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  • Various problems with software raid1 array built with Samsung 840 Pro SSDs

    - by Andy B
    I am bringing to ServerFault a problem that is tormenting me for 6+ months. I have a CentOS 6 (64bit) server with an md software raid-1 array with 2 x Samsung 840 Pro SSDs (512GB). Problems: Serious write speed problems: root [~]# time dd if=arch.tar.gz of=test4 bs=2M oflag=sync 146+1 records in 146+1 records out 307191761 bytes (307 MB) copied, 23.6788 s, 13.0 MB/s real 0m23.680s user 0m0.000s sys 0m0.932s When doing the above (or any other larger copy) the load spikes to unbelievable values (even over 100) going up from ~ 1. When doing the above I've also noticed very weird iostat results: Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util sda 0.00 1589.50 0.00 54.00 0.00 13148.00 243.48 0.60 11.17 0.46 2.50 sdb 0.00 1627.50 0.00 16.50 0.00 9524.00 577.21 144.25 1439.33 60.61 100.00 md1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 md2 0.00 0.00 0.00 1602.00 0.00 12816.00 8.00 0.00 0.00 0.00 0.00 md0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 And it keeps it this way until it actually writes the file to the device (out from swap/cache/memory). The problem is that the second SSD in the array has svctm and await roughly 100 times larger than the second. For some reason the wear is different between the 2 members of the array root [~]# smartctl --attributes /dev/sda | grep -i wear 177 Wear_Leveling_Count 0x0013 094% 094 000 Pre-fail Always - 180 root [~]# smartctl --attributes /dev/sdb | grep -i wear 177 Wear_Leveling_Count 0x0013 070% 070 000 Pre-fail Always - 1005 The first SSD has a wear of 6% while the second SSD has a wear of 30%!! It's like the second SSD in the array works at least 5 times as hard as the first one as proven by the first iteration of iostat (the averages since reboot): Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util sda 10.44 51.06 790.39 125.41 8803.98 1633.11 11.40 0.33 0.37 0.06 5.64 sdb 9.53 58.35 322.37 118.11 4835.59 1633.11 14.69 0.33 0.76 0.29 12.97 md1 0.00 0.00 1.88 1.33 15.07 10.68 8.00 0.00 0.00 0.00 0.00 md2 0.00 0.00 1109.02 173.12 10881.59 1620.39 9.75 0.00 0.00 0.00 0.00 md0 0.00 0.00 0.41 0.01 3.10 0.02 7.42 0.00 0.00 0.00 0.00 What I've tried: I've updated the firmware to DXM05B0Q (following reports of dramatic improvements for 840Ps after this update). I have looked for "hard resetting link" in dmesg to check for cable/backplane issues but nothing. I have checked the alignment and I believe they are aligned correctly (1MB boundary, listing below) I have checked /proc/mdstat and the array is Optimal (second listing below). root [~]# fdisk -ul /dev/sda Disk /dev/sda: 512.1 GB, 512110190592 bytes 255 heads, 63 sectors/track, 62260 cylinders, total 1000215216 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00026d59 Device Boot Start End Blocks Id System /dev/sda1 2048 4196351 2097152 fd Linux raid autodetect Partition 1 does not end on cylinder boundary. /dev/sda2 * 4196352 4605951 204800 fd Linux raid autodetect Partition 2 does not end on cylinder boundary. /dev/sda3 4605952 814106623 404750336 fd Linux raid autodetect root [~]# fdisk -ul /dev/sdb Disk /dev/sdb: 512.1 GB, 512110190592 bytes 255 heads, 63 sectors/track, 62260 cylinders, total 1000215216 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0003dede Device Boot Start End Blocks Id System /dev/sdb1 2048 4196351 2097152 fd Linux raid autodetect Partition 1 does not end on cylinder boundary. /dev/sdb2 * 4196352 4605951 204800 fd Linux raid autodetect Partition 2 does not end on cylinder boundary. /dev/sdb3 4605952 814106623 404750336 fd Linux raid autodetect /proc/mdstat root # cat /proc/mdstat Personalities : [raid1] md0 : active raid1 sdb2[1] sda2[0] 204736 blocks super 1.0 [2/2] [UU] md2 : active raid1 sdb3[1] sda3[0] 404750144 blocks super 1.0 [2/2] [UU] md1 : active raid1 sdb1[1] sda1[0] 2096064 blocks super 1.1 [2/2] [UU] unused devices: Running a read test with hdparm root [~]# hdparm -t /dev/sda /dev/sda: Timing buffered disk reads: 664 MB in 3.00 seconds = 221.33 MB/sec root [~]# hdparm -t /dev/sdb /dev/sdb: Timing buffered disk reads: 288 MB in 3.01 seconds = 95.77 MB/sec But look what happens if I add --direct root [~]# hdparm --direct -t /dev/sda /dev/sda: Timing O_DIRECT disk reads: 788 MB in 3.01 seconds = 262.08 MB/sec root [~]# hdparm --direct -t /dev/sdb /dev/sdb: Timing O_DIRECT disk reads: 534 MB in 3.02 seconds = 176.90 MB/sec Both tests increase but /dev/sdb doubles while /dev/sda increases maybe 20%. I just don't know what to make of this. As suggested by Mr. Wagner I've done another read test with dd this time and it confirms the hdparm test: root [/home2]# dd if=/dev/sda of=/dev/null bs=1G count=10 10+0 records in 10+0 records out 10737418240 bytes (11 GB) copied, 38.0855 s, 282 MB/s root [/home2]# dd if=/dev/sdb of=/dev/null bs=1G count=10 10+0 records in 10+0 records out 10737418240 bytes (11 GB) copied, 115.24 s, 93.2 MB/s So sda is 3 times faster than sdb. Or maybe sdb is doing also something else besides what sda does. Is there some way to find out if sdb is doing more than what sda does? UPDATE Again, as suggested by Mr. Wagner, I have swapped the 2 SSDs. And as he thought it would happen, the problem moved from sdb to sda. So I guess I'll RMA one of the SSDs. I wonder if the cage might be problematic. What is wrong with this array? Please help!

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  • inotifywait usage and exclude

    - by user58542
    I want to monitor special path to any event of create or modified files recursively in it via inotifywait but i cant know what's problem. i have some folder that i want to exclude thame. watchpath -> folder1 -> file1 -> ingnorefile1 [IG] -> ignorefolder1 [IG] i have problem to exclude them. inotifywait -mr --exclude '(ignorefolder1|folder1\/ingnorefile1)' -e modify -e create -e delete . | while read date time dir file; do what is correct regular expression ?

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  • MapReduce job is hung after 1 of 5 reducers completed on single-node environment

    - by Marboni
    I have only one Data Node on my dev environment on EC2. I ran heavy MR job and in 6 hours noticed that 100% of mappers and 20% of reducers finished (1 of reducer shows 100% competition, other ones - 0%). Looks like job is hung between 2 reducer runs. I don't see any errors in log files. What it can be? P.S. Last logs of successfully finished reducer: 2012-11-09 11:29:21,576 INFO org.apache.hadoop.mapred.Task: Task:attempt_201211090523_0004_r_000000_0 is done. And is in the process of commiting 2012-11-09 11:29:22,692 INFO org.apache.hadoop.mapred.Task: Task attempt_201211090523_0004_r_000000_0 is allowed to commit now 2012-11-09 11:29:22,719 INFO org.apache.hadoop.mapreduce.lib.output.FileOutputCommitter: Saved output of task 'attempt_201211090523_0004_r_000000_0' to /data/output/1352457275873/20121109-053433-common 2012-11-09 11:29:22,721 INFO org.apache.hadoop.mapred.Task: Task 'attempt_201211090523_0004_r_000000_0' done. 2012-11-09 11:29:22,725 INFO org.apache.hadoop.mapred.TaskLogsTruncater: Initializing logs' truncater with mapRetainSize=-1 and reduceRetainSize=-1

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  • Office 2007 Mail Merge: How do I view field names instead of data?

    - by One Monkey
    I've just received a document which forms the basis of a mail merge as an attachment and I need to view the field names like they display in 2003 with the double chevrons e.g. <<titles>><<initials>><<surname>> However even though I get a dialogue as I open the docx file saying that it is going to attempt to merge from a file (which I don't have) and I cancel that operation the document still displays merge data e.g. Mr A Test Instead of the field names. I have clicked on the fields which turn grey to demonstrate that they are fields but I can't find a way to make it display the field names not the data. I don't even know where it's getting the data from as I don't have the data source file for the document to use.

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  • Productive Toolset for C# Developer

    - by Marko Apfel
    Programming Visual Studio ReSharper Agent Johnson Agent Smith StyleCop for ReSharper Keymaps SettingsManager Git Source Control Provider Gist NuGet Package Manager NDepend Productivity Power Tools PowerCommands for Visual Studio PostSharp Indent Guides Typemock Isolator VSCommands Ressource Refactor Clone Detective GhostDoc CR_Documentor AnkSVN Expression Blend SharpDevelop Notepad++, PS Pad StyleCop, FxCop, .. .NET Reflector, ILSpy, dotPeek, Just Decompile Git Extensions inkl. MSysGit, MinGW Github for Windows SmartGit PoSH-Git Console Enhancement Project LINQPad Mercurial RapidSVN SQL Management Studio Adventure Works Sample DB AdventureWorksLT Toad for SQL Server yEd Graph Editor TeX, LateX MiKTeX, TeXworks Pandoc Jenkins, TeamCity KompoZer XML Notepad Kaxaml KDiff3, WinMerge, Perforce Merge Handle DbgView FusLogVw FTP Commander HTML Help Workshop, Sandcastle, SHFB WiX Enterprise Architect InsightProfiler Putty Cygwin DXCore, DXCore Plugins FreeMind ProcessExplorer, ProcessMonitor Social Networking, Community Windows Live Writer Disgsby Skype TweetDeck FeedReader Sytem and others Microsoft Office (notably OneNote!!!) Adobe Reader PDF Creator SRWare Iron (Chrome) AddThis bit-ly del.icio.us InstaPaper Leo Dictionary Google Bookmarks Proxy Switchy! StumbleUpon K-Meleon FreeCommander, FAR 7-Zip Keyboard Jedi Launchy TrueCrypt Dropbox Ditto Greenshot Rainlendar2 Everything Daemon Tools inSSIDer VirtualBox Stardock Fences Media Player Classic VLC Media Player Winamp WinAmp Cue Player LAME Encoder CamStudio Youtube to MP3 Converter VirtualDub Image Resizer Powertoy Clone 2.0 Paint.NET Picasa Windy JediConcentrate, Ghoster TeamViewer Timerle TreeSizeFree WinDirStat Windows Sizer, WinResizer ZoomIt Sometimes nice to have ArcGIS TortoiseSVN, TortoiseCVS XnView GitJungle CowSpy Grindstone Free Download Manager CDBurnerXP Free Audio CD Burner SmartAssembly intellibook GMX SMS Manager BlackBerry Desktop Cisco Any Connect eRoom Foxit Reader Google Earth ThinkVantage GPS Gridy Bluefish The GodFather Tor Browser, Charon YouTube Downloader NCover Network Stumbler Remote Debugger WScite XML Pad DBVisualizer Microsoft Network Monitor, Fiddler2 Eclipse IDE Oracle Client, Oracle SQL Developer Bookmarks, Links http://pastebin.de/, http://pastebin.com/ http://followup.cc  http://trello.com http://tumblr.com https://bitly.com/, http://is.gd http://www.famkruithof.net/uuid/uuidgen, http://www.guidgenerator.com/ https://github.com/, https://bitbucket.org/ http://dict.leo.org/, http://translate.google.com/ http://prezi.com/ http://geekswithblogs.net/Default.aspx, http://codebetter.com/ http://duckduckgo.com/bang.html   http://de.schreibtrainer.com/index.php?site=3&menuId=3 http://www.mr-wetter.de/ this is an update to http://geekswithblogs.net/mapfel/archive/2010/07/12/140877.aspx

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  • Buy HTC HD7 Windows Phone 7 From Airtel In India @ Rs. 29990

    - by Gopinath
    Are you looking for HTC HD 7 Windows Phone 7 in India? Head over to Airtel showroom near you to grab one. Airtel in partnership with HTC is offering HD 7 Windows Phone 7 for Rs. 29990 and users will get 2 GB of data usage for 6 months at Rs. 300. Mr. Shireesh Joshi, CMO-Mobile Services of Bharti Airtel,  in a press conference says We are delighted with the opportunity to bring the eagerly-awaited HTC HD7 Smartphone in India. Combining the strength of the airtel brand and network with the innovation and design of HTC and the great user-interface of Windows Phone 7, we are happy to bring another first for our customers that will take mobile communications to a whole new level. The HD7 has a 4.3-inch display, kickstand to rest your phone on a table, 5MP autofocus camera that allows you to record 720p videos, 1GHz processor, 576MB of RAM and has 16GB of internal memory. Even though this is the official launch of HTC HD7 in India, this phone is available in the market for quite sometime at an approximate price of Rs. 27000/-. So it’s your call to decide whether buy it at HTC authorized retailers like Airtel for Rs.29K  or in the market for Rs 27K. HTC HD 7 Promo Video Thanks Fonearena This article titled,Buy HTC HD7 Windows Phone 7 From Airtel In India @ Rs. 29990, was originally published at Tech Dreams. Grab our rss feed or fan us on Facebook to get updates from us.

