gtpd3m0uLibrary Guide with Master Index and Glossary

R

rapid transport protocol (RTP) connection
A connection between two high-performance routing (HPR) nodes that may traverse one or more intermediate HPR nodes and links. The connection endpoints provide error recovery and adaptive rate-based flow control for the connection traffic, and nondisruptive switching of the underlying physical path if there is a route outage. The intermediate HPR nodes minimize their routing overhead using automatic network routing (ANR) protocols, which rely on header information to permit effective source routing and prioritized transmission along the RTP connection.

rapid transport protocol control block (RTPCB) table
A core-resident table that contains an entry for each rapid transport protocol (RTP) connection in the TPF system. Each entry contains all the relevant information about that RTP connection, such as the transport connection identifiers (TCIDs) and the forward automatic network routing (FANR) field.

ratio dispensing
A technique to dispense addresses from the various pool sections (for a particular pool record type) based on a ratio factor.

ratio factor
Specifies the number of addresses to dispense from a pool section before selecting another pool section from which to dispense addresses.

RBA
Relative byte address.

RC
Record cache.

RCAT
Routing control application table.

RCB
Routing control block.

RCC
Record code check.

RCPL
Routing control parameter list.

RCS
Record cache subsystem.

RCS I/O queue thresholding
The process of monitoring the overall queue depth of a 3990 record cache controller while it is processing in a degraded state. The degraded state is defined as any functional capability being inhibited at either the subsystem or attached device level.

RCS I/O queue threshold value
A number that represents the maximum number of queued I/O requests tolerated by a DASD device attached to a 3990 caching control unit operating in a degraded state.

RCS subsystem ID
A number identifying the physical components of a logical DASD subsystem in a 3990 storage control configuration.

RDLR
Root dynamic load record.

RDW
Record descriptor word.

ReadWrite cursor
A cursor that puts an exclusive lock on a collection for read and write operations.

ready list
A high-priority CPU loop list used to return to an entry already in progress when system activity is completed. It is interrogated after the cross list processing is completed.

real address
An address before prefixing, such as found in the instruction address portion of the channel status word (CSW). If translation is off, the logical address is the real address. See also absolute address, logical address, physical address, and virtual address.

real group ID
The attribute of a process that, at the time of process creation, identifies the group of the user who created the process. This value is subject to change during the process lifetime. (POSIX.1)

real-time tapes
Write-only tapes that may be written to by any entry at any time. They are used to collect TPF system data that may be analyzed by offline maintenance and reporting procedures. By convention, the first 2 characters of the 3-character tape name are RT.

real-time trace (RTT)
(1) A system utility that counts or traces the use of specific macros and related system activity; activated by commands issued from CRAS terminals. (2) The facility that monitors and records system activity when activated through a command. RTT can provide a historical record of input messages, I/O and macro activity, and output messages.

real user ID
The attribute of a process that, at the time of process creation, identifies the user who created the process. This value is subject to change during the process lifetime. (POSIX.1)

receive-only (RO) CRAS
The device that records all TPF system output to the system console.

receiver channel
In message queuing, a channel that responds to a sender channel, takes messages from a communication link, and puts them on a local queue.

reclaim function
The E-type loader function that rebuilds the E-type loader database to recover any E-type loader fixed file records that have been lost.

reconstruction
A process that provides a way to have a damaged persistent collection at least partially restored automatically. The process of reconstruction involves rebuilding a control record of the collection and the chains that the collection anchors.

record cache (RC)
The name given to the TPF system support for the 3880 caching control unit with the record cache RPQ.

record cache subsystem (RCS)
Name given to the TPF system support for the 3990 caching control unit with the record cache RPQ.

record code
A field in record headers that can be used to ensure the correct record was retrieved for processing.

record code check (RCC)
A means of accomplishing an additional data integrity check on subelements of a record by using the 1-record code field in the record header.

record descriptor word (RDW)
The first 4 bytes of a variable block length (format-VB) logical record.

record duplication
In the TPF system, data records (on DASD) can be duplicated, which means that there are 2 copies of a data record on the database. The copies are referred to as the primary record and the backup record (sometimes called the duplicate record or dupe).

