castanyes blaves

Random ramblings about some random stuff, and things; but more stuff than things -- all in a mesmerizing and kaleidoscopic soapbox-like flow of words.



Coordinated releases

Mark Shuttleworth » Blog Archive » Economic clustering and Free Software release coordination
I had the opportunity to present at the Linux Symposium on Friday, and talked further about my hope that we can improve the coordination and cadence of the entire free software stack. I tried to present both the obvious benefits and the controversies the idea has thrown up.

Afterwards, a number of people came up to talk about it further, with generally positive feedback.

Christopher Curtis, for example, emailed to say that the idea of economic clustering in the motor car industry goes far further than the location of car dealerships. He writes:

Firstly, every car maker releases their new models at about the same time. Each car maker has similar products - economy, sedan, light truck. They copy each other prolifically. Eventually, they all adopt a certain baseline - seatbelts, bumpers, airbags, anti-lock brakes. Yet they compete fiercely (OnStar from GM; Microsoft Sync from Ford) and people remain brand loyal. This isn’t going to change in the Linux world. Even better, relations like Debian->Ubuntu match car maker relations like Toyota->Lexus.

I agree with him wholeheartedly. Linux distributions and car manufacturers are very similar: we’re selling products that reach the same basic audience (there are niche specialists in real-time or embedded or regional markets) with a similar range (desktop, workstation, server, mobile), and we use many of the same components just as the motor industry uses common suppliers. That commonality and coordination benefits the motor industry, and yet individual brands and products retain their identity.

Let’s do a small thought experiment. Can you name, for the last major enterprise release of your favourite distribution, the specific major versions of kernel, gcc, X, GNOME, KDE, or Mozilla that were shipped? And can you say whether those major versions were the same or different to any of the enterprise releases of Ubuntu, SLES, Debian, or RHEL which shipped at roughly the same time? I’m willing to bet that any particular customer would say that they can’t remember either which versions were involved, or how those stacked up against the competition, and don’t care either. So looking backwards, differences in versions weren’t a customer-differentiating item. We can do the same thought experiment looking forwards. WHAT IF you knew that the next long-term supported releases of Ubuntu, Debian, Red Hat and Novell Linux would all have the same major versions of kernel, GCC, X, GNOME, KDE, OO.o and Mozilla. Would that make a major difference for you? I’m willing to bet not - that from a customer view, folks who prefer X will still prefer X. A person who prefers Red Hat will stick with Red Hat. But from a developer view, would that make it easier to collaborate? Dramatically so.

Another member of the audience came up to talk about the fashion industry. That’s also converged on a highly coordinated model - fabrics and technologies “release” first, then designers introduce their work simultaneously at fashion shows around the world. “Spring 2009″ sees new collections from all the major houses, many re-using similar ideas or components. That hasn’t hurt their industry, rather it helps to build awareness amongst the potential audience.

The ultimate laboratory, nature, has also adopted release coordination. Anil Somayaji, who was in the audience for the keynote, subsequently emailed this:

Basically, trees of a given species will synchronize their seed releases in time and in amount, potentially to overwhelm predators and to coordinate with environmental conditions. In effect, synchronized seed releases is a strategy for competitors to work together to ensure that they all have the best chance of succeeding. In a similar fashion, if free software were to “release its seeds” in a synchronized fashion (with similar types of software or distributions having coordinated schedules, but software in different niches having different schedules), it might maximize the chances of all of their survival and prosperity.

There’s no doubt in my mind that the stronger the “pulse” we are able to create, by coordinating the freezes and releases of major pieces of the free software stack, the stronger our impact on the global software market will be, and the better for all companies - from MySQL to Alfresco, from Zimbra to OBM, from Red Hat to Ubuntu.

The basic idea is that if companies are coordinated in synchronized time-based releases, they create an environment that is predictable. Even though each company or project will compete for a given market or user base, there is always a common ground. Time-based software or data releases facilitate the integration between different projects. When the releases are feature-based, there is always a tendency of delaying the next version until the new features and perfectly shaped. This doesn't mean that time-based releases should not be focused in delivering great features, but it's more a case where features should be granular enough so that they can be both very innovative and striking and quickly released and used. When time-based releases are coordinated, everybody will be honest and balance their interests in generating new interesting features with the need of delivering them in time. The granularity of new features doesn't have to be strict, and a feature can be developed in parallel to a number of releases, being kept in a development branch, until it's ready to be merged to the main branch.




Havoc's Blog July, 2008
Posted 2008-07-27

If assembling a system from parts, it looks better to get a somewhat larger case with a case fan, rather than a tiny case with a CPU fan. A maybe-working example of this could be:

* Silverstone GD02 case $160
* Silverstone fanless power supply $140
* An oddly-shaped heatsink apparently designed to fit in the GD02 case (advertised to run fanless for CPUs up to 65W) $50
* Celeron 430 $40
* DG45ID board $140
* 2G RAM $50
* 2.5-inch notebook drive $100
* Standard-def read-only DVD drive $20
* Wi-Fi card $50

Total hypothetical cost: $750

This has case fans, but with the slow CPU and notebook drive it may be possible to turn them off or dial them way down. The fanless power supply is expensive; the Nexus quiet power supply fan in my development system is pretty inaudible, so perhaps that is a better option, saving $70 or so and bringing total cost to only $680. A power supply fan could reduce the need to run the case fans. Scrounging for stuff on sale could save a few more dollars no doubt.

These built-from-parts systems always run over budget when it turns out some part doesn't work with some other part.