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  • Oracle @ AIIM Conference

    - by [email protected]
    Oracle will be at the AIIM Conference and Exposition next week in Philadelphia. On the opening morning, Robert Shimp, Group Vice President, Global Technology Business Unit, of Oracle Corporation, will moderate an executive keynote panel. Mr. Shimp will lead four Oracle customer executives through a lively discussion of how innovative organizations are driving the integration of content management with their core business processes on Tuesday April 20th at 8:45 AM. Our panelists are: CINDY BIXLER, CIO, Embry Riddle Aeronautical University TOM SHOWALTER, Managing Director, JP Morgan Chase IRFAN MOTIWALA, Vice President, Moody's Investors Service MIT MONICA CROCKER, CRM, PMP, Corporate Records Manager, Land O'Lakes For more information on our panelists, click here. Oracle will be in booth #2113 at the AIIM Expo. Come by and enter the daily raffle to win a Netbook! Oracle and Oracle partners will demonstrate solutions that increase productivity, reduce costs and ensure compliance for business processes such as accounts payable, human resource onboarding, marketing campaigns, sales management, large scale diagrams for facilities and manufacturing, case management, and others Oracle products including Oracle Universal Content Management, Oracle Imaging and Process Management, Oracle Universal Records Management, Oracle WebCenter, Oracle AutoVue, and Oracle Secure Enterprise Search will be demonstrated in the booth. Oracle will host a private event at The Field House Sports Bar - see your Oracle representative for more details Oracle customers can meet in private meeting rooms with their Oracle representatives Key Sessions Besides the opening morning keynote panel, Oracle will have a number of other sessions at the conference. Oracle Content Management will be featured in the session G08 - A Passage to Improving Healthcare: Enhancing EMR with Electronic Records Wednesday April 21st 2:25PM-3:10PM Kristina Parma of Oracle partner ImageSource will deliver this session, along with Pam Doyle of Fujitsu and Nancy Gladish of Swedish Medical Center. Kristina will also be in the Oracle booth to talk about this solution. On Tuesday April 20th at 4:05 PM Ajay Gandhi of Oracle will deliver a session entitled Harnessing SharePoint Content for Enterprise Processes in PeopleSoft, Siebel, E-Business Suite and JD Edwards Tuesday April 20th 1:15PM-1:45PM - Bringing Content Management to Your AP, HR, Sales and Marketing Processes - Application Showcase Theater (on the AIIM Expo Floor - Booth 1549 Wednesday April 21st 12:30PM-1:00PM - Embed and Edit Content Anywhere - Application Showcase Theater (on the AIIM Expo Floor - Booth 1549 For more information, see the AIIM Expo page on the Oracle website.

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  • New site – and a special offer

    - by Red Gate Software BI Tools Team
    SSAS Compare has a brand new website! The old page was thrown together in the way that most Red Gate labs sites tend to be — as experimental sites for experimental products. We’ve been developing SSAS Compare for a while now, so we decided it was time for something a bit prettier. The new site is mostly the work of Andrew, our marketing manager, who has all sorts of opinions about websites. One of the opinions Andrew has is that his photo should be on every site on the internet, or at least every Red Gate site on the internet, and that’s why his handsome visage now appears on the SSAS Compare page. Well, that isn’t quite true. According to Andrew, people download more software when they have photos of human beings to look at. We want as many people to try SSAS Compare as possible, so we got the team together for an intimate photoshoot directed by Red Gate’s resident recorder of light, Dom Reed (aka Mr Flibble). The photo will appear on the site as soon as Dom is finished photoshopping us into something more palatable, which is a big job. Until then, you’ll have to put up with Andrew. We’ve also used the new site to announce a special offer. Right now, SSAS Compare is still a free beta, but by signing up to our Early Access Program, you’ll get a 20% discount when we release SSAS Compare as a fully-fledged product. We’ll use your email address to send you news and updates about business intelligence tools from Red Gate (and nothing else). If that sounds good to you, go to the SSAS Compare site to sign up. By the way, the BI Tools team wasn’t the only thing Dom photographed last week. Remember Noemi’s blog about the flamenco dance? We’ll be at SQL Saturday in our home town of Cambridge this Saturday (8th September), handing out flyers of a distinctly Mediterranean flavour. If you’re attending, be sure to say hello!

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  • Frank Buytendijk on Prahalad, Business Best Practices

    - by Bob Rhubart
      In his video on the questionable value of some business best practices, Frank Buytendijk mentions a recent HBR article by business guru C.K. Prahalad. I just learned that Prahalad passed away this past weekend at the age of 68. (Information Week obit) A couple of years ago I had the good fortune to attend Mr. Prahalad’s keynote address at a Gartner event.  He had an audience of software architects absolutely mesmerized as he discussed technology’s role in the changing nature of business competition.  The often dysfunctional relationship between IT and business has and will probably always be hot-button issue. But during Prahalad’s keynote,  there was a palpable sense that the largely technical audience was having some kind of breakthrough, that they had achieved a new level of understanding about the importance of the relationship between the two camps. Fortunately, Prahalad leaves behind a significant body of work that will remain a valuable resource as business and the technology that supports it continues to evolve. Technorati Tags: business best practices,enterprise architecture,prahalad,oracle del.icio.us Tags: business best practices,enterprise architecture,prahalad,oracle

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  • links for 2010-04-29

    - by Bob Rhubart
    AS11 Oracle B2B Sync Support - Series 1 (Oracle Fusion Middleware - B2B Team Blog) Sinkarbabu Kirubanithi with part 1 of a planned 3-part series on synchronous message support in Oracle B2B 11g. (tags: oracle otn fusionmiddleware b2b) Java 2 Go!: How to write a simple yet “bullet-proof” object cache "So, while we were thinking hard to come up with the most efficient, generic and elegant way of finally implementing our weak and soft caches, Mr. Eric Chan, who is one of the main architects in Oracle Beehive team, had a very interesting breakthrough. In short terms, he thought of a very nice way of combining both WeakReference and SoftReference in our weak and soft caches so that they would provide exactly the same functionality without having to deal with those reference queues at all. Basically, instead of using a plain HashMap as our backing storage, we used a java.util.WeakHashMap in both our cache implementations. The hat trick was what and how to store things in it." - Eduardo Rodrigues (tags: oracle java sun) @jamet123: First Look – Oracle Data Mining "[Oracle Data Mining] is a nice product for Oracle database customers and well worth looking into. The new UI will only make it more so." James Taylor (tags: oracle otn datamining database) Live Webcast: Social BPM: Integrating Enterprise 2.0 with Business Applications #oracle Peggy Chen and Dan Tortorici show you how to take your business to the next level with a unified solution that fosters process-based collaboration between employees, partners, and customers. Wednesday, May 12, 2010 at 11:00am PT / 2:00pm ET (tags: oracle otn enterprise2.0 webcast)

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  • myToys.de GmbH announces integration of ZVT payment terminal interface with Oracle Retail Point-of-Service

    - by user801960
    In our latest guest post, Sascha Kraatz, Developer Oracle E-Business Suite of myToys.de announces the development and integration of its ZVT payment terminal interface with the Oracle Retail Point-of-Service solution. myToys.de GmbH, which runs Oracle Retail Point-of-Service (ORPOS) in its 13 retail stores in Germany (see press release), has developed and implemented a Java-based interface for integrating the ZVT payment terminal with ORPOS. Through the combined support of payment service provider, easycash GmbH, and Ingenico GmbH, Germany´s leading payment terminal provider, myToys.de has become the first organisation to create this new automated solution for the Oracle Retail Point-of-Service, which has eliminated input errors that could occur with manual payment terminals and is localised for the German market. Ingo Stober, head of retail business at myToys.de confirms: “With this solution, we can speed up the payment process, reduce manual errors and enhance the customer experience in our stores”. myToys.de GmbH is a member of the Otto Group and one of the leading multichannel retailers for toys and other kids products in Germany. Customers can choose from over 100,000 attractive products, starting with items for expectant mothers or basic baby equipment to items for school children and beyond. In 2006, the first of 13 myToys.de retail branches was opened. If you would like to find out more about this solution, please contact the head of Oracle E-Business Suite Development at myToys.de, Mr. Ralf Schmilewski, or leave a comment below.

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  • AIOUG TechDay @ Lovely Professional University, Jalandhar, India

    - by Tori Wieldt
    by guest blogger Jitendra Chittoda, co-leader, Delhi and NCR JUG On 30 August 2013, Lovely Professional University (LPU) Jalandhar organized an All India Oracle User Group (AIOUG) TechDay event on Oracle and Java. This was a full day event with various sessions on J2EE 6, Java Concurrency, NoSQL, MongoDB, Oracle 12c, Oracle ADF etc. It was an overwhelming response from students, auditorium was jam packed with 600+ LPU energetic students of B.Tech and MCA stream. Navein Juneja Sr. Director LPU gave the keynote and introduced the speakers of AIOUG and Delhi & NCR Java User Group (DaNJUG). Mr. Juneja explained about the LPU and its students. He explained how Oracle and Java is most used and accepted technologies in world. Rohit Dhand Additional Dean LPU came on stage and share about how his career started with Oracle databases. He encouraged students to learn these technologies and build their career. Satyendra Kumar vice-president AIOUG thanked LPU and their stuff for organizing such a good technical event and students for their overwhelming response.  He talked about the India Oracle group and its events at various geographical locations all over India. Jitendra Chittoda Co-Leader DaNJUG explained how to make a new Java User Groups (JUG), what are its benefits and how to promote it. He explained how the Indian JUGs are contributing to the different initiatives like Adopt-a-JSR and Adopt-OpenJDK. After the inaugural address event started with two different tracks one for Oracle Database and another for Java and its related technologies. Speakers: Satyendra Kumar Pasalapudi (Co-founder and Vice President of AIOUG) Aman Sharma (Oracle Database Consultant and Instructor) Shekhar Gulati (OpenShift Developer Evangelist at RedHat) Rohan Walia (Oracle ADF Consultant at Oracle) Jitendra Chittoda (Co-leader Delhi & NCR JUG and Senior Developer at ION Trading)

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  • Friday Fun: Wake Up the Box