record header
The standard header in data records that contains the record ID, record code, control data, program name, and chaining address fields.

record hold
The protocol and facility that secures data records with an exclusive hold. It must be used by all programs when updating file records to ensure the proper sequencing of updates and data integrity.

record ID
Two bytes that identify the function or type of data a given record contains. By convention, it appears in the first 2 bytes of the record header. Also called a RIAT ID.

record ID attribute table (RIAT)
A table used to define the characteristics of fixed and pool file system records in terms of size, longevity, duplication status, device type, exception recording or logging status, user exits, and VFA status. RIAT also defines restore status, RCS caching status, and locking status.

record sharing table (RST)
A system table that links the VFA hash tables to the VFA buffers.

record type
A group of logically related, predefined records residing in the fixed file area.

record type indicator
A hexadecimal value identifying a record type in the fixed file area. Each record type indicator is assigned a symbolic name, the first character of which is #, used by programs when accessing records of that type.

record type name
The symbolic name assigned to a record type.

record type uniqueness group
A group of records that have the same record type name and user uniqueness.

recoup
The utility that determines if pool records are valid or not valid (lost), recovers records that are not valid, and produces a report that indicates the E-type programs that may have lost the pool references.

recoup index
A system collection that describes the location of persistent identifiers (PIDs) and file addresses embedded in all collections associated with that recoup index.

recovery log
A log that holds the data that is necessary to recover resources following a system failure without compromising the integrity of the database. The recovery log is written to DASD.

redirect
Diverting data from a process to a file or device to which it would not normally go.

register
A storage area commonly associated with fast-access storage, capable of storing a specified amount of data such as a bit or an address.

regular expression A mechanism to select specific strings from a set of character strings. (POSIX.2)
A set of characters, metacharacters, and operators that define a string or group of strings in a search pattern. (OSF)
A string containing wildcard characters and operations that define a set of one or more possible strings. (OSF)
A more technical term for pattern.
See also wildcard character.

reinclude function
An E-type loader function that adds 1 or more programs to a specified loadset. Only programs that were previously excluded from the loadset can be reincluded in the loadset.

relative byte address (RBA)
In TPF collection support (TPFCS), the 1-based (the first element in the collection has an index of 1) displacement of a byte from the beginning of a binary large object (BLOB) collection.

relative path name
The name of a directory or file expressed as a sequence of directories followed by a file name, beginning from the current directory. Relative path names do not begin with a slash (/) but are relative to the current directory. A path name that does not begin with a slash. The predecessor of the first file name in the path name is taken to be the current working directory of the process. (POSIX.1) See also absolute path name, path name.

relative record number (RRN)
A number that specifies the location of a record in relation to the beginning of a database file member or subfile. In TPF collection support (TPFCS), it is the number returned by the TO2_getNumberOfRecords C function. A number that describes the order in which a record occurs in the abstract flat file representation of the extended-resident collection data and associated control information.

remote procedure call (RPC)
A process that allows applications on one workstation to call functions that reside on and are run by another workstation.

remote unit of work
A method of accessing distributed relational data in which users or applications can, in a single unit of work, read and update 1 system using multiple structured query language (SQL) statements.

reply-to queue
The name of a queue to which the program that issued an MQPUT call wants a reply message or report message sent.

REQTAIL
A private protocol RU sent by a TPF control point LU (CLU) to the VTAM logon manager to request a different route for starting a session.

Request for Comments (RFC)
In Internet communications, the document series that describes a part of the Internet suite of protocols and related experiments. All Internet standards are documented as RFCs.

residency
A characteristic of TPF collection support (TPFCS) that determines what the layout of the data is in the internal objects that comprise a collection.

resource identifier (RID)
The ordinal number representing an addressable unit in the ACF/SNA network.

resource manager (RM)
The SNA component that provides the services required to establish, manage, and deactivate conversations on an already established LU-LU session. In TPF transaction services, there are two resource managers that work with the transaction manager to identify and harden resources used by the application in a commit scope. TPF DASD and pool support are the resource managers supplied by IBM for TPF transaction services.

resource name hash control table (RNHCT)
A record that contains pointers to the other resource name hash (RNH) tables, the resource vector table (RVT) available list, and the RVT termination list.

