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ProbeVue
ProbeVue is IBM's implementation of a lightweight dynamic tracing environment introduced in AIX version 6.1. ProbeVue provides the ability to probe running processes in order to provide statistical analysis as well as retrieve data from the probed process. The dynamic nature of ProbeVue allows it to be used as a global system performance tool while retaining the ability to drill into very specific events on a single process or thread. Because modifications are not required of a probed process or system and the lightweight design of ProbeVue as a tracing tool, it is suitable for use in a production environment where previous tracing tools would have been performance prohibitive. Description ProbeVue provides a series of probe point specifications that are potential events that can be probed. A script written in the Vue language allows the user to define a probe that is a block of code called an action block that will run when those events occur on the system. The execution of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM AIX
AIX (pronounced ) is a series of Proprietary software, proprietary Unix operating systems developed and sold by IBM since 1986. The name stands for "Advanced Interactive eXecutive". Current versions are designed to work with Power ISA based Server (computing), server and workstation computers such as IBM's IBM Power Systems, Power line. Background Originally released for the IBM RT PC Reduced instruction set computer, RISC workstation in 1986, AIX has supported a wide range of hardware platforms, including the IBM IBM RS/6000, RS/6000 series and later IBM Power microprocessors, Power and PowerPC-based systems, IBM System i, System/370 mainframes, IBM PS/2, PS/2 personal computers, and the Apple Network Server. Currently, it is supported on IBM Power Systems alongside IBM i and Linux. AIX is based on UNIX System V with 4.3BSD-compatible extensions. It is certified to the UNIX 03 and UNIX V7 specifications of the Single UNIX Specification, beginning with AIX versions 5.3 an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SystemTap
In computing, SystemTap () is a scripting language and tool for dynamically instrumenting running production Linux-based operating systems. System administrators can use SystemTap to extract, filter and summarize data in order to enable diagnosis of complex performance or functional problems. SystemTap consists of free and open-source software and includes contributions from Red Hat, IBM, Intel, Hitachi, Oracle, the University of Wisconsin-Madison and other community members. History SystemTap debuted in 2005 in Red Hat Enterprise Linux 4 Update 2 as a technology preview. After four years in development, SystemTap 1.0 was released in 2009. , SystemTap runs fully supported in all Linux distributions including RHEL / CentOS 5 since update 2, SLES 10, Fedora, Debian and Ubuntu. Tracepoints in the CPython VM and JVM were added in SystemTap 1.2 in 2009. In November 2019, SystemTap 4.2 included prometheus exporter. Usage SystemTap files are written in the SystemTap language (sav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DTrace
DTrace is a comprehensive dynamic tracing framework originally created by Sun Microsystems for troubleshooting kernel and application problems on production systems in real time. Originally developed for Solaris, it has since been released under the free Common Development and Distribution License (CDDL) in OpenSolaris and its descendant illumos, and has been ported to several other Unix-like systems. Windows Server systems froWindow Server 2025will have DTrace as part of the system. DTrace can be used to get a global overview of a running system, such as the amount of memory, CPU time, filesystem and network resources used by the active processes. It can also provide much more fine-grained information, such as a log of the arguments with which a specific function is being called, or a list of the processes accessing a specific file. In 2010, Oracle Corporation acquired Sun Microsystems and announced the discontinuation of OpenSolaris. As a community effort of some core S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tracing (software)
Tracing in software engineering refers to the process of capturing and recording information about the execution of a software program. This information is typically used by programmers for debugging purposes, and additionally, depending on the type and detail of information contained in a trace log, by experienced system administrators or technical-support personnel and by software monitoring tools to diagnose common problems with software. Tracing is a cross-cutting concern. There is not always a clear distinction between ''tracing'' and other forms of ''logging'', except that the term ''tracing'' is almost never applied to logging that is a functional requirement of a program (therefore excluding logging of data from an external source, such as data acquisition in a high-energy physics experiment, and write-ahead logging). Logs that record program usage (such as a server log) or operating-system events primarily of interest to a system administrator (see for example '' E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Associative Array
In computer science, an associative array, key-value store, map, symbol table, or dictionary is an abstract data type that stores a collection of (key, value) pairs, such that each possible key appears at most once in the collection. In mathematical terms, an associative array is a function with ''finite'' domain. It supports 'lookup', 'remove', and 'insert' operations. The dictionary problem is the classic problem of designing efficient data structures that implement associative arrays. The two major solutions to the dictionary problem are hash tables and search trees..Dietzfelbinger, M., Karlin, A., Mehlhorn, K., Meyer auf der Heide, F., Rohnert, H., and Tarjan, R. E. 1994"Dynamic Perfect Hashing: Upper and Lower Bounds". SIAM J. Comput. 23, 4 (Aug. 1994), 738-761. http://portal.acm.org/citation.cfm?id=182370 It is sometimes also possible to solve the problem using directly addressed arrays, binary search trees, or other more specialized structures. Many programmin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aggregate Function
