Apple unveiled the new iPad Wednesday calling the third-generation device simply the new iPad, not iPad 3 or iPad HD. The dingus does, however, have that to-die-for high-resolution retina display it was rumored to have. It also has a souped-up A5X chip, and a new five-megapixel iSight camera. The new chip includes quad-core graphics said to be 4x better than a Tegra 3 or 2x better than the performance of the iPad 2. The camera’s advanced optics can capture 1080p HD video and includes a new video image stabilization feature that removes the bumps and shakes typically seen when filming with a handheld device. The screen, the same 9.4-inch size as the iPad 2, offers 264 PPI, which means the human eye can’t see an isolated pixel. The resolution, as expected, comes in at 2,048 by 1,536, or 3.1 million pixels, a million more than HDTV.
Whether ‘tis nobler in the mind to suffer the slings and arrows of your IT manager or to take up cache against a sea of data. With apologies to Bill Shakespeare, the IT Dog is discussing two different cache write policies: write through and write back. Let me take a run at telling you what they are, why they are different and what you need to think about when you decide what policy to use.
Cache Write Through
This is the easier to explain and understand of the two policies discussed here. Cache write through is like having your cake and eating it too. Data is written into cache for fast retrieval when needed for a future operation and at the same time, the data is written into the underlying memory location (think central database or primary storage here). Why is cache write through good? Because it insures the integrity of the data in the database so if another application needs to access the same data, you can be sure the data in the database is correct or ‘fresh’. Another benefit to cache write through is there is always a good, reliable copy of the data in the database if something happens to the cache itself (e.g. power failure). “So Dog, why wouldn’t I do cache write through all the time?” Well, because cache write through has a little problem in that the writing application must wait for the completion of the write into the primary storage before it can proceed with the next operation and as you well know, writing to primary storage can be slow which is why you are using cache in the first place. Write through cache can therefore slow down the application. So you get data integrity and assurance at the expense of application speed.
Getting Down And Dirty
We need to get a little dirty here to explain cache write back. No, not that kind of dirty; we are still talking about data and applications here. Cache write back uses cache as the temporary storage for the ‘freshest’ data and that same data is updated in the primary storage at a later time. This means that when a data location is updated, it is written to only to cache, not to primary storage and the data in cache is termed ‘fresh’. The corresponding data location in primary storage now does not match the ‘fresh’ cache data and is now considered ‘stale’. The cache controller keeps track of the state of the primary storage (fresh or stale) by using a ‘dirty’ bit to indicate if the data in the primary storage matches the cache data copy or does not. If a request for the stale data from primary storage comes in from another application, then the controller has to update the primary storage location before the application can use the data. “Why would I use this cache policy?” Well, because data is not written into slower, primary storage each time it is updated, the writing application does not have to wait for the write to primary storage to be completed before moving on to the next operation so the application runs faster. The problem with this policy is there is a small chance that the fresh cache data (or the dirty bit) can be corrupted before the data is written into primary storage. So you get speed at the expense of possible loss of data integrity.
What To Do When?
The question on which of these two cache policies to use depends on the application. Applications that absolutely cannot risk data loss (banks storing real-time trading info, continuous data protection in back store) should use write through cache policy and applications that can tolerate data loss (back end, analytics, etc.) can speed performance by using write back cache policy.
Tell Me What Your Policy Is
Let me know if you have experience with using either write back or write through cache policy and what you have learned from deploying that technique.
The Spring Data Neo4j Project This project is part of the Spring Data project, which brings the convenient programming model of the Spring Framework to modern NOSQL databases. Spring Data Neo4j, as the name alludes to, aims to provide support for the graph database Neo4j. The first part of the book provides a tutorial that walks through the creation of a complete web application called cineasts.net, built with Spring Data Neo4j. Cineasts are people who love movies, and the site is a gathering place for moviegoers. For cineasts.net we decided to add a social aspect to the rating of movies, allowing friends to share their scores and get recommendations for new friends and movies. The tutorial takes the reader through the steps necessary to create the application. It provides the configuration and code examples that are needed to understand what's happening in Spring Data Neo4j. The complete source code for the app is available on Github.
