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  • Reduce durability in MySQL for performance

    - by Paul Prescod
    My site occasionally has fairly predictable bursts of traffic that increase the throughput by 100 times more than normal. For example, we are going to be featured on a television show, and I expect in the hour after the show, I'll get more than 100 times more traffic than normal. My understanding is that MySQL (InnoDB) generally keeps my data in a bunch of different places: RAM Buffers commitlog binary log actual tables All of the above places on my DB slave This is too much "durability" given that I'm on an EC2 node and most of the stuff goes across the same network pipe (file systems are network attached). Plus the drives are just slow. The data is not high value and I'd rather take a small chance of a few minutes of data loss rather than have a high probability of an outage when the crowd arrives. During these traffic bursts I would like to do all of that I/O only if I can afford it. I'd like to just keep as much in RAM as possible (I have a fair chunk of RAM compared to the data size that would be touched over an hour). If buffers get scarce, or the I/O channel is not too overloaded, then sure, I'd like things to go to the commitlog or binary log to be sent to the slave. If, and only if, the I/O channel is not overloaded, I'd like to write back to the actual tables. In other words, I'd like MySQL/InnoDB to use a "write back" cache algorithm rather than a "write through" cache algorithm. Can I convince it to do that? If this is not possible, I am interested in general MySQL write-performance optimization tips. Most of the docs are about optimizing read performance, but when I get a crowd of users, I am creating accounts for all of them, so that's a write-heavy workload.

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  • Randomly sorting an array

    - by Cam
    Does there exist an algorithm which, given an ordered list of symbols {a1, a2, a3, ..., ak}, produces in O(n) time a new list of the same symbols in a random order without bias? "Without bias" means the probability that any symbol s will end up in some position p in the list is 1/k. Assume it is possible to generate a non-biased integer from 1-k inclusive in O(1) time. Also assume that O(1) element access/mutation is possible, and that it is possible to create a new list of size k in O(k) time. In particular, I would be interested in a 'generative' algorithm. That is, I would be interested in an algorithm that has O(1) initial overhead, and then produces a new element for each slot in the list, taking O(1) time per slot. If no solution exists to the problem as described, I would still like to know about solutions that do not meet my constraints in one or more of the following ways (and/or in other ways if necessary): the time complexity is worse than O(n). the algorithm is biased with regards to the final positions of the symbols. the algorithm is not generative. I should add that this problem appears to be the same as the problem of randomly sorting the integers from 1-k, since we can sort the list of integers from 1-k and then for each integer i in the new list, we can produce the symbol ai.

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  • How do I become better in math, after being a programmer for several years.

    - by loxs
    I've had quite a weird career till now. First I graduated from a medical school. Then I went into marketing (pharmaceuticals). And then umm, after some time, I decided to go for my (till then) hobby and became a "professional" programmer. I've been quite successful at this ever since. I have quite some languages "under my belt". I earn not bad and I have been involved in the opensource community quite heavily. The thing is that I suck at math :). Well, not totally of course, as I get my work done. But I don't know how much I suck. And I don't know how to find out. Math has never really been of any priority during my middle/high school years. I only picked as little as I could afford, because I was always getting ready to go for Medicine. Of course I know the basics of algebra. Things like "normal" and square equations. Also the basics of geometry. But well, there are things that I have missed. And lately I am being fascinated by things like probability theory, infinity, chaos/order etc. But every time I try to learn something about these topics, I hit a wall of terminology, special symbols, and some special kind of thinking, that is quite like mine (a programmer), but also a lot different (and appears weird to me). So, what kinds of books would you recommend me? It's very hard to find something suitable. All that I find are either too easy (and boring) or totally impenetrable.

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  • setting the openCV configuration in an openGL project produce several errors

    - by GolSa
    I have a win32 solution which is set for openGL; it works well; but I want to write a function which use functions of openCV; I set the configuration for openCV for both X86 and X64;;I commented the openCV function and just to test the correctness of configuration, I run it; but when I want to run it on X64 I faced with the error below: Error 1 error C2065: 'GWL_HINSTANCE' : undeclared identifier D:\matrix\matrixProjection\src\ControllerMain.cpp 35 1 matrixProjection Error 2 error C2664: 'CreateDialogParamW' : cannot convert parameter 4 from 'BOOL (__cdecl *)(HWND,UINT,WPARAM,LPARAM)' to 'DLGPROC' D:\matrix\matrixProjection\src\DialogWindow.cpp 47 1 matrixProjection Error 2 points to this line of code: HWND DialogWindow::create() { /*-->this line*/ handle = ::CreateDialogParam(instance, MAKEINTRESOURCE(id), parentHandle, Win::dialogProcedure, (LPARAM)controller); return handle; } but on Debug Win32 configure, it runs; I used openGL32 in my project; is there any probability to be the cause? is there any X64 version for openGL? I know that there is something needed in X64 mode which my solution can not handle it; I googled a lot about it but I did not find any solution; How can I solve that?

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  • Why doesn't String's hashCode() cache 0?

    - by polygenelubricants
    I noticed in the Java 6 source code for String that hashCode only caches values other than 0. The difference in performance is exhibited by the following snippet: public class Main{ static void test(String s) { long start = System.currentTimeMillis(); for (int i = 0; i < 10000000; i++) { s.hashCode(); } System.out.format("Took %d ms.%n", System.currentTimeMillis() - start); } public static void main(String[] args) { String z = "Allocator redistricts; strict allocator redistricts strictly."; test(z); test(z.toUpperCase()); } } Running this in ideone.com gives the following output: Took 1470 ms. Took 58 ms. So my questions are: Why doesn't String's hashCode() cache 0? What is the probability that a Java string hashes to 0? What's the best way to avoid the performance penalty of recomputing the hash value every time for strings that hash to 0? Is this the best-practice way of caching values? (i.e. cache all except one?) For your amusement, each line here is a string that hash to 0: pollinating sandboxes amusement & hemophilias schoolworks = perversive electrolysissweeteners.net constitutionalunstableness.net grinnerslaphappier.org BLEACHINGFEMININELY.NET WWW.BUMRACEGOERS.ORG WWW.RACCOONPRUDENTIALS.NET Microcomputers: the unredeemed lollipop... Incentively, my dear, I don't tessellate a derangement. A person who never yodelled an apology, never preened vocalizing transsexuals.

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  • Handle complex options with Boost's program_options

    - by R S
    I have a program that generates graphs using different multi-level models. Each multi-level model consists of a generation of a smaller seed graph (say, 50 nodes) which can be created from several models (for example - for each possible edge, choose to include it with probability p). After the seed graph generation, the graph is expanded into a larger one (say 1000 nodes), using one of another set of models. In each of the two stages, each model require a different number of parameters. I would like to be have program_options parse the different possible parameters, according to the names of the models. For example, say I have two seed graphs models: SA, which has 1 parameters, and SB, which has two. Also for the expansion part, I have two models: A and B, again with 1 and 2 parameters, respectively. I would like to be able do something like: ./graph_generator --seed=SA 0.1 --expansion=A 0.2 ./graph_generator --seed=SB 0.1 3 --expansion=A 0.2 ./graph_generator --seed=SA 0.1 --expansion=B 10 20 ./graph_generator --seed=SB 0.1 3 --expansion=B 10 20 and have the parameters parsed correctly. Is that even possible?

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  • How to enjoy DVD on Apple iPad

    - by user44251
    I believe many people spent a sleepless night yesterday waiting for the new Apple Tablet to come, just a few days ago or perhaps longer I noticed fierce debate about it, its name, size, capacity, processor, main features, price etc. And now, they can take a long breath with the new Apple Tablet named iPad officially released on 28, January, 2010 (Beijing Time). But I know a new battle just begins. iPad, sounds somewhat like iPod and it really shares some similarities in terms of shape like smart, light and portable. It has a 9.7-inch, LED-backlit, IPS display with a remarkable precise Multi-Touch screen. And yet, at just 1.5 lbs and 0.5 inches thin, it's easy to carry and use everywhere. It can greatly facilitates your experience with the web, emails, photos and videos. Right now, it can run almost 140.000 of the apps on the Apple store. It can even run the apps you have downloaded for your iPhone or iPod touch. But so far, I haven't seen any possibility that it can work with DVD, probability there is no built-in DVD-ROM or DVD player which can play DVD directly. As Apple iPad states, the video formats supported are MPEG-4 (MP4, M4V), H.264, MOV etc and audio formats accepted are AAC, Proteceted AAC, MP3, AIFF and WAV etc, those are formats that are commonly used with iMac. This could really a hard nut to crack if you want to watch your favourite DVD on this magic Apple iPad. But don't worry, there is still way out, you just need a few steps for ripping and importing DVD movies to Apple iPad with a simple application DVD to iPad converter What's on DVD to iPad Converter for Mac DVD to iPad converter for Mac is a powerful and professional application designed for the newly released Apple iPad which can rip, convert your DVD contents to Apple iPad compatible MPEG-4 (MP4, M4V), H.264, MOV etc, and other popular file formats like AVI, WMV, MPG, MKV, VOB, 3GP, FLV etc can also be converted so that you can put on your portable devices like iPod, iPhone, iRiver, BlackBerry etc. Besides, it can also extract audio from DVD videos and save as MP3, AIFF, AAC, WAV etc. Mac DVD to iPad converter has also been enhanced that can run both on PowerPC and Intel (Snow Leopard included). It can offer versatile editing features which allows you to make your own DVD videos. For example, you can cut your DVD to whatever length you like by Trim, crop off unwanted parts from DVD clips by Crop, add special effect like Gray, Emboss and Old film to make your videos more artistic. Besides, its built-in merging feature and batch mode allows you to join several DVD clips into a single one and do batch conversion. And more features can be expected if you afford a few minutes to try.