    - by Mysticgeek
    Another Friday and it’s time to waste the rest of your Friday playing a  fun flash game online. Today we take a look at a relaxing physic based puzzle game called Wake Up the Box. Wake Up the Box This goal of this game is to wake up the box character by attaching parts of existing wood objects in each stage. You can start a new game or continue your progress from where you left off. At the beginning you get a tutorial showing what you need to do to wake the box. You get wood parts and can attach them to other wood pieces but not metal or brick. After successfully waking up Mr. Box, you can go to the next level or restart a level at any time if your having problems figuring out the puzzle. Each level gets more difficult and the puzzles are more challenging. Wake Up the Box is a relaxing and challenging game that will allow you to have fun, not working on TPS reports until the whistle blows. Play Wake Up the Box at FreeWebArcade Similar Articles Productive Geek Tips Stop the Mouse From Waking Up Your Computer from Sleep ModeFix "Sleep Mode Randomly Waking Up" Issue in Windows VistaStop Your Mouse from Waking Up Your Windows 7 ComputerPrevent Windows Asking for a Password on Wake Up from Sleep/StandbyUse Sleep.FM to Wake Up with the Web TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Microsoft’s “How Do I ?” Videos Home Networks – How do they look like & the problems they cause Check Your IMAP Mail Offline In Thunderbird Follow Finder Finds You Twitter Users To Follow Combine MP3 Files Easily QuicklyCode Provides Cheatsheets & Other Programming Stuff

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  • A tale from a Stalker

    - by Peter Larsson
    Today I thought I should write something about a stalker I've got. Don't get me wrong, I have way more fans than stalkers, but this stalker is particular persistent towards me. It all started when I wrote about Relational Division with Sets late last year(http://weblogs.sqlteam.com/peterl/archive/2010/07/02/Proper-Relational-Division-With-Sets.aspx) and no matter what he tried, he didn't get a better performing query than me. But this I didn't click until later into this conversation. He must have saved himself for 9 months before posting to me again. Well... Some days ago I get an email from someone I thought i didn't know. Here is his first email Hi, I want a proper solution for achievement the result. The solution must be standard query, means no using as any native code like TOP clause, also the query should run in SQL Server 2000 (no CTE use). We have a table with consecutive keys (nbr) that is not exact sequence. We need bringing all values related with nearest key in the current key row. See the DDL: CREATE TABLE Nums(nbr INTEGER NOT NULL PRIMARY KEY, val INTEGER NOT NULL); INSERT INTO Nums(nbr, val) VALUES (1, 0),(5, 7),(9, 4); See the Result: pre_nbr     pre_val     nbr         val         nxt_nbr     nxt_val ----------- ----------- ----------- ----------- ----------- ----------- NULL        NULL        1           0           5           7 1           0           5           7           9           4 5           7           9           4           NULL        NULL The goal is suggesting most elegant solution. I would like see your best solution first, after that I will send my best (if not same with yours)   Notice there is no name, no please or nothing polite asking for my help. So, on the top of my head I sent him two solutions, following the rule "Work on SQL Server 2000 and only standard non-native code".     -- Peso 1 SELECT               pre_nbr,                              (                                                           SELECT               x.val                                                           FROM                dbo.Nums AS x                                                           WHERE              x.nbr = d.pre_nbr                              ) AS pre_val,                              d.nbr,                              d.val,                              d.nxt_nbr,                              (                                                           SELECT               x.val                                                           FROM                dbo.Nums AS x                                                           WHERE              x.nbr = d.nxt_nbr                              ) AS nxt_val FROM                (                                                           SELECT               (                                                                                                                     SELECT               MAX(x.nbr) AS nbr                                                                                                                     FROM                dbo.Nums AS x                                                                                                                     WHERE              x.nbr < n.nbr                                                                                        ) AS pre_nbr,                                                                                        n.nbr,                                                                                        n.val,                                                                                        (                                                                                                                     SELECT               MIN(x.nbr) AS nbr                                                                                                                     FROM                dbo.Nums AS x                                                                                                                     WHERE              x.nbr > n.nbr                                                                                        ) AS nxt_nbr                                                           FROM                dbo.Nums AS n                              ) AS d -- Peso 2 CREATE TABLE #Temp                                                         (                                                                                        ID INT IDENTITY(1, 1) PRIMARY KEY,                                                                                        nbr INT,                                                                                        val INT                                                           )   INSERT                                            #Temp                                                           (                                                                                        nbr,                                                                                        val                                                           ) SELECT                                            nbr,                                                           val FROM                                             dbo.Nums ORDER BY         nbr   SELECT                                            pre.nbr AS pre_nbr,                                                           pre.val AS pre_val,                                                           t.nbr,                                                           t.val,                                                           nxt.nbr AS nxt_nbr,                                                           nxt.val AS nxt_val FROM                                             #Temp AS pre RIGHT JOIN      #Temp AS t ON t.ID = pre.ID + 1 LEFT JOIN         #Temp AS nxt ON nxt.ID = t.ID + 1   DROP TABLE    #Temp Notice there are no indexes on #Temp table yet. And here is where the conversation derailed. First I got this response back Now my solutions: --My 1st Slt SELECT T2.*, T1.*, T3.*   FROM Nums AS T1        LEFT JOIN Nums AS T2          ON T2.nbr = (SELECT MAX(nbr)                         FROM Nums                        WHERE nbr < T1.nbr)        LEFT JOIN Nums AS T3          ON T3.nbr = (SELECT MIN(nbr)                         FROM Nums                        WHERE nbr > T1.nbr); --My 2nd Slt SELECT MAX(CASE WHEN N1.nbr > N2.nbr THEN N2.nbr ELSE NULL END) AS pre_nbr,        (SELECT val FROM Nums WHERE nbr = MAX(CASE WHEN N1.nbr > N2.nbr THEN N2.nbr ELSE NULL END)) AS pre_val,        N1.nbr AS cur_nbr, N1.val AS cur_val,        MIN(CASE WHEN N1.nbr < N2.nbr THEN N2.nbr ELSE NULL END) AS nxt_nbr,        (SELECT val FROM Nums WHERE nbr = MIN(CASE WHEN N1.nbr < N2.nbr THEN N2.nbr ELSE NULL END)) AS nxt_val   FROM Nums AS N1,        Nums AS N2  GROUP BY N1.nbr, N1.val;   /* My 1st Slt Table 'Nums'. Scan count 7, logical reads 14 My 2nd Slt Table 'Nums'. Scan count 4, logical reads 23 Peso 1 Table 'Nums'. Scan count 9, logical reads 28 Peso 2 Table '#Temp'. Scan count 0, logical reads 7 Table 'Nums'. Scan count 1, logical reads 2 Table '#Temp'. Scan count 3, logical reads 16 */  To this, I emailed him back asking for a scalability test What if you try with a Nums table with 100,000 rows? His response to that started to get nasty.  I have to say Peso 2 is not acceptable. As I said before the solution must be standard, ORDER BY is not part of standard SELECT. Try this without ORDER BY:  Truncate Table Nums INSERT INTO Nums (nbr, val) VALUES (1, 0),(9,4), (5, 7)  So now we have new rules. No ORDER BY because it's not standard SQL! Of course I asked him  Why do you have that idea? ORDER BY is not standard? To this, his replies went stranger and stranger Standard Select = Set-based (no any cursor) It’s free to know, just refer to Advanced SQL Programming by Celko or mail to him if you accept comments from him. What the stalker probably doesn't know, is that I and Mr Celko occasionally are involved in some conversation and thus we exchange emails. I don't know if this reference to Mr Celko was made to intimidate me either. So I answered him, still polite, this What do you mean? The SELECT itself has a ”cursor under the hood”. Now the stalker gets rude  But however I mean the solution must no containing any order by, top... No problem, I do not like Peso 2, it’s very non-intelligent and elementary. Yes, Peso 2 is elementary but most performing queries are... And now is the time where I started to feel the stalker really wanted to achieve something else, so I wrote to him So what is your goal? Have a query that performs well, or a query that is super-portable? My Peso 2 outperforms any of your code with a factor of 100 when using more than 100,000 rows. While I awaited his answer, I posted him this query Ok, here is another one -- Peso 3 SELECT             MAX(CASE WHEN d = 1 THEN nbr ELSE NULL END) AS pre_nbr,                    MAX(CASE WHEN d = 1 THEN val ELSE NULL END) AS pre_val,                    MAX(CASE WHEN d = 0 THEN nbr ELSE NULL END) AS nbr,                    MAX(CASE WHEN d = 0 THEN val ELSE NULL END) AS val,                    MAX(CASE WHEN d = -1 THEN nbr ELSE NULL END) AS nxt_nbr,                    MAX(CASE WHEN d = -1 THEN val ELSE NULL END) AS nxt_val FROM               (                              SELECT    nbr,                                        val,                                        ROW_NUMBER() OVER (ORDER BY nbr) AS SeqID                              FROM      dbo.Nums                    ) AS s CROSS JOIN         (                              VALUES    (-1),                                        (0),                                        (1)                    ) AS x(d) GROUP BY           SeqID + x.d HAVING             COUNT(*) > 1 And here is the stats Table 'Nums'. Scan count 1, logical reads 2, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. It beats the hell out of your queries…. Now I finally got a response from my stalker and now I also clicked who he was. This is his reponse Why you post my original method with a bit change under you name? I do not like it. See: http://www.sqlservercentral.com/Forums/Topic468501-362-14.aspx ;WITH C AS ( SELECT seq_nbr, k,        DENSE_RANK() OVER(ORDER BY seq_nbr ASC) + k AS grp_fct   FROM [Sample]         CROSS JOIN         (VALUES (-1), (0), (1)         ) AS D(k) ) SELECT MIN(seq_nbr) AS pre_value,        MAX(CASE WHEN k = 0 THEN seq_nbr END) AS current_value,        MAX(seq_nbr) AS next_value   FROM C GROUP BY grp_fct HAVING min(seq_nbr) < max(seq_nbr); These posts: Posted Tuesday, April 12, 2011 10:04 AM Posted Tuesday, April 12, 2011 1:22 PM Why post a solution where will not work in SQL Server 2000? Wait a minute! His own solution is using both a CTE and a ranking function so his query will not work on SQL Server 2000! Bummer... The reference to "Me not like" are my exact words in a previous topic on SQLTeam.com and when I remembered the phrasing, I also knew who he was. See this topic http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=159262 where he writes a query and posts it under my name, as if I wrote it. So I answered him this (less polite). Like I keep track of all topics in the whole world… J So you think you are the only one coming up with this idea? Besides, “M S solution” doesn’t work.   This is the result I get pre_value        current_value                             next_value 1                           1                           5 1                           5                           9 5                           9                           9   And I did nothing like you did here, where you posted a solution which you “thought” I should write http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=159262 So why are you yourself using ranking function when this was not allowed per your original email, and no cte? You use CTE in your link above, which do not work in SQL Server 2000. All this makes no sense to me, other than you are trying your best to once in a lifetime create a better performing query than me? After a few hours I get this email back. I don't fully understand it, but it's probably a language barrier. >>Like I keep track of all topics in the whole world… J So you think you are the only one coming up with this idea?<< You right, but do not think you are the first creator of this.   >>Besides, “M S Solution” doesn’t work. This is the result I get <<   Why you get so unimportant mistake? See this post to correct it: Posted 4/12/2011 8:22:23 PM >> So why are you yourself using ranking function when this was not allowed per your original email, and no cte? You use CTE in your link above, which do not work in SQL Server 2000. <<  Again, why you get some unimportant incompatibility? You offer that solution for current goals not me  >> All this makes no sense to me, other than you are trying your best to once in a lifetime create a better performing query than me? <<  No, I only wanted to know who you will solve it. Now I know you do not have a special solution. No problem. No problem for me either. So I just answered him I am not the first, and you are not the first to come up with this idea. So what is your problem? I am pretty sure other people have come up with the same idea before us. I used this technique all the way back to 2007, see http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=93911 Let's see if he returns...  He did! >> So what is your problem? << Nothing Thanks for all replies; maybe we have some competitions in future, maybe. Also I like you but you do not attend it. Your behavior with me is not friendly. Not any meeting… Regards //Peso

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  • My Big Break - this is my story and I am sticking to it ;)

    - by dbasnett
    The value of undertaking new and difficult tasks can have many wonderful consequences, don't you agree? Here is the story of my big break. Remember yours? During the mid 70's I was in the Navy and worked as a computer operator at the CNO's Command and Control computer system (WWMCCS) in the Washington Navy Yard. I was a tape ape, but knew that I wanted to be a systems programmer. One day the Lieutenant in charge of the OS group was running a test that required the development system to be re-booted, and I was politely hinting that I wanted out of computer operations. As he watched the accounting tape rewind to BOT and then search for where it had just been (severalminutes) he told me if I would fix "that" he would have me transferred. I couldn't say "Deal" fast enough. Up until then my programming experience had been on Edsger Dijkstra's favorite computer (sic), an IBM 1620. It took almost 6 months of learning the assembler for the Honeywell 6000 and finding the code responsible for rewinding the tape and then forwarding it. After much trial and error at o’dark thirty I succeeded. The tape barely moved and my “patch” was later adopted by many other sites. Lieutenant Jack Cowan kept his promise and I have gone on to have a varied and enjoyable career. To Jack, and the rest of the crew (Ken, Stu, Neil, Tom, Silent W, Mr. Jacobs, Roy, Rocco, etc.) I’d like to thank you all.