You bought a static rule-based correlation and you want to get the most out of it, or are you planning on getting and deploying one? There are some simple steps you can take to maximize its efficiency. The main use case for correlation is real-time incident management, so you need a 24x7x365 team of forensics experts to validate and follow-up on alerts - in real time. No need to have real-time correlation if you only have a 9-5 operation... If an alarm goes on at 3.a.m., do you have the skilled staff to act on it? If the answer is no, can you afford such a team? If you can't afford a 24x7 staff of experts, ask yourself if correlation is really the most appropriate effort for you.
There’s no iPad 3, CNET said Tuesday, hours before the dingus is supposed to be unveiled Wednesday. It’s going to be called iPad HD after the gadget’s reported new retina-like 2,048 x 1,536 screen. CNET got it from a developer “who’s previously provided reliable information with respect to things Apple.” VentureBeat, using similar sourcing, is saying the same thing, following Gizmodo last week and the Verge last July. VentureBeat says, “ The higher-resolution display will not only make text and pictures sharper, it’ll also make the iPad HD the only tablet to support 1080p high-definition at its full resolution (1,920 by 1,080). Expect Apple to market the hell out of that feature.” Then it added, “Android tablets have been sporting 720p HD displays (1,280 by 720) for some time now, but if the reports are true, the iPad 3’s display will blow Android slates out of the water.”
As evident from various social media interactions, blogs, tech news sites and other Google searches, the two events that clearly brought the attention of every one happened in quick succession. Interestingly there are huge discussions about the issue of ‘Windows 8 vs iPad 3,' while the former is an operating system, latter is a tablet device, yet the discussions are pointing to the fact that Windows 8 will facilitate other non-iPad tablet manufacturers to pose a serious challenge to iPad3. Analysts claim that while Apple iPad3 is expected to increase the market size further in the tablet field, Windows 8 has enough features to induce a new Windows 8 tablet market that can pose a serious challenge to iPad 3. As it always happens in any kind of competition between innovative products, only time and their respective marketing strategies will provide the final results.
Over the last five years one of my responsibilities was interviewing and hiring software developers and many of them were physically located overseas. In this post I’d like to share with you my thoughts (and get your feedback) on one of the aspects for offshore hiring: pros and cons of hiring individuals vs. teams.
Alexander Podelko, a performance expert working with Oracle, recently wrote a blog post in which he takes a look at the current state of the APM market and what he thinks needs to change in order for companies to get … Continue reading
Apple’s App Store hit 25 billion downloads Saturday. That’s up 10 billion since July and 15 billion since last January. The App Store opened in July of 2008 so it’s not yet four-years-old. It now stocks 500,000 iPhone apps and 140,000 iPad-specific apps. Google’s Android Market, which opened a few months later in October 2008, had wracked up 10 billion downloads this past December, when the Mac App Store, which opened in January of 2011, had 100 million downloads.
In its biggest enterprise move ever RightScale has cut a strategic partnership with Equinix, the ubiquitous co-location peddler tight with a lot of the world’s high and mighty, folks RightScale expects to make a happy hunting ground. After all Equinix services more than 4,000 companies and 300 cloud service providers – a lot of them Fortune accounts – out of 38 data centers in the Americas, Europe/Middle East/Africa, and Asia-Pacific. Anyway, the pair will deliver what is called a complete cloud package for SPs and corporations, dangling RightScale’s Cloud Management Platform in front of prospective and existing Platform Equinix customers along with the prospect of managing all their clouds – public, private, hybrid and multi-cloud – from a single dashboard.