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  • Repair corrupt hard disk on Mac without install CD

    - by Sarah
    The hard disk of my late 2009 MacBook Pro appears to have become corrupted. I am traveling and do not have my install CD (and won't for several weeks, nor will I be anywhere near an Apple store). The hard disk is not the original, which failed in June 2011. It's some Hitachi replacement installed by IT. History: I was typing an email this afternoon, my computer suddenly started making soft clicking sounds and then froze. I was not moving around. I rebooted, which took a while. I heard more clicking sounds and the computer froze at least once again. It's now kind of working, with mdworker sucking up one CPU. There are no awkward hard drive sounds when I run Chrome or play music. However, when I launched Stickies, I found no trace of my saved Stickies. I ran a live disk verification from within Disk Utility, and it reported Problem: As reported, I don't have access to an installation disc and am nowhere near an area where I can get one for at least two weeks. I have the option of asking someone to go to some trouble and expense to get one for me, but I'm not sure it's worth it: I've read that I can use fsck from single-user mode to repair the disk. Should I just try this? Is it risky? I'm concerned that the clicky sound portends imminent (mechanical) hard drive failure, so it's not worth doing a silly repair. This hard disk is backed up, but I definitely won't be able to access the backup while traveling. I'd like to maximize the probability that I can keep using my computer (and all its current files) while traveling. Update I bit the bullet and ran fsck -fy from single-user mode. It only needed one pass (modification) to reach the "okay" stage. However, rebooting took nearly 5 min and involved several rounds of scratchy sounds and a few bad clicks. I'm now back to kind of using my computer (the same files are missing as before). When I ran live disk verification from Disk Utility this time, however, it reported that the volume appears to be OK. Am I right to infer from the scratchy sounds, however, that my hard drive is still rapidly on its way out? Is there anything else I can do to increase its functionality over the next few weeks?

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  • Ranking - an Introduction

    - by PointsToShare
    © 2011 By: Dov Trietsch. All rights reserved Ranking Ranking is quite common in the internet. Readers are asked to rank their latest reading by clicking on one of 5 (sometimes 10) stars. The number of stars is then converted to a number and the average number of stars as selected by all the readers is proudly (or shamefully) displayed for future readers. SharePoint 2007 lacked this feature altogether. SharePoint 2010 allows the users to rank items in a list or documents in a library (the two are actually the same because a library is actually a list). But in SP2010 the computation of the average is done later on a timer rather than on-the-spot as it should be. I suspect that the reason for this shortcoming is that they did not involve a mathematician! Let me explain. Ranking is kept in a related list. When a user rates a document the rank-list is added an item with the item id, the user name, and his number of stars. The fact that a user already ranked an item prevents him from ranking it again. This prevents the creator of the item from asking his mother to rank it a 5 and do it 753 times, thus stacking the ballot. Some systems will allow a user to change his rating and this will be done by updating the rank-list item. Now, when the timer kicks off, the list is spanned and for each item the rank-list items containing this id are summed up and divided by the number of votes thus yielding the new average. This is obviously very time consuming and very server intensive. In the 18th century an early actuary named James Dodson used what the great Augustus De Morgan (of De Morgan’s law) later named Commutation tables. The labor involved in computing a life insurance premium was staggering and also very error prone. Clerks with pencil and paper would multiply and add mountains of numbers to do the task. The more steps the greater the probability of error and the more expensive the process. Commutation tables created a “summary” of many steps and reduced the work 100 fold. So had Microsoft taken a lesson in the history of computation, they would have developed a much faster way for rating that may be done in real-time and is also 100 times faster and less CPU intensive. How do we do this? We use a form of commutation. We always keep the number of votes and the total of stars. One simple division gives us the average. So we write an event receiver. When a vote is added, we just add the stars to the total-stars and 1 to the number of votes. We then recomputed the average. When a vote is updated, we reduce the total by the old vote, increase it by the new vote and leave the number of votes the same. Again we do the division to get the new average. When a vote is deleted (highly unlikely and maybe even prohibited), we reduce the total by that vote and reduce the number of votes by 1… Gone are the days of spanning lists, counting items, and tallying votes and we have no need for a timer process to run it all. This is the first of a few treatises on ranking. Even though I discussed the math and the history thereof, in here I am only going to solve the presentation issue. I wanted to create the CSS and Jscript needed to display the stars, create the various effects like hovering and clicking (onmouseover, onmouseout, onclick, etc.) and I wanted to create a general solution with any number of stars. When I had it all done, I created the ranking game so that I could test it. The game is interesting in and on itself, so here it is (or go to the games page and select “rank the stars”). BTW, when you play it, look at the source code and see how it was all done.  Next, how the 5 stars are displayed in the New and Update forms. When the whole set of articles will be done, you’ll be able to create the complete solution. That’s all folks!

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  • Merck Serono Gains Deep Understanding of Product Portfolio Value-Drivers, Risks, and Sales Expectations Through Forecasting Solution

    - by Melissa Centurio Lopes
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Merck Serono S.A. is the biopharmaceutical division of Merck KGaA. It offers leading brands in 150 countries to help patients with cancer, multiple sclerosis, infertility, endocrine and metabolic disorders, as well as cardiovascular diseases. Challenges: Establish a better decision-making framework for its complex, development portfolio of pharmaceutical products, where single-point estimates or expected averages of portfolio values, portfolio risks, and sales forecasts are insufficient and can be misleading Enable the company to be aware at all times of the range of possible outcomes of technical and market risks and uncertainties, such as the technical uncertainty of whether a product will produce the desired clinical outcomes, or the market-related uncertainty of whether a product will be outperformed by its competitors Solutions to Overcome the Challenges: Used Oracle Crystal Ball to devise a Monte-Carlo-based approach to better analyze and define the values and risks of the company’s development portfolio, laying the groundwork for optimized decision-making Enabled a better understanding of the range of potential values and risks to improve portfolio planning Enabled detailed analysis of the likelihood of favorable or unfavorable outcomes, such as the likelihood of whether Merck Serono can meet its sales targets planned for the next ten years with its existing product portfolio Gained the ability to take into account correlative risks, synergies and project interactions, enabling Merck Serono to better forecast what the company may achieve—for example, that there is a 70% probability of a particular sales target being met Established Monte-Carlo-based analysis using Oracle Crystal Ball as a useful element in decision-making at the board level, as the approach provides a better analysis of values and risks associated with the company’s product portfolio “Oracle Crystal Ball enables us to make Monte Carlo simulations of the potential value and sales of our development portfolio. It is a very powerful tool for gaining a thorough understanding and improved awareness of value drivers, uncertainties, and risks, along with associated probabilities.” – Riccardo Lampariello, Associate Director, Merck Serono S.A Why Oracle “We chose Oracle Crystal Ball to enable us to perform Monte Carlo analysis, which gives us a deeper understanding and improved awareness of the value drivers, uncertainties and risks of our portfolio of development projects,” said Kimber Hardy, head of valuation and analysis, Merck Serono S.A. Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Click here to read the full version of the customer success story Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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  • Employee Engagement Q&A with John Brunswick