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  • WebLogic and Java EE Roadmap and Strategy Session at OOW

    - by Ruma Sanyal
    If you are developing, managing or planning enterprise Java and business application deployments on Oracle WebLogic Server with Coherence or continue to have deployments of Oracle Application Server, then this session will give you the roadmap of how Oracle is evolving this infrastructure to be the next generation cloud application foundation for its customers. Mike Lehmann (aka Mr. WebLogic :), Senior Director of Product Management, will share Oracle's vision, product plans and roadmap for this server infrastructure and how it will be used in the rapidly maturing cloud infrastructure space. Attend this to help you make key decisions about running your enterprise applications on Oracle's enterprise Java server foundation. For more information about this and other WebLogic sessions, review the WebLogic Focus on document.  What you will learn? Learn the benefits of using WebLogic Server and Coherence in the cloud. Learn how Java EE 7 is going to change cloud development and deployment     Understand how to address large-scale infrastructures with WebLogic Server and Coherence     Details: Monday, 10/1; 1.45-2.45pm; Moscone West Room 2011  

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  • CEO Taken Captive in His Own Factory?

    - by Stephen Slade
    Last Friday was no ordinary day for Chip Starnes, the 42 year old factory owner of Specialty Medical Supplies in China. He recently announced movement of some of the production of their diabetes testing equipment from Beijing to Mumbai India.  Of the 110 employees at the facility, about 80 protested by blocking the doors and refusing to let Chip Starnes out of the facility.  He has been trapped in his office several days now.  The employees think the factory was closing but Mr. Starnes said it was not. Mis-information? Poor communications? Work-stoppage. This is a good example of supply chain disruption. Parked cars are blocking the entrance to the facility, front gates are chained close, the CEO a prisoner in his own factory. Chip Starnes was presented with documents to sign in Chinese indicating he would pay severance and other demands he did not understand, possibly bankrupting the company.    If you depend on supply from China and other foreign suppliers, how reliable are your sources? For example how are the shopfloor employee relations? Is it possible to predict these types of HR risks and plan around them? What are your contingencies? It's important to ask the right questions and hear good answers. Having tools in place to rapidly evaluate, assess and react to these disruptions are the keys to survival. Hear how leading organizations are reinforcing their supply chains and mitigating risk through technology with Oracle's latest release of Oracle Supply Chain Management. Source: WSJ pg.B1, June 25, 2013

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  • Rankings dropping after small URL-change WITH 301-redirect

    - by David
    Two weeks ago, we attempted to make the URLs of ca. 12 pages more search-engine friendly. We changed three things. 1. Make URLs more SEF from: /????-????/brandname.html (meaning: /aircon-price/daikin.html to: /????-brandnameinenglish-brandnameinthai.html We set up 301-redirects from the old to the new URLs. You can find an example and the link to our page here: http://bit.ly/XRoTOK There are no direct external links to the old URLs. 2. Added text to img-links from homepage to brand-pages Before those changes, we only linked to those brands with a picture, so we added some text under the picture. You can see that here, in the left submenu: http://bit.ly/XRpfoF 3. Minor changes to Title, h1-Tags, Meta Description, etc. Only minor changes, to better match the on-site optimization with targeted keywords. For example, before we used full brand names, after we used what was really searched for: from: Mitsubishi Electric Mr. Slim to: ???? Mitsubishi (means: Aircon Mitsubishi) Three days after these changes, we noticed a heavy drop (80% loss in non-paid search traffic) in rankings and traffic for those pages, and also for all pages which are sub-categorized. Rankings for all keywords not affected by the changes stayed the same. Any ideas, what happened, and how we can regain our old rankings? What we already did, was submitting a new sitemap. Help much appreciated. Best regards, David

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  • Today's Links (6/23/2011)

    - by Bob Rhubart
    Lydia Smyers interviews Justin "Mr. OTN" Kestelyn on the Oracle ACE Program Justin Kestelyn describes the Oracle ACE program, what it means to the developer community, and how to get involved. Incremental Essbase Metadata Imports Now Possible with OBIEE 11g | Mark Rittman "So, how does this work, and how easy is it to implement?" asks Oracle ACE Director Mark Rittman, and then he dives in to find out. ORACLENERD: The Podcast Oracle ACE Chet "ORACLENERD" Justice recounts his brush with stardom on Christian Screen's The Art of Business Intelligence podcast. Bay Area Coherence Special Interest Group Next Meeting July 21, 2011 | Cristóbal Soto Soto shares information on next month's Bay Area Coherence SIG shindig. New Cloud Security Book: Securing the Cloud by Vic Winkler | Dr Cloud's Flying Software Circus "Securing the Cloud is the most useful and informative about all aspects of cloud security," says Harry "Dr. Cloud" Foxwell. Oracle MDM Maturity Model | David Butler "The model covers maturity levels around five key areas: Profiling data sources; Defining a data strategy; Defining a data consolidation plan; Data maintenance; and Data utilization," says Butler. Integrating Strategic Planning for Cloud and SOA | David Sprott "Full blown Cloud adoption implies mature and sophisticated SOA implementation and impacts many business processes," says Sprott.

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  • Large enterprise application - clients wish to use duplicate e-mails addresses?

    - by Alex Key
    I'd like to know people's opinions, reactions to clients and technical work arounds (if applicable), to the issue of an enterprise application where a client wishes to use duplicate e-mail addresses? To clarify, when I say duplicate e-mail addresses I mean within the same client system, having multiple users that have the same e-mail address. So not just using generic e-mail addresses but using the e-mail address of another user. e.g. Bob Jenkins: [email protected] James Jeffery: [email protected] Context To give this some further context, in the e-learning sector it is common that although all staff in an organisation must complete e-learning - they may not have their own e-mail address so they choose to use their managers e-mail address. Albeit against good practice in public sites... it's a requirement we've over and over again where an organisation is split between office based staff and perhaps e.g. staff in a warehouse. Where problem lies Mr Steak, good point, the problem lies in password resets and perhaps in situations where semi-personal information could be sent (not confidential enough to worry about the insecurities of email). Perhaps reminders for specific system actions, which would be confusing for the unintended party to see (if perhaps misreading the e-mail's intended recipient) Possible solutions System knowing the difference between a "for the attention of" and direct to the person e-mails, including this in the body text. Using alternative communication such as SMS Simply not having e-mails sent to people who are not the intended recipient. Providing an e-mail service ourselfs (not really viable for a corporate IT dept) Thoughts?

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  • Oracle Solaris ??????? #2 ??!

    - by Kazuyuki.Sato
    ??!! Oracle Solaris ??????? #1 ????????????????? ??????????!???????????????????????????????????????????????????????????????????? ?????????????????? ?????????????????????????????#1 ??????????Mr. Solaris ????? Solaris ???????????????????????????? 2 ??????Oracle Solaris ??????? #2???????????????????????????! ??????????????????????????:ATND(????)????????? ATND ??? ???????????????????????????????????????????? ???????????????????????????????????? ???????Oracle Solaris ??????? # 2???2012/04/20 (?) 18:30 ????? ??????????????Oracle Solaris 11?????·????·???? 1 ????????????????????????Oracle Solaris 11?????·????·???? 1 ? ?????????????ZFS ?????????????????? ????? 1 ??Solaris ????????????????ZFS ?????????????????? Solaris 11 ???? ZFS ????????? ???????ZFS??????????????! ????? 2 ?????????????????? “COMSTAR”????????????????????????????????????????? ????????????????????????????????! – Solaris 3 ???????! ???????????????????ZFS ????????????????????????????ZFS, dedup ??????????! ???????????????????????????????????????????????? ATND ????????! Oracle Solaris ??????? # 2 http://atnd.org/event/solarisns2 ??????????????????? ??????????????????Solaris 11 ??? #1 ? 2 ??!

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  • Using an alternate JSON Serializer in ASP.NET Web API

