The much anticipated DTrace that is incorporated into the upcoming SolarisTM 10 Operating System (Solaris OS) was recently evaluated by eWeek Labs. Senior Analyst Jason Brooks described it as "one compelling new Solaris component...that opens to developers and system administrators a window onto the workings of the operating system and the applications that run on it."

DTrace is a comprehensive dynamic tracing framework tool that provides a powerful infrastructure to permit administrators, developers and service personnel to concisely answer questions regarding an operating system's and user program's behavior. Not only does it allow system wide diagnostic information to be seen, it also permits access to minute, detailed information "providing an exploded view of system calls, application function calls and instructions executed by running programs," writes Brooks.

The article highlights some of DTrace's features such as:

• Command-line directives or scripts written in D, called recipes, are the methods used to interact with the tool. Various recipes are included in the DTrace manual.

• The DTrace commands or scripts utilize loadable kernel modules called providers that create individual points of potential instrumentation within the system identified as probes. Probes are activated only when DTrace makes a request thus maintaining a low overhead.

• Built-in safeguards allow the tool to be used with live production systems without interference to the system it is active on.

• No code changes are required of applications that are to be examined. Therefore, examining any operation of an application running on Solaris 10 OS is permissible. Brooks speculates that applications set to run on earlier Solaris OS versions or Linux might also find DTrace useful. "Provided a developer could compile and run the application on Solaris 10 -- as is possible with most Linux or UNIXR applications -- optimizations produced with the aid of DTrace could benefit the application once it's been brought back to its original platform."

The lack of a GUI for DTrace is mentioned and Brooks surmises the challenge of encompassing DTrace's open-ended function and wide scope into an interface may be difficult. However, the article notes that Sun officials are contemplating the idea.

IBM's Dynamic Probes, with similarities to DTrace, is mentioned as a possible alternative for Linux users. Brooks does write that "some of the major advantages of DTrace over Dynamic Probes include better system stability safeguards, a more robust language and the fact that DTrace will ship as a standard part of Solaris."

Solaris 10 OS is expected to begin shipping by year's end. A tutorial-style manual on DTrace is available at:

www.sun.com/bigadmin/content/dtrace [...read more...]

		fullsource
Print Email Current Profile Archive Blog Generate newsletter