Monday, May 04, 2009

Closing this Blog

I moved all my book related postings to here: Good Reads

Check there if you are interested in seeing what I'm reading now.

Tuesday, November 06, 2007

Technical - "Release It!"

This is another very nice book from Pragmatic Programmers written by Micheal T. Nygard. The main topic of "Release it!" is about putting software into production and what can happen there.

The book discusses a number of principals to consider when setting up large production systems. They are divided into anti-patterns (what not to do) and patterns (what to do). The two major parts of the book deal with stability - what to do to prevent systems from crashing, and capacity - how to design systems that will not crumple under load.

But perhaps the best part of the book is the examples of failures that occured in the real world and how those could be avoided. This is in tradition of best engineering books - which analyze failure in order to avoid it in the future.

Here is a one example. The author had to find a problem with a web based system that would "crash" every morning because its connections to a backend databases became "broken". Typically these sorts of systems have a pool of available connections that sit idle and are used when needed. The idle connections are kept, because creating a new connection to a database server is slow.

Now a connection to a database server means a TCP/IP socket connection. When a socket connection is established the two end system agree to communicate over a certain route, and the data between them can pass via some other computers or routers etc. However, when the connection is idle no data is sent at all.

Now it turns out that there was a firewall system between the web application and the database server (a typical set up). A firewall needs to keep track of all the connections that go through it. Firewalls are limited in how many concurrent connections they can handle, and if they see a connection that is idle they will drop it after some suitable time interval (could be hours of inactivity).

It turned out that during the night there was not enough activity in the system to use the pooled connections to the database, so the firewall silently dropped them. Then when people began to use the system in the morning all of a sudden the connections to the database were gone and the system had to be restarted.

The solution was simple - database connections had to be kept active by periodically sending some data to the database server. But this is not the kind of thing that people think about while developing systems.

As with most of the Pragmatic Programmer books I found this one very useful and entertaining.

Sunday, October 28, 2007

Science Fiction - "Space Merchants"

"Space Merchants" is a novel by Fredrik Pohl and C.M. Kornbluth about marketing in the future. The main character of the book, Mitch Courtenay, is an executive at an advertising agency and he is given the project to market colonization of Venus. At this point in time, only one person has gone to Venus (a rather short astronaut - since weight was a consideration) and he found that the environment on Venus is not particularly hospitable to human life. Still, good marketing can overcome such problems, especially in the hands of a talented executive.

In the "Space Merchants" universe the world is controlled by large corporations, which fight among themselves like gangsters. There is also a large working underclass, who are also the consumers. The consumers are not smart enough to understand the subtleties of marketing.

In any case the Venus campain does not go as expected. Our hero winds up in strange places (still on Earth), is forced to live and work as part of the consumer class and has to fight his way back to his rightful executive position.

The book was fun to read, as the plot twisted and turned in unexpected ways. I also like the slight fun poking at marketers. On the other hand, the technology was all wrong. Everyone travelled via rockets, but there were no computers or computer networks.

There is a sequel to this novel, I think it is called "The Merchant's War" - but I am not planning to read that.

Saturday, October 13, 2007

Non-fiction "The Big Con"

This is a political book written by Jonthan Chait, a writer for the New Republic. In the book he tries to explain how certain economical theories became to dominate the public policies (especially of the Republic party), even though they are considered wrong.

The principal idea he criticizes is "supply-side" economics and the now famous Laffer Curve. The premise is that reducing taxes will actually result in more revenues for the goverment. Since supply side economics was first
applied under President Regan, historically the principal appears to be incorrect. Deficits rose during the Regan era, and went down during the Clintor ear when taxes were raised.

Supply side economics benefits mostly very rich people, especially those who get most of their money as investment income. The puzzle then is why do regular working class people keep voting for Republicans (or were until 2006), even though this is not in their economic interest.

The author's main theses that the people in power simply con the voters, by obfuscating the actual issues (eg. "death tax") and distracting them with social issues that have no economic impact.

This was an interesting book to read - sort of a companion to "What's the Matter With Kansas?" (although I haven't read that book).

Monday, October 01, 2007

Science Fiction - "The Gods Themselves"

This particular novel written by Asimov started as challenge issued to Asimov by a fellow SF writer Rober Silverberg. He dared him to write a story about Plutonium 186 (which does not exist in our Universe). Asimov started writing and instead of a story wrote an entire novel.

The book has three distinct parts, and the three items motif repeats though the whole book.

The first part speaks of discovery of the Electron Pump. An Elecron Pump is a device build around plutonium 186. Plutonium 186 is unstable in our Universe and transforms into another element, giving off energy at the same time. It turns out that this element is "pushed" into our Universe from a parallel Universe with slighthly different laws of physics - there Plutonium 186 is possible.

The man who accidently discovers the bit of Plutonium 93 uses it to create essentialy free source of energy the world. Naturally, he becomes quite famous and admired as the Father of the Electron Pump. Everyone accepts the Pump, except few malcontents who look for a problem with the Electron Pump, in order to discredit the discoverer.