    - by Rick Strahl
    The new ASP.NET Web API that Microsoft released alongside MVC 4.0 Beta last week is a great framework for building REST and AJAX APIs. I've been working with it for quite a while now and I really like the way it works and the complete set of features it provides 'in the box'. It's about time that Microsoft gets a decent API for building generic HTTP endpoints into the framework. DataContractJsonSerializer sucks As nice as Web API's overall design is one thing still sucks: The built-in JSON Serialization uses the DataContractJsonSerializer which is just too limiting for many scenarios. The biggest issues I have with it are: No support for untyped values (object, dynamic, Anonymous Types) MS AJAX style Date Formatting Ugly serialization formats for types like Dictionaries To me the most serious issue is dealing with serialization of untyped objects. I have number of applications with AJAX front ends that dynamically reformat data from business objects to fit a specific message format that certain UI components require. The most common scenario I have there are IEnumerable query results from a database with fields from the result set rearranged to fit the sometimes unconventional formats required for the UI components (like jqGrid for example). Creating custom types to fit these messages seems like overkill and projections using Linq makes this much easier to code up. Alas DataContractJsonSerializer doesn't support it. Neither does DataContractSerializer for XML output for that matter. What this means is that you can't do stuff like this in Web API out of the box:public object GetAnonymousType() { return new { name = "Rick", company = "West Wind", entered= DateTime.Now }; } Basically anything that doesn't have an explicit type DataContractJsonSerializer will not let you return. FWIW, the same is true for XmlSerializer which also doesn't work with non-typed values for serialization. The example above is obviously contrived with a hardcoded object graph, but it's not uncommon to get dynamic values returned from queries that have anonymous types for their result projections. Apparently there's a good possibility that Microsoft will ship Json.NET as part of Web API RTM release.  Scott Hanselman confirmed this as a footnote in his JSON Dates post a few days ago. I've heard several other people from Microsoft confirm that Json.NET will be included and be the default JSON serializer, but no details yet in what capacity it will show up. Let's hope it ends up as the default in the box. Meanwhile this post will show you how you can use it today with the beta and get JSON that matches what you should see in the RTM version. What about JsonValue? To be fair Web API DOES include a new JsonValue/JsonObject/JsonArray type that allow you to address some of these scenarios. JsonValue is a new type in the System.Json assembly that can be used to build up an object graph based on a dictionary. It's actually a really cool implementation of a dynamic type that allows you to create an object graph and spit it out to JSON without having to create .NET type first. JsonValue can also receive a JSON string and parse it without having to actually load it into a .NET type (which is something that's been missing in the core framework). This is really useful if you get a JSON result from an arbitrary service and you don't want to explicitly create a mapping type for the data returned. For serialization you can create an object structure on the fly and pass it back as part of an Web API action method like this:public JsonValue GetJsonValue() { dynamic json = new JsonObject(); json.name = "Rick"; json.company = "West Wind"; json.entered = DateTime.Now; dynamic address = new JsonObject(); address.street = "32 Kaiea"; address.zip = "96779"; json.address = address; dynamic phones = new JsonArray(); json.phoneNumbers = phones; dynamic phone = new JsonObject(); phone.type = "Home"; phone.number = "808 123-1233"; phones.Add(phone); phone = new JsonObject(); phone.type = "Home"; phone.number = "808 123-1233"; phones.Add(phone); //var jsonString = json.ToString(); return json; } which produces the following output (formatted here for easier reading):{ name: "rick", company: "West Wind", entered: "2012-03-08T15:33:19.673-10:00", address: { street: "32 Kaiea", zip: "96779" }, phoneNumbers: [ { type: "Home", number: "808 123-1233" }, { type: "Mobile", number: "808 123-1234" }] } If you need to build a simple JSON type on the fly these types work great. But if you have an existing type - or worse a query result/list that's already formatted JsonValue et al. become a pain to work with. As far as I can see there's no way to just throw an object instance at JsonValue and have it convert into JsonValue dictionary. It's a manual process. Using alternate Serializers in Web API So, currently the default serializer in WebAPI is DataContractJsonSeriaizer and I don't like it. You may not either, but luckily you can swap the serializer fairly easily. If you'd rather use the JavaScriptSerializer built into System.Web.Extensions or Json.NET today, it's not too difficult to create a custom MediaTypeFormatter that uses these serializers and can replace or partially replace the native serializer. Here's a MediaTypeFormatter implementation using the ASP.NET JavaScriptSerializer:using System; using System.Net.Http.Formatting; using System.Threading.Tasks; using System.Web.Script.Serialization; using System.Json; using System.IO; namespace Westwind.Web.WebApi { public class JavaScriptSerializerFormatter : MediaTypeFormatter { public JavaScriptSerializerFormatter() { SupportedMediaTypes.Add(new System.Net.Http.Headers.MediaTypeHeaderValue("application/json")); } protected override bool CanWriteType(Type type) { // don't serialize JsonValue structure use default for that if (type == typeof(JsonValue) || type == typeof(JsonObject) || type== typeof(JsonArray) ) return false; return true; } protected override bool CanReadType(Type type) { if (type == typeof(IKeyValueModel)) return false; return true; } protected override System.Threading.Tasks.Taskobject OnReadFromStreamAsync(Type type, System.IO.Stream stream, System.Net.Http.Headers.HttpContentHeaders contentHeaders, FormatterContext formatterContext) { var task = Taskobject.Factory.StartNew(() = { var ser = new JavaScriptSerializer(); string json; using (var sr = new StreamReader(stream)) { json = sr.ReadToEnd(); sr.Close(); } object val = ser.Deserialize(json,type); return val; }); return task; } protected override System.Threading.Tasks.Task OnWriteToStreamAsync(Type type, object value, System.IO.Stream stream, System.Net.Http.Headers.HttpContentHeaders contentHeaders, FormatterContext formatterContext, System.Net.TransportContext transportContext) { var task = Task.Factory.StartNew( () = { var ser = new JavaScriptSerializer(); var json = ser.Serialize(value); byte[] buf = System.Text.Encoding.Default.GetBytes(json); stream.Write(buf,0,buf.Length); stream.Flush(); }); return task; } } } Formatter implementation is pretty simple: You override 4 methods to tell which types you can handle and then handle the input or output streams to create/parse the JSON data. Note that when creating output you want to take care to still allow JsonValue/JsonObject/JsonArray types to be handled by the default serializer so those objects serialize properly - if you let either JavaScriptSerializer or JSON.NET handle them they'd try to render the dictionaries which is very undesirable. If you'd rather use Json.NET here's the JSON.NET version of the formatter:// this code requires a reference to JSON.NET in your project #if true using System; using System.Net.Http.Formatting; using System.Threading.Tasks; using System.Web.Script.Serialization; using System.Json; using Newtonsoft.Json; using System.IO; using Newtonsoft.Json.Converters; namespace Westwind.Web.WebApi { public class JsonNetFormatter : MediaTypeFormatter { public JsonNetFormatter() { SupportedMediaTypes.Add(new System.Net.Http.Headers.MediaTypeHeaderValue("application/json")); } protected override bool CanWriteType(Type type) { // don't serialize JsonValue structure use default for that if (type == typeof(JsonValue) || type == typeof(JsonObject) || type == typeof(JsonArray)) return false; return true; } protected override bool CanReadType(Type type) { if (type == typeof(IKeyValueModel)) return false; return true; } protected override System.Threading.Tasks.Taskobject OnReadFromStreamAsync(Type type, System.IO.Stream stream, System.Net.Http.Headers.HttpContentHeaders contentHeaders, FormatterContext formatterContext) { var task = Taskobject.Factory.StartNew(() = { var settings = new JsonSerializerSettings() { NullValueHandling = NullValueHandling.Ignore, }; var sr = new StreamReader(stream); var jreader = new JsonTextReader(sr); var ser = new JsonSerializer(); ser.Converters.Add(new IsoDateTimeConverter()); object val = ser.Deserialize(jreader, type); return val; }); return task; } protected override System.Threading.Tasks.Task OnWriteToStreamAsync(Type type, object value, System.IO.Stream stream, System.Net.Http.Headers.HttpContentHeaders contentHeaders, FormatterContext formatterContext, System.Net.TransportContext transportContext) { var task = Task.Factory.StartNew( () = { var settings = new JsonSerializerSettings() { NullValueHandling = NullValueHandling.Ignore, }; string json = JsonConvert.SerializeObject(value, Formatting.Indented, new JsonConverter[1] { new IsoDateTimeConverter() } ); byte[] buf = System.Text.Encoding.Default.GetBytes(json); stream.Write(buf,0,buf.Length); stream.Flush(); }); return task; } } } #endif   One advantage of the Json.NET serializer is that you can specify a few options on how things are formatted and handled. You get null value handling and you can plug in the IsoDateTimeConverter which is nice to product proper ISO dates that I would expect any Json serializer to output these days. Hooking up the Formatters Once you've created the custom formatters you need to enable them for your Web API application. To do this use the GlobalConfiguration.Configuration object and add the formatter to the Formatters collection. Here's what this looks like hooked up from Application_Start in a Web project:protected void Application_Start(object sender, EventArgs e) { // Action based routing (used for RPC calls) RouteTable.Routes.MapHttpRoute( name: "StockApi", routeTemplate: "stocks/{action}/{symbol}", defaults: new { symbol = RouteParameter.Optional, controller = "StockApi" } ); // WebApi Configuration to hook up formatters and message handlers // optional RegisterApis(GlobalConfiguration.Configuration); } public static void RegisterApis(HttpConfiguration config) { // Add JavaScriptSerializer formatter instead - add at top to make default //config.Formatters.Insert(0, new JavaScriptSerializerFormatter()); // Add Json.net formatter - add at the top so it fires first! // This leaves the old one in place so JsonValue/JsonObject/JsonArray still are handled config.Formatters.Insert(0, new JsonNetFormatter()); } One thing to remember here is the GlobalConfiguration object which is Web API's static configuration instance. I think this thing is seriously misnamed given that GlobalConfiguration could stand for anything and so is hard to discover if you don't know what you're looking for. How about WebApiConfiguration or something more descriptive? Anyway, once you know what it is you can use the Formatters collection to insert your custom formatter. Note that I insert my formatter at the top of the list so it takes precedence over the default formatter. I also am not removing the old formatter because I still want JsonValue/JsonObject/JsonArray to be handled by the default serialization mechanism. Since they process in sequence and I exclude processing for these types JsonValue et al. still get properly serialized/deserialized. Summary Currently DataContractJsonSerializer in Web API is a pain, but at least we have the ability with relatively limited effort to replace the MediaTypeFormatter and plug in our own JSON serializer. This is useful for many scenarios - if you have existing client applications that used MVC JsonResult or ASP.NET AJAX results from ASMX AJAX services you can plug in the JavaScript serializer and get exactly the same serializer you used in the past so your results will be the same and don't potentially break clients. JSON serializers do vary a bit in how they serialize some of the more complex types (like Dictionaries and dates for example) and so if you're migrating it might be helpful to ensure your client code doesn't break when you switch to ASP.NET Web API. Going forward it looks like Microsoft is planning on plugging in Json.Net into Web API and make that the default. I think that's an awesome choice since Json.net has been around forever, is fast and easy to use and provides a ton of functionality as part of this great library. I just wish Microsoft would have figured this out sooner instead of now at the last minute integrating with it especially given that Json.Net has a similar set of lower level JSON objects JsonValue/JsonObject etc. which now will end up being duplicated by the native System.Json stuff. It's not like we don't already have enough confusion regarding which JSON serializer to use (JavaScriptSerializer, DataContractJsonSerializer, JsonValue/JsonObject/JsonArray and now Json.net). For years I've been using my own JSON serializer because the built in choices are both limited. However, with an official encorsement of Json.Net I'm happily moving on to use that in my applications. Let's see and hope Microsoft gets this right before ASP.NET Web API goes gold.© Rick Strahl, West Wind Technologies, 2005-2012Posted in Web Api  AJAX  ASP.NET   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Yet Another ASP.NET MVC CRUD Tutorial