In database management, an aggregate function or aggregation function is a function where multiple values are processed together to form a single summary statistic. Common aggregate functions include: * Average (i.e., arithmetic mean) * Count * Maximum * Median * Minimum * Mode * Range * Sum Others include: * Nanmean (mean ignoring NaN values, also known as "nil" or "null") * Stddev Formally, an aggregate function takes as input a set, a multiset (bag), or a list from some input domain and outputs an element of an output domain . The input and output domains may be the same, such as for SUM, or may be different, such as for COUNT. Aggregate functions occur commonly in numerous programming languages, in spreadsheets, and in relational algebra. The listagg function, as defined in the SQL:2016 standard aggregates data from multiple rows into a single concatenated string. In the entity relationship diagram, aggregation is represented as seen in Figure 1 with a rectang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solaris (operating System)
Oracle Solaris is a proprietary software, proprietary Unix operating system offered by Oracle Corporation, Oracle for SPARC and x86-64 based workstations and server (computing), servers. Originally developed by Sun Microsystems as Solaris, it superseded the company's earlier SunOS in 1993 and became known for its scalability, especially on SPARC systems, and for originating many innovative features such as DTrace, ZFS and Time Slider. After the Acquisition of Sun Microsystems by Oracle Corporation, Sun acquisition by Oracle in 2010, it was renamed Oracle Solaris. Solaris was registered as compliant with the Single UNIX Specification until April 29, 2019. Historically, Solaris was developed as proprietary software. In June 2005, Sun Microsystems released most of the codebase under the CDDL license, and founded the OpenSolaris Open-source software, open-source project. Sun aimed to build a developer and user community with OpenSolaris; after the Oracle acquisition in 2010, the Open ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shebang (Unix)
In computing, a shebang is the character sequence , consisting of the characters number sign (also known as sharp or hash) and exclamation mark (also known as bang), at the beginning of a script. It is also called sharp-exclamation, sha-bang, hashbang, pound-bang, or hash-pling. When a text file with a shebang is used as if it were an executable in a Unix-like operating system, the program loader mechanism parses the rest of the file's initial line as an interpreter directive. The loader executes the specified interpreter program, passing to it as an argument the path that was initially used when attempting to run the script, so that the program may use the file as input data. For example, if a script is named with the path ''path/to/script'', and it starts with the line #! /bin/sh, then the program loader is instructed to run the program ''/bin/sh'', passing ''path/to/script'' as the first argument. The shebang line is usually ignored by the interpreter, because the "#" cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recursion (computer Science)
In computer science, recursion is a method of solving a computational problem where the solution depends on solutions to smaller instances of the same problem. Recursion solves such recursion, recursive problems by using function (computer science), functions that call themselves from within their own code. The approach can be applied to many types of problems, and recursion is one of the central ideas of computer science. Most computer programming languages support recursion by allowing a function to call itself from within its own code. Some functional programming languages (for instance, Clojure) do not define any looping constructs but rely solely on recursion to repeatedly call code. It is proved in computability theory that these recursive-only languages are Turing complete; this means that they are as powerful (they can be used to solve the same problems) as imperative languages based on control structures such as and . Repeatedly calling a function from within itse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operator (programming)
In computer programming, an operator is a programming language construct that provides functionality that may not be possible to define as a user-defined function (i.e. sizeof in C) or has syntax different than a function (i.e. infix addition as in a+b). Like other programming language concepts, ''operator'' has a generally accepted, although debatable meaning among practitioners while at the same time each language gives it specific meaning in that context, and therefore the meaning varies by language. Some operators are represented with symbols characters typically not allowed for a function identifier to allow for presentation that is more familiar looking than typical function syntax. For example, a function that tests for greater-than could be named gt, but many languages provide an infix symbolic operator so that code looks more familiar. For example, this: if gt(x, y) then return Can be: if x > y then return Some languages allow a language-defined operator to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kernel (operating System)
A kernel is a computer program at the core of a computer's operating system that always has complete control over everything in the system. The kernel is also responsible for preventing and mitigating conflicts between different processes. It is the portion of the operating system code that is always resident in memory and facilitates interactions between hardware and software components. A full kernel controls all hardware resources (e.g. I/O, memory, cryptography) via device drivers, arbitrates conflicts between processes concerning such resources, and optimizes the use of common resources, such as CPU, cache, file systems, and network sockets. On most systems, the kernel is one of the first programs loaded on startup (after the bootloader). It handles the rest of startup as well as memory, peripherals, and input/output (I/O) requests from software, translating them into data-processing instructions for the central processing unit. The critical code of the kernel is usua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scope (programming)
In computer programming, the scope of a name binding (an association of a name to an entity, such as a variable) is the part of a program where the name binding is valid; that is, where the name can be used to refer to the entity. In other parts of the program, the name may refer to a different entity (it may have a different binding), or to nothing at all (it may be unbound). Scope helps prevent name collisions by allowing the same name to refer to different objects – as long as the names have separate scopes. The scope of a name binding is also known as the visibility of an entity, particularly in older or more technical literature—this is in relation to the referenced entity, not the referencing name. The term "scope" is also used to refer to the set of ''all'' name bindings that are valid within a part of a program or at a given point in a program, which is more correctly referred to as ''context'' or ''environment''. Strictly speaking and in practice for most programmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