Okay, so you’ve got all this Big Data. Now what? According to Alpine Data Labs, the two-year-old Big Data start-up incubated inside Greenplum, all that stuff bulging out of your storage is useless. Unless it’s susceptible to predictive analytics, but finding those nuggets of insight can be a pretty pricey exercise. Alpine set out to take the sticker shock out of the equation with its initial product, Alpine Miner, which simplifies the process of building predictive models for massive datasets without using a single line of code. It’s supposed to be fast and intuitive, streamlining and enhancing data scoring and fully capturing organizational knowledge basically on the cheap. It works in the enterprise data cloud or in the data warehouse to make sure you’re using everything and are therefore accurate. Fancy that. The widgetry was advertised as the first predictive modeling solution for Big Data.
VMware has integrated the Spring Framework with Apache Hadoop to create what it straightforwardly calls simply Spring Hadoop. It’s supposed to make it easier for enterprise developers to build distributed processing solutions with Apache Hadoop. Spring is supposed to simplify data access and be a “natural way to integrate Hadoop systems into the enterprise application landscape.” The widgetry is downloadable and available under the Apache 2 license. Among other things it supports configuration, creation and execution of MapReduce, Streaming, Hive, Pig and Cascading jobs via the Spring container and comprehensive HDFS data access support through JVM scripting languages (Groovy, JRuby, Jython, Rhino, etc.).
One of the really great features in Tiggzi mobile app builder is that you can quickly export the app as mobile Web, Android or iOS: For Android, you can get a ready for the app market binary file (Release binary). Just take the file and upload it to Android Market. It’s that simple.
Apple Thursday won an injunction in Germany against all Motorola Mobility devices that infringe a photo gallery patent. If Apple enforces it, MMI will have to destroy all the implicated widgets in its possession and recall those out in the channel. That currently means the Xoom tablet and two smartphones. The FOSS Patents blog says MMI’s only recourse is to modify the Android operating system, drop the zoom-in feature and degrade the user experience. MMI successfully defended the zoom-out mode. It’s the second injunction Apple has won from the same Munich Regional Court against Motorola in the last two weeks, making Apple’s score two for two. It’ll cost Apple a €35 million bond to enforce both injunctions.
Here we are on the cusp of the iPad 3 introduction next week and Apple, whose market cap has now passed a half-a-trillion dollar, as in trillion – finds itself in the ludicrous position of being sued by a bankrupt Chinese company on the verge of being delisted from the Hong Kong Stock Exchange over the iPad trademark. Proview may be flat broke but it seems to have money enough for lawyers and press agents and that may be because Proview’s assets including the trademark was seized by three big Chinese banks in 2009 after it defaulted on a $400 million loan. Anyway, Proview has opened a legal front in the US where it is now suing Apple in California’s Superior Court in Santa Clara for fraud and unfair competition. It figures it was snookered because Apple used a third party to buy the trademark rights, a common enough device in both the US and China, but Proview alleges fraud by intentional misrepresentation, fraud by concealment and fraudulent inducement.
Design patterns were not born equal. Some of them are boring, while others are special. Do you remember your feelings after learning what the Data Transfer Object is? Don’t remember? Of course – cause you didn’t have any special feelings about it other than “It’s easy”. What do you say about Singleton? Yeah, this is [...]
Apple Tuesday sent out an invitation for what is assumed to be the iPad 3 unveiling next week on Wednesday March 7. The festivities will be held in San Francisco, not New York as CNBC put out there for a while. The invite makes no mention of what Apple’s announcing. It just reads: “We have something you really have to see. And touch.” All the signs of course point to the next-generation tablet that may or may not be called the iPad 3. The device could be based on souped-up new Apple-made dual- or quad-core ARM chip. The rumor mill had also suggested it will be 4G LTE-capable, with a higher-resolution screen and camera and perhaps function as a new stage for Siri to beguile. First deliveries are reputedly set up to start March 9.
Java is the technology of choice for high-end enterprise applications. The most common applications that developers are involved with are JavaServer Pages web applications, also known as JSP applications. JSP has become one of the two standards for developing high traffic web applications, the other being Microsoft ASP.NET. Being part of Java, JSP has been popular for a long time and is highly instrumental in promoting Web technologies for developing high-traffic applications. Millions of people are using JSP applications and those numbers keep growing. These JSP applications are endowed with an architecture that scales very nicely. You can handle more and more users by adding more web servers to a load-balanced Web farm. As you have an increasing amount of transaction load, you just keep adding more servers to the Web farm. That way you can handle more transactions and more concurrent users.
