“race condition” to “runtime system”

race condition

(n.) Competition by two or more processes for the same resource (counter variables, files, buffers) without a defined synchronization mechanism. Unlike “deadlock,” which causes processes to hang, race conditions result in data corruption because of the unpredictable order in which processes change and access the shared data.

rack-mounted

(adj.) Characteristic of components that are installed in a cabinet with a standard panel width of 19 inches or 23 inches. Components can be bolted to the rack or put on shelves. The height of a rack-mounted component is measured in rack units (RUs). An example is 1.75 inches. See also cabinet-mounted.

radio button

(n.) A button that the user clicks to set an option. Unlike checkboxes, radio buttons are mutually exclusive—selecting one radio button deselects all other radio buttons in the group. In the Java^TM look and feel, radio buttons are created by using the JRadioButton component.

radio button menu item

(n.) A menu item that is displayed with a radio button next to it. Separators indicate which radio button menu items are in a group. Selecting one radio button menu item deselects all others in that group. In the Java^TM look and feel, radio button menu items are created by using the JRadioButtonMenuItem component.

radio group

(n.) A box that contains a set of radio buttons that might have a distinct label. At most, one of the radio buttons can be activated at a time. Also called radio button group.

RAID

See redundant array of independent disks.

RAID-0 volume

(n.) A class of volume that can be a stripe or a concatenation. These components are also called submirrors. A strip or concatenation is the basic building block for a mirror. See also redundant array of independent disks. Compare to RAID-1 volume.

RAID-1 volume

(n.) A class of volume that replicates data by maintaining multiple copies. A RAID-1 volume is sometimes called a mirror. A RAID-1 volume is composed of one or more RAID-0 volumes that are called submirrors. See also redundant array of independent disks.

RAS

(n.) reliability, availability, serviceability.

raster file

(n.) A bitmap file or a file that contains a gray-scale or color image.

raster ops

(ROP) (n.) The logical operations (typically called ANDs, ORs, and NORs) that are performed on portions of the bit planes—called bitmaps or pixmaps—in the frame buffer. These operations perform fundamental movements and transfers of pixel data. See also bit BLT.

read-ahead

(adj.) Characteristic of the capability of the UNIX® system to read and interpret your input while sending output information to the terminal in response to previous input. The UNIX system separates input from output and processes each correctly.

redirection

(1) (n.) The channeling of output to a file or device instead of to the standard output.

(2) (n.) The channeling of input from a file or device instead of from the standard input.

redirect output

(n.) The result of sending to a file what the system would normally display on the screen as the result of a command. Basic output redirection requires the use of the > or >> symbols. Also called redirection.

redundant array of independent disks

(RAID) ( n.) A subsystem for expanding disk storage. Used in the SPARCstorage^TM Array Subsystem for Disk Expansion.

regular expression

(n.) A pattern that represents a class of character strings. For example, grep interprets the regular expression h.t as any three-character string that begins with “h” and ends with “t.”

reinstallation

(n.) An installation, automatically initiated by Change Manager, that overwrites the system's disks with the new version of the Solaris operating environment. You can perform a reinstallation if the system is already running the Solaris operating environment that contains the Change Manager agent. The reinstallation operation requires only one boot environment.

relative path name

(n.) A series of directory names that are separated by the slash (/) character, which locates a file or directory that is relative to the working directory. See also absolute path name, simple path name.

relay host

(n.) A system that transmits to and receives mail from outside the network or domain by using the same communications protocol. See also local host, mail host.

remark

(n.) See comment.

remote

(adj.) Characteristic of a system or other device in another location (room or building) that can be accessed through a network.

remote control file

(n.) See C shell remote control file.

remote procedure call

(RPC) (n.) The process of executing an apparently normal procedure call (or method invocation) by sending network packets to a remote host.

Remote Shared Memory

(RSM) (n.) A mechanism for user-level messaging between nodes based on direct access to memory that is resident on remote nodes, using a memory-based hardware connection.

Remote Shared Memory API

(RSMAPI) (n.) An application programming interface for the development of applications that use the Remote Shared Memory capability of interconnect devices such as Sun Fire^TM Link and SCI-PCI D320.

remote shell

(n.) A command interpreter that you initiate on one machine, but that executes on another machine which is specified on the command line.

replaceable unit

(n.) A subassembly that trained, qualified service personnel can replace at the customer site.

resize handle

(n.) A control that is used to change the size of a window or a pane in a window.

resize pointer

(n.) The mouse pointer that is displayed when an object, such as a window, is being resized.

resource

(1) (n.) A mechanism of the X Window system for specifying an attribute (appearance or behavior) of a window or application. Resources are usually named after the elements that they control.