    - by Kellsey Ruppel
    As we are focusing this week on Employee Engagement, I recently sat down with industry expert and thought leader John Brunswick on the topic. Here is the Q&A dialogue we shared.  Q: How do you effectively engage employees to drive business value?A: Motivation, both extrinsic and intrinsic, combined with the relevancy of various channels to support it.  Beyond chaining business strategies like compensation models within an organization, engagement ultimately is most successful when driven by employee's motivations.  Business value derived from engagement through technical capabilities can be objectively measured through metrics like the rate and accuracy of problem solving for a given business function or frequency of innovation created.  Providing employees performing "knowledge work" with capabilities that allow them to perform work with a higher degree of accuracy in the same or ideally less time, adds value for that individual and in turn, drives their level of engagement to drive business value. Q: Organizations with high levels of employee engagement outperform the total stock market index by 22%. Can you comment on why you think this might be? A: Alignment through shared purpose.  Zappos is an excellent example of a culture that arguably has higher than average levels of employee engagement and it permeates every aspect of their organization – embodied externally through their customer experience.  I recently made my first purchase with them and it was obvious through their web experience, visual design, communication style, customer service and attention to detail down to green packaging, that they have an amazingly strong shared purpose.  The Zappos.com ‘About page’ outlines their "Family Core Values", the first three being "Deliver WOW Through Service, Embrace and Drive Change & Create Fun and A Little Weirdness" – all reflected externally in my interaction with them.  Strong shared purpose enables higher product and service experience, equating to a dedicated customer base, repeat purchases and expanded marketshare. Q: Have you seen any trends in the market regarding employee engagement? A: Some companies now see offering a form of social engagement similar to Facebook and LinkedIn as standard communication infrastructure like email or instant messaging.  Originally offered as standalone tools, the value is now seen when these capabilities are offered in an integrated fashion in the context of business entities.  An emerging area of focus is around employee activities related to their organization on external social platforms, implicitly creating external communities with employees acting on behalf of the brand and interacting with each other (e.g. Twitter).  Companies have reached a formal understand that this now established communication medium requires strategies allowing employees to engage.  I have personally met colleagues from Oracle, like Oracle User Experience Director Ultan O'Broin (@ultan), via Twitter before meeting first through internal channels. Q: Employee engagement is important, but what about engaging customers and partners? A: The last few years we have witnessed an interesting evolution from the novelty of self-service to expectations of "intelligent" self-service.  From a consumer standpoint, engagement can end up being a key differentiator, especially in mature markets.  Customers that perform some level of interaction with a brand develop greater affinity for the brand and have a greater probability of acting as an advocate.  As organizations move toward a model of deeper engagement, they must ensure that their business is positioned to support deeper relationships, offering potentially greater transparency. From a partner standpoint greater engagement can lead to new types of business opportunities, much in the way that Amazon.com offers a unified shopping experience that can potentially span various vendors.  This same model can be extended to blending services and product delivery models, based on a closeness not easily possible before increased capability of engagement mechanisms. Q: What types of solutions are available to successfully deliver employee engagement? A: Solutions enabling higher levels of engagement do so on the basis of relevancy.  This relevancy is generally supported by aspects of content management, social collaboration, business intelligence, portal and process management technologies.  These technologies can help deliver an experience tailored to a given role or process within an organization that applies equally to work that is structured or unstructured, appearing in the form of functionality as simple as an online employee directory search, knowledge communities supported by social collaboration, as well as more feature rich business intelligence dashboards and portals. Looking to learn more about how to effectively engage your employees? Check out this webcast, or read more from John Brunswick. 

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  • Deep in the Heart of Texas

    - by Applications User Experience
    Author: Erika Webb, Manager, Fusion Applications UX User Assistance When I was first working in the usability field, the only way I could consider conducting a usability study was to bring a potential user to a lab environment where I could show them whatever I was interested in learning more about and ask them questions. While I hate to reveal just how long I have been working in this field, let's just say that pads of paper and a stopwatch were key tools for any test I conducted. Over the years, I have worked in simple labs with basic video taping equipment and not much else, and I have worked in corporate environments with sophisticated usability labs and state-of-the-art equipment. Years ago, we conducted all usability studies at the location of the user. If we wanted to see if there were any differences between users in New York, Chicago, and Los Angeles, we went to those places to run the test. A lab environment is very useful for many test situations. However, there has always been a debate in the usability field about whether bringing someone into a lab environment, however friendly we make it, somehow intrinsically changes the behavior of the user as compared to having them work in their own environment, at their own desk, and on their own computer. We developed systems to create a portable usability lab, so that we could go to the users that we needed to test.  Do lab environments change user behavior patterns? Then 9/11 hit. You may not remember, but no planes flew for weeks afterwards. Companies all over the world couldn't fly-in employees for meetings. Suddenly, traveling to the location of the users had an additional difficulty. The company I was working for at the time had usability specialists stuck in New York for days before they could finally rent a car and drive home to Colorado. This changed the world pretty suddenly, and technology jumped on the change. Companies offering Internet meeting tools were strugglinguntil no one could travel. The Internet boomed with collaboration tools that enabled people to work together wherever they happened to be. This change in technology has made a huge difference in my world. We use collaborative tools to bring our product concepts and ideas to the user across the Internet. As a global company, we benefit from having users from all over the world inform our designs. We now run usability studies with users all over the world in a single day, a feat we couldn't have accomplished 10 years ago by plane! Other technology companies have started to do more of this type of usability testing, since the tools have improved so dramatically. Plus, in our busy world, it's not always easy to find users who can take the time away from their jobs to come to our labs. reaching users where it is convenient for them greatly improves the odds that people do participate. I manage a team of usability specialists who live in India and California, whlie I live in Colorado. We have wonderful labs that we bring users into to show them our products. But very often, we run our studies remotely. We used to take the lab to the users now we use the labs, but we let the users stay where they are. We gain users who might not have been able to leave work to come to our labs, and they get to use the system they are familiar with. And we gain users nearly anywhere that we can set up an Internet connection, as long as the users have a phone, a broadband connection, and a compatible Web browser (with no pop-up blockers). After we recruit participants in a traditional manner, we send them an invitation to participate through the use of a telephone conference call and Web conferencing tool. At Oracle, we use Oracle Web Conference part of Oracle Collaboration Suite, which enables us to give the user control of the mouse, while we present a prototype or wireframe pictures. We can record the sessions over the Web and phone conference. We send the users instructions, plus tips to ensure that we won't have problems sharing screens. In some cases, when time is tight, we even run a five-minute "test session" with users a day in advance to be sure that we can connect. Prior to the test, we send users a participant script that contains information about the study, including any questionnaires. This is exactly the same script we give to participants who come to the labs. We ask users to print this before the beginning of the session. We generally run these studies by having a usability engineer in our usability labs, so that we can record the session as though the user were in the lab with us. Roughly 80% of our application software usability testing at Oracle is performed using remote methods. The probability of getting a   remote test participant decreases the higher up the person is in the target organization. We have a methodology checklist available to help our usability engineers work through the remote processes.

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  • Lazy HTML attributes wrapping in Internet Explorer

    - by AGS777
    Having encountered this Internet Explorer (all versions) behavior several times previously, I eventually decided to share this most probably useless knowledge. Excuse my lengthy explanations because I am going to show the behavior along with a very simple case when one can come across it inadvertently. Let's say I want to implement some simple templating solution in JavaScript. I wrote an HTML template with an intention to bind data to it on the client side: Please note, that name of the “sys-template” class is just a coincidence. I do not use any ASP.NET AJAX code in this simple example. As you can see we need to replace placeholders (property name wrapped with curly braces) with actual data. Also, as you can see, many of the placeholders are situated within attribute values and it is where the danger lies. I am going to use <a /> element HTML as a template and replace each placeholder pattern with respective properties’ values with a little bit of jQuery like this: You can find complete code along with the contextFormat() method definition at the end of the post. Let’s assume that value for the name property (that we want to put in the title attribute) of the first data item is “first tooltip”. So it consists of two words. When the replacement occurred, title attribute should contain the “first tooltip” text which we are going to see as a tooltip for the <a /> element. But let’s run the sample code in Internet Explorer and check it out. What you’ll see is that only the first word of the supposed “title” attribute’s content is shown. So, were is the rest of my attribute and what happened? The answer is obvious once you see the result of jQuery(“.sys-template”).html() line for the given HTML markup. In IE you’ll get the following <A id={id} class={cssClass} title={name} href="{source}" myAttr="{attr}">Link to {source}</A> See any difference between this HTML and the one shown earlier? No? Then look carefully. While the original HTML of the <a /> element is well-formed and all the attributes are correctly quoted, when you take the same HTML back in Internet Explorer (it doesn’t matter whether you use html() method from jQuery library or IE’s innerHTML directly), you lose attributes’ quotes for some of the attributes. Then, after replacement, we’ll get following HTML for our first data item. I marked the attribute value in question with italic: <A id=1 class=first title=first tooltip href="first.html" myAttr="firstAttr">Link to first.html</A> Now you can easily imagine for yourself what happens when this HTML is inserted into the document and why we do not see the second (and any subsequent words if any) of our title attribute in the tooltip. There are still two important things to note. The first one (and it actually the reason why I named the post “lazy wrapping” is that if value of the HTML attribute does contains spaces in the original HTML, then it WILL be wrapped with quotation marks. For example, if I wrote following on my page (note the trailing space for the title attribute value) <a href="{source}" title="{name}  " id="{id}" myAttr="{attr}" class="{cssClass}">Link to {source}</a> then I would have my placeholder quoted correctly and the result of the replacement would render as expected: The second important thing to note is that there are exceptions for the lazy attributes wrapping rule in IE. As you can see href attribute value did not contain spaces exactly as all the other attributes with placeholders, but it was still returned correctly quoted Custom attribute myAttr is also quoted correctly when returned back from document, though its placeholder value does not contain spaces either. Now, on account of the highly unlikely probability that you found this information useful and need a solution to the problem the aforementioned behavior introduces for Internet Explorer browser, I can suggest a simple workaround – manually quote the mischievous attributes prior the placeholder pattern is replaced. Using the code of contextFormat() method shown below, you would need to add following line right before the return statement: result = result.replace(/=({([^}]+)})/g, '="$1"'); Below please find original sample code:

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  • Modeling distribution of performance measurements

