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, [...]
While debugging another NFSv3 problem this week, I came across a create procedure with the “GUARDED” flag set: $ snoop -d hme0 host netapp1 yappy -> netapp1 NFS C CREATE3 FH=C5D2 (GUARDED) file.dat netapp1 -> yappy NFS R CREATE3 OK FH=E700 This was the first time I have reviewed an NFSv3 packet capture with the [...]
While debugging an interesting NFSv3 problem last week, I came across the following information in one of my snoop captures: $ snoop -d hme0 host netapp1 yappy -> netapp1 NFS C WRITE3 FH=94EC at 0 for 824 (ASYNC) netapp1 -> yappy NFS R WRITE3 OK 824 (FSYNC) yappy -> nfsfly1 NFS C WRITE3 FH=30D9 at [...]
I support BIND on a few servers, and when run as a caching name server, BIND can consume a fair amount of memory if you have lots of clients. There are two ways to restrict the amount of memory BIND uses. The first method, which is described in Pro DNS and BIND, is to set [...]
I got a couple of patches for ssl-cert-check, and released version 3.4 to my website. The patches address a couple of annoying bugs, and I changed the global binary paths to to work by default on Solaris, BSD and Solaris systems. If you haven’t used ssl-cert-check before, you can check out my article Proactively handling [...]
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 [...]
