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• Rkhunter 122 suspect files; do I have a problem?

  - by user276166

  I am new to ubuntu. I am using Xfce Ubuntu 14.04 LTS. I have ran rkhunter a few weeks age and only got a few warnings. The forum said that they were normal. But, this time rkhunter reported 122 warnings. Please advise. casey@Shaman:~$ sudo rkhunter -c [ Rootkit Hunter version 1.4.0 ] Checking system commands... Performing 'strings' command checks Checking 'strings' command [ OK ] Performing 'shared libraries' checks Checking for preloading variables [ None found ] Checking for preloaded libraries [ None found ] Checking LD_LIBRARY_PATH variable [ Not found ] Performing file properties checks Checking for prerequisites [ Warning ] /usr/sbin/adduser [ Warning ] /usr/sbin/chroot [ Warning ] /usr/sbin/cron [ OK ] /usr/sbin/groupadd [ Warning ] /usr/sbin/groupdel [ Warning ] /usr/sbin/groupmod [ Warning ] /usr/sbin/grpck [ Warning ] /usr/sbin/nologin [ Warning ] /usr/sbin/pwck [ Warning ] /usr/sbin/rsyslogd [ Warning ] /usr/sbin/useradd [ Warning ] /usr/sbin/userdel [ Warning ] /usr/sbin/usermod [ Warning ] /usr/sbin/vipw [ Warning ] /usr/bin/awk [ Warning ] /usr/bin/basename [ Warning ] /usr/bin/chattr [ Warning ] /usr/bin/cut [ Warning ] /usr/bin/diff [ Warning ] /usr/bin/dirname [ Warning ] /usr/bin/dpkg [ Warning ] /usr/bin/dpkg-query [ Warning ] /usr/bin/du [ Warning ] /usr/bin/env [ Warning ] /usr/bin/file [ Warning ] /usr/bin/find [ Warning ] /usr/bin/GET [ Warning ] /usr/bin/groups [ Warning ] /usr/bin/head [ Warning ] /usr/bin/id [ Warning ] /usr/bin/killall [ OK ] /usr/bin/last [ Warning ] /usr/bin/lastlog [ Warning ] /usr/bin/ldd [ Warning ] /usr/bin/less [ OK ] /usr/bin/locate [ OK ] /usr/bin/logger [ Warning ] /usr/bin/lsattr [ Warning ] /usr/bin/lsof [ OK ] /usr/bin/mail [ OK ] /usr/bin/md5sum [ Warning ] /usr/bin/mlocate [ OK ] /usr/bin/newgrp [ Warning ] /usr/bin/passwd [ Warning ] /usr/bin/perl [ Warning ] /usr/bin/pgrep [ Warning ] /usr/bin/pkill [ Warning ] /usr/bin/pstree [ OK ] /usr/bin/rkhunter [ OK ] /usr/bin/rpm [ Warning ] /usr/bin/runcon [ Warning ] /usr/bin/sha1sum [ Warning ] /usr/bin/sha224sum [ Warning ] /usr/bin/sha256sum [ Warning ] /usr/bin/sha384sum [ Warning ] /usr/bin/sha512sum [ Warning ] /usr/bin/size [ Warning ] /usr/bin/sort [ Warning ] /usr/bin/stat [ Warning ] /usr/bin/strace [ Warning ] /usr/bin/strings [ Warning ] /usr/bin/sudo [ Warning ] /usr/bin/tail [ Warning ] /usr/bin/test [ Warning ] /usr/bin/top [ Warning ] /usr/bin/touch [ Warning ] /usr/bin/tr [ Warning ] /usr/bin/uniq [ Warning ] /usr/bin/users [ Warning ] /usr/bin/vmstat [ Warning ] /usr/bin/w [ Warning ] /usr/bin/watch [ Warning ] /usr/bin/wc [ Warning ] /usr/bin/wget [ Warning ] /usr/bin/whatis [ Warning ] /usr/bin/whereis [ Warning ] /usr/bin/which [ OK ] /usr/bin/who [ Warning ] /usr/bin/whoami [ Warning ] /usr/bin/unhide.rb [ Warning ] /usr/bin/mawk [ Warning ] /usr/bin/lwp-request [ Warning ] /usr/bin/heirloom-mailx [ OK ] /usr/bin/w.procps [ Warning ] /sbin/depmod [ Warning ] /sbin/fsck [ Warning ] /sbin/ifconfig [ Warning ] /sbin/ifdown [ Warning ] /sbin/ifup [ Warning ] /sbin/init [ Warning ] /sbin/insmod [ Warning ] /sbin/ip [ Warning ] /sbin/lsmod [ Warning ] /sbin/modinfo [ Warning ] /sbin/modprobe [ Warning ] /sbin/rmmod [ Warning ] /sbin/route [ Warning ] /sbin/runlevel [ Warning ] /sbin/sulogin [ Warning ] /sbin/sysctl [ Warning ] /bin/bash [ Warning ] /bin/cat [ Warning ] /bin/chmod [ Warning ] /bin/chown [ Warning ] /bin/cp [ Warning ] /bin/date [ Warning ] /bin/df [ Warning ] /bin/dmesg [ Warning ] /bin/echo [ Warning ] /bin/ed [ OK ] /bin/egrep [ Warning ] /bin/fgrep [ Warning ] /bin/fuser [ OK ] /bin/grep [ Warning ] /bin/ip [ Warning ] /bin/kill [ Warning ] /bin/less [ OK ] /bin/login [ Warning ] /bin/ls [ Warning ] /bin/lsmod [ Warning ] /bin/mktemp [ Warning ] /bin/more [ Warning ] /bin/mount [ Warning ] /bin/mv [ Warning ] /bin/netstat [ Warning ] /bin/ping [ Warning ] /bin/ps [ Warning ] /bin/pwd [ Warning ] /bin/readlink [ Warning ] /bin/sed [ Warning ] /bin/sh [ Warning ] /bin/su [ Warning ] /bin/touch [ Warning ] /bin/uname [ Warning ] /bin/which [ OK ] /bin/kmod [ Warning ] /bin/dash [ Warning ] [Press <ENTER> to continue] Checking for rootkits... Performing check of known rootkit files and directories 55808 Trojan - Variant A [ Not found ] ADM Worm [ Not found ] AjaKit Rootkit [ Not found ] Adore Rootkit [ Not found ] aPa Kit [ Not found ] Apache Worm [ Not found ] Ambient (ark) Rootkit [ Not found ] Balaur Rootkit [ Not found ] BeastKit Rootkit [ Not found ] beX2 Rootkit [ Not found ] BOBKit Rootkit [ Not found ] cb Rootkit [ Not found ] CiNIK Worm (Slapper.B variant) [ Not found ] Danny-Boy's Abuse Kit [ Not found ] Devil RootKit [ Not found ] Dica-Kit Rootkit [ Not found ] Dreams Rootkit [ Not found ] Duarawkz Rootkit [ Not found ] Enye LKM [ Not found ] Flea Linux Rootkit [ Not found ] Fu Rootkit [ Not found ] Fuck`it Rootkit [ Not found ] GasKit Rootkit [ Not found ] Heroin LKM [ Not found ] HjC Kit [ Not found ] ignoKit Rootkit [ Not found ] IntoXonia-NG Rootkit [ Not found ] Irix Rootkit [ Not found ] Jynx Rootkit [ Not found ] KBeast Rootkit [ Not found ] Kitko Rootkit [ Not found ] Knark Rootkit [ Not found ] ld-linuxv.so Rootkit [ Not found ] Li0n Worm [ Not found ] Lockit / LJK2 Rootkit [ Not found ] Mood-NT Rootkit [ Not found ] MRK Rootkit [ Not found ] Ni0 Rootkit [ Not found ] Ohhara Rootkit [ Not found ] Optic Kit (Tux) Worm [ Not found ] Oz Rootkit [ Not found ] Phalanx Rootkit [ Not found ] Phalanx2 Rootkit [ Not found ] Phalanx2 Rootkit (extended tests) [ Not found ] Portacelo Rootkit [ Not found ] R3dstorm Toolkit [ Not found ] RH-Sharpe's Rootkit [ Not found ] RSHA's Rootkit [ Not found ] Scalper Worm [ Not found ] Sebek LKM [ Not found ] Shutdown Rootkit [ Not found ] SHV4 Rootkit [ Not found ] SHV5 Rootkit [ Not found ] Sin Rootkit [ Not found ] Slapper Worm [ Not found ] Sneakin Rootkit [ Not found ] 'Spanish' Rootkit [ Not found ] Suckit Rootkit [ Not found ] Superkit Rootkit [ Not found ] TBD (Telnet BackDoor) [ Not found ] TeLeKiT Rootkit [ Not found ] T0rn Rootkit [ Not found ] trNkit Rootkit [ Not found ] Trojanit Kit [ Not found ] Tuxtendo Rootkit [ Not found ] URK Rootkit [ Not found ] Vampire Rootkit [ Not found ] VcKit Rootkit [ Not found ] Volc Rootkit [ Not found ] Xzibit Rootkit [ Not found ] zaRwT.KiT Rootkit [ Not found ] ZK Rootkit [ Not found ] [Press <ENTER> to continue] Performing additional rootkit checks Suckit Rookit additional checks [ OK ] Checking for possible rootkit files and directories [ None found ] Checking for possible rootkit strings [ None found ] Performing malware checks Checking running processes for suspicious files [ None found ] Checking for login backdoors [ None found ] Checking for suspicious directories [ None found ] Checking for sniffer log files [ None found ] Performing Linux specific checks Checking loaded kernel modules [ OK ] Checking kernel module names [ OK ] [Press <ENTER> to continue] Checking the network... Performing checks on the network ports Checking for backdoor ports [ None found ] Checking for hidden ports [ Skipped ] Performing checks on the network interfaces Checking for promiscuous interfaces [ None found ] Checking the local host... Performing system boot checks Checking for local host name [ Found ] Checking for system startup files [ Found ] Checking system startup files for malware [ None found ] Performing group and account checks Checking for passwd file [ Found ] Checking for root equivalent (UID 0) accounts [ None found ] Checking for passwordless accounts [ None found ] Checking for passwd file changes [ Warning ] Checking for group file changes [ Warning ] Checking root account shell history files [ None found ] Performing system configuration file checks Checking for SSH configuration file [ Not found ] Checking for running syslog daemon [ Found ] Checking for syslog configuration file [ Found ] Checking if syslog remote logging is allowed [ Not allowed ] Performing filesystem checks Checking /dev for suspicious file types [ Warning ] Checking for hidden files and directories [ Warning ] [Press <ENTER> to continue] System checks summary ===================== File properties checks... Required commands check failed Files checked: 137 Suspect files: 122 Rootkit checks... Rootkits checked : 291 Possible rootkits: 0 Applications checks... All checks skipped The system checks took: 5 minutes and 11 seconds All results have been written to the log file (/var/log/rkhunter.log)

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• Career guidance/advice for Junior-level Software Engineer [closed]

  - by John Do

  I have quite a few questions on my mind, so please bare with me. Please don't feel obligated to answer all of them, any as you choose will do. I'd appreciate if you could share some insight on any of these. Before I begin, some context: I currently have almost two years of professional experience as a Software Engineer, mainly developing software in Java. At this point, I feel that I have reached the peak in my career growth at the current company I am at and therefore I am looking for a new job, ideally again, as a Software Engineer. I have been interviewing for the past few months casually but have not had luck with companies I have a passion for. So, in no particular order - 1) In general, what are your thoughts on having graduate degrees in CS / Software Engineering. How much does it influence a salary increase, and do you think it's beneficial when working on real-world problems? I get the sense that a graduate degree in the field is trivial unless you really have a passion for research. 2) In general, in professional practice, how often had you have to write your own data structures and "complex" algorithms from scratch? In my own work, I have found myself relying mainly on third-party frameworks and the Java standard library to implement solutions as per business requirements. What are your thoughts on this? 3) In terms of resume, I feel the most ambivalent here. I want to be able to "blemish" my resume to a certain extent so that it stands out from others', but at the same time I do not want to over-exagerate my abilities. How do you strike a balance here? For example: I say that I am proficient in Java with data structures and algorithms. This is obviously a subjective and relative statement. I've taken the classes in my undergrad, and I've applied it in my work experience. What I feel as "prociency" can be seen as junior-level to others. How do you know what to say? Most of the time, recruiters (with no technical background) will be looking for keywords that stand out. This leads me to my next question (4). 4) Just from interviewing for the past few months (and getting plenty of rejections), I've come to realize that I may not be as proficient in data structures and algorithms as I thought I was. Do you think it's a good idea to remove the "proficient in java/data structure and algorithms"? I feel that being too hoenst on the resume will impede me from scoring opportunities to even have an interview with top-notch companies. What are your thoughts? 5) What is the absolute "must-have" knowledge going into a technical interview? I've been practicing several algorithmic and data sturcture problems now, and I feel that my abilities to solve arbitrary problems efficiently has not gotten significantly better. Do you think these abilities are something innate - it's either you have in you, or you don't? How can you teach yourself to learn, if you will? 6) How easy is it to go from industry/function to the next? I work mainly with backend technologies and I'm now interested in working with the frontend, i.e javascript,jquery,php or even mobile development. In your own experience, how did you not get pidgeon holed in your career? I feel that the choices you make now ultimately decide your future. As cliche as it sounds, I think it may be true. Here's what I mean: you've worked mainly as a backend engineer, people are interested in you doing the same thing since you've already accumulated experience in that function. How do get experience in a new function if people won't accept you because you don't already have it? It's a catch 22, you see... Are side projects the only real way to help you move from one function to another that you're truly interested in? For example: I could start writing my own mobile applications, even though I've worked mainly on the backend. Thanks so much for the long read. As a relatively new engineer to the real world, I am very humble and would like those who are experienced to shed some light. Thank you so much.