    - by peterchen
    How would you mathematically model the distribution of repeated real life performance measurements - "Real life" meaning you are not just looping over the code in question, but it is just a short snippet within a large application running in a typical user scenario? My experience shows that you usually have a peak around the average execution time that can be modeled adequately with a Gaussian distribution. In addition, there's a "long tail" containing outliers - often with a multiple of the average time. (The behavior is understandable considering the factors contributing to first execution penalty). My goal is to model aggregate values that reasonably reflect this, and can be calculated from aggregate values (like for the Gaussian, calculate mu and sigma from N, sum of values and sum of squares). In other terms, number of repetitions is unlimited, but memory and calculation requirements should be minimized. A normal Gaussian distribution can't model the long tail appropriately and will have the average biased strongly even by a very small percentage of outliers. I am looking for ideas, especially if this has been attempted/analysed before. I've checked various distributions models, and I think I could work out something, but my statistics is rusty and I might end up with an overblown solution. Oh, a complete shrink-wrapped solution would be fine, too ;) Other aspects / ideas: Sometimes you get "two humps" distributions, which would be acceptable in my scenario with a single mu/sigma covering both, but ideally would be identified separately. Extrapolating this, another approach would be a "floating probability density calculation" that uses only a limited buffer and adjusts automatically to the range (due to the long tail, bins may not be spaced evenly) - haven't found anything, but with some assumptions about the distribution it should be possible in principle. Why (since it was asked) - For a complex process we need to make guarantees such as "only 0.1% of runs exceed a limit of 3 seconds, and the average processing time is 2.8 seconds". The performance of an isolated piece of code can be very different from a normal run-time environment involving varying levels of disk and network access, background services, scheduled events that occur within a day, etc. This can be solved trivially by accumulating all data. However, to accumulate this data in production, the data produced needs to be limited. For analysis of isolated pieces of code, a gaussian deviation plus first run penalty is ok. That doesn't work anymore for the distributions found above. [edit] I've already got very good answers (and finally - maybe - some time to work on this). I'm starting a bounty to look for more input / ideas.

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  • Are there programs that iteratively write new programs?

    - by chris
    For about a year I have been thinking about writing a program that writes programs. This would primarily be a playful exercise that might teach me some new concepts. My inspiration came from negentropy and the ability for order to emerge from chaos and new chaos to arise out of order in infinite succession. To be more specific, the program would start by writing a short random string. If the string compiles the programs will log it for later comparison. If the string does not compile the program will try to rewrite it until it does compile. As more strings (mini 'useless' programs) are logged they can be parsed for similarities and used to generate a grammar. This grammar can then be drawn on to write more strings that have a higher probability of compilation than purely random strings. This is obviously more than a little silly, but I thought it would be fun to try and grow a program like this. And as a byproduct I get a bunch of unique programs that I can visualize and call art. I'll probably write this in Ruby due to its simple syntax and dynamic compilation and then I will visualize in processing using ruby-processing. What I would like to know is: Is there a name for this type of programming? What currently exists in this field? Who are the primary contributors? BONUS! - In what ways can I procedurally assign value to output programs beyond compiles(y/n)? I may want to extend the functionality of this program to generate a program based on parameters, but I want the program to define those parameters through running the programs that compile and assigning meaning to the programs output. This question is probably more involved than reasonable for a bonus, but if you can think of a simple way to get something like this done in less than 23 lines or one hyperlink, please toss it into your response. I know that this is not quite meta-programming and from the little I know of AI and generative algorithms they are usually more goal oriented than what I am thinking. What would be optimal is a program that continually rewrites and improves itself so I don't have to ^_^

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  • Increase efficiency for an R simulator of the Monty Hall Puzzle

    - by jahan_m
    The Monty Hall Problem is a simple puzzle involving probability that even stumps professionals in careers dealing with some heavy-duty math. Here's the basic problem: Suppose you're on a game show, and you're given the choice of three doors: Behind one door is a car; behind the others, goats. You pick a door, say No. 1, and the host, who knows what's behind the doors, opens another door, say No. 3, which has a goat. He then says to you, "Do you want to pick door No. 2?" Is it to your advantage to switch your choice? You can find numerous explanations of the solution here: http://en.wikipedia.org/wiki/Monty_Hall_problem Goal of my simulation: Prove that a switching strategy will win you the car 2/3 of the time. I got curious and wanted to write a little function that simulates the problem many times and returns the proportion of wins if you switched and the proportion of wins if you stayed with your first choice. The function then plots the cumulative wins. First and foremost, I'm interested in hearing if my simulation is indeed replicating the Monty Problem, or if some aspect of the code got it wrong. Secondly, this function takes a long time to run once I get to about 10,000 simulations. I know I don't need this many simulations to prove this but I'd love to hear some ideas on how to make it more efficient. Thanks for your feedback! Monty_Hall=function(repetitions){ doors=c('A','B','C') stay_wins=0 switch_wins=0 series=data.frame(sim_num=seq(repetitions),cum_sum_stay=replicate(repetitions,0),cum_sum_switch=replicate(repetitions,0)) for(i in seq(repetitions)){ winning_door=sample(doors,1) contestant_chooses=sample(doors,1) if(contestant_chooses==winning_door) stay_wins=stay_wins+1 else switch_wins=switch_wins+1 series[i,'cum_sum_stay']=stay_wins series[i,'cum_sum_switch']=switch_wins } plot(series$sim_num,series$cum_sum_switch,col=2,ylab='Cumulative # of wins', xlab='Simulation #',main=sprintf('%d Simulations of the Monty Hall Paradox',repetitions),type='l') lines(series$sim_num,series$cum_sum_stay,col=4) legend('topleft',legend=c('Cumulative wins from switching', 'Cumulative wins from staying'),col=c(2,4),lty=1) result=list(series=series,stay_wins=stay_wins,switch_wins=switch_wins, proportion_stay_wins=stay_wins/repetitions, proportion_switch_wins=switch_wins/repetitions) return(result) } #Theory predicts that it is to the contestant's advantage if he #switches his choice to the other door. This function simulates the game #many times, and shows you the proportion of games in which staying or #switching would win the car. It also plots the cumulative wins for each strategy. Monty_Hall(100)

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  • how to develop a program to minimize errors in human transcription of hand written surveys

    - by Alex. S.
    I need to develop custom software to do surveys. Questions may be of multiple choice, or free text in a very few cases. I was asked to design a subsystem to check if there is any error in the manual data entry for the multiple choices part. We're trying to speed up the user data entry process and to minimize human input differences between digital forms and the original questionnaires. The surveys are filled with handwritten marks and text by human interviewers, so it's possible to find hard to read marks, or also the user could accidentally select a different value in some question, and we would like to avoid that. The software must include some automatic control to detect possible typing differences. Each answer of the multiple choice questions has the same probability of being selected. This question has two parts: The GUI. The most simple thing I have in mind is to implement the most usable design of the questions display: use of large and readable fonts and space generously the choices. Is there something else? For faster input, I would like to use drop down lists (favoring keyboard over mouse). Given the questions are grouped in sections, I would like to show the answers selected for the questions of that section, but this could slow down the process. Any other ideas? The error checking subsystem. What else can I do to minimize or to check human typos in the multiple choice questions? Is this a solvable problem? is there some statistical methodology to check values that were entered by the users are the same from the hand filled forms? For example, let's suppose the survey has 5 questions, and each has 4 options. Let's say I have n survey forms filled in paper by interviewers, and they're ready to be entered in the software, then how to minimize the accidental differences that can have the manual transcription of the n surveys, without having to double check everything in the 5 questions of the n surveys? My first suggestion is that at the end of the processing of all the hand filled forms, the software could choose some forms randomly to make a double check of the responses in a few instances, but on what criteria can I make this selection? This validation would be enough to cover everything in a significant way? The actual survey is nation level and it has 56 pages with over 200 questions in total, so it will be a lot of hand written pages by many people, and the intention is to reduce the likelihood of errors and to optimize speed in the data entry process. The surveys must filled in paper first, given the complications of taking laptops or handhelds with the interviewers.

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  • Security review of an authenticated Diffie Hellman variant

    - by mtraut
    EDIT I'm still hoping for some advice on this, i tried to clarify my intentions... When i came upon device pairing in my mobile communication framework i studied a lot of papers on this topic and and also got some input from previous questions here. But, i didn't find a ready to implement protocol solution - so i invented a derivate and as i'm no crypto geek i'm not sure about the security caveats of the final solution: The main questions are Is SHA256 sufficient as a commit function? Is the addition of the shared secret as an authentication info in the commit string safe? What is the overall security of the 1024 bit group DH I assume at most 2^-24 bit probability of succesful MITM attack (because of 24 bit challenge). Is this plausible? What may be the most promising attack (besides ripping the device out off my numb, cold hands) This is the algorithm sketch For first time pairing, a solution proposed in "Key agreement in peer-to-peer wireless networks" (DH-SC) is implemented. I based it on a commitment derived from: A fix "UUID" for the communicating entity/role (128 bit, sent at protocol start, before commitment) The public DH key (192 bit private key, based on the 1024 bit Oakley group) A 24 bit random challenge Commit is computed using SHA256 c = sha256( UUID || DH pub || Chall) Both parties exchange this commitment, open and transfer the plain content of the above values. The 24 bit random is displayed to the user for manual authentication DH session key (128 bytes, see above) is computed When the user opts for persistent pairing, the session key is stored with the remote UUID as a shared secret Next time devices connect, commit is computed by additionally hashing the previous DH session key before the random challenge. For sure it is not transfered when opening. c = sha256( UUID || DH pub || DH sess || Chall) Now the user is not bothered authenticating when the local party can derive the same commitment using his own, stored previous DH session key. After succesful connection the new DH session key becomes the new shared secret. As this does not exactly fit the protocols i found so far (and as such their security proofs), i'd be very interested to get an opinion from some more crypto enabled guys here. BTW. i did read about the "EKE" protocol, but i'm not sure what the extra security level is.

