Company blog

First impression on Windows Vista

nospam@example.com (Andrey Kosyakow) — Fri, 08 Dec 2006 15:18:39 +0300

Well, long awaiting new version of Windows is coming. I'll not want to discuss its new visual enhancements, because personally I still working in Windows 2000 and happy with it. Might be others will find them useful, but I not think they can really increase production of average user greatly.

What I really interested in is a compatibility of our programs with this system. And what we found about this not makes us too optimistic. In addition to visual changes Vista announce new security changes. Microsoft consider them as enhancements, but I can't agree. Enhancements that get pain from MS and bring this pain to end-user are just changes, which makes the things for average user more complex.

So, the main change in Windows Vista is serious restrictions for all running programs. Programs now can work in three modes: restricted or protected, user mode and admin mode. In restricted mode programs do not have access to local file system (except temp folders) and system registry. Actually access to registry is provided, but each protected program will work in its own branch of registry. User mode programs will gain access to HKCR registry and users Documents and Settings folder (easier to say Home folder). When accessing to HKLM registry they also will be redirected to some specific branches of registry visible only for this program. Admin mode programs will gain almost full access, except several critical folders. However it is not enough to be a user with admin rights to run admin mode programs, now each time Vista will request your permission to launch such programs. And to addition to this three modes now appears Super Admin account (as root on unix) which will will have almost full access, but once again except some critical folders.

The main issue caused by above enchantments is that you not know, if not specify explicitly, in which mode will run your program. More other for one user it can work in one mode and for other in another. This especially makes sense when you developing not an standalone application but just some extension module (dll). Running from different programs from the same user account it will access to different areas of registry and has a different limitation accessing to local file system.

All this is just pain, both for developers and for users. It is impossible to realize that now when you will try to store image file from IE, Vista will ask your permission to do that. Permission request dialogs occurs so often, that after some time you just ignore them.

Might be all above is really reasonable, but this is not the OS which I'll like, this is OS for dummies. Any normal user which is smart enough to not open I love you letters and use windows update functionality will get pain. My advise is not to move on Vista and wait for some time while probably Microsoft makes limitations softer, or at least all vendors adopt their programs for Vista.

Satellite Internet requires accelerator

nospam@example.com (Sergey Korotkov) — Tue, 04 Jul 2006 17:18:33 +0400

Our company uses satellite access for inbound Internet traffic. This allows us to save money and download faster. We use «planetsky» satellite provider. Few months we not used any accelerator and come to wrong conclusion that satellite access is cheaper but cannot provide adequate speed for us. In the our working hours we get average throughput about 256kbps and less. At night hours throughput was near to ordered 1mbps.

When we managed to install and configure tellitec accelerator (free for planetsky), speed increases significantly. Now during entire day we can borrow ordered 1mbs and more.

So, as the general conclusion if you use satellite access you have to use accelerator. Accelerator is a piece of software which provide http proxy and(or) SOCKS proxy interfaces. Accelerator rely on great fault tolerance of satellite (DVB) traffic, which allows to remove extra TCP service packets (confirmations). This allows to send several TCP packets as one large packet. Accelerator also compresses this large packet, that increases effectiveness.

MS Installer upgrade policy moot point: what mean small, minor and major modes.

nospam@example.com (Sergey Korotkov) — Tue, 04 Jul 2006 15:01:30 +0400

The starting point for issue was just the desire to make .msi package which can be installed on user PC with single click not depending on existence of previous version. We use the WIX tool set to build an MSI packages. Without any efforts for upgrade policy every new installer version shows old version un-install dialog and on second run install dialog. Such behavior confuses users because they click on .msi file of new version but un-install dialog from previous versions are shown up.

We quickly found the reason and solution of for this issue. It is required to follow upgrade policy for MSI packages: put the UpgradeCode attribute and change correctly GUIDs of Product ID, PackageID and Product Version. Depending on what from above is changed upgrade can be "small", "minor" and "major". As described in MSDN:
* Small updates mean small changes to one or a few files where the change doesn't warrant changing the product version (major.minor.build). You don't have to change the Product GUID, either. Note that you always have to change the Package GUID when you create a new .msi file that is different from the previous ones in any respect. The Installer keeps track of your installed programs and finds them when the user wants to change or remove the installation using these GUIDs. Using the same GUID for different packages will confuse the Installer.
* Minor upgrades denote changes where the product version will already change. Modify the Version attribute of the Product tag. The product will remain the same, so you don't need to change the Product GUID but, of course, get a new Package GUID.
* Major upgrades denote significant changes like going from one full version to another. Change everything: Version attribute, Product and Package GUIDs.

So, definitely if we release "minor" (or bugfix) release then we have to use "minor" upgrade. When we release new major version of product then we have to use "major" upgrade. All seems to be smart and clear. But there are one cavern: when new MSI is a "small" or "minor" upgrade .msi file cannot be installed by single click because it asks to explicitly un-install old version. The surprising fact is that "major" upgrade does not ask this and installs silently as required. It is not an issue for us and we can build "major" upgrades each time, but this is the thing that I not understand. Why "minor" upgrade which intended to be a "bug fix" which does not make any serious changes cannot install silently, but "major" upgrade which can break anything is allowed for silent install.

Even this seems to be a logic breaking behavior nothing understandable can be found from Microsoft. The only thing we have found is:
You Need to Uninstall Previous Versions with Add/Remove Programs in some Situations When an administrator installs an application with an .msi file, they can choose whether it is installed "For Everyone" or for "Just Me." If the administrator chooses "For Everyone" and then you subsequently provide an upgraded version of the installer that specifies earlier versions should be removed (by setting the RemovePreviousVersion property), this setting does not work correctly and instead the installation overwrites files without prompting. This can obviously cause serious problems for your application. As of this writing, there is not a good workaround for this, so users must use the Add/Remove Programs utility to remove the earlier version before installing a later one.
I cannot understand what they explain here, especially taken into account that major upgrade does work and not require manual de-installation. The work around which make possible silent launch of small/minor upgrades is launch of msiexec with specific parameters:

msiexec /i SampleUpgrade2.msi REINSTALL=ALL REINSTALLMODE=vomus

Don't ask me how this would fare with the average user... You'd better start it from an Autorun.inf file or devise an outer Setup.exe shell to launch it.

May be somebody knows why this works so? I'm appreciate any comments.

Slow boot and work of Linux 2.6 686 kernel

nospam@example.com (Sergey Korotkov) — Thu, 25 May 2006 17:54:30 +0400

Last days I got this problem with our debian installation. Generic 486 kernel were working fine, but when I tried to upgrade to 686 smp kernel, machine started to work extremely slow. I have found few articles on the web with same problem but without any resolution.

After few hours of experiments I had solved the problem. This was wrong configuration of integrated video. We use this PC as server and configure minimal possible video RAM size - 8 mb. After enlarging this to 32 mb and assigning the AGP aperture size to the same 32 mb kernel begin to work fast.

We also noticed that small video RAM size also slowdown WinXP on the same PC, but it has another behavior. After rebooting PC works fine, but then it became slower, slower and slower. Adjusting of video RAM size solved the issue.

And finally the issue happened on ASUS P4V8X-MX motherboard.

GCC compiler seems to be very smart

nospam@example.com (Andrey Kosyakow) — Thu, 25 May 2006 17:51:22 +0400

Working on integration of ffmpeg library which only can be compiled with GCC compiler I had found that GCC compiler can validate type and number of parameters of printf function. Very smart, in contrast, MS compiler ignores that and program can crash due to this.