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• Silverlight Reporting Application Part 3.5 - Prism Background and WCF RIA [Series Intermission]

  Taking a step back before I dive into the details and full-on coding fun, I wanted to once again respond to a comment on my last post to clear up some things in regards to how I'm setting up my project and some of the choices I've made. Aka, thanks Ben. :) Prism Project Setup For starters, I'm not the ideal use case for a Prism application. In most cases where you've got a one-man team, Prism can be overkill as it is more intended for large teams who are geographically dispersed or in applications that have a larger scale than my Recruiting application in which you'll greatly benefit from modularity, delayed loading of xaps, etc. What Prism offers, though, is a manner for handling UI, commands, and events with the idea that, through a modular approach in which no parts really need to know about one another, I can update this application bit by bit as hiring needs change or requirements differ between offices without having to worry that changing something in the Jobs module will break something in, say, the Scheduling module. All that being said, here's a look at how our project breakdown for Recruit (MVVM/Prism implementation) looks: This could be a little misleading though, as each of those modules is actually another project in the overall Recruit solution. As far as what the projects actually are, that looks a bit like this: Recruiting Solution Recruit (Shell up there) - Main Silverlight Application .Web - Default .Web application to host the Silverlight app Infrastructure - Silverlight Class Library Project Modules - Silverlight Class Library Projects Infrastructure &Modules The Infrastructure project is probably something you'll see to some degree in any composite application. In this application, it is going to contain custom commands (you'll see the joy of these in a post or two down the road), events, helper classes, and any custom classes I need to share between different modules. Think of this as a handy little crossroad between any parts of your application. Modules on the other hand are the bread and butter of this application. Besides the shell, which holds the UI skeleton, and the infrastructure, which holds all those shared goodies, the modules are self-contained bundles of functionality to handle different concerns. In my scenario, I need a way to look up and edit Jobs, Applicants, and Schedule interviews, a Notification module to handle telling the user when different things are happening (i.e., loading from database), and a Menu to control interaction and moving between different views. All modules are going to follow the following pattern: The module class will inherit from IModule and handle initialization and loading the correct view into the correct region, whereas the Views and ViewModels folders will contain paired Silverlight user controls and ViewModel class backings. WCF RIA Services Since we've got all the projects in a single solution, we did not have to go the route of creating a WCR RIA Services Class Library. Every module has it's WCF RIA link back to the main .Web project, so the single Linq-2-SQL (yes, I said Linq-2-SQL, but I'll soon be switching to OpenAccess due to the new visual designer) context I'm using there works nicely with the scope of my project. If I were going for completely separating this project out and doing different, dynamically loaded elements, I'd probably go for the separate class library. Hope that clears that up. In the future though, I will be using that in a project that I've got in the "when I've got enough time to work on this" pipeline, so we'll get into that eventually- and hopefully when WCF RIA is in full release! Why Not use Silverlight Navigation/Business Template? The short answer- I'm a creature of habit, and having used Silverlight for a few years now, I'm used to doing lots of things manually. :) Plus, starting with a blank slate of a project I'm able to set up things exactly as I want them to be. In this case, rather than the navigation frame we would see in one of the templates, the MainRegion/ContentControl is working as our main navigation window. In many cases I will use theSilverlight navigation template to start things off, however in this case I did not need those features so I opted out of using that. Next time when I actually hit post #4, we're going to get into the modules and starting to get functionality into this application. Next week is also release week for the Q1 2010 release, so be sure to check out our annualWebinar Week (I might be biased, but Wednesday is my favorite out of the group). Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• XBRL - Moving from Production to Consumption

  - by jmorourke

  Here's an update on what’s new with XBRL and how it can actually benefit your organization versus adding extra time and costs to financial reporting.  On February 29th (leap day) of 2012 I attended the XBRL and Financial Analysis Technology Conference at Baruch College in NYC.  The event, which attracted over 300 XBRL gurus and fans was presented by XBRL US, The New York Society of Security Analysts’ Improved Corporate Reporting Committee, and Baruch College’s Robert Zicklin Center for Corporate Integrity.  The event featured keynotes from the U.S. Securities and Exchange Commission (SEC), and the CFA Institute as well as panels covering alternative research tools and data, corporate reporting to stakeholders and a demonstration of XBRL analysis tools.  The program culminated in a presentation of the finalists and the winner of the $20,000 XBRL Challenge.    Some of the key points made in the sessions included: The focus of XBRL tools is moving from production to consumption. As of February 2012, over 9000 companies are reporting in XBRL, with over 10 million facts filed to date XBRL taxonomy extensions have dropped from 27% to 11% making comparisons easier The SEC reports that XBRL makes it easier to analyze disclosures, focus on accounting issues XBRL is helping standards-setters like the FASB speed their analysis of impacts of proposed accounting rule changes Companies like Thomson Reuters report that XBRL is helping speed the delivery of data to clients The most interesting part of the program though, was the session highlighting the 5 finalists in the XBRL Challenge competition and the winning solution.  The XBRL Challenge was launched in 2011 as a means of spurring the development of more end-user tools to help with the consumption of XBRL-based financial information.       Over an 8-month process handled by 5 judges, there were 84 registrants, 15 completed submissions, 5 finalists and one winner of the challenge.  All of the solutions are open-sourced tools and most of them focus on consuming XBRL-based data.  The 5 finalists included: Advanced XBRL Processing from Oxide solutions – XBRL viewer for taxonomies, filings and company data with peer comparison capabilities. Arrelle – API for XBRL processes, supports SEC Validations, RSS Feeds to access filings etc. Calcbench – XBRL data analysis tool that can be embedded in other web applications.  This tool can combine XBRL filings with real-time market data. XBRL to XL – allows the importing of XBRL data into Microsoft Excel for analysis, comparisons.  Users start on the web and populate Excel with XBRL data. XBurble – allows users to search and view XBRL filings, export to Excel, merge for comparison, and includes a workflow interface. The winner of the $20,000 XBRL Challenge prize was CalcBench.  More information about the XBRL Challenge and the finalists can be found at www.XBRLUS.org/challenge XBRL for Sustainability Reporting – other recent news on the XBRL front was the announcement by the Global Reporting Initiative (GRI) of an XBRL taxonomy for Sustainability Reporting.  This taxonomy was co-developed by the GRI and Deloitte and is designed to make the consumption of data found in Sustainability Reports much easier.  Although there is no government mandate to file Sustainability Reports in XBRL format, organizations that do use the GRI guidelines for Sustainability Reporting are encouraged to tag and submit their data voluntarily to the GRI – who will populate a database with Sustainability Reporting data and make this available to the public.  For more information about this initiative, you can go to the GRI web site:  www.globalreporting.org. So how does all of this benefit corporate filers and investors?  Since its introduction, the consensus in the market is that XBRL has mainly benefited the regulators and investment analysts who need to consume and analyze large volumes of financial data.  But with the emergence of more end-user tools for consuming and analyzing XBRL-based data, and the ability to perform quick comparisons of one company versus its peers and competitors in an industry group, will soon accelerate the benefits to corporate finance staff, as well as individual investors.  This could apply to financial results tagged in XBRL, as well as non-financial information such as Sustainability Reporting – which over the long-term will likely be integrated with financial reporting.   And as multiple regulators and agencies in a country adopt the XBRL standard for corporate filings, more benefits will accrue as companies will be able to leverage one set of XBRL-based financial data for multiple regulatory filings.     For more information about the latest developments in XBRL, check out the XBRL US or XBRL International web sites:  www.xbrl.org, www.xbrlus.org. For more information about what Oracle is doing to support XBRL, here are some links: http://www.oracle.com/us/solutions/ent-performance-bi/disclosure-management-065892.html http://www.oracle.com/technetwork/database/features/xmldb/index-087631.html Feel free to contact me if you have any questions or need more information:  [email protected]

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• Silverlight Relay Commands

  - by George Evjen

  v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Normal 0 false false false false EN-US X-NONE X-NONE /* 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-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; 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;} I am fairly new at Silverlight development and I usually have an issue that needs research every day. Which I enjoy, since I like the idea of going into a day knowing that I am  going to learn something new. The issue that I am currently working on centers around relay commands. I have a pretty good handle on Relay Commands and how we use them within our applications. <Button Command="{Binding ButtonCommand}" CommandParameter="NewRecruit" Content="New Recruit" /> Here in our xaml we have a button. The button has a Command and a CommandParameter. The command binds to the ButtonCommand that we have in our ViewModel RelayCommand _buttonCommand;         /// <summary>         /// Gets the button command.         /// </summary>         /// <value>The button command.</value>         public RelayCommand ButtonCommand         {             get             {                 if (_buttonCommand == null)                 {                     _buttonCommand = new RelayCommand(                         x => x != null && x.ToString().Length > 0 && CheckCommandAvailable(x.ToString()),                         x => ExecuteCommand(x.ToString()));                 }                 return _buttonCommand;             }         }   In our relay command we then do some checks with a lambda expression. We check if the command  parameter is null, is the length greater than 0 and we have a CheckCommandAvailable method that will tell  us if the button is even enabled. After we check on these three items we then pass the command parameter to an action method. This is all pretty straight forward, the issue that we solved a few days ago centered around having a control that needed to use a Relay Command and this control was a nested control and was using a different DataContext. The example below illustrates how we handled this scenario. In our xaml usercontrol we had to set a name to this control. <Controls3:RadTileViewItem x:Class="RecruitStatusTileView"     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"      xmlns:Controls1="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls"      xmlns:Controls2="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls.Input"      xmlns:Controls3="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls.Navigation"      mc:Ignorable="d" d:DesignHeight="400" d:DesignWidth="800" Header="{Binding Title,Mode=TwoWay}" MinimizedHeight="100"                             x:Name="StatusView"> Here we are using a telerik RadTileViewItem. We set the name of this control to “StatusView”. In our button control we set our command parameters and commands different than the example above. <HyperlinkButton Content="{Binding BigBoardButtonText, Mode=TwoWay}" CommandParameter="{Binding 'Position.PositionName'}" Command="{Binding ElementName=StatusView, Path=DataContext.BigBoardCommand, Mode=TwoWay}" /> This hyperlink button lives in a ListBox control and this listbox has an ItemSource of PositionSelectors. The Command Parameter is binding to the Position.Position property of that PositionSelectors object. This again is pretty straight forward again. What gets a bit tricky is the Command property in the hyperlink. It is binding to the element name we created in the user control (StatusView) Because this hyperlink is in a listbox and is in the item template it doesn’t have a direct handle on the DataContext that the RadTileViewItem has so we have to make sure it does. We do that by binding to the element name of status view then set the path to DataContext.BigBoardCommand. BigBoardCommand is the name of the RelayCommand in the view model. private RelayCommand _bigBoardCommand = null;         /// <summary>         /// Gets the big board command.         /// </summary>         /// <value>The big board command.</value>         public RelayCommand BigBoardCommand         {             get             {                 if (_bigBoardCommand == null)                 {                     _bigBoardCommand = new RelayCommand(x => true, x => AddToBigBoard(x.ToString()));                 }                 return _bigBoardCommand;             }         } From there we check for true again and then call the action and pass in the parameter that we had as the command parameter. What we are working on now is a bit trickier than this second example. In the above example we are only creating this TileViewItem with this name “StatusView” once. In another part of our application we are generating multiple TileViewItems, so we cannot set the name in the control as we cant have multiple controls with the same name. When we run the application we get an error that reads that the value is out of expected range. My searching has led me to think we cannot have multiple controls with the same name. This is today’s problem and Ill post the solution to this once it is found.