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  • Calling compiled C from R with .C()

    - by Sarah
    I'm trying to call a program (function getNBDensities in the C executable measurementDensities_out) from R. The function is passed several arrays and the variable double runsum. Right now, the getNBDensities function basically does nothing: it prints to screen the values of passed parameters. My problem is the syntax of calling the function: array(.C("getNBDensities", hr = as.double(hosp.rate), # a vector (s x 1) sp = as.double(samplingProbabilities), # another vector (s x 1) odh = as.double(odh), # another vector (s x 1) simCases = as.integer(x[c("xC1","xC2","xC3")]), # another vector (s x 1) obsCases = as.integer(y[c("yC1","yC2","yC3")]), # another vector (s x 1) runsum = as.double(runsum), # double DUP = TRUE, NAOK = TRUE, PACKAGE = "measurementDensities_out")$f, dim = length(y[c("yC1","yC2","yC3")]), dimnames = c("yC1","yC2","yC3")) The error I get, after proper execution of the function (i.e., the right output is printed to screen), is Error in dim(data) <- dim : attempt to set an attribute on NULL I'm unclear what the dimensions are that I should be passing the function: should it be s x 5 + 1 (five vectors of length s and one double)? I've tried all sorts of combinations (including sx5+1) and have found only seemingly conflicting descriptions/examples online of what's supposed to happen here. For those who are interested, the C code is below: #include <R.h> #include <Rmath.h> #include <math.h> #include <Rdefines.h> #include <R_ext/PrtUtil.h> #define NUM_STRAINS 3 #define DEBUG void getNBDensities( double *hr, double *sp, double *odh, int *simCases, int *obsCases, double *runsum ); void getNBDensities( double *hr, double *sp, double *odh, int *simCases, int *obsCases, double *runsum ) { #ifdef DEBUG for ( int s = 0; s < NUM_STRAINS; s++ ) { Rprintf("\nFor strain %d",s); Rprintf("\n\tHospitalization rate = %lg", hr[s]); Rprintf("\n\tSimulation probability = %lg",sp[s]); Rprintf("\n\tSimulated cases = %d",simCases[s]); Rprintf("\n\tObserved cases = %d",obsCases[s]); Rprintf("\n\tOverdispersion parameter = %lg",odh[s]); } Rprintf("\nRunning sum = %lg",runsum[0]); #endif } naive solution While better (i.e., potentially faster or syntactically clearer) solutions may exist (see Dirk's answer below), the following simplification of the code works: out<-.C("getNBDensities", hr = as.double(hosp.rate), sp = as.double(samplingProbabilities), odh = as.double(odh), simCases = as.integer(x[c("xC1","xC2","xC3")]), obsCases = as.integer(y[c("yC1","yC2","yC3")]), runsum = as.double(runsum)) The variables can be accessed in >out.

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  • creating a heirarchy of terminals or workspaces

    - by intuited
    <rant This question occurred to me ('occurred' meaning 'whispered seductively in my ear for the 100th time') while using GNU-screen, so I'll make that my example. However this is a much more general question about user interfaces and what I perceive as a flawmissing feature in every implementation I've yet seen. I'm wondering if there is some way to create a heirarchy/tree of terminals in a screen session. EG I'd like to have something like 1 bash 1.1 bash 1.2 bash 2 bash 3 bash 3.1 bash 3.1.1 bash 3.1.2 bash It would be good if the terminals could be labelled instead of having to be navigated to via some arrangement that I suspect doesn't exist. So then you could jump to one using eg ^A:goto happydays or ^A:goto dykstra.angry. So to generalize that: Firefox, Chrome, Internet Explorer, gnome-terminal, roxterm, konsole, yakuake, OpenOffice, Microsoft Office, Mr. Snuffaluppagus's Funtime Carousel™, and Your Mom's Jam Browser™ all offer the ability to create a flat set of tabs containing documents of an identical nature: web pages, terminals, documents, fun rideable animals, and jams. GNU-screen implements the same functionality without using tabs. Linux and OS/X window managers provide the ability to organize windows into an array of workspaces, which amounts to again, the same deal. Over the past few years, this has become a more or less ubiquitous concept which has been righteously welcomed into the far reaches of the computer interface funfest. Heavy users of these systems quickly encounter a problem with it: the set of entities is flat. In the case of workspaces, an option may be available to create a 2d array. However none of these applications furnish their users with the ability to create heirarchies, similar to filesystem directory structures, containing instances of their particular contained type. I for one am consistently bothered by this, and am wondering if the community can offer some wisdom as to why this has not happened in any of the foremost collections of computational functionality our culture has yet produced. Or if perhaps it has and I'm just an ignorant savage. I'd like to be able to not only group things into a tree structure, but also to create references (aka symbolic links, aka pointers) from one part of the structure to another, as well as apply properties (eg default directory, colorscheme, ...) recursively downward from a given node. I see no reason why we shouldn't be able to save these structures as known sessions, and apply tags to particular instances. So then you can sort through them by tag, find them by name, or just use the arrow keys (with an appropriate modifier) to move left or right and in or out of a given level. Another key combo would serve to create a branch in the place of the current terminal/webpage/lifelike statue/spreadsheet/spreadsheet sheet/presentation/jam and move that entity into the new branch, then create a fresh one as a sibling to it: a second leaf node within the same branch node. They would get along well. I find it a bit astonishing that this hasn't happened yet, and the only reason I can venture as a guess is that the creators of these fine systems do not consider such functionality to be useful to a significant portion of their userbase. I posit that the probability that that such an assumption would be correct is pretty low. On the other hand, given the relative ease with which such structures can be implemented using modern libraries/languages, it doesn't seem likely that difficulty of implementation would be a major roadblock. If it could be done in 1972 or whenever within the constraints of a filesystem driver, it should be relatively painless to implement in 2010 in a fullblown application. Given that all of these systems are capable of maintaining a set of equivalent entities, it seems unlikely that a major infrastructure overhaul would be necessary in order to enable a navigable heirarchy of them. </rant Mostly I'm just looking to start up a discussion and/or brainstorming on this topic. Any ideas, examples, criticism, or analysis are quite welcome. * Mr. Snuffaluppagus's Funtime Carousel is a registered trademark of Children's Television Workshop Inc. * Your Mom's Jam Browser is a registered trademark of Your Mom Inc.

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  • Does Test Driven Development (TDD) improve Quality and Correctness? (Part 1)