They conclude that the exchange of matter between the two Universes will result in a change of the physical laws of both Universes - this comes from the general principle of conservation of energy. Plus their calculations imply that the Sun will explode as a result of this change and relatively soon. As you can imagine no one believes them, after all this would shut down free supply of energy for the entire Earth.

At this point part one ends. Part two takes place in the parallel universe. There we meet a trio of beings ("the soft ones") who form a family. They are a Rational named Odeen, Emotional named Dua and a Parental named Triit. In Asimov words Dua is the onle "she". It appears that the three are in process of rearing children - they have two already and must create a third one to complete the cycle.

To make children the three must meld together into one entity and stay that way for a while. However, Dua seems to be having some emotional issues, and does not want to meld. In fact, unlike most other Emotionals, she is very interested in what Odin and the "hard ones" are working. The "hard ones" seem to be scientists working on the Positron Pump - but this is not entirely clear.

This part of the book is a bit weird, as Asimov describes how the "soft ones" interact - they can go through rock for example. In the end Dua discovers more about what the hard ones are doing. Plus they all find out what happens after they produce the final child and "move on". But I don't want to give away the details.

Finally, the third section is back in our Universe. Once of the characters from the first part migrates to the Lunar colony and there he finds a way and a device that will allow humans to keep the Electron Pump and not blow up the Sun. This is a good thing.

This book of Asimov was somewhat different than others that I read - the Robot stories or Foundation. It was OK to read, but I don't believe I will read it again.

Oh, the names of the three sections are: "Against stupidity...", "..the Gods Themselves...", "..content in vain".

Wednesday, August 15, 2007

Science Fiction - "Bios"

"Bios" is another book by Robert Charles Wilson (the author "Darwinia"). At the center of the story here is a planet, named Isis which contains very diverse bio-sphere. The problem is that this biosphere is lethal to humans. Any human exposed to any microbe from Isis will in very short time die a very nasty death.

The main main character of the story is a young girl, named Zoe, who has been genetically and mechanically augmented to be able to survive on Isis in light weight gear, as opposed to a fully armored space suit. Her mission is to test out the new gear in the actual environment of Isis.

The human presence on Isis consists of an orbiting space station, and three stations on the planet surface - one at the pole, one in the ocean and one on land. Zoe is sent to the ground based station, which is to be her base of operations.

Zoe gets to explore some of Bios's surface through a flying remote robot. She gets to see some of the larger animals that inhabit Isis In particular she gets to see "the diggers" - a humanoid animals that appear to have some intelligence, who live in underground tunnels (hence the name "diggers").

Shortly after her arrival on Isis she is a witness to an accident which kills a member of the stations crew. He was out fixing stations seals from the outside and his excursion suit is damanged, so that Bios's organims can enter.

While Zoe is getting ready for her first trip outside, bad things begin to happen at the ocean based station. The barrier between the station and the ocean collapses, and sections of the station become uninhabitable. A number of people die, however a small contingent manages to escape up to the space station. At the station these escapees are isolated and quaranteened to prevent any further spread of Isis's microbes.

Meanwhile Zoe goes on her first excursion. Her equipement works well and she is allowed to camp outside overnight. At one point during the night she encounters some diggers, but the encounter does not go well. She is knocked out and dragged into digger's tunnels.

At this point in the story, the microbes on Isis get an upper hand - and all the stations have to be abandoned. Even the space station is not spared.

Unlike in "Darwinia", the author does not pull a trick out of a hat, but takes the story to its logical conclusion. I actually like this - I hate these stories that are "saved" at the last minute by some miracle. There is a touch of mysticism at the end - where Zoe seems to be hearing the voice of the planet, as though Isis itself was a concious, living thing. But the author does not dwell on this.

"Bios" ends with a hopeful postscript - where humans from a later time arrive again on Isis but this time are able survive the enviroment without any problems due to genetic modifications.

Sunday, August 05, 2007

Science Fiction - "The Proteus Operation"

This book, by James P. Hogan, is a book describing an alternate history of the world along with a project - "The Proteus Operation" - that uses time travel to actually correct it. When the story opens in 1960s, United States is the only free country left. All others have been conquered by the Germans and the Japanese. Apparently in early 1940s Germany developed the atomic bomb and was able to defeat Russia and England, and handily win WW II.

In late 1960s time travel is discovered and President Kennedy orders a mission to go back to the 1940s and prevent the Germans from getting the bomb. A team a scientists and military men go back and then the book seems more like a WW II action thriller.

Some historical characters appear at various points: Churchill, Einstein, Roosevelt and other famous scientists.

One unusual feature of the time machines in this book is that they are able to communicate with the future from which they came. The author makes use of the "many-worlds" interpretation of quantum physics and adds the restrictions that the comm link to the future, once established cannot be broken - because on re-connections it may connect to a different world.

I found the book enjoyable, because I do like WW II action/thrillers, but I found that after a while the plot became too large. There were too many countries in the present, past and future involved.

Ultimately there is a happy ending for the team that went back to the 40s. They redirected that wold-line to our time. However, they had to stay there.