Latency and Software Developers

I was recently having a conversation where someone asked me to compare real time and low latency Linux kernels.  I used the phrase “real time is the enemy of low latency.”  This caught some attention and I was asked to explain what I meant.  In order to accommodate the needs of real time processing we need to add a certain amount of overhead so that we can accurately and reliably predicate the amount of time that a procedure will take to complete.  In order to do this we incur a certain amount of overhead and this overhead contributes to latency.  In order to move as quickly as possible we would have to remove this overhead and thereby decrease latency but without having the predictability for which the overhead had allowed.

Today I was reading a paper on Agile development and traditional software development methodologies and it occurred to me that we were essentially talking about the same concept.  Programmers are a lot like organic, squishy CPUs chugging along churning out data.  The concept behind traditional development methodologies (or schedulers, if you will) was to make sure that developers were able to turn out a project or a piece of a project in a predictable nature – so predictable that projects could be projected years in advance with meeting rooms scheduled and the caterers hired for the release party.  This predictability is provided by the inclusion of a large amount of management overhead that hinders rapid development.  All of those status meetings don’t come for free and incur large amounts of lost productivity in exchange for keeping management up to date as to the release schedule.

Agile development takes the opposite approach.  In Agile the idea is not predictability, at least not to the same extreme level.  Agile really focuses on producing software with minimal latency – getting it done and out the door as quickly as possible even if that ends up surprising the marketing and sales departments and no box art has been approved yet.  It does this by lowering the management overhead and reducing artifacts that interfere with the actual job of producing a product allowing the team to move more quickly.

March 29, 2010: And on to home…

Got a good night’s sleep last night and I am ready to hit the road today.  Unfortunately I have to work for the office this morning so I can’t hit the road nearly as early as I would like.  So I was up around nine and worked from my laptop in the hotel until two in the afternoon which is when my gold membership with Choice Hotels entitles me to stay.

Jen was on the road early hoping to be off to Mississippi to hook up with a friend there before continuing on her way to Houston today.  So we parted ways this morning.  The last, long day is a lonely one.  Before she left we went over to a restaurant right next door to the hotel called the Farmer’s Market or something to that effect.  It was a southern style buffet (a la Golden Corral) but much nicer.  The people were very friendly and the food was good.  There was not much in the way of vegetarian as we had missed breakfast by fifteen minutes or so but being a buffet and as they had an all day omelet bar I was able to make due quite well.

I worked until two and was in the car and on the road around two thirty.  It is a long drive from Dickson to Memphis, on to Little Rock and across Texarkana and on to Dallas.  I did the entire route yesterday without the GPS and I did today as well.  I really hate using the GPS unless it is absolutely necessary.  Using it makes you sloppy and makes you stop paying attention to where you are going.  I like learning my way around.

The trip went pretty well.  I mostly listened to my iPod – catching up on IT Conversations podcasts as best as I can.  I was very glad that I was able to drive almost all of the way across Arkansas today in daylight.  The last time we came through it was dark and I missed out on seeing Arkansas on my first time through it.  This was far more interesting.  I got to see Memphis in the daylight and then a very large portion of Arkansas.  It is actually a very beautiful state.  But it is also very large and takes forever to drive across which is rather misleading.  The trip across Arkansas runs from the northeastern corner all the way to the southwestern so it is incredibly long and gives a rather complete survey of the state.

By the time that I was going through Little Rock the sun was starting to go down and it was completely dark an hour or two before I reached Texarkana.  Then I had to drive through East Texas and it was quite late by the time that I finally pulled in to Las Colinas and got into the apartment which I had not seen in over a week.  It was great to be home but awful as the family is not here and we have no plans as to how I will be able to get down to Houston to get them.  I don’t have enough free time in any given day to be able to make the trip.  It is over ten hours round trip and I am worn out from lack of sleep and too much driving.  We are going to start working on a plan tomorrow as to what we are going to do to get them.

March 28, 2010: Chalfont to Nashville

Today the driving begins. Another long, long stretch of blacktop stretches out before me. I can’t believe how much driving I am doing this week. This is definitely a life record for me. In total, not including the extra several hundred miles that I have not figured out when I am going to do yet to go to Houston to pick up Dominica and Liesl, I am going to have driven approximately 4,400 miles or 7,100 kilometers in about eight days!