    - by David V. Corbin
    Since the dawn of the computer age, various methodologies have been introduced to improve quality and reduce cost. In this posting, I will by sharing my experiences with Test Driven Development; both its benefits and limitations. To start this topic, we need to agree on what TDD is. The first is to define each of the three words as used in this context. Test - An item or action which measures something in some quantifiable form. Driven - The primary motivation or focus of a series of activities (process) Development - All phases of a software project/product from concept through delivery. The above are very simple definitions that result in the following: "TDD is a process where the primary focus is on measuring and quantifying all aspects of the creation of a (software) product." There are many places where TDD is used outside of software development, even though it is not known by this name. Consider the (conventional) education process that most of us grew up on. The focus was to get the best grades as measured by different tests. Many of these tests measured rote memorization and not understanding of the subject matter. The result of this that many people graduated with high scores but without "quality and correctness" in their ability to utilize the subject matter (of course, the flip side is true where certain people DID understand the material but were not very good at taking this type of test). Returning to software development, let us look at some common scenarios. While these items are generally applicable regardless of platform, language and tools; the remainder of this post will utilize Microsoft Visual Studio and Team Foundation Server (TFS) for examples. It should be realized that everyone does at least some aspect of TDD. At the most rudimentary level, getting a program to compile involves a "pass/fail" measurement (is the syntax valid) that drives their ability to proceed further (run the program). Other developers may create "Unit Tests" in the belief that having a test for every method/property of a class and good code coverage is the goal of TDD. These items may be helpful and even important, but really only address a small aspect of the overall effort. To see TDD in a bigger view, lets identify the various activities that are part of the Software Development LifeCycle. These are going to be presented in a Waterfall style for simplicity, but each item also occurs within Iterative methodologies such as Agile/Scrum. the key ones here are: Requirements Gathering Architecture Design Implementation Quality Assurance Can each of these items be subjected to a process which establishes metrics (quantified metrics) that reflect both the quality and correctness of each item? It should be clear that conventional Unit Tests do not apply to all of these items; at best they can verify that a local aspect (e.g. a Class/Method) of implementation matches the (test writers perspective of) the appropriate design document. So what can we do? For each of area, the goal is to create tests that are quantifiable and durable. The ability to quantify the measurements (beyond a simple pass/fail) is critical to tracking progress(eventually measuring the level of success that has been achieved) and for providing clear information on what items need to be addressed (along with the appropriate time to address them - in varying levels of detail) . Durability is important so that the test can be reapplied (ideally in an automated fashion) over the entire cycle. Returning for a moment back to our "education example", one must also be careful of how the tests are organized and how the measurements are taken. If a test is in a multiple choice format, there is a significant statistical probability that a correct answer might be the result of a random guess. Also, in many situations, having the student simply provide a final answer can obscure many important elements. For example, on a math test, having the student simply provide a numeric answer (rather than showing the methodology) may result in a complete mismatch between the process and the result. It is hard to determine which is worse: The student who makes a simple arithmetric error at one step of a long process (resulting in a wrong answer) or The student who (without providing the "workflow") uses a completely invalid approach, yet still comes up with the right number. The "Wrong Process"/"Right Answer" is probably the single biggest problem in software development. Even very simple items can suffer from this. As an example consider the following code for a "straight line" calculation....Is it correct? (for Integral Points)         int Solve(int m, int b, int x) { return m * x + b; }   Most people would respond "Yes". But let's take the question one step further... Is it correct for all possible values of m,b,x??? (no fair if you cheated by being focused on the bolded text!)  Without additional information regarding constrains on "the possible values of m,b,x" the answer must be NO, there is the risk of overflow/wraparound that will produce an incorrect result! To properly answer this question (i.e. Test the Code), one MUST be able to backtrack from the implementation through the design, and architecture all the way back to the requirements. And the requirement itself must be tested against the stakeholder(s). It is only when the bounding conditions are defined that it is possible to determine if the code is "Correct" and has "Quality". Yet, how many of us (myself included) have written such code without even thinking about it. In many canses we (think we) "know" what the bounds are, and that the code will be correct. As we all know, requirements change, "code reuse" causes implementations to be applied to different scenarios, etc. This leads directly to the types of system failures that plague so many projects. This approach to TDD is much more holistic than ones which start by focusing on the details. The fundamental concepts still apply: Each item should be tested. The test should be defined/implemented before (or concurrent with) the definition/implementation of the actual item. We also add concepts that expand the scope and alter the style by recognizing: There are many things beside "lines of code" that benefit from testing (measuring/evaluating in a formal way) Correctness and Quality can not be solely measured by "correct results" In the future parts, we will examine in greater detail some of the techniques that can be applied to each of these areas....

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  • Deterministic/Consistent Unique Masking

    - by Dinesh Rajasekharan-Oracle
    One of the key requirements while masking data in large databases or multi database environment is to consistently mask some columns, i.e. for a given input the output should always be the same. At the same time the masked output should not be predictable. Deterministic masking also eliminates the need to spend enormous amount of time spent in identifying data relationships, i.e. parent and child relationships among columns defined in the application tables. In this blog post I will explain different ways of consistently masking the data across databases using Oracle Data Masking and Subsetting The readers of post should have minimal knowledge on Oracle Enterprise Manager 12c, Application Data Modeling, Data Masking concepts. For more information on these concepts, please refer to Oracle Data Masking and Subsetting document Oracle Data Masking and Subsetting 12c provides four methods using which users can consistently yet irreversibly mask their inputs. 1. Substitute 2. SQL Expression 3. Encrypt 4. User Defined Function SUBSTITUTE The substitute masking format replaces the original value with a value from a pre-created database table. As the method uses a hash based algorithm in the back end the mappings are consistent. For example consider DEPARTMENT_ID in EMPLOYEES table is replaced with FAKE_DEPARTMENT_ID from FAKE_TABLE. The substitute masking transformation that all occurrences of DEPARTMENT_ID say ‘101’ will be replaced with ‘502’ provided same substitution table and column is used , i.e. FAKE_TABLE.FAKE_DEPARTMENT_ID. The following screen shot shows the usage of the Substitute masking format with in a masking definition: Note that the uniqueness of the masked value depends on the number of columns being used in the substitution table i.e. if the original table contains 50000 unique values, then for the masked output to be unique and deterministic the substitution column should also contain 50000 unique values without which only consistency is maintained but not uniqueness. SQL EXPRESSION SQL Expression replaces an existing value with the output of a specified SQL Expression. For example while masking an EMPLOYEES table the EMAIL_ID of an employee has to be in the format EMPLOYEE’s [email protected] while FIRST_NAME and LAST_NAME are the actual column names of the EMPLOYEES table then the corresponding SQL Expression will look like %FIRST_NAME%||’.’||%LAST_NAME%||’@COMPANY.COM’. The advantage of this technique is that if you are masking FIRST_NAME and LAST_NAME of the EMPLOYEES table than the corresponding EMAIL ID will be replaced accordingly by the masking scripts. One of the interesting aspect’s of a SQL Expressions is that you can use sub SQL expressions, which means that you can write a nested SQL and use it as SQL Expression to address a complex masking business use cases. SQL Expression can also be used to consistently replace value with hashed value using Oracle’s PL/SQL function ORA_HASH. The following SQL Expression will help in the previous example for replacing the DEPARTMENT_IDs with a hashed number ORA_HASH (%DEPARTMENT_ID%, 1000) The following screen shot shows the usage of encrypt masking format with in the masking definition: ORA_HASH takes three arguments: 1. Expression which can be of any data type except LONG, LOB, User Defined Type [nested table type is allowed]. In the above example I used the Original value as expression. 2. Number of hash buckets which can be number between 0 and 4294967295. The default value is 4294967295. You can also co-relate the number of hash buckets to a range of numbers. In the above example above the bucket value is specified as 1000, so the end result will be a hashed number in between 0 and 1000. 3. Seed, can be any number which decides the consistency, i.e. for a given seed value the output will always be same. The default seed is 0. In the above SQL Expression a seed in not specified, so it to 0. If you have to use a non default seed then the function will look like. ORA_HASH (%DEPARTMENT_ID%, 1000, 1234 The uniqueness depends on the input and the number of hash buckets used. However as ORA_HASH uses a 32 bit algorithm, considering birthday paradox or pigeonhole principle there is a 0.5 probability of collision after 232-1 unique values. ENCRYPT Encrypt masking format uses a blend of 3DES encryption algorithm, hashing, and regular expression to produce a deterministic and unique masked output. The format of the masked output corresponds to the specified regular expression. As this technique uses a key [string] to encrypt the data, the same string can be used to decrypt the data. The key also acts as seed to maintain consistent outputs for a given input. The following screen shot shows the usage of encrypt masking format with in the masking definition: Regular Expressions may look complex for the first time users but you will soon realize that it’s a simple language. There are many resources in internet, oracle documentation, oracle learning library, my oracle support on writing a Regular Expressions, out of all the following My Oracle Support document helped me to get started with Regular Expressions: Oracle SQL Support for Regular Expressions[Video](Doc ID 1369668.1) USER DEFINED FUNCTION [UDF] User Defined Function or UDF provides flexibility for the users to code their own masking logic in PL/SQL, which can be called from masking Defintion. The standard format of an UDF in Oracle Data Masking and Subsetting is: Function udf_func (rowid varchar2, column_name varchar2, original_value varchar2) returns varchar2; Where • rowid is the row identifier of the column that needs to be masked • column_name is the name of the column that needs to be masked • original_value is the column value that needs to be masked You can achieve deterministic masking by using Oracle’s built in hash functions like, ORA_HASH, DBMS_CRYPTO.MD4, DBMS_CRYPTO.MD5, DBMS_UTILITY. GET_HASH_VALUE.Please refers to the Oracle Database Documentation for more information on the Oracle Hash functions. For example the following masking UDF generate deterministic unique hexadecimal values for a given string input: CREATE OR REPLACE FUNCTION RD_DUX (rid varchar2, column_name varchar2, orig_val VARCHAR2) RETURN VARCHAR2 DETERMINISTIC PARALLEL_ENABLE IS stext varchar2 (26); no_of_characters number(2); BEGIN no_of_characters:=6; stext:=substr(RAWTOHEX(DBMS_CRYPTO.HASH(UTL_RAW.CAST_TO_RAW(text),1)),0,no_of_characters); RETURN stext; END; The uniqueness depends on the input and length of the string and number of bits used by hash algorithm. In the above function MD4 hash is used [denoted by argument 1 in the DBMS_CRYPTO.HASH function which is a 128 bit algorithm which produces 2^128-1 unique hashed values , however this is limited by the length of the input string which is 6, so only 6^6 unique values will be generated. Also do not forget about the birthday paradox/pigeonhole principle mentioned earlier in this post. An another example is to consistently replace characters or numbers preserving the length and special characters as shown below: CREATE OR REPLACE FUNCTION RD_DUS(rid varchar2,column_name varchar2,orig_val VARCHAR2) RETURN VARCHAR2 DETERMINISTIC PARALLEL_ENABLE IS stext varchar2(26); BEGIN DBMS_RANDOM.SEED(orig_val); stext:=TRANSLATE(orig_val,'ABCDEFGHILKLMNOPQRSTUVWXYZ',DBMS_RANDOM.STRING('U',26)); stext:=TRANSLATE(stext,'abcdefghijklmnopqrstuvwxyz',DBMS_RANDOM.STRING('L',26)); stext:=TRANSLATE(stext,'0123456789',to_char(DBMS_RANDOM.VALUE(1,9))); stext:=REPLACE(stext,'.','0'); RETURN stext; END; The following screen shot shows the usage of an UDF with in a masking definition: To summarize, Oracle Data Masking and Subsetting helps you to consistently mask data across databases using one or all of the methods described in this post. It saves the hassle of identifying the parent-child relationships defined in the application table. Happy Masking