An expensive version could have instead:

* Extra-quiet case fans +$40
* E7200 processor +$85
* 4G memory +$50
* Blu-Ray drive +$80

Total extra cost +$255 so the "deluxe" approach is $1005.

Though larger and uglier, this system would be roughly comparable in cost to the Mac Mini, despite much better hardware specs. However, if a next-generation Mac Mini ever came out, I'd expect it to have specs and cost similar to the above. It would quite possibly use the X4500HD chipset, even.

Looks like nobody sells the X4500HD Intel motherboards until late August, so I'm not going to run out and buy anything. Maybe better options will come along in the meantime.



Useful Emacs shortcuts for editing R scripts

Editing R scripts and running them in Emacs makes life much easier than using the R console or a decoupled editor.
Here are some of the basic tips:

M-x R to start a R session
C-c C-n to eval a line
C-c C-r to eval a region

Now if you find yourself looking at the documentation a lot, to check the parameters of a function, you can place the cursor over the function and use:

C-c C-v (ENTER to confirm)

Another useful command is for killing an R session that got into trouble because you are trying to load too much stuff or compute something you didn't mean. For that, you can use:

C-c C-\







The killer oceans: What really wiped out the dinosaurs? - Science, News - The Independent
The killer oceans: What really wiped out the dinosaurs?

Did asteroids really wipe out the dinosaurs? Scientists now think rising sea-levels were to blame – and they could threaten our survival too.



Green Cars

BBC NEWS | UK | Brown to call for more green cars
Brown to call for more green cars
Gordon Brown
Gordon Brown wants a revolution in the way Britons drive

Gordon Brown will call for a revolution in the use of electric and low carbon cars when he pays a visit to the British International Motor Show.

The prime minister will say these vehicles must become a common sight on Britain's roads if the UK is to meet its targets on carbon emissions.



Formula 1 technology applied to Hybrid Cars

The Official Formula 1 Website
KERS will enable the regeneration and storage of braking energy, which will then be available on tap as an extra source of power under acceleration to complement the output of a Formula One car’s V8 engine. Flexibility in the regulations will allow for either electric or mechanical solutions, with BMW Sauber opting for the former.

The 2009 BMW Sauber F1.09 will be equipped with a hybrid system consisting of a combination of electric motor and generator, the requisite power electronics and an energy storage module. In accordance with the regulations, this will store enough energy under braking to provide an additional 60 kW of output over around 6.5 seconds of acceleration.

BMW already use a brake energy regeneration system in a large number of their production cars. Although their Formula One KERS will not be dissimilar in principle, its efficiency and packaging - the complete system will weigh under 40 kg - should be in a different league.

“We are standing at the threshold between a conventional package of engine and independent transmission and an integrated drive system. The power density of the KERS components will far exceed that of today’s hybrid vehicles,” added Theissen.



Preloading tables

Quickly preloading Innodb tables in the buffer pool | MySQL Performance Blog
So As I mentioned you can load Innodb Table Clustered Index in the buffer pool pretty efficiently by using something like SELECT count(*) FROM tbl WHERE non_index_col=0 This works relatively well (though can be slow for fragmented tables) but it does not preload indexes in memory neither it does externally stored objects - BLOB and TEXT fields.

If you would like some non PRIMARY Indexes preloaded you can use something like SELECT count(*) from tbl WHERE index_col like “%0%” for each index. Only one such query per index is enough even if it is multiple column index.

To fetch BLOB/TEXT externally stored columns you can use similar query: SELECT count(*) from tbl WHERE blob_col like “%0%”. Note if you preloading BLOB/TEXT columns you do not need to use first query I mentioned because scanning potentially externally stored blobs will also scan Clustered key Anyway.

Now, say you have bunch of tables having few indexes - should you run multiple queries in parallel to get best preload speed ?
It depends - depending on key/clustered key fragmentation it may be faster to run queries one by one (keeping IO more sequential) or run multiple queries at once to get more outstanding requests at the same time - benchmark to find out.

If you just need to preload single large table you can chop it into several ranges and preload in parallel, such as SELECT count(*) FROM tbl WHERE id BETWEEN 1 and 10000000 AND non_index_col=0


Very much like the plot from "I am legend"

BBC NEWS | Health | Virus helps show cancer spread
Virus helps show cancer spread
Prostate cancer cell
A cold virus was used to "infect" prostate cancer cells

Scientists have used a common cold virus to "light up" prostate cancer tumours in different parts of the body.

It could make it easier for doctors to track the spread of the disease, and check the effectiveness of treatment.

A University of California at Los Angeles team found the virus "infected" prostate cancer cells in mice, then made them visible to scanners.

UK experts welcomed the Nature Medicine study, and said a more sensitive scan would be "very valuable".


Building permits / Markets - Why Spain is beating the UK
The main Spanish stock index, the IBEX 35, is down 21 per cent this year, versus 16 per cent for the FTSE 100. Also, OECD projections for economic growth this year and next are better for the UK. And the Spanish construction industry has already cut 300,000 jobs, which puts the 5,000 or so lost in the UK this week into perspective. (The Keynesian joke here is that some Spanish construction workers will find re-employment demolishing the oversupply of homes, as local powers react by discovering the absence of proper building permits.)




From the Independent:

Brown oblivious as tiny terrorist makes attempt on Rice's head.

President Bush, nervous because terrorists take advantage of his attendance at primary schools, remains unaware of small missile disguised as blackboard eraser creeping slowly toward his right arm.


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