We were not up all that early this morning.  Sleep was more important than an early start.  We are cutting the drive to Texas in half which makes it not really all that bad, considering.  Driving from Chalfont, on the north side of Philadelphia, to the west side of Nashville should actually be quite easy.

SpiceWorks at the SpiceRack

I don’t know exactly what time we got onto the road but I am guessing that it was around ten this morning when Jen and I headed out the door from Tara’s house to start out journey south.  Jen is driving the Mazda and I am driving the BMW.

The weather was perfect today and we made awesome time as we worked out way south down towards Knoxville where we had scheduled to meet up for dinner and to get our picture taken at the new Spice Rack Cantina which is a new restaurant in town.  SpiceWorks is running a photo contest for the Spiciest photograph and we are guessing that that can be had by stopping in there.  We have our SpiceWorks nylon bags from SpiceWorld 2009 to use for the photo.  We figure that there is no way that we can lose with a picture from there.

We got into Knoxville pretty late considering that it was a Sunday and we were definitely worried that Spice Rack would be closed by the time that we got to it.  It was not although it was quite slow and seemed like it would not be open for much longer.  We got dinner there and then asked the crew if they wouldn’t mind getting a picture with us for our competition.  They were happy to oblige and when the picture was posted to SpiceWorks we were told that we pretty much have the competition in the bag, so to speak.  It will certainly be hard for anyone to beat out this picture for the spiciest SpiceWorks picture!

After dinner it was back on the road for several more hours.  We drove through Nashville and started looking for a hotel on the far side so that when we hit the road in the morning Nashville would be behind us as would its traffic.  We ended up finding a Comfort Inn in Dickson, Tennessee which was very cheap and worked out great.  Tomorrow night I will be home in Dallas.

March 27, 2010: Packing Day in Peekskill

Today is the big packing day up here in Peekskill.  I was up by eight this morning having gotten practically no sleep.  Jen slept in a few hours longer which was pretty amazing as she was sleeping on the love seat in the living room with me going all over the house cleaning and packing to get ready for the house showing that was going on later today!

We had to be out of the house by around a quarter to eleven.  We waited until the last minute then went to the Westchester Diner for some lunch and to wait out the showing.  After lunch we drove down to the storage unit just to assess the situation and get a feel for how much work there was going to be in packing it all up.  Then back to the house to meet Brian who had arrived with his Trailblazer while we had been at the storage unit.

Storage

We were only at the house for a few minutes before we had to drive down to White Plains to the UHaul location there to pick up our trailer.  We got one of those massive 6’x12′ trailers with the double axle.  This is not a fooling around trailer.  This thing is a lot wider than the Trailblazer and no fun at all to drive around Westchester’s narrow streets.

We got to the storage unit and got straight into the crazy packing frenzy.  It actually went very well and before long the storage unit was actually empty!  We had not really been sure if that was going to be possible or not but there it is, completely empty.  Not only was it empty but there was a bit of room left that we needed to fill in the trailer so that it would be stable for the long drive down to Texas.  So we parked the trailer in the parking lot of the storage unit and drove back up to the house with the X3 and the PR5 to load up on new stuff to put into the trailer.

We did a bit of packing from the house getting all of the kitchen stuff out and miscellaneous large items from around the house like the one remaining SunFire V240 server, several plastic drawer systems, the printer, the last of Liesl’s toys, etc.  Now there is really nothing left in that house.  I can’t believe how bare it is.

We drove down and got Brian all packed up and from there he went straight out towards Philadelphia.  Jen and I returned to the house to get the last load into the cars and to lock everything up so that it is ready to be left again.

There really was very little for us to get in this last load.  We had left a few fragile items behind that we didn’t want to ship in the bumping trailer like all of the remaining monitors.  Those all went on car seats and then Jen and I left Peekskill to drive down to Philadelphia in our separate cars.

It was almost midnight when we arrived down at Tara’s house in Chalfont, PA.  Another really long day.  We are all very exhausted.  It was straight off to bed.  Tomorrow is a big travel day.  Driving from Philadelphia to Nashville, we hope.  Brian is not coming for another week with the trailer.  It is just Jen and I driving this leg of the trip.

