on all output to the connected adapters. A hub has a large collision domain and shared media. See also shipment, site.
- A point, or piece of hardware, that connects multiple devices in a network.
- An intermediate site between source sites and destination sites.
- A customer-facing store that enables partners or clients.
See Hardware Management Console Application.
See high watermark setup.
hybrid analysis engine
An aggregate analysis engine where more than one of its component analysis engines are deployed in the same address space and one or more are deployed remotely. See also analysis engine.
Program statements that have not been internationalized with respect to code page, especially where data constants contain variant characters. Such statements can be found in applications written in older implementations of MVS, which required syntax statements to be written using code page IBM-1047 exclusively. Such applications cannot be converted from one code page to another using iconv().
A link that has multiple sources and multiple sinks. A hyperedge connects multiple nodes and is used in applications such as electrical signal diagrams, multiflow visualization, network management, and UML diagrams. See also hypergraph.
A graph that contains a finite set of nodes connected by a finite set of hyperedges. See also hyperedge.
- A direct connection between the data in one CICSPlex SM view and a view containing related information. For example, from a view that lists multiple CICS resources, there may be a hyperlink to a detailed view for one of the resources. To use a hyperlink, place the cursor in the data portion of a hyperlink field and press Enter.
- An element in an electronic document, such as a web page that links to another area in that document or a different document. See also permalink.
An IBM software technology that can substitute Peer-to-Peer Remote Copy (PPRC) secondary devices for PPRC primary devices and that is managed exclusively through Geographically Dispersed Parallel Sysplex (GDPS). HyperSwap is designed to swap a large number of devices quickly so that there is minimal impact to application availability.
- A connection between one piece of online information and another.
- The connection between one hypertext node and another.
Hypertext Markup Language (HTML)
A markup language that conforms to the Standard Generalized Markup Language (SGML) standard and was designed primarily to support the online display of textual and graphical information, including hypertext links.