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• Windows for IoT, continued

  - by Valter Minute

  Originally posted on: http://geekswithblogs.net/WindowsEmbeddedCookbook/archive/2014/08/05/windows-for-iot-continued.aspxI received many interesting feedbacks on my previous blog post and I tried to find some time to do some additional tests. Bert Kleinschmidt pointed out that pins 2,3 and 10 of the Galileo are connected directly to the SOC, while pin 13, the one used for the sample sketch is controlled via an I2C I/O expander. I changed my code to use pin 2 instead of 13 (just changing the variable assignment at the beginning of the code) and latency was greatly reduced. Now each pulse lasts for 1.44ms, 44% more than the expected time, but ways better that the result we got using pin 13. I also used SetThreadPriority to increase the priority of the thread that was running the sketch to THREAD_PRIORITY_HIGHEST but that didn't change the results. When I was using the I2C-controlled pin I tried the same and the timings got ways worse (increasing more than 10 times) and so I did not commented on that part, wanting to investigate the issua a bit more in detail. It seems that increasing the priority of the application thread impacts negatively the I2C communication. I tried to use also the Linux-based implementation (using a different Galileo board since the one provided by MS seems to use a different firmware) and the results of running the sample blink sketch modified to use pin 2 and blink the led for 1ms are similar to those we got on the same board running Windows. Here the difference between expected time and measured time is worse, getting around 3.2ms instead of 1 (320% compared to 150% using Windows but far from the 100.1% we got with the 8-bit Arduino). Both systems were not under load during the test, maybe loading some applications that use part of the CPU time would make those timings even less reliable, but I think that those numbers are enough to draw some conclusions. It may not be worth running a full OS if what you need is Arduino compatibility. The Arduino UNO is probably the best Arduino you can find to perform this kind of development. The Galileo running the Linux-based stack or running Windows for IoT is targeted to be a platform for "Internet of Things" devices, whatever that means. At the moment I don't see the "I" part of IoT. We have low level interfaces (SPI, I2C, the GPIO pins) that can be used to connect sensors but the support for connectivity is limited and the amount of work required to deliver some data to the cloud (using a secure HTTP request or a message queuing system like APMQS or MQTT) is still big and the rich OS underneath seems to not provide any help doing that.Why should I use sockets and can't access all the high level connectivity features we have on "full" Windows?I know that it's possible to use some third party libraries, try to build them using the Windows For IoT SDK etc. but this means re-inventing the wheel every time and can also lead to some IP concerns if used for products meant to be closed-source. I hope that MS and Intel (and others) will focus less on the "coolness" of running (some) Arduino sketches and more on providing a better platform to people that really want to design devices that leverage internet connectivity and the cloud processing power to deliver better products and services. Providing a reliable set of connectivity services would be a great start. Providing support for .NET would be even better, leaving native code available for hardware access etc. I know that those components may require additional storage and memory etc. So making the OS componentizable (or, at least, provide a way to install additional components) would be a great way to let developers pick the parts of the system they need to develop their solution, knowing that they will integrate well together. I can understand that the Arduino and Raspberry Pi* success may have attracted the attention of marketing departments worldwide and almost any new development board those days is promoted as "XXX response to Arduino" or "YYYY alternative to Raspberry Pi", but this is misleading and prevents companies from focusing on how to deliver good products and how to integrate "IoT" features with their existing offer to provide, at the end, a better product or service to their customers. Marketing is important, but can't decide the key features of a product (the OS) that is going to be used to develop full products for end customers integrating it with hardware and application software. I really like the "hackable" nature of open-source devices and like to see that companies are getting more and more open in releasing information, providing "hackable" devices and supporting developers with documentation, good samples etc. On the other side being able to run a sketch designed for an 8 bit microcontroller on a full-featured application processor may sound cool and an easy upgrade path for people that just experimented with sensors etc. on Arduino but it's not, in my humble opinion, the main path to follow for people who want to deliver real products.   *Shameless self-promotion: if you are looking for a good book in Italian about the Raspberry Pi , try mine: http://www.amazon.it/Raspberry-Pi-alluso-Digital-LifeStyle-ebook/dp/B00GYY3OKO

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• Unexpected advantage of Engineered Systems

  - by user12244672

  It's not surprising that Engineered Systems accelerate the debugging and resolution of customer issues. But what has surprised me is just how much faster issue resolution is with Engineered Systems such as SPARC SuperCluster. These are powerful, complex, systems used by customers wanting extreme database performance, app performance, and cost saving server consolidation. A SPARC SuperCluster consists or 2 or 4 powerful T4-4 compute nodes, 3 or 6 extreme performance Exadata Storage Cells, a ZFS Storage Appliance 7320 for general purpose storage, and ultra fast Infiniband switches.  Each with its own firmware. It runs Solaris 11, Solaris 10, 11gR2, LDoms virtualization, and Zones virtualization on the T4-4 compute nodes, a modified version of Solaris 11 in the ZFS Storage Appliance, a modified and highly tuned version of Oracle Linux running Exadata software on the Storage Cells, another Linux derivative in the Infiniband switches, etc. It has an Infiniband data network between the components, a 10Gb data network to the outside world, and a 1Gb management network. And customers can run whatever middleware and apps they want on it, clustered in whatever way they want. In one word, powerful.  In another, complex. The system is highly Engineered.  But it's designed to run general purpose applications. That is, the physical components, configuration, cabling, virtualization technologies, switches, firmware, Operating System versions, network protocols, tunables, etc. are all preset for optimum performance and robustness. That improves the customer experience as what the customer runs leverages our technical know-how and best practices and is what we've tested intensely within Oracle. It should also make debugging easier by fixing a large number of variables which would otherwise be in play if a customer or Systems Integrator had assembled such a complex system themselves from the constituent components.  For example, there's myriad network protocols which could be used with Infiniband.  Myriad ways the components could be interconnected, myriad tunable settings, etc. But what has really surprised me - and I've been working in this area for 15 years now - is just how much easier and faster Engineered Systems have made debugging and issue resolution. All those error opportunities for sub-optimal cabling, unusual network protocols, sub-optimal deployment of virtualization technologies, issues with 3rd party storage, issues with 3rd party multi-pathing products, etc., are simply taken out of the equation. All those error opportunities for making an issue unique to a particular set-up, the "why aren't we seeing this on any other system ?" type questions, the doubts, just go away when we or a customer discover an issue on an Engineered System. It enables a really honed response, getting to the root cause much, much faster than would otherwise be the case. Here's a couple of examples from the last month, one found in-house by my team, one found by a customer: Example 1: We found a node eviction issue running 11gR2 with Solaris 11 SRU 12 under extreme load on what we call our ExaLego test system (mimics an Exadata / SuperCluster 11gR2 Exadata Storage Cell set-up).  We quickly established that an enhancement in SRU12 enabled an 11gR2 process to query Infiniband's Subnet Manager, replacing a fallback mechanism it had used previously.  Under abnormally heavy load, the query could return results which were misinterpreted resulting in node eviction.  In several daily joint debugging sessions between the Solaris, Infiniband, and 11gR2 teams, the issue was fully root caused, evaluated, and a fix agreed upon.  That fix went back into all Solaris releases the following Monday.  From initial issue discovery to the fix being put back into all Solaris releases was just 10 days. Example 2: A customer reported sporadic performance degradation.  The reasons were unclear and the information sparse.  The SPARC SuperCluster Engineered Systems support teams which comprises both SPARC/Solaris and Database/Exadata experts worked to root cause the issue.  A number of contributing factors were discovered, including tunable parameters.  An intense collaborative investigation between the engineering teams identified the root cause to a CPU bound networking thread which was being starved of CPU cycles under extreme load.  Workarounds were identified.  Modifications have been put back into 11gR2 to alleviate the issue and a development project already underway within Solaris has been sped up to provide the final resolution on the Solaris side.  The fixed SPARC SuperCluster configuration greatly aided issue reproduction and dramatically sped up root cause analysis, allowing the correct workarounds and fixes to be identified, prioritized, and implemented.  The customer is now extremely happy with performance and robustness.  Since the configuration is common to other customers, the lessons learned are being proactively rolled out to other customers and incorporated into the installation procedures for future customers.  This effectively acts as a turbo-boost to performance and reliability for all SPARC SuperCluster customers.  If this had occurred in a "home grown" system of this complexity, I expect it would have taken at least 6 months to get to the bottom of the issue.  But because it was an Engineered System, known, understood, and qualified by both the Solaris and Database teams, we were able to collaborate closely to identify cause and effect and expedite a solution for the customer.  That is a key advantage of Engineered Systems which should not be underestimated.  Indeed, the initial issue mitigation on the Database side followed by final fix on the Solaris side, highlights the high degree of collaboration and excellent teamwork between the Oracle engineering teams.  It's a compelling advantage of the integrated Oracle Red Stack in general and Engineered Systems in particular.

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• Best Practices - Dynamic Reconfiguration

  - by jsavit

  This post is one of a series of "best practices" notes for Oracle VM Server for SPARC (formerly named Logical Domains) Overview of dynamic Reconfiguration Oracle VM Server for SPARC supports Dynamic Reconfiguration (DR), making it possible to add or remove resources to or from a domain (virtual machine) while it is running. This is extremely useful because resources can be shifted to or from virtual machines in response to load conditions without having to reboot or interrupt running applications. For example, if an application requires more CPU capacity, you can add CPUs to improve performance, and remove them when they are no longer needed. You can use even use Dynamic Resource Management (DRM) policies that automatically add and remove CPUs to domains based on load. How it works (in broad general terms) Dynamic Reconfiguration is done in coordination with Solaris, which recognises a hypervisor request to change its virtual machine configuration and responds appropriately. In essence, Solaris receives a message saying "you now have 16 more CPUs numbered 16 to 31" or "8GB more RAM starting at address X" or "here's a new network or disk device - have fun with it". These actions take very little time. Solaris then can start using the new resource. In the case of added CPUs, that means dispatching processes and potentially binding interrupts to the new CPUs. For memory, Solaris adds the new memory pages to its "free" list and starts using them. Comparable actions occur with network and disk devices: they are recognised by Solaris and then used. Removing is the reverse process: after receiving the DR message to free specific CPUs, Solaris unbinds interrupts assigned to the CPUs and stops dispatching process threads. That takes very little time. primary # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 16 4G 1.0% 6d 22h 29m ldom1 active -n---- 5000 16 8G 0.9% 6h 59m primary # ldm set-core 5 ldom1 primary # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 16 4G 0.2% 6d 22h 29m ldom1 active -n---- 5000 40 8G 0.1% 6h 59m primary # ldm set-core 2 ldom1 primary # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 16 4G 1.0% 6d 22h 29m ldom1 active -n---- 5000 16 8G 0.9% 6h 59m Memory pages are vacated by copying their contents to other memory locations and wiping them clean. Solaris may have to swap memory contents to disk if the remaining RAM isn't enough to hold all the contents. For this reason, deallocating memory can take longer on a loaded system. Even on a lightly loaded system it took several 7 or 8 seconds to switch the domain below between 8GB and 24GB of RAM. primary # ldm set-mem 24g ldom1 primary # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 16 4G 0.1% 6d 22h 36m ldom1 active -n---- 5000 16 24G 0.2% 7h 6m primary # ldm set-mem 8g ldom1 primary # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 16 4G 0.7% 6d 22h 37m ldom1 active -n---- 5000 16 8G 0.3% 7h 7m What if the device is in use? (this is the anecdote that inspired this blog post) If CPU or memory is being removed, releasing it pretty straightforward, using the method described above. The resources are released, and Solaris continues with less capacity. It's not as simple with a network or I/O device: you don't want to yank a device out from underneath an application that might be using it. In the following example, I've added a virtual network device to ldom1 and want to take it away, even though it's been plumbed. primary # ldm rm-vnet vnet19 ldom1 Guest LDom returned the following reason for failing the operation: Resource Information ---------------------------------------------------------- ----------------------- /devices/virtual-devices@100/channel-devices@200/network@1 Network interface net1 VIO operation failed because device is being used in LDom ldom1 Failed to remove VNET instance That's what I call a helpful error message - telling me exactly what was wrong. In this case the problem is easily solved. I know this NIC is seen in the guest as net1 so: ldom1 # ifconfig net1 down unplumb Now I can dispose of it, and even the virtual switch I had created for it: primary # ldm rm-vnet vnet19 ldom1 primary # ldm rm-vsw primary-vsw9 If I had to take away the device disruptively, I could have used ldm rm-vnet -f but that could disrupt whoever was using it. It's better if that can be avoided. Summary Oracle VM Server for SPARC provides dynamic reconfiguration, which lets you modify a guest domain's CPU, memory and I/O configuration on the fly without reboot. You can add and remove resources as needed, and even automate this for CPUs by setting up resource policies. Taking things away can be more complicated than giving, especially for devices like disks and networks that may contain application and system state or be involved in a transaction. LDoms and Solaris cooperative work together to coordinate resource allocation and de-allocation in a safe and effective way. For best practices, use dynamic reconfiguration to make the best use of your system's resources.

