Today while installing Sun’s directory server, I kept getting the error “No components have been selected for installation in the selected directory” after selecting numerous components for installation: Directory Server components showing a checked box will be installed. [X] 1 Sun Java(TM) System Directory Suite 0 bytes [X] 2 Sun Java(TM) System Directory Server 0 [...]
While load-testing a MySQL back-end last weekend, I wanted to be able to monitor read and write utilization per file descriptor. The DTraceToolkit comes with a nifty script named pfilestat that does just that: $ pfilestat 841 STATE FDNUM Time Filename read 63 0% /tmp/#sql_349_0.MYI write 64 0% /tmp/#sql_349_0.MYD read 64 0% /tmp/#sql_349_0.MYD write 63 [...]
I spent some time last night catching up with mailing lists, and saw that Brendan Gregg recently added DTrace SDT probes to one of the Javascript engines. If you don’t know who Brendan is, he is a brilliant guy, and the author of the DTraceToolkit among other things. I always love reading about his work, [...]
The DTraceToolkit comes with two super useful scripts to observe the “randonmess” or “sequentialness” of an application. The first script is iopattern, which provides a system-wide view of random and sequential I/O, the total amount of I/O generated, and an I/O size distribution: $ iopattern 5 %RAN %SEQ COUNT MIN MAX AVG KR KW 100 [...]
Tonight I gave a talk at the local opensolaris users group titled “DTrace for SysAdmins: An introduction to the DTraceToolkit.” I would like to thank everyone for coming out, and for putting up with my broken voice (I am currently getting over a cold). I put the presentation slides up on prefetch.net, and I hope [...]
I came across a couple of super useful DTrace links, and thought I would pass them on: Brendan Gregg’s DTrace presentation in London: http://www.context-switch.com/performance/dtrace_workshop01_slides.pdf Opensolaris student guide (the chapter on using DTrace to debug device drivers is awesome): http://opensolaris.org/os/community/documentation/files/studentguide.pdf
