MSDN has released a guide on how to harness the power of P2P in Windows Vista for developers. Microsoft P2P solution intends to reduce the barriers that are common to traditional P2P applications.
Traditionally, challenges to P2P application development have included the need to develop proprietary protocols for message exchange, having to locate and connect with instances of an application that are hidden behind a Network Address Translation (NAT) or a firewall, and the need to support the inevitable infrastructure required to locate applications in a wide-area network (WAN). These challenges, while surmountable, have represented a substantial barrier, and as a result, many of us never consider the amazing collaborative functionality P2P applications provide.
Schools Interoperability Framework (SIF) Overview
0 Comments Published September 29th, 2006 in Infrastructure.
The Schools Interoperability Framework Association (SIFA) is a non-profit membership organization whose members include over 300 software vendors, school districts, state departments of education and other organizations active in primary and secondary (pK-12) markets. These organizations have come together to create a set of rules and definitions which enable software programs from different companies to share information. This set of platform-independent, vendor-neutral rules and definitions is called the SIF Implementation Specification. The SIF Specification makes it possible for programs within a school or district to share data without any additional programming and without requiring each vendor to learn and support the intricacies of other vendors’ applications.
The Implementation Specification defines the software implementation guidelines for SIF; it does not make any assumption of what hardware and software products need to be used to develop SIF-certified applications. Instead, it defines the requirements of architecture, communication, software components, and interfaces between them.
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Jini and Universal Plug & Play are the prominent device coordination frameworks for information appliances. These architectures are essentially coordination frameworks that propose certain ways and means of device interaction with the ultimate aim of simple, seamless and scalable device interoperability.
Device coordination provide a subset of the following capabilities to a device:
- Ability to announce its presence to the network
- Automatic discovery of devices in the neighborhood and even those located remotely
- Ability to describe its capabilities as well as query/understand the capabilities of other devices
- Self configuration without administrative intervention
- Seamless interoperability with other devices wherever meaningful
Top 5 Risks to Use Public IM Within an Organization
1 Comment Published September 28th, 2006 in Technology.
As instant messaging technology is embraced by information workers and their organizations, it is important that system administrators and information technology (IT) professionals within these organizations recognize both the value and the potential risks posed by this new technology.
For some organizations, the use of public IM clients is an acceptable, low-cost alternative to traditional forms of communication. However, reliance on public or consumer-class IM applications creates some unique obstacles:
Risk 1
The organization has little or no control over how IM applications are used and implemented. Public IM applications cannot be easily “locked” to constrain the types of messages sent or with whom they may be exchanged.
Risk 2
The lack of interoperability between major IM applications makes standardization difficult. Users may have to install multiple IM clients to communicate with all of their intended parties.
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Ever been asked a question similar to “I wanna to find out who is logged in last night at 8:34″?
The last command for Solaris tells who was or still is on the system. You may want to use with ‘| more‘ to be able to page through the log. It offers great feature for tracking who was on your system last, how long they stayed logged in and from which terminal or machine (IP) they came from. It will save your day by tracking those would-be party-crashers.
If you want an enhanced version of last, you may want to try out Matty’s lastx. lastx is an extension of the last utility shipped with Solaris. It prints all 32-characters of the users utmpx entry, and provides facilities to display last data over a period of days. It also allows the user to print unique logins, and the total number of attempted logins. However, you need to compile the program yourself as it comes with source only.
How successful is mobile Java? Everybody will have to agree that you hardly see any mobile Java applications. You will see far more Symbian applications than mobile Java application. This is in contrary to Nokia, the largest player who has outshipped the entire PC industry by a factor of close to three, delivering 153 million mobile phones to consumers in the first half of this year. What went wrong?
According to Nokia, “What happened is that in the early days of J2ME we had MIDP and a bunch of different APIs, but nobody defined a framework that every handset should support. A lot of handsets offered MIDP support, but what additional APIs were supported varied between different operators and different handset manufacturers.” This is no surprise in an industry where APIs go through cycles of consolidation from day one they are published. The solution is naturally another consolidation, this time under the name of Mobile Service Architecture, or MSA.
Web 1.0 was about building websites to publish contents in HTML and sell things. Search engines are the single point of access for most web users. The higher the hit rate a website has, the higher the value it has.
Web 2.0 is about using the Web collaboratively — sharing and mixing up information and resources. The whole content pool is being analyzed by millions of talented web users. Users can consume or create contents in a personalized way either through blogs or wiki.
Search engines provide ad-hoc searching for unorganized contents as well as channels to deliver targeted contents. The playing field is spending money inside the Web to promote websites by creating as much links as possible. The higher the number of links a website has, the higher the value it can generate.
O’Reilly gives as examples: eBay, craigslist, Wikipedia, del.icio.us, Skype and Adsense
.mobi is a top-level domain approved by ICANN as a sponsored TLD. It will be restricted to mobile devices and sites providing services for them on the Mobile Web. It is sponsored by a consortium of companies including Google, Microsoft, Vodafone, Samsung, Ericsson and Nokia. As of November 2005, the domain had been added to the global internet root and was getting ready for its opening. Starting May 22, 2006 industry members can register a .mobi domain name, June 12 for trademark holders, and Sept. 26 general registration. Over 12,000 companies have already registered their brands online for their .mobi site and some sites are even launched.
So why is this exciting ? Well how many times have you tried to surf the Internet from your device only to find that all the sites have been designed for a 17″ 1024×768 screen? How many times have you waited for a complex site to download and then given up? So if you access a .mobi site you’ll know that it will work on a mobile device! Try out live.mobi where you can now access your hotmail/live mail, spaces and even mobile search!
Jason Langridge has provided a list of sites that you can browse using any WAP browser or Opera Mini Simulator (require Java).
- info services: weather.mobi, msn.mobi
- sport & leisure: kicker.mobi
- entertainment: Tipp24.mobi
- retail: neckermann.mobi
- cars: bmw.mobi
Mr. Cantrill came up with the general idea for DTrace in 1996, while he was a computer-science student at Brown University, but didn’t get to start work on it until late 2001. It took nearly three years for him and his team — Michael Shapiro, a Sun distinguished engineer, and Adam Leventhal, a staff engineer — to make it work; a final version shipped early last year as part of Sun’s Solaris 10 operating system.
Where most debugging takes place as software is being developed, DTrace analyzes problems with systems that are in production — running a company’s database, say, or executing stock trades. It does this with a process called “dynamic tracing,” which enables a developer or systems administrator to run diagnostic tests on a system without causing it to crash. Before DTrace, such tests often took days or weeks to reproduce the problem and identify the cause. With DTrace, performance problems can be tracked to their underlying causes in hours, even minutes.
It is time to get serious about DTrace folks. Sun has provided quite a number of guides to get you started. You can find the official resources at BigAdmin DTrace and also enough examples to get you excited at Brendan Gregg’s Homepage.
via WSJ
Large sequential I/O can cause performance problems due to excessive use of the memory page cache. One way to avoid this problem is to use direct I/O on filesystems where large sequential I/Os are common. Direct I/O is a mechanism for bypassing the memory page cache alltogether.
DIRECTIO_ON allows you to force directio per-file and is used by Oracle database. The idea is that with a properly sized memory area the database can manage its own buffering and avoid the overhead of copying to kernel buffers. Even after the database is shut down directio will persist for a long time. The flag is set in the inode’s i_flag and hangs around cached within the inode in the DNLC and will effect files until the inode is flushed from the DNLC.
John Alderson demonstrated the problem using two simple C programs.