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  • SQL Server Developer Tools &ndash; Codename Juneau vs. Red-Gate SQL Source Control

    - by Ajarn Mark Caldwell
    So how do the new SQL Server Developer Tools (previously code-named Juneau) stack up against SQL Source Control?  Read on to find out. At the PASS Community Summit a couple of weeks ago, it was announced that the previously code-named Juneau software would be released under the name of SQL Server Developer Tools with the release of SQL Server 2012.  This replacement for Database Projects in Visual Studio (also known in a former life as Data Dude) has some great new features.  I won’t attempt to describe them all here, but I will applaud Microsoft for making major improvements.  One of my favorite changes is the way database elements are broken down.  Previously every little thing was in its own file.  For example, indexes were each in their own file.  I always hated that.  Now, SSDT uses a pattern similar to Red-Gate’s and puts the indexes and keys into the same file as the overall table definition. Of course there are really cool features to keep your database model in sync with the actual source scripts, and the rename refactoring feature is now touted as being more than just a search and replace, but rather a “semantic-aware” search and replace.  Funny, it reminds me of SQL Prompt’s Smart Rename feature.  But I’m not writing this just to criticize Microsoft and argue that they are late to the party with this feature set.  Instead, I do see it as a viable alternative for folks who want all of their source code to be version controlled, but there are a couple of key trade-offs that you need to know about when you choose which tool set to use. First, the basics Both tool sets integrate with a wide variety of source control systems including the most popular: Subversion, GIT, Vault, and Team Foundation Server.  Both tools have integrated functionality to produce objects to upgrade your target database when you are ready (DACPACs in SSDT, integration with SQL Compare for SQL Source Control).  If you regularly live in Visual Studio or the Business Intelligence Development Studio (BIDS) then SSDT will likely be comfortable for you.  Like BIDS, SSDT is a Visual Studio Project Type that comes with SQL Server, and if you don’t already have Visual Studio installed, it will install the shell for you.  If you already have Visual Studio 2010 installed, then it will just add this as an available project type.  On the other hand, if you regularly live in SQL Server Management Studio (SSMS) then you will really enjoy the SQL Source Control integration from within SSMS.  Both tool sets store their database model in script files.  In SSDT, these are on your file system like other source files; in SQL Source Control, these are stored in the folder structure in your source control system, and you can always GET them to your file system if you want to browse them directly. For me, the key differentiating factors are 1) a single, unified check-in, and 2) migration scripts.  How you value those two features will likely make your decision for you. Unified Check-In If you do a continuous-integration (CI) style of development that triggers an automated build with unit testing on every check-in of source code, and you use Visual Studio for the rest of your development, then you will want to really consider SSDT.  Because it is just another project in Visual Studio, it can be added to your existing Solution, and you can then do a complete, or unified single check-in of all changes whether they are application or database changes.  This is simply not possible with SQL Source Control because it is in a different development tool (SSMS instead of Visual Studio) and there is no way to do one unified check-in between the two.  You CAN do really fast back-to-back check-ins, but there is the possibility that the automated build that is triggered from the first check-in will cause your unit tests to fail and the CI tool to report that you broke the build.  Of course, the automated build that is triggered from the second check-in which contains the “other half” of your changes should pass and so the amount of time that the build was broken may be very, very short, but if that is very, very important to you, then SQL Source Control just won’t work; you’ll have to use SSDT. Refactoring and Migrations If you work on a mature system, or on a not-so-mature but also not-so-well-designed system, where you want to refactor the database schema as you go along, but you can’t have data suddenly disappearing from your target system, then you’ll probably want to go with SQL Source Control.  As I wrote previously, there are a number of changes which you can make to your database that the comparison tools (both from Microsoft and Red Gate) simply cannot handle without the possibility (or probability) of data loss.  Currently, SSDT only offers you the ability to inject PRE and POST custom deployment scripts.  There is no way to insert your own script in the middle to override the default behavior of the tool.  In version 3.0 of SQL Source Control (Early Access version now available) you have that ability to create your own custom migration script to take the place of the commands that the tool would have done, and ensure the preservation of your data.  Or, even if the default tool behavior would have worked, but you simply know a better way then you can take control and do things your way instead of theirs. You Decide In the environment I work in, our automated builds are not triggered off of check-ins, but off of the clock (currently once per night) and so there is no point at which the automated build and unit tests will be triggered without having both sides of the development effort already checked-in.  Therefore having a unified check-in, while handy, is not critical for us.  As for migration scripts, these are critically important to us.  We do a lot of new development on systems that have already been in production for years, and it is not uncommon for us to need to do a refactoring of the database.  Because of the maturity of the existing system, that often involves data migrations or other additional SQL tasks that the comparison tools just can’t detect on their own.  Therefore, the ability to create a custom migration script to override the tool’s default behavior is very important to us.  And so, you can see why we will continue to use Red Gate SQL Source Control for the foreseeable future.

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  • How to set up spf records to send mail from google hosted apps to gmail addresses

    - by Chris Adams
    Hi there, I'm trying to work out why email I send from one domain I own is rejected by another that I own, and while I think it may be related to how I've setup spf records, I'm not sure what steps I need to take to fix it. Here's the error message I receive: Technical details of permanent failure: Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 550 550-Verification failed for <[email protected]> 550-No Such User Here 550 Sender verify failed (state 14). Here's the response from [email protected] Delivered-To: [email protected] Received: by 10.86.92.9 with SMTP id p9cs85371fgb; Wed, 2 Sep 2009 22:33:32 -0700 (PDT) Received: by 10.90.205.4 with SMTP id c4mr2406190agg.29.1251956007562; Wed, 02 Sep 2009 22:33:27 -0700 (PDT) Return-Path: <[email protected]> Received: from verifier.port25.com (207-36-201-235.ptr.primarydns.com [207.36.201.235]) by mx.google.com with ESMTP id 26si831174aga.24.2009.09.02.22.33.25; Wed, 02 Sep 2009 22:33:26 -0700 (PDT) Received-SPF: pass (google.com: domain of [email protected] designates 207.36.201.235 as permitted sender) client-ip=207.36.201.235; Authentication-Results: mx.google.com; spf=pass (google.com: domain of [email protected] designates 207.36.201.235 as permitted sender) [email protected]; dkim=pass [email protected] DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; s=auth; d=port25.com; h=Date:From:To:Subject:Message-Id:In-Reply-To; [email protected]; bh=GRMrcnoucTl4upzqJYTG5sOZMLU=; b=uk6TjADEyZVRkceQGjH94ZzfVeRTsiZPzbXuhlqDt1m+kh1zmdUEoiTOzd89ryCHMbVcnG1JajBj 5vOMKYtA3g== DomainKey-Signature: a=rsa-sha1; c=nofws; q=dns; s=auth; d=port25.com; b=NqKCPK00Xt49lbeO009xy4ZRgMGpghvcgfhjNy7+qI89XKTzi6IUW0hYqCQyHkd2p5a1Zjez2ZMC l0u9CpZD3Q==; Received: from verifier.port25.com (127.0.0.1) by verifier.port25.com (PowerMTA(TM) v3.6a1) id hjt9pq0hse8u for <[email protected]>; Thu, 3 Sep 2009 01:26:52 -0400 (envelope-from <[email protected]>) Date: Thu, 3 Sep 2009 01:26:52 -0400 From: [email protected] To: [email protected] Subject: Authentication Report Message-Id: <[email protected]> Precedence: junk (auto_reply) In-Reply-To: <[email protected]> This message is an automatic response from Port25's authentication verifier service at verifier.port25.com. The service allows email senders to perform a simple check of various sender authentication mechanisms. It is provided free of charge, in the hope that it is useful to the email community. While it is not officially supported, we welcome any feedback you may have at <[email protected]>. Thank you for using the verifier, The Port25 Solutions, Inc. team ========================================================== Summary of Results ========================================================== SPF check: pass DomainKeys check: neutral DKIM check: neutral Sender-ID check: pass SpamAssassin check: ham ========================================================== Details: ========================================================== HELO hostname: fg-out-1718.google.com Source IP: 72.14.220.158 mail-from: [email protected] ---------------------------------------------------------- SPF check details: ---------------------------------------------------------- Result: pass ID(s) verified: [email protected] DNS record(s): stemcel.co.uk. 14400 IN TXT "v=spf1 include:aspmx.googlemail.com ~all" aspmx.googlemail.com. 7200 IN TXT "v=spf1 redirect=_spf.google.com" _spf.google.com. 300 IN TXT "v=spf1 ip4:216.239.32.0/19 ip4:64.233.160.0/19 ip4:66.249.80.0/20 ip4:72.14.192.0/18 ip4:209.85.128.0/17 ip4:66.102.0.0/20 ip4:74.125.0.0/16 ip4:64.18.0.0/20 ip4:207.126.144.0/20 ?all" ---------------------------------------------------------- DomainKeys check details: ---------------------------------------------------------- Result: neutral (message not signed) ID(s) verified: [email protected] DNS record(s): ---------------------------------------------------------- DKIM check details: ---------------------------------------------------------- Result: neutral (message not signed) ID(s) verified: NOTE: DKIM checking has been performed based on the latest DKIM specs (RFC 4871 or draft-ietf-dkim-base-10) and verification may fail for older versions. If you are using Port25's PowerMTA, you need to use version 3.2r11 or later to get a compatible version of DKIM. ---------------------------------------------------------- Sender-ID check details: ---------------------------------------------------------- Result: pass ID(s) verified: [email protected] DNS record(s): stemcel.co.uk. 14400 IN TXT "v=spf1 include:aspmx.googlemail.com ~all" aspmx.googlemail.com. 7200 IN TXT "v=spf1 redirect=_spf.google.com" _spf.google.com. 300 IN TXT "v=spf1 ip4:216.239.32.0/19 ip4:64.233.160.0/19 ip4:66.249.80.0/20 ip4:72.14.192.0/18 ip4:209.85.128.0/17 ip4:66.102.0.0/20 ip4:74.125.0.0/16 ip4:64.18.0.0/20 ip4:207.126.144.0/20 ?all" ---------------------------------------------------------- SpamAssassin check details: ---------------------------------------------------------- SpamAssassin v3.2.5 (2008-06-10) Result: ham (-2.6 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] 0.0 HTML_MESSAGE BODY: HTML included in message I've registered the spf records for my domain, as advised here Both domains pass validate according to Kitterman's spf record testing tools, so I'm somewhat confused about this. I also have the catchall address set up on the stemcel.co.uk domain here, but I don't have one setup for chrisadams.me.uk. Instead, we have the following forwarders setup [email protected] to [email protected] [email protected] to [email protected] [email protected] to [email protected] [email protected] to [email protected] Any ideas how to get this working? I'm not sure what I should be looking for here.

