DTrace is a comprehensive dynamic tracing framework created by Sun Microsystems. It was released under the Common Development and Distribution License (CDDL) in January 2005 and included in Sun's Solaris 10 for troubleshooting system problems in real time. DTrace was the first component of the OpenSolaris project to be released under the CDDL. DTrace is designed to give operational insights that allow users to tune and troubleshoot applications and the OS itself. Special consideration has been taken to make it safe to use in a production environment. For example, there is minimal probe effect when tracing is underway, and no performance impact associated with any disabled probe; this is important since there are tens of thousands of DTrace probes that can be enabled. Tracing programs (also referred to as scripts) can be written using the D programming language (not to be confused with other programming languages named "D"). The language is a subset of C with added functions and variables specific to tracing. D programs most resemble awk programs in structure; they consist of a set of actions rather than a top-down structured program. In a DTrace program, one or more probes (instrumentation points) are enabled; whenever the condition for the probe is met (the probe "fires"), the action associated with the probe in the DTrace program is executed. DTrace was designed and implemented by Bryan Cantrill, Mike Shapiro, and Adam Leventhal. The authors received recognition in 2005 for the innovations in DTrace from InfoWorld and Technology Review.[1][2] DTrace won the top prize in the Wall Street Journal's 2006 Technology Innovation Awards competition.[3] DTrace implementations require tight integration with the operating system kernel. Although DTrace was initially written for Solaris, its source code is freely available as part of the OpenSolaris project, and work is in progress to port it to FreeBSD (in which there has been initial success[4] as a substitute for the ktrace utility) and QNX[5]. Apple has included DTrace in Mac OS X 10.5 "Leopard" with GUI Instruments.[6]
Bryan M. Cantrill, Michael W. Shapiro and Adam H. Leventhal (June 2004). "Dynamic Instrumentation of Production Systems". Proceedings of the 2004 USENIX Annual Technical Conference. Retrieved on 2006-09-08.