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• C#/.NET Little Wonders: Getting Caller Information

  - by James Michael Hare

  Originally posted on: http://geekswithblogs.net/BlackRabbitCoder/archive/2013/07/25/c.net-little-wonders-getting-caller-information.aspx Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. There are times when it is desirable to know who called the method or property you are currently executing.  Some applications of this could include logging libraries, or possibly even something more advanced that may server up different objects depending on who called the method. In the past, we mostly relied on the System.Diagnostics namespace and its classes such as StackTrace and StackFrame to see who our caller was, but now in C# 5, we can also get much of this data at compile-time. Determining the caller using the stack One of the ways of doing this is to examine the call stack.  The classes that allow you to examine the call stack have been around for a long time and can give you a very deep view of the calling chain all the way back to the beginning for the thread that has called you. You can get caller information by either instantiating the StackTrace class (which will give you the complete stack trace, much like you see when an exception is generated), or by using StackFrame which gets a single frame of the stack trace.  Both involve examining the call stack, which is a non-trivial task, so care should be done not to do this in a performance-intensive situation. For our simple example let's say we are going to recreate the wheel and construct our own logging framework.  Perhaps we wish to create a simple method Log which will log the string-ified form of an object and some information about the caller.  We could easily do this as follows: 1: static void Log(object message) 2: { 3: // frame 1, true for source info 4: StackFrame frame = new StackFrame(1, true); 5: var method = frame.GetMethod(); 6: var fileName = frame.GetFileName(); 7: var lineNumber = frame.GetFileLineNumber(); 8: 9: // we'll just use a simple Console write for now 10: Console.WriteLine("{0}({1}):{2} - {3}", 11: fileName, lineNumber, method.Name, message); 12: } So, what we are doing here is grabbing the 2nd stack frame (the 1st is our current method) using a 2nd argument of true to specify we want source information (if available) and then taking the information from the frame.  This works fine, and if we tested it out by calling from a file such as this: 1: // File c:\projects\test\CallerInfo\CallerInfo.cs 2:  3: public class CallerInfo 4: { 5: Log("Hello Logger!"); 6: } We'd see this: 1: c:\projects\test\CallerInfo\CallerInfo.cs(5):Main - Hello Logger! This works well, and in fact CallStack and StackFrame are still the best ways to examine deeper into the call stack.  But if you only want to get information on the caller of your method, there is another option… Determining the caller at compile-time In C# 5 (.NET 4.5) they added some attributes that can be supplied to optional parameters on a method to receive caller information.  These attributes can only be applied to methods with optional parameters with explicit defaults.  Then, as the compiler determines who is calling your method with these attributes, it will fill in the values at compile-time. These are the currently supported attributes available in the  System.Runtime.CompilerServices namespace": CallerFilePathAttribute – The path and name of the file that is calling your method. CallerLineNumberAttribute – The line number in the file where your method is being called. CallerMemberName – The member that is calling your method. So let’s take a look at how our Log method would look using these attributes instead: 1: static int Log(object message, 2: [CallerMemberName] string memberName = "", 3: [CallerFilePath] string fileName = "", 4: [CallerLineNumber] int lineNumber = 0) 5: { 6: // we'll just use a simple Console write for now 7: Console.WriteLine("{0}({1}):{2} - {3}", 8: fileName, lineNumber, memberName, message); 9: } Again, calling this from our sample Main would give us the same result: 1: c:\projects\test\CallerInfo\CallerInfo.cs(5):Main - Hello Logger! However, though this seems the same, there are a few key differences. First of all, there are only 3 supported attributes (at this time) that give you the file path, line number, and calling member.  Thus, it does not give you as rich of detail as a StackFrame (which can give you the calling type as well and deeper frames, for example).  Also, these are supported through optional parameters, which means we could call our new Log method like this: 1: // They're defaults, why not fill 'em in 2: Log("My message.", "Some member", "Some file", -13); In addition, since these attributes require optional parameters, they cannot be used in properties, only in methods. These caveats aside, they do let you get similar information inside of methods at a much greater speed!  How much greater?  Well lets crank through 1,000,000 iterations of each.  instead of logging to console, I’ll return the formatted string length of each.  Doing this, we get: 1: Time for 1,000,000 iterations with StackTrace: 5096 ms 2: Time for 1,000,000 iterations with Attributes: 196 ms So you see, using the attributes is much, much faster!  Nearly 25x faster in fact.  Summary There are a few ways to get caller information for a method.  The StackFrame allows you to get a comprehensive set of information spanning the whole call stack, but at a heavier cost.  On the other hand, the attributes allow you to quickly get at caller information baked in at compile-time, but to do so you need to create optional parameters in your methods to support it. Technorati Tags: Little Wonders,CSharp,C#,.NET,StackFrame,CallStack,CallerFilePathAttribute,CallerLineNumberAttribute,CallerMemberName

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• Is Data Science “Science”?

  - by BuckWoody

  I hold the term “science” in very high esteem. I grew up on the Space Coast in Florida, and eventually worked at the Kennedy Space Center, surrounded by very intelligent people who worked in various scientific fields. Recently a new term has entered the computing dialog – “Data Scientist”. Since it’s not a standard term, it has a lot of definitions, and in fact has been disputed as a correct term. After all, the reasoning goes, if there’s no such thing as “Data Science” then how can there be a Data Scientist? This argument has been made before, albeit with a different term – “Computer Science”. In Peter Denning’s excellent article “Is Computer Science Science” (April  2005/Vol. 48, No. 4 COMMUNICATIONS OF THE ACM) there are many points that separate “science” from “engineering” and even “art”.  I won’t repeat the content of that article here (I recommend you read it on your own) but will leverage the points he makes there. Definition of Science To ask the question “is data science ‘science’” then we need to start with a definition of terms. Various references put the definition into the same basic areas: Study of the physical world Systematic and/or disciplined study of a subject area ...and then they include the things studied, the bodies of knowledge and so on. The word itself comes from Latin, and means merely “to know” or “to study to know”. Greek divides knowledge further into “truth” (episteme), and practical use or effects (tekhne). Normally computing falls into the second realm. Definition of Data Science And now a more controversial definition: Data Science. This term is so new and perhaps so niche that the major dictionaries haven’t yet picked it up (my OED reference is older – can’t afford to pop for the online registration at present). Researching the term's general use I created an amalgam of the definitions this way: “Studying and applying mathematical and other techniques to derive information from complex data sets.” Using this definition, data science certainly seems to be science - it's learning about and studying some object or area using systematic methods. But implicit within the definition is the word “application”, which makes the process more akin to engineering or even technology than science. In fact, I find that using these techniques – and data itself – part of science, not science itself. I leave out the concept of studying data patterns or algorithms as part of this discipline. That is actually a domain I see within research, mathematics or computer science. That of course is a type of science, but does not seek for practical applications. As part of the argument against calling it “Data Science”, some point to the scientific method of creating a hypothesis, testing with controls, testing results against the hypothesis, and documenting for repeatability.  These are not steps that we often take in working with data. We normally start with a question, and fit patterns and algorithms to predict outcomes and find correlations. In this way Data Science is more akin to statistics (and in fact makes heavy use of them) in the process rather than starting with an assumption and following on with it. So, is Data Science “Science”? I’m uncertain – and I’m uncertain it matters. Even if we are facing rampant “title inflation” these days (does anyone introduce themselves as a secretary or supervisor anymore?) I can tolerate the term at least from the intent that we use data to study problems across a wide spectrum, rather than restricting it to a single domain. And I also understand those who have worked hard to achieve the very honorable title of “scientist” who have issues with those who borrow the term without asking. What do you think? Science, or not? Does it matter?

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• Data management in unexpected places

  - by Ashok_Ora

  Normal 0 false false false EN-US X-NONE X-NONE Data management in unexpected places When you think of network switches, routers, firewall appliances, etc., it may not be obvious that at the heart of these kinds of solutions is an engine that can manage huge amounts of data at very high throughput with low latencies and high availability. Consider a network router that is processing tens (or hundreds) of thousands of network packets per second. So what really happens inside a router? Packets are streaming in at the rate of tens of thousands per second. Each packet has multiple attributes, for example, a destination, associated SLAs etc. For each packet, the router has to determine the address of the next “hop” to the destination; it has to determine how to prioritize this packet. If it’s a high priority packet, then it has to be sent on its way before lower priority packets. As a consequence of prioritizing high priority packets, lower priority data packets may need to be temporarily stored (held back), but addressed fairly. If there are security or privacy requirements associated with the data packet, those have to be enforced. You probably need to keep track of statistics related to the packets processed (someone’s sure to ask). You have to do all this (and more) while preserving high availability i.e. if one of the processors in the router goes down, you have to have a way to continue processing without interruption (the customer won’t be happy with a “choppy” VoIP conversation, right?). And all this has to be achieved without ANY intervention from a human operator – the router is most likely to be in a remote location – it must JUST CONTINUE TO WORK CORRECTLY, even when bad things happen. How is this implemented? As soon as a packet arrives, it is interpreted by the receiving software. The software decodes the packet headers in order to determine the destination, kind of packet (e.g. voice vs. data), SLAs associated with the “owner” of the packet etc. It looks up the internal database of “rules” of how to process this packet and handles the packet accordingly. The software might choose to hold on to the packet safely for some period of time, if it’s a low priority packet. Ah – this sounds very much like a database problem. For each packet, you have to minimally · Look up the most efficient next “hop” towards the destination. The “most efficient” next hop can change, depending on latency, availability etc. · Look up the SLA and determine the priority of this packet (e.g. voice calls get priority over data ftp) · Look up security information associated with this data packet. It may be necessary to retrieve the context for this network packet since a network packet is a small “slice” of a session. The context for the “header” packet needs to be stored in the router, in order to make this work. · If the priority of the packet is low, then “store” the packet temporarily in the router until it is time to forward the packet to the next hop. · Update various statistics about the packet. In most cases, you have to do all this in the context of a single transaction. For example, you want to look up the forwarding address and perform the “send” in a single transaction so that the forwarding address doesn’t change while you’re sending the packet. So, how do you do all this? Berkeley DB is a proven, reliable, high performance, highly available embeddable database, designed for exactly these kinds of usage scenarios. Berkeley DB is a robust, reliable, proven solution that is currently being used in these scenarios. First and foremost, Berkeley DB (or BDB for short) is very very fast. It can process tens or hundreds of thousands of transactions per second. It can be used as a pure in-memory database, or as a disk-persistent database. BDB provides high availability – if one board in the router fails, the system can automatically failover to another board – no manual intervention required. BDB is self-administering – there’s no need for manual intervention in order to maintain a BDB application. No need to send a technician to a remote site in the middle of nowhere on a freezing winter day to perform maintenance operations. BDB is used in over 200 million deployments worldwide for the past two decades for mission-critical applications such as the one described here. You have a choice of spending valuable resources to implement similar functionality, or, you could simply embed BDB in your application and off you go! I know what I’d do – choose BDB, so I can focus on my business problem. What will you do? /* 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;}