resource name hash entry table (RNHET)
A table that contains pointers to the resource vector table (RVT). It also contains pointers that maintain the RNHET synonym chain, RVT available list, and RVT termination list.

resource name hash prime table (RNHPT)
A table that contains entries referred to as RNHPT hash buckets. Each RNHPT hash bucket points to the first entry on its RNHET synonym chain and contains a count of the number of RNHET entries on that RNHET synonym chain.

resource name hash sort table (RNHST)
A table that is used to sort the RNHET entries that are placed on the resource vector table (RVT) termination list.

resource name hash (RNH) tables
Tables used to access the resource vector table (RVT). These tables include the resource name hash control table (RNHCT), resource name hash prime table (RNHPT), resource name hash entry table (RNHET), and resource name hash sort table (RNHST).

resource vector table (RVT)
A directory of all network addressable units in the ACF/SNA portion of the system network.

restart
The facility started to restore the system to operational state after an outage. Restart involves IPL, initialization, and the restart scheduler.

restart scheduler
A program containing a sequence of ENTERs to ECB-controlled system programs that build system tables for resource management and provide services required for system processing.

restore
A program used to regain, update, and restore disk files from the previously captured records on tape.

RES0
The common name for an application called airlines reservations; often used as an application name in the RCAT.

retentive (RET) attribute
A user-specified caching attribute that allows a data record to be written to cache and to the DASD surface. Access to data with this attribute has performance benefits for read operations.

RFC
Request for Comments.

RIAT
Record ID attribute table.

RID
Resource identifier.

RM
Resource manager.

RNHCT
Resource name hash control table.

RNHET
Resource name hash entry table.

RNHET synonym chain
A linked list of the RNHET entries that are assigned to a particular RNHPT hash bucket. One RNHET synonym chain exists for each RNHPT hash bucket.

RNHPT
Resource name hash prime table.

RNHPT hash bucket
An entry in the RNHPT table.

RNHST
Resource name hash sort table.

RNH tables
Resource name hash tables.

RO CRAS
Receive-only CRAS.

rollback
To return to a previous state. In TPF transaction services, the file changes that were made inside a commit scope when a transaction fails are not applied. The database remains consistent with its state before the commit scope was opened.

root directory
The first directory in the file system hierarchy. A slash (/) at the beginning of a path name represents the root directory.

root dynamic load record (RDLR)
The record that is used to keep status of the dynamic load of resources in NORM state.

root scope
In TPF transaction services, the first, or highest-level, commit scope activated by an application.

router
In TCP/IP support, a device that connects networks at the network layer level and routes packets between them. Routers have the ability to select the best transmission paths and optimum packet sizes.

Route Selection control vector (RSCV)
A control vector that describes a route in an Advanced Peer-to-Peer Networking (APPN) network. The RSCV consists of an ordered sequence of control vectors that identify the transmission groups (TGs) and nodes that make up the path from an origin node to a destination node.

routing control application table (RCAT)
The system table that contains the identification information required by the control program to start a particular application for message processing.

routing control block (RCB)
A fixed file terminal control block, associated with a particular terminal, used to pass system and application information.

routing control parameter list (RCPL)
A data area, associated with each input or output message, that identifies the origin, destination, and characteristics of the message.

RPC
Remote procedure call.

RRN
Relative record number.

RSCV
Route Selection control vector.

RST
Record sharing table.

RTA
A symbolic tape name, reserved to TPF systems, denoting the primary real-time tape.

RTC
A symbolic tape name, reserved to TPF systems, denoting the tape produced by the data collection programs and analyzed by the data reduction programs.

RTL
A symbolic tape name, reserved to TPF systems, denoting the real-time tape used for logging system data.

RTP connection
Rapid transport protocol connection.

RTPCB table
Rapid transport protocol control block table.

RTT
Real-time trace.

RU
An SNA request or response unit.

run
To cause a program, utility, or other machine function to be performed.

RVT
Resource vector table.

RVT available list
A linked list that contains the RNHET entries for all of the available (or spare) resource vector table (RVT) entries in the LU section of the RVT.

RVT termination list
A linked list that contains the RNHET entries for all of the dynamic LU resources that no longer have sessions established.