Thrashing (computer science)In computer science, thrashing occurs in a system with virtual memory when a computer's real storage resources are overcommitted, leading to a constant state of paging and page faults, slowing most application-level processing. This causes the performance of the computer to degrade or collapse. The situation can continue indefinitely until either the user closes some running applications or the active processes free up additional virtual memory resources.
Wear levelingWear leveling (also written as wear levelling) is a technique for prolonging the service life of some kinds of erasable computer storage media, such as flash memory, which is used in solid-state drives (SSDs) and USB flash drives, and phase-change memory. There are several wear leveling mechanisms that provide varying levels of longevity enhancement in such memory systems. The term preemptive wear leveling (PWL) has been used by Western Digital to describe their preservation technique used on hard disk drives (HDDs) designed for storing audio and video data.
Instructions per cycleIn computer architecture, instructions per cycle (IPC), commonly called instructions per clock is one aspect of a processor's performance: the average number of instructions executed for each clock cycle. It is the multiplicative inverse of cycles per instruction. While early generations of CPUs carried out all the steps to execute an instruction sequentially, modern CPUs can do many things in parallel.
Database scalabilityDatabase scalability is the ability of a database to handle changing demands by adding/removing resources. Databases use a host of techniques to cope. The initial history of database scalability was to provide service on ever smaller computers. The first database management systems such as IMS ran on mainframe computers. The second generation, including Ingres, Informix, Sybase, RDB and Oracle emerged on minicomputers. The third generation, including dBase and Oracle (again), ran on personal computers.
NetWareNetWare is a discontinued computer network operating system developed by Novell, Inc. It initially used cooperative multitasking to run various services on a personal computer, using the IPX network protocol. The original NetWare product in 1983 supported clients running both CP/M and MS-DOS, ran over a proprietary star network topology and was based on a Novell-built file server using the Motorola 68000 processor.
Erlang (programming language)Erlang (ˈɜrlæŋ ) is a general-purpose, concurrent, functional high-level programming language, and a garbage-collected runtime system. The term Erlang is used interchangeably with Erlang/OTP, or Open Telecom Platform (OTP), which consists of the Erlang runtime system, several ready-to-use components (OTP) mainly written in Erlang, and a set of design principles for Erlang programs. The Erlang runtime system is designed for systems with these traits: Distributed Fault-tolerant Soft real-time Highly available, non-stop applications Hot swapping, where code can be changed without stopping a system.
Hardware-based full disk encryptionHardware-based full disk encryption (FDE) is available from many hard disk drive (HDD/SSD) vendors, including: ClevX, Hitachi, Integral Memory, iStorage Limited, Micron, Seagate Technology, Samsung, Toshiba, Viasat UK, Western Digital. The symmetric encryption key is maintained independently from the computer's CPU, thus allowing the complete data store to be encrypted and removing computer memory as a potential attack vector. Hardware-FDE has two major components: the hardware encryptor and the data store.
Windows Vista I/O technologiesWindows Vista introduced a number of new I/O functions to the Microsoft Windows line of operating systems. They are intended to shorten the time taken to boot the system, improve the responsiveness of the system, and improve the reliability of data storage. Vista modifies the behavior of asynchronous I/O operations. With the new asynchronous I/O APIs, a thread, different from the one that issued the I/O request, can be notified when the operation completes.
SpinlockIn software engineering, a spinlock is a lock that causes a thread trying to acquire it to simply wait in a loop ("spin") while repeatedly checking whether the lock is available. Since the thread remains active but is not performing a useful task, the use of such a lock is a kind of busy waiting. Once acquired, spinlocks will usually be held until they are explicitly released, although in some implementations they may be automatically released if the thread being waited on (the one that holds the lock) blocks or "goes to sleep".