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• Visual Tree Enumeration

  - by codingbloke

  I feel compelled to post this blog because I find I’m repeatedly posting this same code in silverlight and windows-phone-7 answers in Stackoverflow. One common task that we feel we need to do is burrow into the visual tree in a Silverlight or Windows Phone 7 application (actually more recently I found myself doing this in WPF as well).  This allows access to details that aren’t exposed directly by some controls.  A good example of this sort of requirement is found in the “Restoring exact scroll position of a listbox in Windows Phone 7”  question on stackoverflow.  This required that the scroll position of the scroll viewer internal to a listbox be accessed. A caveat One caveat here is that we should seriously challenge the need for this burrowing since it may indicate that there is a design problem.  Burrowing into the visual tree or indeed burrowing out to containing ancestors could represent significant coupling between module boundaries and that generally isn’t a good idea. Why isn’t this idea just not cast aside as a no-no?  Well the whole concept of a “Templated Control”, which are in extensive use in these applications, opens the coupling between the content of the visual tree and the internal code of a control.   For example, I can completely change the appearance and positioning of elements that make up a ComboBox.  The ComboBox control relies on specific template parts having set names of a specified type being present in my template.  Rightly or wrongly this does kind of give license to writing code that has similar coupling. Hasn’t this been done already? Yes it has.  There are number of blogs already out there with similar solutions.  In fact if you are using Silverlight toolkit the VisualTreeExtensions class already provides this feature.  However I prefer my specific code because of the simplicity principle I hold to.  Only write the minimum code necessary to give all the features needed.  In this case I add just two extension methods Ancestors and Descendents, note I don’t bother with “Get” or “Visual” prefixes.  Also I haven’t added Parent or Children methods nor additional “AndSelf” methods because all but Children is achievable with the addition of some other Linq methods.  I decided to give Descendents an additional overload for depth hence a depth of 1 is equivalent to Children but this overload is a little more flexible than simply Children. So here is the code:- VisualTreeEnumeration public static class VisualTreeEnumeration {     public static IEnumerable<DependencyObject> Descendents(this DependencyObject root, int depth)     {         int count = VisualTreeHelper.GetChildrenCount(root);         for (int i = 0; i < count; i++)         {             var child = VisualTreeHelper.GetChild(root, i);             yield return child;             if (depth > 0)             {                 foreach (var descendent in Descendents(child, --depth))                     yield return descendent;             }         }     }     public static IEnumerable<DependencyObject> Descendents(this DependencyObject root)     {         return Descendents(root, Int32.MaxValue);     }     public static IEnumerable<DependencyObject> Ancestors(this DependencyObject root)     {         DependencyObject current = VisualTreeHelper.GetParent(root);         while (current != null)         {             yield return current;             current = VisualTreeHelper.GetParent(current);         }     } }   Usage examples The following are some examples of how to combine the above extension methods with Linq to generate the other axis scenarios that tree traversal code might require. Missing Axis Scenarios var parent = control.Ancestors().Take(1).FirstOrDefault(); var children = control.Descendents(1); var previousSiblings = control.Ancestors().Take(1)     .SelectMany(p => p.Descendents(1).TakeWhile(c => c != control)); var followingSiblings = control.Ancestors().Take(1)     .SelectMany(p => p.Descendents(1).SkipWhile(c => c != control).Skip(1)); var ancestorsAndSelf = Enumerable.Repeat((DependencyObject)control, 1)     .Concat(control.Ancestors()); var descendentsAndSelf = Enumerable.Repeat((DependencyObject)control, 1)     .Concat(control.Descendents()); You might ask why I don’t just include these in the VisualTreeEnumerator.  I don’t on the principle of only including code that is actually needed.  If you find that one or more of the above  is needed in your code then go ahead and create additional methods.  One of the downsides to Extension methods is that they can make finding the method you actually want in intellisense harder. Here are some real world usage scenarios for these methods:- Real World Scenarios //Gets the internal scrollviewer of a ListBox ScrollViewer sv = someListBox.Descendents().OfType<ScrollViewer>().FirstOrDefault(); // Get all text boxes in current UserControl:- var textBoxes = this.Descendents().OfType<TextBox>(); // All UIElement direct children of the layout root grid:- var topLevelElements = LayoutRoot.Descendents(0).OfType<UIElement>(); // Find the containing `ListBoxItem` for a UIElement:- var container = elem.Ancestors().OfType<ListBoxItem>().FirstOrDefault(); // Seek a button with the name "PinkElephants" even if outside of the current Namescope:- var pinkElephantsButton = this.Descendents()     .OfType<Button>()     .FirstOrDefault(b => b.Name == "PinkElephants"); //Clear all checkboxes with the name "Selector" in a Treeview foreach (CheckBox checkBox in elem.Descendents()     .OfType<CheckBox>().Where(c => c.Name == "Selector")) {     checkBox.IsChecked = false; }   The last couple of examples above demonstrate a common requirement of finding controls that have a specific name.  FindName will often not find these controls because they exist in a different namescope. Hope you find this useful, if not I’m just glad to be able to link to this blog in future stackoverflow answers.

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• C# Open Source software that is useful for learning Design Patterns

  - by Fathom Savvy

  In college I took a class in Expert Systems. The language the book taught (CLIPS) was esoteric - Expert Systems: Principles and Programming, Fourth Edition. I remember having a tough time with it. So, after almost failing the class, I needed to create the most awesome Expert System for my final presentation. I chose to create an expert system that would calculate risk analysis for a person's retirement portfolio. In short, the system would provide the services normally performed by one's financial adviser. In other words, based on personality, age, state of the macro economy, and other factors, should one's portfolio be conservative, moderate, or aggressive? In the appendix of the book (or on the CD-ROM), there was this in-depth example program for something unrelated to my presentation. Over my break, I read and re-read every line of that program until I understood it to the letter. Even though it was unrelated, I learned more than I ever could by reading all of the chapters. My presentation turned out to be pretty damn good and I received praises from my professor and classmates. So, the moral of the story is..., by understanding other people's code, you can gain greater insight into a language/paradigm than by reading canonical examples. Still, to this day, I am having trouble with everyday design patterns such as the Factory Pattern. I would like to know if anyone could recommend open source software that would help me understand the Gang of Four design patterns, at the very least. I have read the books, but I'm having trouble writing code for the concepts in the real world. Perhaps, by studying code used in today's real world applications, it might just "click". I realize a piece of software may only implement one kind of design pattern. But, if the pattern is an implementation you think is good for learning, and you know what pattern to look for within the source, I'm hoping you can tell me about it. For example, the System.Linq.Expressions namespace has a good example of the Visitor Pattern. The client calls Expression.Accept(new ExpressionVisitor()), which calls ExpressionVisitor (VisitExtension), which calls back to Expression (VisitChildren), which then calls Expression (Accept) again - wooah, kinda convoluted. The point to note here is that VisitChildren is a virtual method. Both Expression and those classes derived from Expression can implement the VisitChildren method any way they want. This means that one type of Expression can run code that is completely different from another type of derived Expression, even though the ExpressionVisitor class is the same in the Accept method. (As a side note Expression.Accept is also virtual). In the end, the code provides a real world example that you won't get in any book because it's kinda confusing. To summarize, If you know of any open source software that uses a design pattern implementation you were impressed by, please list it here. I'm sure it will help many others besides just me. public class VisitorPatternTest { public void Main() { Expression normalExpr = new Expression(); normalExpr.Accept(new ExpressionVisitor()); Expression binExpr = new BinaryExpression(); binExpr.Accept(new ExpressionVisitor()); } } public class Expression { protected internal virtual Expression Accept(ExpressionVisitor visitor) { return visitor.VisitExtension(this); } protected internal virtual Expression VisitChildren(ExpressionVisitor visitor) { if (!this.CanReduce) { throw Error.MustBeReducible(); } return visitor.Visit(this.ReduceAndCheck()); } public virtual Expression Visit(Expression node) { if (node != null) { return node.Accept(this); } return null; } public Expression ReduceAndCheck() { if (!this.CanReduce) { throw Error.MustBeReducible(); } Expression expression = this.Reduce(); if ((expression == null) || (expression == this)) { throw Error.MustReduceToDifferent(); } if (!TypeUtils.AreReferenceAssignable(this.Type, expression.Type)) { throw Error.ReducedNotCompatible(); } return expression; } } public class BinaryExpression : Expression { protected internal override Expression Accept(ExpressionVisitor visitor) { return visitor.VisitBinary(this); } protected internal override Expression VisitChildren(ExpressionVisitor visitor) { return CreateDummyExpression(); } protected internal Expression CreateDummyExpression() { Expression dummy = new Expression(); return dummy; } } public class ExpressionVisitor { public virtual Expression Visit(Expression node) { if (node != null) { return node.Accept(this); } return null; } protected internal virtual Expression VisitExtension(Expression node) { return node.VisitChildren(this); } protected internal virtual Expression VisitBinary(BinaryExpression node) { return ValidateBinary(node, node.Update(this.Visit(node.Left), this.VisitAndConvert<LambdaExpression>(node.Conversion, "VisitBinary"), this.Visit(node.Right))); } }

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• java.util.zip.ZipException: Error opening file When Deploying an Application to Weblogic Server

  - by lmestre

  The latest weeks we had a hard time trying to solve a deployment issue.* WebLogic Server 10.3.6* Target: WLS Cluster<21-10-2013 05:29:40 PM CLST> <Error> <Console> <BEA-240003> <Console encountered the following error weblogic.management.DeploymentException:        at weblogic.servlet.internal.WarDeploymentFactory.findOrCreateComponentMBeans(WarDeploymentFactory.java:69)        at weblogic.application.internal.MBeanFactoryImpl.findOrCreateComponentMBeans(MBeanFactoryImpl.java:48)        at weblogic.application.internal.MBeanFactoryImpl.createComponentMBeans(MBeanFactoryImpl.java:110)        at weblogic.application.internal.MBeanFactoryImpl.initializeMBeans(MBeanFactoryImpl.java:76)        at weblogic.management.deploy.internal.MBeanConverter.createApplicationMBean(MBeanConverter.java:89)        at weblogic.management.deploy.internal.MBeanConverter.createApplicationForAppDeployment(MBeanConverter.java:67)        at weblogic.management.deploy.internal.MBeanConverter.setupNew81MBean(MBeanConverter.java:315)        at weblogic.deploy.internal.targetserver.operations.ActivateOperation.compatibilityProcessor(ActivateOperation.java:81)        at weblogic.deploy.internal.targetserver.operations.AbstractOperation.setupPrepare(AbstractOperation.java:295)        at weblogic.deploy.internal.targetserver.operations.ActivateOperation.doPrepare(ActivateOperation.java:97)        at weblogic.deploy.internal.targetserver.operations.AbstractOperation.prepare(AbstractOperation.java:217)        at weblogic.deploy.internal.targetserver.DeploymentManager.handleDeploymentPrepare(DeploymentManager.java:747)        at weblogic.deploy.internal.targetserver.DeploymentManager.prepareDeploymentList(DeploymentManager.java:1216)        at weblogic.deploy.internal.targetserver.DeploymentManager.handlePrepare(DeploymentManager.java:250)        at weblogic.deploy.internal.targetserver.DeploymentServiceDispatcher.prepare(DeploymentServiceDispatcher.java:159)        at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer.doPrepareCallback(DeploymentReceiverCallbackDeliverer.java:171)        at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer.access$000(DeploymentReceiverCallbackDeliverer.java:13)        at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer$1.run(DeploymentReceiverCallbackDeliverer.java:46)        at weblogic.work.SelfTuningWorkManagerImpl$WorkAdapterImpl.run(SelfTuningWorkManagerImpl.java:545)        at weblogic.work.ExecuteThread.execute(ExecuteThread.java:256)        at weblogic.work.ExecuteThread.run(ExecuteThread.java:221)Caused by: java.util.zip.ZipException: Error opening file - C:\Oracle\Middleware\user_projects\domains\MyDomain\servers\MyServer\stage\myapp\myapp.war Message - error in opening zip file        at weblogic.servlet.utils.WarUtils.existsInWar(WarUtils.java:87)        at weblogic.servlet.utils.WarUtils.isWebServices(WarUtils.java:76)        at weblogic.servlet.internal.WarDeploymentFactory.findOrCreateComponentMBeans(WarDeploymentFactory.java:61) So the first idea you have with that error is that the war file is corrupted or has incorrect privileges.        We tried:1. Unzipping the  war file, the file was perfect.2. Checking the size, same size as in other environments.3. Checking the ownership of the file, same as in other environments.4. Checking the permissions of the file, same as other applications.Then we accepted the file was fine, so we tried enabling some deployment debugs, but no clues.We also tried:1. Delete all contents of <MyDomain/servers/<MyServer>/tmp> a and <MyDomain/servers/<MyServer>/cache> folders, the issue persisted.2. When renaming the application the deployment was sucessful3. When targeting to the Admin Server, deployment was also working.4. Using 'Copy this application onto every target for me' didn't help either.Finally, my friend 'Test Case' solved the issue again.I saw this name in the config.xml<jdbc-system-resource>    <name>myapp</name>    <target></target>    <descriptor-file-name>jdbc/myapp-jdbc.xml</descriptor-file-name>  </jdbc-system-resource> So, it turned out that customer had created a DataSource with the same name as the application 'myapp' in the above example.By deleting the datasource and created another exact DataSource with a different name the issue was solved.At this point, Do you know Why 'java.util.zip.ZipException: Error opening file' was occurring?Because all names is WebLogic Server need to be unique.References: http://docs.oracle.com/cd/E23943_01/web.1111/e13709/setup.htm"Assigning Names to WebLogic Server ResourcesMake sure that each configurable resource in your WebLogic Server environment has a unique name. Each, domain, server, machine, cluster, JDBC data source, virtual host, or other resource must have a unique name." Enjoy!

