Archive for August, 2010

Apple’s iOS iTunes App review, how long?

Friday, August 27th, 2010

This overzealous review process and random rejections of Apple’s iTunes iOS App store has been discussed in all lengths all over the internet by now. It is just that recently we found enough time to finish the first App to be submitted into said App store.

You may wonder how long their review process does take, and so do I, … Until now it took them 7 full days to answer a basic question regarding a minor application meta info detail, and it has been a whole week the App is still pending for review on their side!

The sad thing is that by now we even have a version with the first post release polishing, but are afraid to reject and reload the binary, as according to the iTunes connect documents this would make the updated binary start at the very end of the review queue, again :-(


Update: just after posting this the iTunes connect status flipped to “In Review”, keeping my fingers crossed!

Update 2: now “In Review” for 24h, fun, … (more…)

So how good is the new xz compressor?

Monday, August 23rd, 2010

Recently Roger Mason sent in a patch for T2 adding a new compressor named xz, apparently a successor of lzma.

The google results where a bit brief on comparison between xz, lzma, and the well known bzip2 (and gzip).

So here goes a tiny test, I modified T2 to add support to compress the binary packages with xz, and got this results for a quick test (all compressors are run with -9 for best compression):

204800 lzma-4.32.7.tar
75248 lzma-4.32.7.tar.gz
74304 lzma-4.32.7.tar.bz2
62736 lzma-4.32.7.tar.xz
62655 lzma-4.32.7.tar.lzma

Bzip2 does not particularly shine, and xz neither, … Ok, let us try with something bigger, containing some more raw test, the apache package:

14090240 apache-2.2.16.tar
3098510 apache-2.2.16.tar.gz user 0m1.040s
2331497 apache-2.2.16.tar.bz2 user 0m2.124s
2069252 apache-2.2.16.tar.xz user 0m6.700s
2037338 apache-2.2.16.tar.lzma user 0m13.089s

Hm, xz still does not come out smallest, at least it is not as exorbitant slow as lzma, …

One last try for xz to show it’s potential, let’s use the millions of lines of code that form the current linux kernel:

412897280 linux-2.6.35.tar
88300782 linux-2.6.35.tar.gz user 0m35.118s
69305709 linux-2.6.35.tar.bz2 user 0m54.431s
57065123 linux-2.6.35.tar.lzma user 7m50.453s
56921708 linux-2.6.35.tar.xz user 5m44.266s

Finally! Some 140kB smaller, still slightly faster than lzma, but 10 times(!!!) slower than bzip2, sigh.

All run on an Intel(R) Xeon(R) CPU X5365 @ 3.00GHz, while apparently even the new tools (lzma, xz) only used one of it’s cores (by default).

Your milage may vary.

So why the heck do I blog in English?

Sunday, August 22nd, 2010

Ok, it is the time. Some German people keep bugging me why the heck I do write in English, for example even when I am commenting German topics?

Well, this is due multiple reasons:

First of all I mostly discuss non-German subjects, such as computer science stuff, and other international topics. And I would rather not switch between English and German in every second post. It would also rather confuse readers.

Then, there are also so few people who speak German, according to Wikipedia approximately some 200 million of the nearly 7 billion people on earth. I could rather write in Spanish or Chinese and reach more people than writing in German, … after all I do not want to write a minority report.

Last but not least it is also an protest against the 23 official languages as used in the EU, into which all official papers have to be translated. A process which apparently cost over a billion Euro in 2005!

I find it particularly embarrassing that many politicians in the EU do not speak English, or at least not very well. Even many employees in the food court of the Q205 where I often go for lunch speak better English with tourists than this!!!

I’m all for a United States of Europe, with just English being the official language. This would not only help inter-cultural communication, but also free some billion worth of € for more useful projects, such as education, research and infrastructure development. All certainly more important than producing tons of translated paper every year.

In memories to Knight Rider?

Sunday, August 15th, 2010

Recently a radio broadcast of “Gossip’s Music for Men” made me curious to go to a nearby music store (yeah, I love those old fashioned CDs that you actually own, can listen to in a decade, not until some DRM server goes down), and it struck me: They must be watching too much “Knight Rider” in the 80’s – the base theme line of “Heavy Cross” and “Vertical rhythm” resembles the series’ soundtrack pretty much, … :-)

Linux IEEE 802.1q VLAN the new iproute2 way

Tuesday, August 3rd, 2010

You need to add Linux system (router, server, etc.) directly onto an 802.1q VLAN trunk? Well, for one there is this old (read: deprecated) vlan, the new way is simply via iproute2’s ip:

ip link add link eth0 name eth0.1234 type vlan id 1234

As usual: just substitute the ethernet interface name, alias, and VLAN ID as needed :-)