EXPOSED in Vegas!

I arrived last evening in Las Vegas for the Conference. So far, not so good, but nothing major wrong. I’ve just been a dolt. All I can hope for is that I can get it all out of my system before my talk.

Largely, its been a matter of rushing things along and not paying attention — being in Vegas, who can blame me?

So far my follies have included:

• Heading in the wrong direction out of the airport for a good ten miles (and I DID follow the provided directions — it clearly says to take a LEFT onto Warm Springs Rd). I guess this is a new rental center, and they’ll probably fix the error after they go through their warehouses of stockpiled maps.
• Packing clothing suitable for New Hampshire Spring weather
• Pulling into the convention center rather than the hotel
• Parking at the wrong end of the parking garage
• Learning that the hotel at Mandalay Bay is called THEhotel. While it is THEhotel, I learned that it is not MYhotel. Getting to MYhotel, which is on the same property, but apparently has no name, required that I schlep my luggage across the entire casino floor.
• After touring the premises this morning, I headed over to McDonald’s for a healthy breakfast, because it’s what i eat and what i do, where the order-taker informed me that I was XYZ — no wonder I was getting so many stares! Another reason not to travel alone.

What I learned (or remembered t00 late):

• On average, Las Vegas is warmer than New Hampshire
• Know where you are going
• Use Valet
• Look in the mirror each morning before heading out for the day
• Being cheap frugal doesn’t seem to correlate with a healthy lifestyle; at least when it comes to eating and parking.

On a positive note, on the flight out, I ended up seated with Jerry Ireland who is also speaking at the conference. He is, in addition to being a modest fellow, quite a nice guy.

All about Direct IO

Bob Sneed has a great write-up on Direct IO. Great coverage and a good read.

He also offers some good advice for those considering a move to Oracle RAC.

Is 100% CPU Utilization a Bad Thing?

It isn’t necessarily a bad thing, but I’m not sure it is ever a good thing either.

It simply means that there are potentially other threads that are ready to run that aren’t being serviced that could be if other resources were available. It equates to lower throughput than might be possible for that interval of time. That is about it in terms of downside in the short-term. If this isn’t a problem for the company, it isn’t a problem. It could turn into a more significant problem if there is a surge in average workload. They are already topping out and they can’t accommodate more work during that period. As there is more work to be done, throughput continues to fall as resources are consumed via context switches, etc.

The good news is that Solaris has a great scheduler, and the higher priority jobs are going to get the time on CPU that they need.

The utilization number is calculated using sampling. Even with lower reported utilization numbers, the actual utilization might be closer to 100%. This is the reason that some best practices say that utilization should be kept at or below some number (80-90%).

Here is how this can happen. Consider a 1 CPU box. Assume sampling happens at odd numbered timestamps:

TIMESTAMP	THREADS RUNNING
t0	1
t1	0	<- sample 1
t2	1
t3	0	<- sample 2

Reported utilization = 0
Actual utilization = 50%

While the actual utilization is 50%, the system above would report its utilization at 0%. If the sampling had occurred at even numbered times, the reported utilization would have been 100%. In both cases, for this contrived example albeit, the different between reported and actual utilization is vast. I suspect that in practice, the numbers are much more representative of reality.

I don’t think 100% utilization is necessarily a bad thing as long as the proposition is entered with eyes open.

I’m interested in what others think.

Now I Understand the Nickname

Shaggy of Scooby-Doo fame’s real name is Norville. Who knew?

COLLABORATE ‘07

I’ll be heading out to COLLABORATE ‘07 next week where I will be presenting an expert technical session on using DTrace in an Oracle environment on Thursday morning.

If you are a new speaker, I am a new speaker mentor and I’ll be presenting to you on Sunday afternoon.

If you are heading out there, I’d love to see you at the session. If you can’t make it, be sure to catch up with me in the hallways or blackjack tables.

It should be a great time. I’m looking forward to learning alot.

Rome

I’ve got so much that I want to put here and so little time. If you are visiting and don’t find this useful, like the New England weather, just wait a bit. I promise that there is much more to come.

And so it Begins…Again.

There must be a first one, and this is the first post for this blog. I call this blog “scoolin” because I’m always learning and love to share what I learn. The botched spelling of the blog name – I’ve mixed feelings about. Mispelled words are a pet peeve of mine. Let me clarify — purposefully mispelling words is a pet peeve. Yet I sometimes do it myself. Such is life. Aren’t we often our own worst enemy?

Sometimes I mispell for humor — I often mispell infallable for instance. Other times it is to convey a point — such as in this blog name. The point is that we are all learning. We all can learn from each other, and you don’t have to be the master of a subject in order to share what you know with others.

What I’m going to do here is try to document my journey of learning. I’m going to largely be looking at technical issues. I’m hoping that by putting this out in the public, that people will correct me when I am wrong, or provide insight from a different perspective. I’ve got my biases of course, but they aren’t so strong so as that I can’t be open to what you are saying.

Welcome. Let’s have a look at the world. In this case, largely about Oracle, Solaris, and Linux for starters. But there will be more.

Hello world!

Welcome to WordPress.com. This is your first post. Edit or delete it and start blogging!

Interesting how “Hello World” still has a life. Will probably outlive me.