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• MERGE gives better OUTPUT options

  - by Rob Farley

  MERGE is very cool. There are a ton of useful things about it – mostly around the fact that you can implement a ton of change against a table all at once. This is great for data warehousing, handling changes made to relational databases by applications, all kinds of things. One of the more subtle things about MERGE is the power of the OUTPUT clause. Useful for logging.   If you’re not familiar with the OUTPUT clause, you really should be – it basically makes your DML (INSERT/DELETE/UPDATE/MERGE) statement return data back to you. This is a great way of returning identity values from INSERT commands (so much better than SCOPE_IDENTITY() or the older (and worse) @@IDENTITY, because you can get lots of rows back). You can even use it to grab default values that are set using non-deterministic functions like NEWID() – things you couldn’t normally get back without running another query (or with a trigger, I guess, but that’s not pretty). That inserted table I referenced – that’s part of the ‘behind-the-scenes’ work that goes on with all DML changes. When you insert data, this internal table called inserted gets populated with rows, and then used to inflict the appropriate inserts on the various structures that store data (HoBTs – the Heaps or B-Trees used to store data as tables and indexes). When deleting, the deleted table gets populated. Updates get a matching row in both tables (although this doesn’t mean that an update is a delete followed by an inserted, it’s just the way it’s handled with these tables). These tables can be referenced by the OUTPUT clause, which can show you the before and after for any DML statement. Useful stuff. MERGE is slightly different though. With MERGE, you get a mix of entries. Your MERGE statement might be doing some INSERTs, some UPDATEs and some DELETEs. One of the most common examples of MERGE is to perform an UPSERT command, where data is updated if it already exists, or inserted if it’s new. And in a single operation too. Here, you can see the usefulness of the deleted and inserted tables, which clearly reflect the type of operation (but then again, MERGE lets you use an extra column called $action to show this). (Don’t worry about the fact that I turned on IDENTITY_INSERT, that’s just so that I could insert the values) One of the things I love about MERGE is that it feels almost cursor-like – the UPDATE bit feels like “WHERE CURRENT OF …”, and the INSERT bit feels like a single-row insert. And it is – but into the inserted and deleted tables. The operations to maintain the HoBTs are still done using the whole set of changes, which is very cool. And $action – very convenient. But as cool as $action is, that’s not the point of my post. If it were, I hope you’d all be disappointed, as you can’t really go near the MERGE statement without learning about it. The subtle thing that I love about MERGE with OUTPUT is that you can hook into more than just inserted and deleted. Did you notice in my earlier query that my source table had a ‘src’ field, that wasn’t used in the insert? Normally, this would be somewhat pointless to include in my source query. But with MERGE, I can put that in the OUTPUT clause. This is useful stuff, particularly when you’re needing to audit the changes. Suppose your query involved consolidating data from a number of sources, but you didn’t need to insert that into the actual table, just into a table for audit. This is now very doable, either using the INTO clause of OUTPUT, or surrounding the whole MERGE statement in brackets (parentheses if you’re American) and using a regular INSERT statement. This is also doable if you’re using MERGE to just do INSERTs. In case you hadn’t realised, you can use MERGE in place of an INSERT statement. It’s just like the UPSERT-style statement we’ve just seen, except that we want nothing to match. That’s easy to do, we just use ON 1=2. This is obviously more convoluted than a straight INSERT. And it’s slightly more effort for the database engine too. But, if you want the extra audit capabilities, the ability to hook into the other source columns is definitely useful. Oh, and before people ask if you can also hook into the target table’s columns... Yes, of course. That’s what deleted and inserted give you.

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• Think before you animate

  - by David Paquette

  Animations are becoming more and more common in our applications.  With technologies like WPF, Silverlight and jQuery, animations are becoming easier for developers to use (and abuse).  When used properly, animation can augment the user experience.  When used improperly, animation can degrade the user experience.  Sometimes, the differences can be very subtle. I have recently made use of animations in a few projects and I very quickly realized how easy it is to abuse animation techniques.  Here are a few things I have learned along the way. 1) Don’t animate for the sake of animating We’ve all seen the PowerPoint slides with annoying slide transitions that animate 20 different ways.  It’s distracting and tacky.  The same holds true for your application.  While animations are fun and becoming easy to implement, resist the urge to use the technology just because you think the technology is amazing.   2) Animations should (and do) have meaning I recently built a simple Windows Phone 7 (WP7) application, Steeped (download it here).  The application has 2 pages.  The first page lists a number of tea types.  When the user taps on one of the tea types, the application navigates to the second page with information about that tea type and some options for the user to choose from.       One of the last things I did before submitting Steeped to the marketplace was add a page transition between the 2 pages.  I choose the Slide / Fade Out transition.  When the user selects a tea type, the main page slides to the left and fades out.  At the same time, the details page slides in from the right and fades in.  I tested it and thought it looked great so I submitted the app.  A few days later, I asked a friend to try the app.  He selected a tea type, and I was a little surprised by how he used the app.  When he wanted to navigate back to the main page, instead of pressing the back button on the phone, he tried to use a swiping gesture.  Of course, the swiping gesture did nothing because I had not implemented that feature.  After thinking about it for a while, I realized that the page transition I had chosen implied a particular behaviour.  As a user, if an action I perform causes an item (in this case the page) to move, then my expectation is that I should be able to move it back.  I have since added logic to handle the swipe gesture and I think the app flows much better now. When using animation, it pays to ask yourself:  What story does this animation tell my users?   3) Watch the replay Some animations might seem great initially but can get annoying over time.  When you use an animation in your application, make sure you try using it over and over again to make sure it doesn’t get annoying.  When I add an animation, I try watch it at least 25 times in a row.  After watching the animation repeatedly, I can make a more informed decision whether or not I should keep the animation.  Often, I end up shortening the length of the animations.   4) Don’t get in the users way An animation should never slow the user down.  When implemented properly, an animation can give a perceived bump in performance.  A good example of this is a the page transitions in most of the built in apps on WP7.  Obviously, these page animations don’t make the phone any faster, but they do provide a more responsive user experience.  Why?  Because most of the animations begin as soon as the user has performed some action.  The destination page might not be fully loaded yet, but the system responded immediately to user action, giving the impression that the system is more responsive.  If the user did not see anything happen until after the destination page was fully loaded, the application would feel clumsy and slow.  Also, it is important to make sure the animation does not degrade the performance (or perceived performance) of the application.   Jut a few things to consider when using animations.  As is the case with many technologies, we often learn how to misuse it before we learn how to use it effectively.

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• Finding it Hard to Deliver Right Customer Experience: Think BPM!

  - by Ajay Khanna

  Our relationship with our customers is not a just a single interaction and we should not treat it like one. A customer’s relationship with a vendor is like a journey which starts way before customer makes a purchase and lasts long after that. The journey may start with customer researching a product that may lead to the eventual purchase and may continue with support or service needs for the product. A typical customer journey can be represented as shown below: As you may notice, customers tend to use multiple channels to interact with a company throughout their journey.  They also expect that they should get consistent experience, no matter what interaction channel they may choose. Customers do not like to repeat the information they have already provided and expect companies to remember their preferences, and offer them relevant products and services. If the company fails to meet this expectation, customers not only will abandon the purchase and go to the competitor but may also influence others’ purchase decision. Gone are the days when word of mouth was the only medium, and the customer could influence “Six” others. This is the age of social media and customer’s good or bad experience, especially bad get highly amplified and may influence hundreds of others. Challenges that face B2C companies today include: Delivering consistent experience: The reason that delivering consistent experience is challenging is due to fragmented data, disjointed systems and siloed multichannel interactions. Customers tend to get different service quality if they use web vs. phone vs. store. They get different responses from different service agents or get inconsistent answers if they call sales vs. service group in the company. Such inconsistent experiences result in lower customer satisfaction or NPS (net promoter score) numbers. Increasing Revenue: To stay competitive companies frequently introduce new products and services. Delay in launching such offerings has a significant impact on revenue realization. In addition to new product revenue, there are multiple opportunities to up-sell and cross-sell that impact bottom line. If companies are not able to identify such opportunities, bring a product to market quickly, or not offer the right product to the right customer at the right time, significant loss of revenue may occur. Ensuring Compliance: Companies must be compliant to ever changing regulations, these could be about Know Your Customer (KYC), Export/Import regulations, or taxation policies. In addition to government agencies, companies also need to comply with the SLA that they have committed to their customers. Lapse in meeting any of these requirements may lead to serious fines, penalties and loss in business. Companies have to make sure that they are in compliance will all such regulations and SLA commitments, at any given time. With the advent of social networks and mobile technology, companies not only need to focus on process efficiency but also on customer engagement. Improving engagement means delivering the customer experience as the customer is expecting and interacting with the customer at right time using right channel. Customers expect to be able to contact you via any channel of their choice (web, email, chat, mobile, social media), purchase via any viable channel (web, phone, store, mobile). Customers expect companies to understand their particular needs and remember their preferences on repeated visits. To deliver such an integrated, consistent, and contextual experience, power of BPM in must. Your company may be organized in departments like Marketing, Sales, Service. You may hold prospect data in SFA, order information in ERP, customer issues in CRM. However, the experience delivered to the customer must not be constrained by your system legacy. BPM helps in designing the right experience for the right customer and integrates all the underlining channels, systems, applications to make sure right information will be delivered to the right knowledge worker or to the customer every single time.     Orchestrating information across all systems (MDM, CRM, ERP), departments (commerce, merchandising, marketing service) and channels (Email, phone, web, social)  is the key, and that’s what BPM delivers. In addition to orchestrating systems and channels for consistency, BPM also provides an ability for analysis and decision management. By using data from historical transactions, social media and from other systems, users can determine the customer preferences, customer value, and churn propensity. This information, in the context, is then used while making a decision at a process step. Working with real-time decision management system can also suggest right up-sell or cross-sell offers, discounts or next-best-action steps for a particular customer. Timely action on customer issues or request is also a key tenet of a good customer experience. BPM’s complex event processing capabilities help companies to take proactive actions before issues get escalated. BPM system can be designed to listen to a certain event patters then deduce from those customer situations (credit card stolen, baggage lost, change of address) and do a triage before situation goes out of control. If such a situation arises you can send alerts to right people or immediately invoke corrective actions. Last but not least one of BPM’s key values is to drive continuous improvement. Learning about customers past experiences, interactions and social conversations, provide valuable insight. Such insight can be used to improve products, customer facing processes, and customer experience. You may take these insights as an input to design better more efficient and customer friendly sales, contact center or self-service processes. If customer experience is important for your business, make sure you have incorporated BPM as a part of your strategy to design, orchestrate and improve your customer facing processes.

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• Top Questions and Answers for Pluging into Oracle Database as a Service

  - by David Swanger

  Yesterday we hosted a comprehensive online forum that shared a comprehensive path to help your organization design, deploy, and deliver a Database as a Service cloud. If you missed the online forum, you can watch it on demand by registering here. We received numerous questions.  Below are highlights of the most informative: DBaaS requires a lengthy and careful design efforts. What is the minimum requirements of setting up a scaled-down environment and test it out? You should have an OEM 12c environment for DBaaS administration and then a target database deployment platform that has the key characteristics of what your production environment will look like. This could be a single server or it could be a small pool of hosts if your production DBaaS will be larger and you want to test a more robust / real world configuration with Zones and Pools or DR capabilities for example. How does this benefit companies having their own data center? This allows companies to transform their internal IT to a service delivery model for the database. The benefits to the company are significant cost savings, improved business agility and reduced risk. The benefits to the consumers (internal) of services if much fast provisioning, and response to change in business requirements. From a deployment perspective, is DBaaS's job solely DBA's job? The best deployment model enables the DBA (or end-user) to control the entire process. All resources required to deploy the service are pre-provisioned, and there are no external dependencies (on network, storage, sysadmins teams). The service is created either via a self-service portal or by the DBA. The purpose of self service seems to be that the end user does not rely on the DBA. I just need to give him a template. He decides how much AMM he needs. Why shall I set it one by one. That doesn't seem to be the purpose of self service. Most customers we have worked with define a standardized service catalog, with a few (2 to 5) different classes of service. For each of these classes, there is a pre-defined deployment template, and the user has the ability to select from some pre-defined service sizes. The administrator only has to create this catalog once. Each user then simply selects from the options offered in the catalog.  Looking at DBaaS service definition, it seems to be no different from a service definition provided by a well defined DBA team. Why do you attribute it to DBaaS? There are a couple of perspectives. First, some organizations might already be operating with a high level of standardization and a higher level of maturity from an ITIL or Service Management perspective. Their journey to DBaaS could be shorter and their Service Definition will evolve less but they still might need to add capabilities such as Self Service and Metering/Chargeback. Other organizations are still operating in highly siloed environments with little automation and their formal Service Definition (if they have one) will be a lot less mature today. Therefore their future state DBaaS will look a lot different from their current state, as will their Service Definition. How database as a service impact or help with "Click to Compute" or deploying "Database in cloud infrastructure" DBaaS enables Click to Compute. Oracle DBaaS can be implemented using three architecture models: Oracle Multitenant 12c, native consolidation using Oracle Database and consolidation using virtualization in infrastructure cloud. As Deploy session showed, you get higher consolidating density and efficiency using Multitenant and higher isolation using infrastructure cloud. Depending upon your business needs, DBaaS can be implemented using any of these models. How exactly is the DBaaS different from the traditional db? Storage/OS/DB all together to 'transparently' provide service to applications? Will there be across-databases access by application/user. Some key differences are: 1) The services run on a shared platform. 2) The services can be rapidly provisioned (< 15 minutes). 3) The services are dynamic and can be relocated, grown, shrunk as needed to meet business needs without disruption and rapidly. 4) The user is able to provision the services directly from a standardized service catalog.. With 24x7x365 databases its difficult to find off peak hrs to do basic admin tasks such as gathering stats, running backups, batch jobs. How does pluggable database handle this and different needs/patching downtime of apps databases might be serving? You can gather stats in Oracle Multitenant the same way you had been in regular databases. Regarding patching/upgrading, Oracle Multitenant makes patch/upgrade very efficient in that you can pre-provision a new version/patched multitenant db in a different ORACLE_HOME and then unplug a PDB from its CDB and plug it into the newer/patched CDB in seconds.  Thanks for all the great questions!  If you'd like to learn more and missed the online forum, you can watch it on demand here.