March 26, 2010: Ithaca, Binghamton and Beyond

I slept in a little too much this morning but I desperately needed to play a little catch up on my sleep.  Once I was up we were out the door pretty quickly and down to Brian’s USA Diner in Mt. Morris for some breakfast before really getting onto the road.  Brian, Jen and I ate and while we were there Mark and Rhonda Popp stopped by to say hello.

From Mt. Morris it was down 390 to 84 and over to Ithaca.  I haven’t been in Ithaca in quite a while.  I really miss that town.  I love Ithaca.  Such a great city.

We went straight to Autoworks so that we could get the Mazda PR5 and the BMW X3 both inspected since that was the primary reason for the entire trip.  We dare not miss that!  They got us in straight away and it really did not take too long.  I took Jen around and made introductions while we had some time.

Once the cars were finished we drove up the street to Lifestyle Properties but were not able to find anyone there.  We waited a little while and then gave up and drove down to Boynton Middle School to hang out with Nate.  School was just ending at this point (boy schools get done early) and Nate was free to hang out.  Bob was not around as he was in Westchester for a funeral so we did not get to see him.

We hung out at the school for a little while then we all went down to the Ithaca Bakery and had lunch.  I have not had Ithaca Bakery / Collegetown Bagels in so long I can’t believe it.  That was some awesome food.  I had to get two sandwiches just because I missed it to much.  Collegetown Bagels up at Triphammer was the staple of my diet when I first moved to Ithaca in 2000.  I ate there several times a week when we lived at Gaslight Village Apartments right up the road.  Good times.

After lunch Jen and I went downtown to see a client of hers that was not expecting her.  Always nice to surprise people halfway across the country.

From there we dropped off her car, the Mazda, and drove up to the Lucente’s home to see if we could track down Steve and Pat.  It took a while of ringing the doorbell before Max opened the door and did a search for us to see if anyone was home.  No one was.  He said that Steve had mentioned heading off to Barangus in Ulysses so we said that we would head out there to find him.

I haven’t been to Barangus in years.  Not the kind of place that you make a point of stopping into when you are visiting from across the country.  I’ve been there with Steve in the past.

Jen and Steve in BarAngus

Steve is always unmistakable, even from quite a distance.  We found him at the bar with two friends – the bar otherwise empty.  I came up behind him and slapped him on the back and gave him rather a surprise.  We haven’t seen each other since Max’s bar mitzvah three years ago!

Jen and I hung out with Steve at Barangus for several hours.  The place when from empty to pretty busy.  Then around nine we hit the road.  Back down to Ithaca, picked up the other car then down to Binghamton to meet up with John Stephens in Vestal at a diner there.

We had a light dinner and Jen and John got a chance to meet which was handy.  I haven’t seen John in quite some time either.  We did not stay too long as it was getting late.  From there it was on to the road down to Peekskill.

It is a little over two hours from Binghamton to Peekskill.  We got into town and I got to see my house for the first time in more than three months.  What a weird feeling that is.  I’m always awed by the sensation of going to a house that I own after having been away for months.  It is just so weird.

The house was left unlocked – just great.  Not what I wanted to discover when I arrived.  But nothing was touched in the house – not that there is anything at all worth taking.  The place is down to miscellaneous cleaning supplies and the furniture that we are leaving behind.  Everything of value was already removed.

I discovered a lot of spoiled food in the fridge and three dead plants upstairs.  Just what we wanted in the house that is being shown for sale and rent.  Ugh.  I will need to deal with all of that tomorrow.  I was hoping to find that nothing was wrong but apparently leaving things to be done after we aren’t there to supervise doesn’t work very well.

We were pretty wired from the busy day and all of the driving.  It didn’t take long to discover that there is absolutely nothing to do in that house.  No Internet, no television, no books, no nothing.  There is some wine still in the house but it is all wine that has gone to vinegar that we plan to throw out when we move out.

We were bored and had just nothing to do but I discovered that there were fake fireplace logs still there and it was just a little cool outside so I started a fire in the fireplace and opened a bottle of spoiled wine.  Of course, there is no corkscrew in the house.  So I tried several things before I figured out that I could open the wine by drilling it out with my drill – one of the very few items left in the house.  Just working that hard to open bad wine was enough entertainment for us!  The wine was definitely turned and corked though.  About as bad as wine gets I guess.