Concert review: Drivin’ N Cryin’

Last year I did a number of concert reviews, but not nearly as many as I would have liked to. This year I plan to review 2 – 4 shows per month, and the acts will range from small local bands to large national headliners. I am also hoping to get peoples feedback from the shows, and take pictures if the venue allows them. So to start off 2009, I thought I would share my experiences from the Drivin’ N Cryin’ show I attended a few weeks back.

The show was scheduled for a Friday night at a relatively small local venue, and I decided to venture out by myself at the last minute to attend. Once I arrived at the venue, I grabbed a drink from the bar and then proceeded to chat with a bunch of folks who were attending the show. While in the middle of a conversation with a hard core Drivin’ n Cryin’ fan, I heard music off in the distance and realized it was time to make my way into the venue to take in the show.

The show started off with a bang, and I was amazed with Kevn Kinney’s vocals. He had such a way with his delivery, and I am still in awe at how well the guys in the band jived with each other musically. Since this was my first DNC show, I’m not 100% certain what the set list was for the night. I can tell you that my favorite tunes were their huge hit “Straight To Hell”, “Fly Me Courageous” as well as their rendition of Neil Young’s “Rockin’ In The Free World”.

I have to say this was one of the better concert experiences I have ever had, and the folks who were in attendance LOVE this band (seriously, they LOVE them!). Everyone was crazy nice at the show, and I made a couple of new new friends while chatting with random folks at the venue (hi Kelly!). Good times were had, and here’s to some killer shows in 2009! Happy New Years everyone!

Disabling synchronous syslogd updates

Most *NIX implementations ship with a syslog daemon, which is responsible for reading messages from clients and writing these messages to one or more log destinations. Most daemons perform this operation synchronously using the fsync() system call, which can lead to some headaches on super busy log servers. Linux has a nifty option to disable synchronous updates, which can really aide in scaling logging servers to handle lots and lots of clients. To disable synchronous updates (this can result in data loss, so make sure to evaluate all options prior to using this feature), you can prefix the log destination with a hyphen like so:

$ grep daemon /etc/syslog.conf
daemon.* -/var/log/messages

This is super useful, and I wish there was a similar feature available out of the box for Solaris (syslog-ng can do this, but you shouldn’t have to install another syslog daemon to get this functionality IMHO).

IPMP rearchitecture bits now in Nevada build 107

The long awaited IPMP rearchitecture bits just got included into the crossbow integration in OpenSolaris build 107.   A new command, ipmpstat has been introduced.

If you use IPMP in production, take a look at the reachitecture here.   Peter’s documentation on the high level design is quality stuff.   The below was taken from page 3.

3 IPMP Rearchitecture: Basic Operation
3.1 IPMP Network Interface
As previously discussed, the lion’s share of the problems with IPMP stem from not treating each
IPMP group as its own IP interface. As an example, a typical two-interface IPMP group today
looks like:
ce0: flags=9040843<UP,BROADCAST,RUNNING,MULTICAST,DEPRECATED,IPv4,NOFAILOVER> mtu 1500 index 2
inet 129.146.17.56 netmask ffffff00 broadcast 129.146.17.255
groupname a
ce0:1: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 2
inet 129.146.17.55 netmask ffffff00 broadcast 129.146.17.255
ce1: flags=9040843<UP,BROADCAST,RUNNING,MULTICAST,DEPRECATED,IPv4,NOFAILOVER> mtu 1500 index 3
inet 129.146.17.58 netmask ffffff00 broadcast 129.146.17.255
groupname a
ce1:1: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 3
inet 129.146.17.57 netmask ffffff00 broadcast 129.146.17.255

The above output shows ce0 and ce1 with test addresses, and ce0:1 and ce1:1 with data addresses. If ce0 subsequently fails, the data address on ce0:1 will be migrated to ce1:2, but the
test address will remain on ce0 so that the interface can continue to be probed for repair. In the future, this will instead look like:
ce0: flags=9040843<UP,BROADCAST,RUNNING,MULTICAST,DEPRECATED,IPv4,NOFAILOVER> mtu 1500 index 2
inet 129.146.17.56 netmask ffffff00 broadcast 129.146.17.255
groupname a
ce1: flags=9040843<UP,BROADCAST,RUNNING,MULTICAST,DEPRECATED,IPv4,NOFAILOVER> mtu 1500 index 3
inet 129.146.17.58 netmask ffffff00 broadcast 129.146.17.255
groupname a
ipmp0: flags=801000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4,IPMP> mtu 1500 index 4
inet 129.146.17.55 netmask ffffff00 broadcast 129.146.17.255
groupname a
ipmp0:1: flags=801000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4,IPMP> mtu 1500 index 4
inet 129.146.17.57 netmask ffffff00 broadcast 129.146.17.255

That is, all of the IP data addresses associated with the IPMP group will instead be hosted on an IPMP IP interface, such as ipmp013. With this new model, data addresses will no longer be
associated with any specific physical underlying interface, but instead will belong to the IPMP group as a whole. As will become clear, this addresses many outstanding problems and vastly simplifies the implementation. There will be a one-to-one correspondence between IPMP groups and IPMP interfaces. That is, each IPMP group will have exactly one IPMP interface. By default, each IPMP interface will be named ipmpN , but administrators will be encouraged to specify a name of their choosing, as described in section 4.1.5. Since an IPMP interface’s name will not be fixed, the system will set a new IPMP flag on all IPMP interfaces to indicate that the interface has special properties and semantics, as detailed throughout this document.

Brendan Gregg screaming at a 7410!

Slashdot picked up a youtube video of Brendan Gregg, shouting at a Sun 7410.  Its pretty halarious, but it does showcase just how cool the DTrace Analytics visual GUI is on Sun’s new line of Amber Road products.

Brendan is one of the co-authors of Solaris Internals, 2nd Edition.  He also wrote the DTraceToolKit, which has allowed millions of SysAdmins who don’t have the skills to deep dive into DTrace to harness its powa!