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• Profiling Startup Of VS2012 &ndash; YourKit Profiler

  - by Alois Kraus

  The YourKit (v7.0.5) profiler is interesting in terms of price (79€ single place license, 409€ + 1 year support and upgrades) and feature set. You do get a performance and memory profiler in one package for which you normally need also to pay extra from the other vendors. As an interesting side note the profiler UI is written in Java because they do also sell Java profilers with the same feature set. To get all methods of a VS startup you need first to configure it to include System* in the profiled methods and you need to configure * to measure wall clock time. By default it does record only CPU times which allows you to optimize CPU hungry operations. But you will never see a Thread.Sleep(10000) in the profiler blocking the UI in this mode. It can profile as all others processes started from within the profiler but it can also profile the next or all started processes. As usual it can profile in sampling and tracing mode. But since it is a memory profiler as well it does by default also record all object allocations > 1MB. With allocation recording enabled VS2012 did crash but without allocation recording there were no problems. The CPU tab contains the time line of the application and when you click in the graph you the call stacks of all threads at this time. This is really a nice feature. When you select a time region you the CPU Usage estimation for this time window. I have seen many applications consuming 100% CPU only because they did create garbage like crazy. For this is the Garbage Collection tab interesting in conjunction with a time range. This view is like the CPU table only that the CPU graph (green) is missing. All relevant information except for GCs/s is already visible in the CPU tab. Very handy to pinpoint excessive GC or CPU bound issues. The Threads tab does show the thread names and their lifetime. This is useful to see thread interactions or which thread is hottest in terms of CPU consumption. On the CPU tab the call tree does exist in a merged and thread specific view. When you click on a method you get below a list of all called methods. There you can sort for methods with a high own time which are worth optimizing. In the Method List you can select which scope you want to see. Back Traces are the methods which did call you. Callees ist the list of methods called directly or indirectly by your method as a flat list. This is not a call stack but still very useful to see which methods were slow so you can see the “root” cause quite quickly without the need to click trough long call stacks. The last view Merged Calles is a call stacked view of the previous view. This does help a lot to understand did call each method at run time. You would get the same view with a debugger for one call invocation but here you get the full statistics (invocation count) as well. Since YourKit is also a memory profiler you can directly see which objects you have on your managed heap and which objects do hold most of your precious memory. You can in in the Object Explorer view also examine the contents of your objects (strings or whatsoever) to get a better understanding which objects where potentially allocating this stuff.   YourKit is a very easy to use combined memory and performance profiler in one product. The unbeatable single license price makes it very attractive to straightly buy it. Although it is a Java UI it is very responsive and the memory consumption is considerably lower compared to dotTrace and ANTS profiler. What I do really like is to start the YourKit ui and then start the processes I want to profile as usual. There is no need to alter your own application code to be able to inject a profiler into your new started processes. For performance and memory profiling you can simply select the process you want to investigate from the list of started processes. That's the way I like to use profilers. Just get out of the way and let the application run without any special preparations.   Next: Telerik JustTrace

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• #OOW 2012 : IaaS, Private Cloud, Multitenant Database, and X3H2M2

  - by Eric Bezille

  The title of this post is a summary of the 4 announcements made by Larry Ellison today, during the opening session of Oracle Open World 2012... To know what's behind X3H2M2, you will have to wait a little, as I will go in order, beginning with the IaaS - Infrastructure as a Service - announcement. Oracle IaaS goes Public... and Private... Starting in 2004 with Fusion development, Oracle Cloud was launch last year to provide not only SaaS Application, based on standard development, but also the underlying PaaS, required to build the specifics, and required interconnections between applications, in and outside of the Cloud. Still, to cover the end-to-end Cloud  Services spectrum, we had to provide an Infrastructure as a Service, leveraging our Servers, Storage, OS, and Virtualization Technologies, all "Engineered Together". This Cloud Infrastructure, was already available for our customers to build rapidly their own Private Cloud either on SPARC/Solaris or x86/Linux... The second announcement made today bring that proposition a big step further : for cautious customers (like Banks, or sensible industries) who would like to benefits from the Cloud value of "as a Service", but don't want their Data out in the Cloud... We propose to them to operate the same systems, Exadata, Exalogic & SuperCluster, that are providing our Public Cloud Infrastructure, behind their firewall, in a Private Cloud model. Oracle 12c Multitenant Database This is also a major announcement made today, on what's coming with Oracle Database 12c : the ability to consolidate multiple databases with no extra additional  cost especially in terms of memory needed on the server node, which is often THE consolidation limiting factor. The principle could be compare to Solaris Zones, where, you will have a Database Container, who is "owning" the memory and Database background processes, and "Pluggable" Database in this Database Container. This particular feature is a strong compelling event to evaluate rapidly Oracle Database 12c once it will be available, as this is major step forward into true Database consolidation with Multitenancy on a shared (optimized) infrastructure. X3H2M2, enabling the new Exadata X3 in-Memory Database Here we are :  X3H2M2 stands for X3 (the new version of Exadata announced also today) Heuristic Hierarchical Mass Memory, providing the capability to keep most if not all the Data in the memory cache hierarchy. Of course, this is the major software enhancement of the new X3 Exadata machine, but as this is a software, our current customers would be able to benefit from it on their existing systems by upgrading to the new release. But that' not the only thing that we did with X3, at the same time we have upgraded everything : the CPUs, adding more cores per server node (16 vs. 12, with the arrival of Intel E5 / Sandy Bridge), the memory with 512GB memory as well per node,  and the new Flash Fire card, bringing now up to 22 TB of Flash cache. All of this 4TB of RAM + 22TB of Flash being use cleverly not only for read but also for write by the X3H2M2 algorithm... making a very big difference compare to traditional storage flash extension. But what does those extra performances brings to you on an already very efficient system: double your performances compare to the fastest storage array on the market today (including flash) and divide you storage price x10 at the same time... Something to consider closely this days... Especially that we also announced the availability of a new Exadata X3-2 8th rack : a good starting point. As you have seen a major opening for this year again with true innovation. But that was not the only thing that we saw today, as before Larry's talk, Fujitsu did introduce more in deep the up coming new SPARC processor, that they are co-developing with us. And as such Andrew Mendelsohn - Senior Vice President Database Server Technologies came on stage to explain that the next step after I/O optimization for Database with Exadata, was to accelerate the Database at execution level by bringing functions in the SPARC processor silicium. All in all, to process more and more Data... The big theme of the day... and of the Oracle User Groups Conferences that were also happening today and where I had the opportunity to attend some interesting sessions on practical use cases of Big Data one in Finances and Fraud profiling and the other one on practical deployment of Oracle Exalytics for Data Analytics. In conclusion, one picture to try to size Oracle Open World ... and you can understand why, with such a rich content... and this only the first day !

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• What Counts for a DBA: Humility

  - by drsql

  In football (the American sort, naturally,) there are a select group of players who really hope to never have their names called during the game. They are members of the offensive line, and their job is to protect other players so they can deliver the ball to the goal to score points. When you do hear their name called, it is usually because they made a mistake and the player that they were supposed to protect ended up flat on his back admiring the clouds in the sky instead of advancing towards the goal to scoring point. Even on the rare occasion their name is called for a good reason, it is usually because they were making up for a teammate who had made a mistake and they covered up for them. The role of offensive lineman is a very good analogy for the role of the admin DBA. As a DBA, you are called on to be barely visible and rarely heard, protecting the company data assets tenaciously, even though the enemies to our craft surround us on all sides:. Developers: Cries of ‘foul!’ often ensue when the DBA says that they want data integrity to be stringently enforced and that documentation is needed so they can support systems, mostly because every error occurrence in the enterprise will be initially blamed on the database and fall to the DBA to troubleshoot. Insisting too loudly may bring those cries of ‘foul’ that somewhat remind you of when your 2 year old daughter didn't want to go to bed. The result of this petulance is that the next "enemy" gets involved. Managers: The concerns that motivate DBAs to argue will not excite the kind of manager who gets his technical knowledge from a glossy magazine filled with buzzwords, charts, and pretty pictures. However, the other programmers in the organization will tickle the buzzword void with a stream of new-sounding ideas and technologies constantly, along with warnings that if we did care about data integrity and document things, the budget would explode! In contrast, the arguments for integrity of data and supportability tend to be about as exciting as watching grass grow, and far too many manager types seem to prefer to smoke it than watch it. Packaged Applications: The DBA is rarely given a chance to review a new application that is being demonstrated for the enterprise, and rarer still is the DBA that gets a veto of an application because the database it uses has clearly been created by an architect that won't read a data modeling book because he is already married. More often than not this leads to hours of work for the DBA trying to performance-tune a database with a menagerie of rules that must be followed to stay within the  application support agreement, such as no changing indexes on a third party schema even though there are 10 billion rows instead of the 10 thousand when the system was last optimized. Hardware Failures: Physical disks, networking devices, memory, and backup devices all come with a measure known as ‘mean time before failure’ and it is never listed in centuries or eons. More like years, and the term ‘mean’ indicates that half of the devices are expected to fail before that, which by my calendar means any hour of any day that it wants to fail it will. But the DBA sucks it up and does the task at hand with a humility that makes them nearly invisible to all but the most observant person in the organization. The best DBAs I know are so proactive in their relentless pursuit of perfection that they detect many of the bugs (which they seldom caused) in the system well before they become a problem. In the end the DBA gets noticed for one of same two reasons as the offensive lineman. You make a mistake, like dropping a critical production database that had never been backed up; or when a system crashes for any reason whatsoever and they are on the spot with troubleshooting and system restoration plans that have been well thought out, tested, and tested again. Not because there is any glory in it, but because it is what they do.   Note: The characteristics of the professions referred to in this blog are meant to be overstated stereotypes for humorous effect, and even some DBAs aren't quite this perfect. If you are reading this far and haven’t hand written a 10 page flaming comment about how you are a _______ and you aren’t like this, that is awesome. Not every situation applies to everyone, but if you have never worked with a bad packaged app, a magazine trained manager, programmers that aren’t team players, or hardware that occasionally failed, relax and go have a unicorn sandwich before you wake up.

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• Where would a spam bot be located?

  - by Tim

  I have a hosted website using a free hosting service, I received an email this afternoon saying that I have been suspended because my account has been compromised. Basically, someone is using my email account to mass send spam. I've changed all the passwords and everything but when my Gmail pulls the emails from the host it's still downloading loads of spam messages that show like this: This message was created automatically by mail delivery software. A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed: [email protected] SMTP error from remote mail server after end of data: host 198.91.80.251 [198.91.80.251]: 554 5.6.0 id=23634-03 - Rejected by MTA on relaying, from MTA([127.0.0.1]:10030): 554 Error: This email address has lost rights to send email from the system ------ This is a copy of the message, including all the headers. ------ Return-path: <[email protected]> Received: from keenesystems.com ([66.135.33.211]:2370 helo=server211) by absolut.x10hosting.com with esmtpsa (TLSv1:RC4-MD5:128) (Exim 4.77) (envelope-from <[email protected]>) id 1TGwSW-002hHe-Lc for [email protected]; Wed, 26 Sep 2012 13:35:44 -0500 MIME-Version: 1.0 Date: Wed, 26 Sep 2012 13:35:43 -0500 X-Priority: 3 (Normal) X-Mailer: Ximian Evolution 3.9.9 (8.5.3-6) Subject: New staff members wanted at Auction It Online From: [email protected] Reply-To: [email protected] To: "Nadia Monti" <[email protected]> Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Message-ID: <OUTLOOK-IDM-9aed7054-6a3e-e1a4-1d5c-3e73377652a6@server211> Date : 26 September 2012=0ATime : 13:35=0ASender : Dennise Halcomb Head = Office Manager of RJ Auction Drop-Off Int.=0A=0ANice to meet you Nadia M= onti=0A=0ARJ ADO Ltd., a USA based company, offers a significant amount = of goods worldwide for our customers on eBay and other auction venues. = Our company's main target is to provide a suitable and cost-effective se= rvice for any person, company or fundraising company. The main purpose o= f the administrative assistant / sales support representative is to cont= ribute to the sales force and add convenience to our cost-effective serv= ice dedicated to individuals, businesses, and organizations worldwide. O= ur HR department obtained your resume from one of the various job-orient= ed websites just to offer you this post.=0A=0AWorking Schedule: This is = a part time and home-based offer. You won't need to spend more than 3 ho= urs each day. Your =0Aschedule will be flexible.=0A=0ASalary: At the end= of the trial period (it lasts for 1 month) you will be paid 1,800 EUR. = With the average volume of clients your overall income will raise up to = 3,000 EUR per month. After the trial period is over your base salary wil= l grow up to 2,500 EUR per month, so you will earn 5% commission from th= e transactions completed.=0A=0AWhere?: Italy Wide. As it is a stay at ho= me position all the communication will be carried out via email and via = phone.=0A=0ARequirements: Access to the internet during the workday and = basic microsoft office skills are needed. Basic knowledge of English is = required (most of the contacts will be in English).=0A=0ACosts and Fees:= There are NO costs at any time for our employees. All fees related to t= his position are covered by the RJ ADO Co. Ltd..=0A=0AFurther Hiring Pro= cess: If you are interested in position we offer, please reply to this e= mail and send us the copy of your resume for verification.=0A=0AAfter re= viewing all of the received applications we will reply to successful app= licants only. Then we'll offer to these successful applicants a position= within our firm on a trial period basis for one month beginning from th= e date you sign a trial agreement. During this trial period you will rec= eive full guidance and support. Employees on a one monthly trial period = are evaluated at least one week prior to the end of their trial. During = the trial, your supervisor can recommend termination. At the end of the = trial period, the supervisor can offer continued employment, extension o= f trial period, or termination. After the trial period you may ask for m= ore hours or continue full-time.=0A=0AIf you are interested in this posi= tion, just reply to this email and send any questions you have and the c= opy of your resume for verification.=0A=0AThank You,=0AHR-Manager of RJ = ADO Co. Ltd.=0A=0APermission Settings=0AYou have been referred to RJ Auc= tion Drop-Off If you feel you received this email in error or do not wis= h to receive future messages, please reply to this message with "remove"= in the subject field. We will immediately update our database according= ly. =0AWe apologize for any inconvenience caused.=0A=0ARJ Auction Drop-O= ff Co. Ltd. I'm not aware of how this has happened. I'm not sure how anyone could have got hold of my password. It's a simple wordpress install, at some point recently my host went down and there was a fresh install of wordpress with default admin accounts, I have a feeling it could be something to do with this. My question is, even though I've changed all my passwords it's all still happening, is there annywhere in paticular this script would be stored on my host. I really can't deal with having my hosting account suspended and my email account sending all this spam.