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  • DKIM, SPF, PTR records are not working properly with my domain

    - by shihon
    I configured my server and well authenticate email system with DKIM key, SPF record and PTR records, when i start to sent out mails from phplist interface to my users ~50000, my domain is spammed by google. In headers, signed by and mailed by tag shows by my domain : appmail.co, I also test my domain via check mail provide by port25, report is: This message is an automatic response from Port25's authentication verifier service at verifier.port25.com. The service allows email senders to perform a simple check of various sender authentication mechanisms. It is provided free of charge, in the hope that it is useful to the email community. While it is not officially supported, we welcome any feedback you may have at . Thank you for using the verifier, The Port25 Solutions, Inc. team ========================================================== Summary of Results SPF check: pass DomainKeys check: neutral DKIM check: pass Sender-ID check: pass SpamAssassin check: ham ========================================================== Details: HELO hostname: app.appmail.co Source IP: 108.179.192.148 mail-from: [email protected] SPF check details: Result: pass ID(s) verified: [email protected] DNS record(s): appmail.co. SPF (no records) appmail.co. 14400 IN TXT "v=spf1 +a +mx +ip4:108.179.192.148 ?all" appmail.co. 14400 IN A 108.179.192.148 DomainKeys check details: Result: neutral (message not signed) ID(s) verified: [email protected] DNS record(s): DKIM check details: Result: pass (matches From: [email protected]) ID(s) verified: header.d=appmail.co Canonicalized Headers: content-type:multipart/alternative;'20'boundary=047d7b2eda75d8544d04c17b6841'0D''0A' to:[email protected]'0D''0A' from:shashank'20'sharma'20'<[email protected]>'0D''0A' subject:Test'0D''0A' message-id:<CADnDhbH9aDBk3Ho2-CrG7gwOoD6RNX0sFq4bWL64+kmo=9HjWg@mail.gmail.com>'0D''0A' date:Sat,'20'2'20'Jun'20'2012'20'16:44:50'20'+0530'0D''0A' mime-version:1.0'0D''0A' dkim-signature:v=1;'20'a=rsa-sha256;'20'q=dns/txt;'20'c=relaxed/relaxed;'20'd=appmail.co;'20's=default;'20'h=Content-Type:To:From:Subject:Message-ID:Date:MIME-Version;'20'bh=GS6uwlT+weKcrrLJ2I+cjBtWPq9nvhwRlNAJebOiQOk=;'20'b=; Canonicalized Body: --047d7b2eda75d8544d04c17b6841'0D''0A' Content-Type:'20'text/plain;'20'charset=UTF-8'0D''0A' '0D''0A' Hello'20'Senders'0D''0A' '0D''0A' --047d7b2eda75d8544d04c17b6841'0D''0A' Content-Type:'20'text/html;'20'charset=UTF-8'0D''0A' '0D''0A' Hello'20'Senders'0D''0A' '0D''0A' --047d7b2eda75d8544d04c17b6841--'0D''0A' DNS record(s): default._domainkey.appmail.co. 14400 IN TXT "v=DKIM1; k=rsa; p=MHwwDQYJKoZIhvcNAQEBBQADawAwaAJhALGCOdMeZRxRHoatH7/KCvI1CKS0wOOsTAq0LLgPsOpMolifpVQDKOWT2zq/6LHVmDVjXLbnWO2d4ry/riy7ei66pLpnAV5ceIUSjBRusI8jcF9CZhPrh/OImsKVUb9ceQIDAQAB;" NOTE: DKIM checking has been performed based on the latest DKIM specs (RFC 4871 or draft-ietf-dkim-base-10) and verification may fail for older versions. If you are using Port25's PowerMTA, you need to use version 3.2r11 or later to get a compatible version of DKIM. Sender-ID check details: Result: pass ID(s) verified: [email protected] DNS record(s): appmail.co. SPF (no records) appmail.co. 14400 IN TXT "v=spf1 +a +mx +ip4:108.179.192.148 ?all" appmail.co. 14400 IN A 108.179.192.148 SpamAssassin check details: SpamAssassin v3.3.1 (2010-03-16) Result: ham (-0.1 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message -0.5 BAYES_05 BODY: Bayes spam probability is 1 to 5% [score: 0.0288] -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.5 SINGLE_HEADER_1K A single header contains 1K-2K characters ========================================================== Original Email Return-Path: <[email protected]> Received: from app.appmail.co (108.179.192.148) by verifier.port25.com id hp7qqo11u9cc for <[email protected]>; Sat, 2 Jun 2012 07:14:52 -0400 (envelope-from <[email protected]>) Authentication-Results: verifier.port25.com; spf=pass [email protected] Authentication-Results: verifier.port25.com; domainkeys=neutral (message not signed) [email protected] Authentication-Results: verifier.port25.com; dkim=pass (matches From: [email protected]) header.d=appmail.co Authentication-Results: verifier.port25.com; sender-id=pass [email protected] DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=appmail.co; s=default; h=Content-Type:To:From:Subject:Message-ID:Date:MIME-Version; bh=GS6uwlT+weKcrrLJ2I+cjBtWPq9nvhwRlNAJebOiQOk=;b=pNw3UQNMoNyZ2Ujv8omHGodKVu/55S8YdBEsA5TbRciga/H7f+5noiKvo60vU6oXYyzVKeozFHDoOEMV6m5UTgkdBefogl+9cUIbt5CSrTWA97D7tGS97JblTDXApbZH; Received: from mail-pb0-f46.google.com ([209.85.160.46]:57831) by app.appmail.co with esmtpa (Exim 4.77) (envelope-from <[email protected]>) id 1SamIF-00055f-Om for [email protected]; Sat, 02 Jun 2012 16:44:51 +0530 Received: by pbbrp8 with SMTP id rp8so4165728pbb.5 for <[email protected]>; Sat, 02 Jun 2012 04:14:51 -0700 (PDT) MIME-Version: 1.0 Received: by 10.68.216.33 with SMTP id on1mr19414885pbc.105.1338635690988; Sat, 02 Jun 2012 04:14:50 -0700 (PDT) Received: by 10.143.66.13 with HTTP; Sat, 2 Jun 2012 04:14:50 -0700 (PDT) Date: Sat, 2 Jun 2012 16:44:50 +0530 Message-ID: <CADnDhbH9aDBk3Ho2-CrG7gwOoD6RNX0sFq4bWL64+kmo=9HjWg@mail.gmail.com> Subject: Test From: shashank sharma <[email protected]> To: [email protected] Content-Type: multipart/alternative; boundary=047d7b2eda75d8544d04c17b6841 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - app.appmail.co X-AntiAbuse: Original Domain - verifier.port25.com X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - appmail.co --047d7b2eda75d8544d04c17b6841 Content-Type: text/plain; charset=UTF-8 Hello Senders --047d7b2eda75d8544d04c17b6841 Content-Type: text/html; charset=UTF-8 Hello Senders --047d7b2eda75d8544d04c17b6841-- I also tried to send mail on yahoo , rediff but i get mails in spam. Please help me to sort out this issue

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