    - by Ricardo Peres
    I know that I have not posted much on MVC, mostly because I don’t use it on my daily life, but since I find it so interesting, and since it is gaining such popularity, I will be talking about it much more. This time, it’s about the most basic of scenarios: CRUD. Although there are several ASP.NET MVC tutorials out there that cover ordinary CRUD operations, I couldn’t find any that would explain how we can have also AJAX, optimistic concurrency control and validation, using Entity Framework Code First, so I set out to write one! I won’t go into explaining what is MVC, Code First or optimistic concurrency control, or AJAX, I assume you are all familiar with these concepts by now. Let’s consider an hypothetical use case, products. For simplicity, we only want to be able to either view a single product or edit this product. First, we need our model: 1: public class Product 2: { 3: public Product() 4: { 5: this.Details = new HashSet<OrderDetail>(); 6: } 7:  8: [Required] 9: [StringLength(50)] 10: public String Name 11: { 12: get; 13: set; 14: } 15:  16: [Key] 17: [ScaffoldColumn(false)] 18: [DatabaseGenerated(DatabaseGeneratedOption.Identity)] 19: public Int32 ProductId 20: { 21: get; 22: set; 23: } 24:  25: [Required] 26: [Range(1, 100)] 27: public Decimal Price 28: { 29: get; 30: set; 31: } 32:  33: public virtual ISet<OrderDetail> Details 34: { 35: get; 36: protected set; 37: } 38:  39: [Timestamp] 40: [ScaffoldColumn(false)] 41: public Byte[] RowVersion 42: { 43: get; 44: set; 45: } 46: } Keep in mind that this is a simple scenario. Let’s see what we have: A class Product, that maps to a product record on the database; A product has a required (RequiredAttribute) Name property which can contain up to 50 characters (StringLengthAttribute); The product’s Price must be a decimal value between 1 and 100 (RangeAttribute); It contains a set of order details, for each time that it has been ordered, which we will not talk about (Details); The record’s primary key (mapped to property ProductId) comes from a SQL Server IDENTITY column generated by the database (KeyAttribute, DatabaseGeneratedAttribute); The table uses a SQL Server ROWVERSION (previously known as TIMESTAMP) column for optimistic concurrency control mapped to property RowVersion (TimestampAttribute). Then we will need a controller for viewing product details, which will located on folder ~/Controllers under the name ProductController: 1: public class ProductController : Controller 2: { 3: [HttpGet] 4: public ViewResult Get(Int32 id = 0) 5: { 6: if (id != 0) 7: { 8: using (ProductContext ctx = new ProductContext()) 9: { 10: return (this.View("Single", ctx.Products.Find(id) ?? new Product())); 11: } 12: } 13: else 14: { 15: return (this.View("Single", new Product())); 16: } 17: } 18: } If the requested product does not exist, or one was not requested at all, one with default values will be returned. I am using a view named Single to display the product’s details, more on that later. As you can see, it delegates the loading of products to an Entity Framework context, which is defined as: 1: public class ProductContext: DbContext 2: { 3: public DbSet<Product> Products 4: { 5: get; 6: set; 7: } 8: } Like I said before, I’ll keep it simple for now, only aggregate root Product is available. The controller will use the standard routes defined by the Visual Studio ASP.NET MVC 3 template: 1: routes.MapRoute( 2: "Default", // Route name 3: "{controller}/{action}/{id}", // URL with parameters 4: new { controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults 5: ); Next, we need a view for displaying the product details, let’s call it Single, and have it located under ~/Views/Product: 1: <%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<Product>" %> 2: <!DOCTYPE html> 3:  4: <html> 5: <head runat="server"> 6: <title>Product</title> 7: <script src="/Scripts/jquery-1.7.2.js" type="text/javascript"></script> 1:  2: <script src="/Scripts/jquery-ui-1.8.19.js" type="text/javascript"> 1: </script> 2: <script src="/Scripts/jquery.unobtrusive-ajax.js" type="text/javascript"> 1: </script> 2: <script src="/Scripts/jquery.validate.js" type="text/javascript"> 1: </script> 2: <script src="/Scripts/jquery.validate.unobtrusive.js" type="text/javascript"> 1: </script> 2: <script type="text/javascript"> 3: function onFailure(error) 4: { 5: } 6:  7: function onComplete(ctx) 8: { 9: } 10:  11: </script> 8: </head> 9: <body> 10: <div> 11: <% 1: : this.Html.ValidationSummary(false) %> 12: <% 1: using (this.Ajax.BeginForm("Edit", "Product", new AjaxOptions{ HttpMethod = FormMethod.Post.ToString(), OnSuccess = "onSuccess", OnFailure = "onFailure" })) { %> 13: <% 1: : this.Html.EditorForModel() %> 14: <input type="submit" name="submit" value="Submit" /> 15: <% 1: } %> 16: </div> 17: </body> 18: </html> Yes… I am using ASPX syntax… sorry about that!   I implemented an editor template for the Product class, which must be located on the ~/Views/Shared/EditorTemplates folder as file Product.ascx: 1: <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<Product>" %> 2: <div> 3: <%: this.Html.HiddenFor(model => model.ProductId) %> 4: <%: this.Html.HiddenFor(model => model.RowVersion) %> 5: <fieldset> 6: <legend>Product</legend> 7: <div class="editor-label"> 8: <%: this.Html.LabelFor(model => model.Name) %> 9: </div> 10: <div class="editor-field"> 11: <%: this.Html.TextBoxFor(model => model.Name) %> 12: <%: this.Html.ValidationMessageFor(model => model.Name) %> 13: </div> 14: <div class="editor-label"> 15: <%= this.Html.LabelFor(model => model.Price) %> 16: </div> 17: <div class="editor-field"> 18: <%= this.Html.TextBoxFor(model => model.Price) %> 19: <%: this.Html.ValidationMessageFor(model => model.Price) %> 20: </div> 21: </fieldset> 22: </div> One thing you’ll notice is, I am including both the ProductId and the RowVersion properties as hidden fields; they will come handy later or, so that we know what product and version we are editing. The other thing is the included JavaScript files: jQuery, jQuery UI and unobtrusive validations. Also, I am not using the Content extension method for translating relative URLs, because that way I would lose JavaScript intellisense for jQuery functions. OK, so, at this moment, I want to add support for AJAX and optimistic concurrency control. So I write a controller method like this: 1: [HttpPost] 2: [AjaxOnly] 3: [Authorize] 4: public JsonResult Edit(Product product) 5: { 6: if (this.TryValidateModel(product) == true) 7: { 8: using (BlogContext ctx = new BlogContext()) 9: { 10: Boolean success = false; 11:  12: ctx.Entry(product).State = (product.ProductId == 0) ? EntityState.Added : EntityState.Modified; 13:  14: try 15: { 16: success = (ctx.SaveChanges() == 1); 17: } 18: catch (DbUpdateConcurrencyException) 19: { 20: ctx.Entry(product).Reload(); 21: } 22:  23: return (this.Json(new { Success = success, ProductId = product.ProductId, RowVersion = Convert.ToBase64String(product.RowVersion) })); 24: } 25: } 26: else 27: { 28: return (this.Json(new { Success = false, ProductId = 0, RowVersion = String.Empty })); 29: } 30: } So, this method is only valid for HTTP POST requests (HttpPost), coming from AJAX (AjaxOnly, from MVC Futures), and from authenticated users (Authorize). It returns a JSON object, which is what you would normally use for AJAX requests, containing three properties: Success: a boolean flag; RowVersion: the current version of the ROWVERSION column as a Base-64 string; ProductId: the inserted product id, as coming from the database. If the product is new, it will be inserted into the database, and its primary key will be returned into the ProductId property. Success will be set to true; If a DbUpdateConcurrencyException occurs, it means that the value in the RowVersion property does not match the current ROWVERSION column value on the database, so the record must have been modified between the time that the page was loaded and the time we attempted to save the product. In this case, the controller just gets the new value from the database and returns it in the JSON object; Success will be false. Otherwise, it will be updated, and Success, ProductId and RowVersion will all have their values set accordingly. So let’s see how we can react to these situations on the client side. Specifically, we want to deal with these situations: The user is not logged in when the update/create request is made, perhaps the cookie expired; The optimistic concurrency check failed; All went well. So, let’s change our view: 1: <%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<Product>" %> 2: <%@ Import Namespace="System.Web.Security" %> 3:  4: <!DOCTYPE html> 5:  6: <html> 7: <head runat="server"> 8: <title>Product</title> 9: <script src="/Scripts/jquery-1.7.2.js" type="text/javascript"></script> 1:  2: <script src="/Scripts/jquery-ui-1.8.19.js" type="text/javascript"> 1: </script> 2: <script src="/Scripts/jquery.unobtrusive-ajax.js" type="text/javascript"> 1: </script> 2: <script src="/Scripts/jquery.validate.js" type="text/javascript"> 1: </script> 2: <script src="/Scripts/jquery.validate.unobtrusive.js" type="text/javascript"> 1: </script> 2: <script type="text/javascript"> 3: function onFailure(error) 4: { 5: window.alert('An error occurred: ' + error); 6: } 7:  8: function onSuccess(ctx) 9: { 10: if (typeof (ctx.Success) != 'undefined') 11: { 12: $('input#ProductId').val(ctx.ProductId); 13: $('input#RowVersion').val(ctx.RowVersion); 14:  15: if (ctx.Success == false) 16: { 17: window.alert('An error occurred while updating the entity: it may have been modified by third parties. Please try again.'); 18: } 19: else 20: { 21: window.alert('Saved successfully'); 22: } 23: } 24: else 25: { 26: if (window.confirm('Not logged in. Login now?') == true) 27: { 28: document.location.href = '<%: FormsAuthentication.LoginUrl %>?ReturnURL=' + document.location.pathname; 29: } 30: } 31: } 32:  33: </script> 10: </head> 11: <body> 12: <div> 13: <% 1: : this.Html.ValidationSummary(false) %> 14: <% 1: using (this.Ajax.BeginForm("Edit", "Product", new AjaxOptions{ HttpMethod = FormMethod.Post.ToString(), OnSuccess = "onSuccess", OnFailure = "onFailure" })) { %> 15: <% 1: : this.Html.EditorForModel() %> 16: <input type="submit" name="submit" value="Submit" /> 17: <% 1: } %> 18: </div> 19: </body> 20: </html> The implementation of the onSuccess function first checks if the response contains a Success property, if not, the most likely cause is the request was redirected to the login page (using Forms Authentication), because it wasn’t authenticated, so we navigate there as well, keeping the reference to the current page. It then saves the current values of the ProductId and RowVersion properties to their respective hidden fields. They will be sent on each successive post and will be used in determining if the request is for adding a new product or to updating an existing one. The only thing missing is the ability to insert a new product, after inserting/editing an existing one, which can be easily achieved using this snippet: 1: <input type="button" value="New" onclick="$('input#ProductId').val('');$('input#RowVersion').val('');"/> And that’s it.

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  • CLSF & CLK 2013 Trip Report by Jeff Liu