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• A Patent for Workload Management Based on Service Level Objectives

  - by jsavit

  I'm very pleased to announce that after a tiny :-) wait of about 5 years, my patent application for a workload manager was finally approved. Background Many operating systems have a resource manager which lets you control machine resources. For example, Solaris provides controls for CPU with several options: shares for proportional CPU allocation. If you have twice as many shares as me, and we are competing for CPU, you'll get about twice as many CPU cycles), dedicated CPU allocation in which a number of CPUs are exclusively dedicated to an application's use. You can say that a zone or project "owns" 8 CPUs on a 32 CPU machine, for example. And, capped CPU in which you specify the upper bound, or cap, of how much CPU an application gets. For example, you can throttle an application to 0.125 of a CPU. (This isn't meant to be an exhaustive list of Solaris RM controls.) Workload management Useful as that is (and tragic that some other operating systems have little resource management and isolation, and frighten people into running only 1 app per OS instance - and wastefully size every server for the peak workload it might experience) that's not really workload management. With resource management one controls the resources, and hope that's enough to meet application service objectives. In fact, we hold resource distribution constant, see if that was good enough, and adjust resource distribution if that didn't meet service level objectives. Here's an example of what happens today: Let's try 30% dedicated CPU. Not enough? Let's try 80% Oh, that's too much, and we're achieving much better response time than the objective, but other workloads are starving. Let's back that off and try again. It's not the process I object to - it's that we to often do this manually. Worse, we sometimes identify and adjust the wrong resource and fiddle with that to no useful result. Back in my days as a customer managing large systems, one of my users would call me up to beg for a "CPU boost": Me: "it won't make any difference - there's plenty of spare CPU to be had, and your application is completely I/O bound." User: "Please do it anyway." Me: "oh, all right, but it won't do you any good." (I did, because he was a friend, but it didn't help.) Prior art There are some operating environments that take a stab about workload management (rather than resource management) but I find them lacking. I know of one that uses synthetic "service units" composed of the sum of CPU, I/O and memory allocations multiplied by weighting factors. A workload is set to make a target rate of service units consumed per second. But this seems to be missing a key point: what is the relationship between artificial 'service units' and actually meeting a throughput or response time objective? What if I get plenty of one of the components (so am getting enough service units), but not enough of the resource whose needed to remove the bottleneck? Actual workload management That's not really the answer either. What is needed is to specify a workload's service levels in terms of externally visible metrics that are meaningful to a business, such as response times or transactions per second, and have the workload manager figure out which resources are not being adequately provided, and then adjust it as needed. If an application is not meeting its service level objectives and the reason is that it's not getting enough CPU cycles, adjust its CPU resource accordingly. If the reason is that the application isn't getting enough RAM to keep its working set in memory, then adjust its RAM assignment appropriately so it stops swapping. Simple idea, but that's a task we keep dumping on system administrators. In other words - don't hold the number of CPU shares constant and watch the achievement of service level vary. Instead, hold the service level constant, and dynamically adjust the number of CPU shares (or amount of other resources like RAM or I/O bandwidth) in order to meet the objective. Instrumenting non-instrumented applications There's one little problem here: how do I measure application performance in a way relating to a service level. I don't want to do it based on internal resources like number of CPU seconds it received per minute - We need to make resource decisions based on externally visible and meaningful measures of performance, not synthetic items or internal resource counters. If I have a way of marking the beginning and end of a transaction, I can then measure whether or not the application is meeting an objective based on it. If I can observe the delay factors for an application, I can see which resource shortages are slowing an application enough to keep it from meeting its objectives. I can then adjust resource allocations to relieve those shortages. Fortunately, Solaris provides facilities for both marking application progress and determining what factors cause application latency. The Solaris DTrace facility let's me introspect on application behavior: in particular I can see events like "receive a web hit" and "respond to that web hit" so I can get transaction rate and response time. DTrace (and tools like prstat) let me see where latency is being added to an application, so I know which resource to adjust. Summary After a delay of a mere few years, I am the proud creator of a patent (advice to anyone interested in going through the process: don't hold your breath!). The fundamental idea is fairly simple: instead of holding resource constant and suffering variable levels of success meeting service level objectives, properly characterise the service level objective in meaningful terms, instrument the application to see if it's meeting the objective, and then have a workload manager change resource allocations to remove delays preventing service level attainment. I've done it by hand for a long time - I think that's what a computer should do for me.

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• Rebuilding CoasterBuzz, Part IV: Dependency injection, it's what's for breakfast

  - by Jeff

  (Repost from my personal blog.) This is another post in a series about rebuilding one of my Web sites, which has been around for 12 years. I hope to relaunch soon. More: Part I: Evolution, and death to WCF Part II: Hot data objects Part III: The architecture using the "Web stack of love" If anything generally good for the craft has come out of the rise of ASP.NET MVC, it's that people are more likely to use dependency injection, and loosely couple the pieces parts of their applications. A lot of the emphasis on coding this way has been to facilitate unit testing, and that's awesome. Unit testing makes me feel a lot less like a hack, and a lot more confident in what I'm doing. Dependency injection is pretty straight forward. It says, "Given an instance of this class, I need instances of other classes, defined not by their concrete implementations, but their interfaces." Probably the first place a developer exercises this in when having a class talk to some kind of data repository. For a very simple example, pretend the FooService has to get some Foo. It looks like this: public class FooService {    public FooService(IFooRepository fooRepo)    {       _fooRepo = fooRepo;    }    private readonly IFooRepository _fooRepo;    public Foo GetMeFoo()    {       return _fooRepo.FooFromDatabase();    } } When we need the FooService, we ask the dependency container to get it for us. It says, "You'll need an IFooRepository in that, so let me see what that's mapped to, and put it in there for you." Why is this good for you? It's good because your FooService doesn't know or care about how you get some foo. You can stub out what the methods and properties on a fake IFooRepository might return, and test just the FooService. I don't want to get too far into unit testing, but it's the most commonly cited reason to use DI containers in MVC. What I wanted to mention is how there's another benefit in a project like mine, where I have to glue together a bunch of stuff. For example, when I have someone sign up for a new account on CoasterBuzz, I'm actually using POP Forums' new account mailer, which composes a bunch of text that includes a link to verify your account. The thing is, I want to use custom text and some other logic that's specific to CoasterBuzz. To accomplish this, I make a new class that inherits from the forum's NewAccountMailer, and override some stuff. Easy enough. Then I use Ninject, the DI container I'm using, to unbind the forum's implementation, and substitute my own. Ninject uses something called a NinjectModule to bind interfaces to concrete implementations. The forum has its own module, and then the CoasterBuzz module is loaded second. The CB module has two lines of code to swap out the mailer implementation: Unbind<PopForums.Email.INewAccountMailer>(); Bind<PopForums.Email.INewAccountMailer>().To<CbNewAccountMailer>(); Piece of cake! Now, when code asks the DI container for an INewAccountMailer, it gets my custom implementation instead. This is a lot easier to deal with than some of the alternatives. I could do some copy-paste, but then I'm not using well-tested code from the forum. I could write stuff from scratch, but then I'm throwing away a bunch of logic I've already written (in this case, stuff around e-mail, e-mail settings, mail delivery failures). There are other places where the DI container comes in handy. For example, CoasterBuzz does a number of custom things with user profiles, and special content for paid members. It uses the forum as the core piece to managing users, so I can ask the container to get me instances of classes that do user lookups, for example, and have zero care about how the forum handles database calls, configuration, etc. What a great world to live in, compared to ten years ago. Sure, the primary interest in DI is around the "separation of concerns" and facilitating unit testing, but as your library grows and you use more open source, it starts to be the glue that pulls everything together.

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• CPU Usage in Very Large Coherence Clusters

  - by jpurdy

  When sizing Coherence installations, one of the complicating factors is that these installations (by their very nature) tend to be application-specific, with some being large, memory-intensive caches, with others acting as I/O-intensive transaction-processing platforms, and still others performing CPU-intensive calculations across the data grid. Regardless of the primary resource requirements, Coherence sizing calculations are inherently empirical, in that there are so many permutations that a simple spreadsheet approach to sizing is rarely optimal (though it can provide a good starting estimate). So we typically recommend measuring actual resource usage (primarily CPU cycles, network bandwidth and memory) at a given load, and then extrapolating from those measurements. Of course there may be multiple types of load, and these may have varying degrees of correlation -- for example, an increased request rate may drive up the number of objects "pinned" in memory at any point, but the increase may be less than linear if those objects are naturally shared by concurrent requests. But for most reasonably-designed applications, a linear resource model will be reasonably accurate for most levels of scale. However, at extreme scale, sizing becomes a bit more complicated as certain cluster management operations -- while very infrequent -- become increasingly critical. This is because certain operations do not naturally tend to scale out. In a small cluster, sizing is primarily driven by the request rate, required cache size, or other application-driven metrics. In larger clusters (e.g. those with hundreds of cluster members), certain infrastructure tasks become intensive, in particular those related to members joining and leaving the cluster, such as introducing new cluster members to the rest of the cluster, or publishing the location of partitions during rebalancing. These tasks have a strong tendency to require all updates to be routed via a single member for the sake of cluster stability and data integrity. Fortunately that member is dynamically assigned in Coherence, so it is not a single point of failure, but it may still become a single point of bottleneck (until the cluster finishes its reconfiguration, at which point this member will have a similar load to the rest of the members). The most common cause of scaling issues in large clusters is disabling multicast (by configuring well-known addresses, aka WKA). This obviously impacts network usage, but it also has a large impact on CPU usage, primarily since the senior member must directly communicate certain messages with every other cluster member, and this communication requires significant CPU time. In particular, the need to notify the rest of the cluster about membership changes and corresponding partition reassignments adds stress to the senior member. Given that portions of the network stack may tend to be single-threaded (both in Coherence and the underlying OS), this may be even more problematic on servers with poor single-threaded performance. As a result of this, some extremely large clusters may be configured with a smaller number of partitions than ideal. This results in the size of each partition being increased. When a cache server fails, the other servers will use their fractional backups to recover the state of that server (and take over responsibility for their backed-up portion of that state). The finest granularity of this recovery is a single partition, and the single service thread can not accept new requests during this recovery. Ordinarily, recovery is practically instantaneous (it is roughly equivalent to the time required to iterate over a set of backup backing map entries and move them to the primary backing map in the same JVM). But certain factors can increase this duration drastically (to several seconds): large partitions, sufficiently slow single-threaded CPU performance, many or expensive indexes to rebuild, etc. The solution of course is to mitigate each of those factors but in many cases this may be challenging. Larger clusters also lead to the temptation to place more load on the available hardware resources, spreading CPU resources thin. As an example, while we've long been aware of how garbage collection can cause significant pauses, it usually isn't viewed as a major consumer of CPU (in terms of overall system throughput). Typically, the use of a concurrent collector allows greater responsiveness by minimizing pause times, at the cost of reducing system throughput. However, at a recent engagement, we were forced to turn off the concurrent collector and use a traditional parallel "stop the world" collector to reduce CPU usage to an acceptable level. In summary, there are some less obvious factors that may result in excessive CPU consumption in a larger cluster, so it is even more critical to test at full scale, even though allocating sufficient hardware may often be much more difficult for these large clusters.

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