The International Trade Commission has thrown out the first of two HTC infringement complaints against Apple, the one filed in May of 2010. ITC commissioners last Friday upheld the findings of the agency’s administrative law judge last year. He found that Apple doesn’t infringe any of four asserted HTC patents. HTC only appealed on one of the patents. Patent follower Florian Mueller observes that “Smartphone-related patents have a very high drop-out rate at the ITC. In my observation, only about one out of 20 asserted patents is deemed violated. The challenges that patent holders face at the ITC have contributed to the popularity of certain German courts, especially the Mannheim Regional Court and the Munich I Regional Court, among patent plaintiffs.”
Proview, the bankrupt Taiwan-Mainland China display house that apparently – through slight of hand – rooked Apple out of the rights to the iPad trademark in China – is supposedly making settlement noises after a Shanghai court refused to stop iPad sales in the city pending a decision by still another, higher court in another province that won’t hear Apple’s case until next week. Meanwhile Proview reportedly means to appeal. Apple, which has three stores in Shanghai, is itself appealing a decision made by a court in a place called Shenzhen that said Apple doesn’t own the name. Proview has taken advantage of that initial Shenzhen decision to get iPads in the channel confiscated in some Chinese cities.
An outfit called OnLive has put a virus-free Windows 7, not 8, 7, plus the whole Office suite, Adobe Reader and a one gigabit-a-second Internet connection with the data sized to fit, on the iPad. It works virtually through a remote computer farm sort of like GoToMyPC writ large. Microsoft’s helping since its Touch Pack add-on makes Windows iPad-friendly, or at least stylus-friendly. The service, which, by the by, can run Flash content (think Hulu), runs five bucks a month. There’s also a cut-down free version with two gigs of storage and someday a $10-a-month service that puts any Windows program you license on the iPad.
Agile team should self-organize. The Scrum Master can influence the process but not directly intervene. We all know this. Well, if you are not sure how this process works then you should read what Mike Cohn of Mountain Goat Software has to say: Leading a Self-Organizing Team Succeeding with Agile: Leading a Self-Organizing Team The … Read more
Google Analytics (GA) is a free service provided by Google for collecting statistics about website visitors. The product is currently in use by around 57% of the 10,000 most popular websites across the globe. GA can track visitors, sessions, traffic sources, goal conversions, page performance metrics and more. GA is implemented by including what is [...]
Oracle’s vaunted patent infringement case against Google and Android has shrunk to the size of a thong bikini – and like a freshman during spring break, the Patent and Trademark Office is looking forward to another round of strip poker. Of the five patents Oracle started with after ultimately withdrawing two, the PTO’s re-examinations have left it only one. The latest to fall was Java pappy James Gosling’s US patent RE38,104 on a “method and apparatus for resolving data references in generated code.” The PTO says it’s invalid although its decision isn’t absolutely final yet. Before the PTO’s decision, which took an awfully long time, case watcher Florian Mueller was beginning to think Oracle might get a lot of mileage just out of the Gosling patent since it looked pretty fundamental. Now that the PTO has pretty much shot it down he reckons the patent part of Oracle’s case is pretty much lost unless – after a long-winded process – the PTO’s Board of Appeals for Patent Appeals and Interferences or the Court of Appeals for the Federal Circuit overrules the PTO on some counts.
With Cloud Expo 2012 New York (10th Cloud Expo) now just seven weeks away, what better time to introduce you in greater detail to the distinguished individuals in our incredible Speaker Faculty for the technical and strategy sessions at the conference... We have technical and strategy sessions for you every day from June 11 through June 14 dealing with every nook and cranny of Cloud Computing and Big Data, but what of those who are presenting? Who are they, where do they work, what else have they written and/or said about the Cloud that is transforming the world of Enterprise IT, side by side with the exploding use of enterprise Big Data – processed in the Cloud – to drive value for businesses...?