    - by jamesmorris
    This is a contributed post from Jeff Liu, lead XFS developer for the Oracle mainline Linux kernel team. Recently, I attended both the China Linux Storage and Filesystem workshop (CLSF), and the China Linux Kernel conference (CLK), which were held in Shanghai. Here are the highlights for both events. CLSF - 17th October XFS update (led by Jeff Liu) XFS keeps rapid progress with a lot of changes, especially focused on the infrastructure/performance improvements as well as  new feature development.  This can be reflected with a sample statistics among XFS/Ext4+JBD2/Btrfs via: # git diff --stat --minimal -C -M v3.7..v3.12-rc4 -- fs/xfs|fs/ext4+fs/jbd2|fs/btrfs XFS: 141 files changed, 27598 insertions(+), 19113 deletions(-) Ext4+JBD2: 39 files changed, 10487 insertions(+), 5454 deletions(-) Btrfs: 70 files changed, 19875 insertions(+), 8130 deletions(-) What made up those changes in XFS? Self-describing metadata(CRC32c). This is a new feature and it contributed about 70% code changes, it can be enabled via `mkfs.xfs -m crc=1 /dev/xxx` for v5 superblock. Transaction log space reservation improvements. With this change, we can calculate the log space reservation at mount time rather than runtime to reduce the the CPU overhead. User namespace support. So both XFS and USERNS can be enabled on kernel configuration begin from Linux 3.10. Thanks Dwight Engen's efforts for this thing. Split project/group quota inodes. Originally, project quota can not be enabled with group quota at the same time because they were share the same quota file inode, now it works but only for v5 super block. i.e, CRC enabled. CONFIG_XFS_WARN, an new lightweight runtime debugger which can be deployed in production environment. Readahead log object recovery, this change can speed up the log replay progress significantly. Speculative preallocation inode tracking, clearing and throttling. The main purpose is to deal with inodes with post-EOF space due to speculative preallocation, support improved quota management to free up a significant amount of unwritten space when at or near EDQUOT. It support backgroup scanning which occurs on a longish interval(5 mins by default, tunable), and on-demand scanning/trimming via ioctl(2). Bitter arguments ensued from this session, especially for the comparison between Ext4 and Btrfs in different areas, I have to spent a whole morning of the 1st day answering those questions. We basically agreed on XFS is the best choice in Linux nowadays because: Stable, XFS has a good record in stability in the past 10 years. Fengguang Wu who lead the 0-day kernel test project also said that he has observed less error than other filesystems in the past 1+ years, I own it to the XFS upstream code reviewer, they always performing serious code review as well as testing. Good performance for large/small files, XFS does not works very well for small files has already been an old story for years. Best choice (maybe) for distributed PB filesystems. e.g, Ceph recommends delopy OSD daemon on XFS because Ext4 has limited xattr size. Best choice for large storage (>16TB). Ext4 does not support a single file more than around 15.95TB. Scalability, any objection to XFS is best in this point? :) XFS is better to deal with transaction concurrency than Ext4, why? The maximum size of the log in XFS is 2038MB compare to 128MB in Ext4. Misc. Ext4 is widely used and it has been proved fast/stable in various loads and scenarios, XFS just need more customers, and Btrfs is still on the road to be a manhood. Ceph Introduction (Led by Li Wang) This a hot topic.  Li gave us a nice introduction about the design as well as their current works. Actually, Ceph client has been included in Linux kernel since 2.6.34 and supported by Openstack since Folsom but it seems that it has not yet been widely deployment in production environment. Their major work is focus on the inline data support to separate the metadata and data storage, reduce the file access time, i.e, a file access need communication twice, fetch the metadata from MDS and then get data from OSD, and also, the small file access is limited by the network latency. The solution is, for the small files they would like to store the data at metadata so that when accessing a small file, the metadata server can push both metadata and data to the client at the same time. In this way, they can reduce the overhead of calculating the data offset and save the communication to OSD. For this feature, they have only run some small scale testing but really saw noticeable improvements. Test environment: Intel 2 CPU 12 Core, 64GB RAM, Ubuntu 12.04, Ceph 0.56.6 with 200GB SATA disk, 15 OSD, 1 MDS, 1 MON. The sequence read performance for 1K size files improved about 50%. I have asked Li and Zheng Yan (the core developer of Ceph, who also worked on Btrfs) whether Ceph is really stable and can be deployed at production environment for large scale PB level storage, but they can not give a positive answer, looks Ceph even does not spread over Dreamhost (subject to confirmation). From Li, they only deployed Ceph for a small scale storage(32 nodes) although they'd like to try 6000 nodes in the future. Improve Linux swap for Flash storage (led by Shaohua Li) Because of high density, low power and low price, flash storage (SSD) is a good candidate to partially replace DRAM. A quick answer for this is using SSD as swap. But Linux swap is designed for slow hard disk storage, so there are a lot of challenges to efficiently use SSD for swap. SWAPOUT swap_map scan swap_map is the in-memory data structure to track swap disk usage, but it is a slow linear scan. It will become a bottleneck while finding many adjacent pages in the use of SSD. Shaohua Li have changed it to a cluster(128K) list, resulting in O(1) algorithm. However, this apporoach needs restrictive cluster alignment and only enabled for SSD. IO pattern In most cases, the swap io is in interleaved pattern because of mutiple reclaimers or a free cluster is shared by all reclaimers. Even though block layer can merge interleaved IO to some extent, but we cannot count on it completely. Hence the per-cpu cluster is added base on the previous change, it can help reclaimer do sequential IO and the block layer will be easier to merge IO. TLB flush: If we're reclaiming one active page, we should first move the page from active lru list to inactive lru list, and then reclaim the page from inactive lru to swap it out. During the process, we need to clear PTE twice: first is 'A'(ACCESS) bit, second is 'P'(PRESENT) bit. Processors need to send lots of ipi which make the TLB flush really expensive. Some works have been done to improve this, including rework smp_call_functiom_many() or remove the first TLB flush in x86, but there still have some arguments here and only parts of works have been pushed to mainline. SWAPIN: Page fault does iodepth=1 sync io, but it's a little waste if only issue a page size's IO. The obvious solution is doing swap readahead. But the current in-kernel swap readahead is arbitary(always 8 pages), and it always doesn't perform well for both random and sequential access workload. Shaohua introduced a new flag for madvise(MADV_WILLNEED) to do swap prefetch, so the changes happen in userspace API and leave the in-kernel readahead unchanged(but I think some improvement can also be done here). SWAP discard As we know, discard is important for SSD write throughout, but the current swap discard implementation is synchronous. He changed it to async discard which allow discard and write run in the same time. Meanwhile, the unit of discard is also optimized to cluster. Misc: lock contention For many concurrent swapout and swapin , the lock contention such as anon_vma or swap_lock is high, so he changed the swap_lock to a per-swap lock. But there still have some lock contention in very high speed SSD because of swapcache address_space lock. Zproject (led by Bob Liu) Bob gave us a very nice introduction about the current memory compression status. Now there are 3 projects(zswap/zram/zcache) which all aim at smooth swap IO storm and promote performance, but they all have their own pros and cons. ZSWAP It is implemented based on frontswap API and it uses a dynamic allocater named Zbud to allocate free pages. Zbud means pairs of zpages are "buddied" and it can only store at most two compressed pages in one page frame, so the max compress ratio is 50%. Each page frame is lru-linked and can do shink in memory pressure. If the compressed memory pool reach its limitation, shink or reclaim happens. It decompress the page frame into two new allocated pages and then write them to real swap device, but it can fail when allocating the two pages. ZRAM Acts as a compressed ramdisk and used as swap device, and it use zsmalloc as its allocator which has high density but may have fragmentation issues. Besides, page reclaim is hard since it will need more pages to uncompress and free just one page. ZRAM is preferred by embedded system which may not have any real swap device. Now both ZRAM and ZSWAP are in driver/staging tree, and in the mm community there are some disscussions of merging ZRAM into ZSWAP or viceversa, but no agreement yet. ZCACHE Handles file page compression but it is removed out of staging recently. From industry (led by Tang Jie, LSI) An LSI engineer introduced several new produces to us. The first is raid5/6 cards that it use full stripe writes to improve performance. The 2nd one he introduced is SandForce flash controller, who can understand data file types (data entropy) to reduce write amplification (WA) for nearly all writes. It's called DuraWrite and typical WA is 0.5. What's more, if enable its Dynamic Logical Capacity function module, the controller can do data compression which is transparent to upper layer. LSI testing shows that with this virtual capacity enables 1x TB drive can support up to 2x TB capacity, but the application must monitor free flash space to maintain optimal performance and to guard against free flash space exhaustion. He said the most useful application is for datebase. Another thing I think it's worth to mention is that a NV-DRAM memory in NMR/Raptor which is directly exposed to host system. Applications can directly access the NV-DRAM via a memory address - using standard system call mmap(). He said that it is very useful for database logging now. This kind of NVM produces are beginning to appear in recent years, and it is said that Samsung is building a research center in China for related produces. IMHO, NVM will bring an effect to current os layer especially on file system, e.g. its journaling may need to redesign to fully utilize these nonvolatile memory. OCFS2 (led by Canquan Shen) Without a doubt, HuaWei is the biggest contributor to OCFS2 in the past two years. They have posted 46 upstream patches and 39 patches have been merged. Their current project is based on 32/64 nodes cluster, but they also tried 128 nodes at the experimental stage. The major work they are working is to support ATS (atomic test and set), it can be works with DLM at the same time. Looks this idea is inspired by the vmware VMFS locking, i.e, http://blogs.vmware.com/vsphere/2012/05/vmfs-locking-uncovered.html CLK - 18th October 2013 Improving Linux Development with Better Tools (Andi Kleen) This talk focused on how to find/solve bugs along with the Linux complexity growing. Generally, we can do this with the following kind of tools: Static code checkers tools. e.g, sparse, smatch, coccinelle, clang checker, checkpatch, gcc -W/LTO, stanse. This can help check a lot of things, simple mistakes, complex problems, but the challenges are: some are very slow, false positives, may need a concentrated effort to get false positives down. Especially, no static checker I found can follow indirect calls (“OO in C”, common in kernel): struct foo_ops { int (*do_foo)(struct foo *obj); } foo->do_foo(foo); Dynamic runtime checkers, e.g, thread checkers, kmemcheck, lockdep. Ideally all kernel code would come with a test suite, then someone could run all the dynamic checkers. Fuzzers/test suites. e.g, Trinity is a great tool, it finds many bugs, but needs manual model for each syscall. Modern fuzzers around using automatic feedback, but notfor kernel yet: http://taviso.decsystem.org/making_software_dumber.pdf Debuggers/Tracers to understand code, e.g, ftrace, can dump on events/oops/custom triggers, but still too much overhead in many cases to run always during debug. Tools to read/understand source, e.g, grep/cscope work great for many cases, but do not understand indirect pointers (OO in C model used in kernel), give us all “do_foo” instances: struct foo_ops { int (*do_foo)(struct foo *obj); } = { .do_foo = my_foo }; foo>do_foo(foo); That would be great to have a cscope like tool that understands this based on types/initializers XFS: The High Performance Enterprise File System (Jeff Liu) [slides] I gave a talk for introducing the disk layout, unique features, as well as the recent changes.   The slides include some charts to reflect the performances between XFS/Btrfs/Ext4 for small files. About a dozen users raised their hands when I asking who has experienced with XFS. I remembered that when I asked the same question in LinuxCon/Japan, only 3 people raised their hands, but they are Chris Mason, Ric Wheeler, and another attendee. The attendee questions were mainly focused on stability, and comparison with other file systems. Linux Containers (Feng Gao) The speaker introduced us that the purpose for those kind of namespaces, include mount/UTS/IPC/Network/Pid/User, as well as the system API/ABI. For the userspace tools, He mainly focus on the Libvirt LXC rather than us(LXC). Libvirt LXC is another userspace container management tool, implemented as one type of libvirt driver, it can manage containers, create namespace, create private filesystem layout for container, Create devices for container and setup resources controller via cgroup. In this talk, Feng also mentioned another two possible new namespaces in the future, the 1st is the audit, but not sure if it should be assigned to user namespace or not. Another is about syslog, but the question is do we really need it? In-memory Compression (Bob Liu) Same as CLSF, a nice introduction that I have already mentioned above. Misc There were some other talks related to ACPI based memory hotplug, smart wake-affinity in scheduler etc., but my head is not big enough to record all those things. -- Jeff Liu

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  • Upload Certificate and Key to RUEI in order to decrypt SSL traffic

