Tuesday Nov 19, 2013

Extending Your Use of DTrace on Oracle Linux





We just published a new article about using DTrace on Oracle Linux (see below). If you're not already familiar with DTrace on Oracle Linux, you might want to start with these two blogs.



Blog: Trying Out DTrace

by Wim Coekaerts

In October of 2011 Wim Coekaerts described the steps required to use the preview of DTrace on Oracle Linux, and provided a simple example of how to use it.



Blog: How to Get Started Using DTrace on Oracle Linux

by Rick Ramsey

In January of 2013 I described some of the resources that had recently become available to help you start using DTrace on Oracle Linux. They included a video interview with Brendan Gregg, a way to find out which DTrace probes are available on Oracle Linux, a technical article, a book, and more.

New Article: How to Set Up DTrace to Detect PHP Scripting Problems on Oracle Linux

by Christopher Jones

Christopher Jones has just published an OTN tech article that explains how to set up DTrace to detect PHP scripting problems on Oracle Linux. He shows you how to download and install the right version of Oracle Linux, how to install PHP and the OIC18 extensions for Oracle Database, how to verify which PHP probes you have, and how to begin using them.

photograph of Colorado sunset by Beth Ramsey

-Rick

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Friday Jun 07, 2013

How to Get Started Using DTrace on Oracle Linux

I. hate. slow. code. (Image removed from blog.)

We all hate slow code. Bunch of princesses is what we've become. During the American Civil War, they had to deliver their text messages by horseback! It took weeks! And half the time, they got blown off their horse by a cannonball to the neck!

Today? Today we have to have our stuff back in milliseconds, or we start tweeting about it. So, if you're developing or deploying applications, how do you keep them performing at the speed to which we have become accustomed? DTrace, of course.

"But I'm a Linux guy," you say. "I don't DO Oracle Solaris."

That's fine. The folks at Oracle Solaris are not only wicked smart, they are generous. Now you can use DTrace on Oracle Linux. Let me point out, by the way, that DTrace is just as useful for sysadmins as it is for developers. In this video, taken a couple of years ago, Brendan Gregg explains how sysadmins can make their deployed applications run faster even after the developers who wrote them pushed back the last bits of their code:

Video Interview: How to Improve the Performance of Deployed Applications Using DTrace

Brendan Gregg describes the best ways for sysadmins to tune deployed applications to get more performance out of them in their particular computing environment.

Bonus: More info about Brendan Gregg plus links to his personal and professional blogs.

If you'd like to try DTrace on Oracle Linux, here are some resources to get you started.

What DTrace Probes Are Available on Oracle Linux?

If you are running Oracle Linux 6 with the DTrace-enabled Unbreakable Enterprise Kernel Release 2 (2.6.39), you can run this command to list all the DTrace probes available on your system:

dtrace -l

If you are not running that version of Oracle Linux, you can download it from the ol6_x86_64_Dtrace_latest channel on the Unbreakable Linux Network (ULN). For more info about installing and configuring DTrace, see the DTrace chapter in the Oracle Linux Administrator's Solutions Guide for Release 6.

For each probe listed by dtrace -l, the output includes a name, the portion of the program where it resides, and the Oracle Linux kernel module that does the probing. Once you have that, go to Chapter 11 of the DTrace Guide to find out what each probe does.

Article: How to Get Started Using DTrace on Oracle Linux

DTrace is a powerful tool, and it can do some amazing things. But it's not that difficult to get started doing simple things. You can build up from there. In this article, Richard Friedman gives you a high-level overview of DTrace and its major components:providers, modules, functions, and probes. He explains how you can use either one-liner commands on the command line, or write more complex instructions in scripts, using the D language. He provides simple examples for each. It's a great way to get your feet wet.

Article: How to Get Started Using DTrace on Oracle Linux
Bonus: Brendan Gregg's one liners for DTrace (some of the existing DTrace one-liners will require modification to work on Oracle Linux).

The DTrace Book

You can get all the info you need about DTrace through the Dynamic Tracing in Oracle Solaris, Mac OS X, and FreeBSD, by Brendan Gregg and Jim Mauro. Of course, you can also buy your own paper or electronic copy through any of the major retailers. (We're working on getting a good discount for the book, but you'll have to subscribe to the OTN Systems Community Newsletter to find out about it.)

Bonus:How the DTrace book got done, by Deirdre Straughan

DTrace Forums

Lots of developers and sysadmins are using Dtrace and posting their questions and tips on the DTrace Forum. Here's an example of one conversation:

Q: Unexpected output of dtrace script
m1436 wrote a dtrace script to monitor the bytes returned by the read() system call to the user programme, but was getting strange results. He includes the dtrace script and the strange output.

A: kvh responds, explaining that the problem m1436 encountered is the result of a common misconception about copyin(). "It is intended to be used to copy content of userspace memory into a scratch buffer so that it can be accessed directly from within kernel space (where the DTrace core executes). That said, it is often interpreted as somehow being equivalent to malloc() whereas in reality it actually works like alloca() instead. So, what you are seeing is basically the artifact of the scratch buffer being overwritten with other data. ... in order for this to work, you should do things a bit differently.

The DTrace forum always has great discussions. Let me know if you find any that are worthy of highlighting. And good luck!

- Rick

Follow me on:
Blog | Facebook | Twitter | YouTube | The Great Peruvian Novel

Friday Oct 05, 2012

Hurry! See the uncensored OOW videos before they get edited!

source

Uploaded so far:

Which Oracle Solaris 11 Technologies Have Sysadmins Been Using Most?

Director's Cut - Uncensored - Markus Flierl, VP Solaris Core Engineering, describes how Oracle Solaris 11 customers are taking advantage of the Image Packaging System and the snapshot capability of ZFS to run more frequent updates of not only the OS, but also the applications (agile development, anyone?), and how they're using the network virtualization capabilities in Oracle Solaris 11 to isolate applications and manage workloads on the cloud.

Watch How Hybrid Columnar Compression Saves Storage Space

Director's Cut - Uncensored - Art Licht shows how hyprid columnar compression (HCC) compresses data 30x without slowing down other queries that the database is performing. First he shows what happens when he runs database queries without HCC, then he shows what happens when he runs the queries with HCC.

Security Capabilities and Design in Oracle Solaris 11

Director's Cut - Uncensored - Compliance reporting. Extended policy. Immutable zones. Three of the best minds in Oracle Solaris security explain what they are, what customers are doing with them, and how they were engineered. Filmed at Oracle Open World 2012.

Why DTrace and Ksplice Have Made Oracle Linux 6 Popular with Sysadmins

Use the DTrace scripts you wrote for Oracle Solaris on Oracle Linux without modification. Wim Coekaerts, VP of Engineering for Oracle Linux, explains how this capability of DTrace, the zero downtime updates enabled by KSplice, and other performance and stability enhancements have made Oracle Linux 6 popular with sysadmins.

Why Solaris 11 Is Being Adopted Faster Than Solaris 10

Sneak Preview - Uncut Version - Lynn Rohrer, Director of Oracle Solaris Product Management explains why customers are adopting Oracle Solaris 11 at a faster rate than Oracle Solaris 10, and proves why you should never challenge a Montana woman to a test of strength.

What Forsythe Corp Is Helping Its Customers Do With Oracle Solaris 11

Director's Cut - Unedited - Lee Diamante, Solutions Architect for Forsythe Corp, an Oracle Solaris Partner, explains why Forsythe has been recommending Oracle Solaris to its customers, and what those customers have been doing with it.

Lots more to come ...

- Rick

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Contributors:
Rick Ramsey
Kemer Thomson
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