(2) (n.) In resource management, an aspect of the computing system that can be manipulated with the intent to change application behavior.

(3) (n.) resource An instance of a resource type. Many resources of the same type might exist. Each resource has its own name and set of property values. Consequently, many instances of the underlying application might run on the cluster. Resources are managed by the RGM in resource groups.

resource bundle

(n.) The place where an application stores its locale-specific data (isolated from source code).

resource control

(n.) In resource management, a per-process resource limit that is extended to the task and project entities.

resource group

(n.) A collection of resources that are managed by the RGM as a unit. Each resource that is to be managed by the RGM must be configured in a resource group. Typically, related and interdependent resources are grouped.

resource-group state

(n.) The state of a resource group on any given node.

resource management

(n.) A functionality that enables you to control how applications use available system resources.

Resource Management API

(RMAPI) (n.) The application programming interface within a Sun^TM Cluster system that makes an application highly available in a cluster environment.

resource monitor

(n.) An optional part of a resource type implementation that runs periodic fault probes on resources to determine if they are running correctly and how they are performing.

resource pool

(n.) A collection of resources. When bound to a resource pool, any of the resources from which the pool is composed are available to the resource consumers.

resource state

(n.) The state of a resource on a particular node.

resource status

(n.) The condition of the resources as reported by the fault monitor.

resource type

(n.) A defined set of properties that identify the characteristics and behavior of a cluster object to be managed by the Resource Group Manager (RGM). Resource types are predefined for objects such as data services, logical hostnames, and shared addresses. A generic resource type is also available, and additional resource types may be defined. Data service resource types are defined to be either failover type or scalable type. This definition of the resource type determines how RGM will handle the resources. A resource type is identified by its name. See also data service, failover resource, scalable resource.

resource type property

(n.) A key-value pair, stored by the RGM as part of the resource type, that is used to describe and manage resources of the particular type.

RFI

(n.) radio frequency interference.

right to use

(RTU) (n.) The Sun^TM software licensing, usually included in the price of the software.

rolling upgrade

(n.) In a Sun^TM Cluster configuration, an upgrade that is performed sequentially on one cluster node at a time. During a rolling upgrade, the cluster remains in production and services continue to run on the other nodes.

root

(n.) In a hierarchy of items, the one item from which all other items are descended. The root item has nothing above it in the hierarchy. See also class, package, root directory, root file system, root user name.

root directory

(n.) The base directory from which all other directories stem, directly or indirectly.

root disk

(n.) On Sun^TM server systems, the disk drive where the operating system resides. The root disk is located in the SCSI tray behind the front panel.

root file system

(n.) A file system that resides on the root device, a device which is predefined by the system at initialization. The root file system anchors the overall file system.

root user name

(n.) The SunOS^TM user name that grants special privileges to the person who logs in with that ID. The user who can supply the correct password for the root user name is given superuser privileges for the particular machine.

ROP

See raster ops.

Routing Information Protocol

(RIP) (n.) An Interior Gateway Protocol in Berkeley UNIX®.

RPC

See remote procedure call.

RTU

See right to use.

RU

(n.) rack unit.

run code

(n.) A way of indicating the number of identical tokens that appear contiguously within a data stream. For example, the SunVideo^TM capture- and-compression single SBus card uses 32-bit run codes to indicate that some number of consecutive cells within a frame have a constant intensity.

run level

(n.) The system initialization state. In the SunOS^TM 4.0 (minimum) system, the run levels are PROM monitor, single user, and multiuser. In the SunOS 5.0 (minimum) system, the run levels are shutdown, single user, normal multiuser without NFS^TM file systems exported, normal multiuser with NFS file systems exported, alternative multiuser (not used), software reboot, reboot, and single-user state with all file systems mounted. See also init states.

runnable process

(n.) A program that is ready to run, that is, it is not waiting for resources to become available (for example, data from disk or a user).

runtime library

(n.) A file of written routines that do specific tasks, eliminating the need for redundant programming.

runtime system

(n.) The software environment in which programs that are compiled for the Java^TM virtual machine (JVM) can run. The runtime system includes all the code that is necessary to load programs which are written in the Java programming language. The runtime system also includes code that dynamically links native methods, manages memory, handles exceptions, and presents an implementation of the Java virtual machine, which might be a Java interpreter.