    - by stefan.thieme(at)oracle.com
    So you want to monitor encrypted traffic with your RUEI collector ?Actually this is an easy thing if you follow the lines below...I will start out with creating a pair of snakeoil (so called self-signed) certificate and key with the make-ssl-cert tool which comes pre-packaged with apache only for the purpose of this example.$ sudo make-ssl-cert generate-default-snakeoil$ sudo ls -l /etc/ssl/certs/ssl-cert-snakeoil.pem /etc/ssl/private/ssl-cert-snakeoil.key-rw-r--r-- 1 root root     615 2010-06-07 10:03 /etc/ssl/certs/ssl-cert-snakeoil.pem-rw-r----- 1 root ssl-cert 891 2010-06-07 10:03 /etc/ssl/private/ssl-cert-snakeoil.keyRUEI Configuration of Security SSL Keys You will most likely get these two files from your Certificate Authority (CA) and/or your system administrators should be able to extract this from your WebServer or LoadBalancer handling SSL encryption for your infrastructure.Now let's look at the content of these two files, the certificate (apache assumes this is in PEM format) is called a public key and the private key is used by the apache server to encrypt traffic for a client using the certificate to initiate the SSL connection with the server.In case you already know that these two match, you simply have to paste them in one text file and upload this text file to your RUEI instance.$ sudo cat /etc/ssl/certs/ssl-cert-snakeoil.pem /etc/ssl/private/ssl-cert-snakeoil.key > /tmp/ruei.cert_and_key$ sudo cat /tmp/ruei.cert_and_key -----BEGIN CERTIFICATE----- MIIBmTCCAQICCQD7O3XXwVilWzANBgkqhkiG9w0BAQUFADARMQ8wDQYDVQQDEwZ1 YnVudHUwHhcNMTAwNjA3MDgwMzUzWhcNMjAwNjA0MDgwMzUzWjARMQ8wDQYDVQQD EwZ1YnVudHUwgZ8wDQYJKoZIhvcNAQEBBQADgY0AMIGJAoGBALbs+JnI+p+K7Iqa SQZdnYBxOpdRH0/9jt1QKvmH68v81h9+f1Z2rVR7Zrd/l+ruE3H9VvuzxMlKuMH7 qBX/gmjDZTlj9WJM+zc0tSk+e2udy9he20lGzTxv0vaykJkuKcvSWNk4WE9NuAdg IHZvjKgoTSVmvM1ApMCg69nyOy97AgMBAAEwDQYJKoZIhvcNAQEFBQADgYEAk2rv VEkxR1qPSpJiudDuGUHtWKBKWiWbmSwI3REZT+0vG+YDG5a55NdxgRk3zhQntqF7 gNYjKxblBByBpY7W0ci00kf7kFgvXWMeU96NSQJdnid/YxzQYn0dGL2rSh1dwdPN NPQlNSfnEQ1yxFevR7aRdCqTbTXU3mxi8YaSscE= -----END CERTIFICATE----- -----BEGIN RSA PRIVATE KEY----- MIICXgIBAAKBgQC27PiZyPqfiuyKmkkGXZ2AcTqXUR9P/Y7dUCr5h+vL/NYffn9W dq1Ue2a3f5fq7hNx/Vb7s8TJSrjB+6gV/4Jow2U5Y/ViTPs3NLUpPntrncvYXttJ Rs08b9L2spCZLinL0ljZOFhPTbgHYCB2b4yoKE0lZrzNQKTAoOvZ8jsvewIDAQAB AoGBAJ7LCWeeUwnKNFqBYmD3RTFpmX4furnal3lBDX0945BZtJr0WZ/6N679zIYA aiVTdGfgjvDC9lHy3n3uctRd0Jqdh2QoSSxNBhq5elIApNIIYzu7w/XI/VhGcDlA b6uadURQEC2q+M8YYjw3mwR2omhCWlHIViOHe/9T8jfP/8pxAkEA7k39WRcQildH DFKcj7gurqlkElHysacMTFWf0ZDTEUS6bdkmNXwK6mH63BlmGLrYAP5AMgKgeDf8 D+WRfv8YKQJBAMSCQ7UGDN3ysyfIIrdc1RBEAk4BOrKHKtD5Ux0z5lcQkaCYrK8J DuSldreN2yOhS99/S4CRWmGkTj04wRSnjwMCQQCaR5mW3QzTU4/m1XEQxsBKSdZE 2hMSmsCmhuSyK13Kl0FPLr/C7qyuc4KSjksABa8kbXaoKfUz/6LLs+ePXZ2JAkAv +mIPk5+WnQgS4XFgdYDrzL8HTpOHPSs+BHG/goltnnT/0ebvgXWqa5+1pyPm6h29 PrYveM2pY1Va6z1xDowDAkEAttfzAwAHz+FUhWQCmOBpvBuW/KhYWKZTMpvxFMSY YD5PH6NNyLfBx0J4nGPN5n/f6il0s9pzt3ko++/eUtWSnQ== -----END RSA PRIVATE KEY----- Simply click on the add new key and browse for the cert_and_key file on your desktop which you concatenated earlier using any text editor. You may need to add a passphrase in order to decrypt the RSA key in some cases (it should tell you BEGIN ENCRYPTED PRIVATE KEY in the header line). I will show you the success screen after uploading the certificate to RUEI. You may want to restart your collector once you have uploaded all the certificate/key pairs you want to use in order to make sure they get picked up asap.You should be able to see the number of SSL Connections rising in the Collector statistics screen below. The figures for decrypt errors should slowly go down and the usage figures for your encryption algortihm on the subsequent SSL Encryption screen should go up. You should be 100% sure everything works fine by now, otherwise see below to distinguish the remaining 1% from your 99% certainty.Verify Certificate and Key are matchingYou can compare the modulus of private key and public certificate and they should match in order for the key to fit the lock. You only want to make sure they both fit each other.We are actually interested only in the following details of the two files, which can be determined by using the -subject, -dates and -modulus command line switches instead of the complete -text output of the x509 certificate/rsa key contents.$ sudo openssl x509 -noout -subject -in /etc/ssl/certs/ssl-cert-snakeoil.pemsubject= /CN=ubuntu$ sudo openssl x509 -noout -dates -in /etc/ssl/certs/ssl-cert-snakeoil.pemnotBefore=Jun  7 08:03:53 2010 GMTnotAfter=Jun  4 08:03:53 2020 GMT$ sudo openssl x509 -noout -modulus -in /etc/ssl/certs/ssl-cert-snakeoil.pem Modulus=B6ECF899C8FA9F8AEC8A9A49065D9D80713A97511F4FFD8EDD502AF987EBCBFCD61F7E7F5676AD547B66B77F97EAEE1371FD56FBB3C4C94AB8C1FBA815FF8268C3653963F5624CFB3734B5293E7B6B9DCBD85EDB4946CD3C6FD2F6B290992E29CBD258D938584F4DB8076020766F8CA8284D2566BCCD40A4C0A0EBD9F23B2F7B $ sudo openssl rsa -noout -modulus -in /etc/ssl/private/ssl-cert-snakeoil.keyModulus=B6ECF899C8FA9F8AEC8A9A49065D9D80713A97511F4FFD8EDD502AF987EBCBFCD61F7E7F5676AD547B66B77F97EAEE1371FD56FBB3C4C94AB8C1FBA815FF8268C3653963F5624CFB3734B5293E7B6B9DCBD85EDB4946CD3C6FD2F6B290992E29CBD258D938584F4DB8076020766F8CA8284D2566BCCD40A4C0A0EBD9F23B2F7BAs you can see the modulus matches exactly and we have the proof that the certificate has been created using the private key. OpenSSL Certificate and Key DetailsAs I already told you, you do not need all the greedy details, but in case you want to know it in depth what is actually in those hex-blocks can be made visible with the following commands which show you the actual content in a human readable format.Note: You may not want to post all the details of your private key =^) I told you I have been using a self-signed certificate only for showing you these details.$ sudo openssl rsa -noout -text -in /etc/ssl/private/ssl-cert-snakeoil.keyPrivate-Key: (1024 bit)modulus:    00:b6:ec:f8:99:c8:fa:9f:8a:ec:8a:9a:49:06:5d:    9d:80:71:3a:97:51:1f:4f:fd:8e:dd:50:2a:f9:87:    eb:cb:fc:d6:1f:7e:7f:56:76:ad:54:7b:66:b7:7f:    97:ea:ee:13:71:fd:56:fb:b3:c4:c9:4a:b8:c1:fb:    a8:15:ff:82:68:c3:65:39:63:f5:62:4c:fb:37:34:    b5:29:3e:7b:6b:9d:cb:d8:5e:db:49:46:cd:3c:6f:    d2:f6:b2:90:99:2e:29:cb:d2:58:d9:38:58:4f:4d:    b8:07:60:20:76:6f:8c:a8:28:4d:25:66:bc:cd:40:    a4:c0:a0:eb:d9:f2:3b:2f:7bpublicExponent: 65537 (0x10001)privateExponent:    00:9e:cb:09:67:9e:53:09:ca:34:5a:81:62:60:f7:    45:31:69:99:7e:1f:ba:b9:da:97:79:41:0d:7d:3d:    e3:90:59:b4:9a:f4:59:9f:fa:37:ae:fd:cc:86:00:    6a:25:53:74:67:e0:8e:f0:c2:f6:51:f2:de:7d:ee:    72:d4:5d:d0:9a:9d:87:64:28:49:2c:4d:06:1a:b9:    7a:52:00:a4:d2:08:63:3b:bb:c3:f5:c8:fd:58:46:    70:39:40:6f:ab:9a:75:44:50:10:2d:aa:f8:cf:18:    62:3c:37:9b:04:76:a2:68:42:5a:51:c8:56:23:87:    7b:ff:53:f2:37:cf:ff:ca:71prime1:    00:ee:4d:fd:59:17:10:8a:57:47:0c:52:9c:8f:b8:    2e:ae:a9:64:12:51:f2:b1:a7:0c:4c:55:9f:d1:90:    d3:11:44:ba:6d:d9:26:35:7c:0a:ea:61:fa:dc:19:    66:18:ba:d8:00:fe:40:32:02:a0:78:37:fc:0f:e5:    91:7e:ff:18:29prime2:    00:c4:82:43:b5:06:0c:dd:f2:b3:27:c8:22:b7:5c:    d5:10:44:02:4e:01:3a:b2:87:2a:d0:f9:53:1d:33:    e6:57:10:91:a0:98:ac:af:09:0e:e4:a5:76:b7:8d:    db:23:a1:4b:df:7f:4b:80:91:5a:61:a4:4e:3d:38:    c1:14:a7:8f:03exponent1:    00:9a:47:99:96:dd:0c:d3:53:8f:e6:d5:71:10:c6:    c0:4a:49:d6:44:da:13:12:9a:c0:a6:86:e4:b2:2b:    5d:ca:97:41:4f:2e:bf:c2:ee:ac:ae:73:82:92:8e:    4b:00:05:af:24:6d:76:a8:29:f5:33:ff:a2:cb:b3:    e7:8f:5d:9d:89exponent2:    2f:fa:62:0f:93:9f:96:9d:08:12:e1:71:60:75:80:    eb:cc:bf:07:4e:93:87:3d:2b:3e:04:71:bf:82:89:    6d:9e:74:ff:d1:e6:ef:81:75:aa:6b:9f:b5:a7:23:    e6:ea:1d:bd:3e:b6:2f:78:cd:a9:63:55:5a:eb:3d:    71:0e:8c:03coefficient:    00:b6:d7:f3:03:00:07:cf:e1:54:85:64:02:98:e0:    69:bc:1b:96:fc:a8:58:58:a6:53:32:9b:f1:14:c4:    98:60:3e:4f:1f:a3:4d:c8:b7:c1:c7:42:78:9c:63:    cd:e6:7f:df:ea:29:74:b3:da:73:b7:79:28:fb:ef:    de:52:d5:92:9d$ sudo openssl x509 -noout -text -in /etc/ssl/certs/ssl-cert-snakeoil.pemCertificate:    Data:        Version: 1 (0x0)        Serial Number:            fb:3b:75:d7:c1:58:a5:5b        Signature Algorithm: sha1WithRSAEncryption        Issuer: CN=ubuntu        Validity            Not Before: Jun  7 08:03:53 2010 GMT            Not After : Jun  4 08:03:53 2020 GMT        Subject: CN=ubuntu        Subject Public Key Info:            Public Key Algorithm: rsaEncryption            RSA Public Key: (1024 bit)                Modulus (1024 bit):                    00:b6:ec:f8:99:c8:fa:9f:8a:ec:8a:9a:49:06:5d:                    9d:80:71:3a:97:51:1f:4f:fd:8e:dd:50:2a:f9:87:                    eb:cb:fc:d6:1f:7e:7f:56:76:ad:54:7b:66:b7:7f:                    97:ea:ee:13:71:fd:56:fb:b3:c4:c9:4a:b8:c1:fb:                    a8:15:ff:82:68:c3:65:39:63:f5:62:4c:fb:37:34:                    b5:29:3e:7b:6b:9d:cb:d8:5e:db:49:46:cd:3c:6f:                    d2:f6:b2:90:99:2e:29:cb:d2:58:d9:38:58:4f:4d:                    b8:07:60:20:76:6f:8c:a8:28:4d:25:66:bc:cd:40:                    a4:c0:a0:eb:d9:f2:3b:2f:7b                Exponent: 65537 (0x10001)    Signature Algorithm: sha1WithRSAEncryption        93:6a:ef:54:49:31:47:5a:8f:4a:92:62:b9:d0:ee:19:41:ed:        58:a0:4a:5a:25:9b:99:2c:08:dd:11:19:4f:ed:2f:1b:e6:03:        1b:96:b9:e4:d7:71:81:19:37:ce:14:27:b6:a1:7b:80:d6:23:        2b:16:e5:04:1c:81:a5:8e:d6:d1:c8:b4:d2:47:fb:90:58:2f:        5d:63:1e:53:de:8d:49:02:5d:9e:27:7f:63:1c:d0:62:7d:1d:        18:bd:ab:4a:1d:5d:c1:d3:cd:34:f4:25:35:27:e7:11:0d:72:        c4:57:af:47:b6:91:74:2a:93:6d:35:d4:de:6c:62:f1:86:92:        b1:c1The above output can also be seen if you direct your browser client to your website and check the certificate sent by the server to your browser. You will be able to lookup all the details including the validity dates, subject common name and the public key modulus.Capture an SSL connection using WiresharkAnd as you would have expected, looking at the low-level tcp data that has been exchanged between the client and server with a tcp-diagnostics tool (i.e. wireshark/tcpdump) you can also see the modulus in there.These were the settings I used to capture all traffic on the local loopback interface, matching the filter expression: tcp and ip and host 127.0.0.1 and port 443. This tells Wireshark to leave out any other information, I may not have been interested in showing you.

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