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  • HTG Explains: Are You Using IPv6 Yet? Should You Even Care?

    - by Chris Hoffman
    IPv6 is extremely important for the long-term health of the Internet. But is your Internet service provider providing IPv6 connectivity yet? Does your home network support it? Should you even care if you’re using IPv6 yet? Switching from IPv4 to IPv6 will give the Internet a much larger pool of IP addresses. It should also allow every device to have its own public IP address, rather than be hidden behind a NAT router. IPv6 is Important Long-Term IPv6 is very important for the long-term health of the Internet. There are only about 3.7 billion public IPv4 addresses. This may sound like a lot, but it isn’t even one IP address for each person on the planet. Considering people have more and more Internet-connected devices — everything from light bulbs to thermostats are starting to become network-connected — the lack of IP addresses is already proving to be a serious problem. This may not affect those of us in well-off developed countries just yet, but developing countries are already running out of IPv4 addresses. So, if you work at an Internet service provider, manage Internet-connected servers, or develop software or hardware — yes, you should care about IPv6! You should be deploying it and ensuring your software and hardware works properly with it. It’s important to prepare for the future before the current IPv4 situation becomes completely unworkable. But, if you’re just typical user or even a typical geek with a home Internet connection and a home network, should you really care about your home network just yet? Probably not. What You Need to Use IPv6 To use IPv6, you’ll need three things: An IPv6-Compatible Operating System: Your operating system’s software must be capable of using IPv6. All modern desktop operating systems should be compatible — Windows Vista and newer versions of Windows, as well as modern versions of Mac OS X and Linux. Windows XP doesn’t have IPv6 support installed by default, but you shouldn’t be using Windows XP anymore, anyway. A Router With IPv6 Support: Many — maybe even most — consumer routers in the wild don’t support IPv6. Check your router’s specifications details to see if it supports IPv6 if you’re curious. If you’re going to buy a new router, you’ll probably want to get one with IPv6 support to future-proof yourself. If you don’t have an IPv6-enabled router yet, you don’t need to buy a new one just to get it. An ISP With IPv6 Enabled:  Your Internet service provider must also have IPv6 set up on their end. Even if you have modern software and hardware on your end, your ISP has to provide an IPv6 connection for you to use it. IPv6 is rolling out steadily, but slowly — there’s a good chance your ISP hasn’t enabled it for you yet. How to Tell If You’re Using IPv6 The easiest way to tell if you have IPv6 connectivity is to visit a website like testmyipv6.com. This website allows you to connect to it in different ways — click the links near the top to see if you can connect to the website via different types of connections. If you can’t connect via IPv6, it’s either because your operating system is too old (unlikely), your router doesn’t support IPv6 (very possible), or because your ISP hasn’t enabled it for you yet (very likely). Now What? If you can connect to the test website above via IPv6, congratulations! Everything is working as it should. Your ISP is doing a good job of rolling out IPv6 rather than dragging its feet. There’s a good chance you won’t have IPv6 working properly, however. So what should you do about this — should you head to Amazon and buy a new IPv6-enabled router or switch to an ISP that offers IPv6? Should you use a “tunnel broker,” as the test site recommends, to tunnel into IPv6 via your IPv4 connection? Well, probably not. Typical users shouldn’t have to worry about this yet. Connecting to the Internet via IPv6 shouldn’t be perceptibly faster, for example. It’s important for operating system vendors, hardware companies, and Internet service providers to prepare for the future and get IPv6 working, but you don’t need to worry about this on your home network. IPv6 is all about future-proofing. You shouldn’t be racing to implement this at home yet or worrying about it too much — but, when you need to buy a new router, try to buy one that supports IPv6. Image Credit: Adobe of Chaos on Flickr, hisperati on Flickr, Vox Efx on Flickr     

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  • SQL SERVER – CXPACKET – Parallelism – Usual Solution – Wait Type – Day 6 of 28

    - by pinaldave
    CXPACKET has to be most popular one of all wait stats. I have commonly seen this wait stat as one of the top 5 wait stats in most of the systems with more than one CPU. Books On-Line: Occurs when trying to synchronize the query processor exchange iterator. You may consider lowering the degree of parallelism if contention on this wait type becomes a problem. CXPACKET Explanation: When a parallel operation is created for SQL Query, there are multiple threads for a single query. Each query deals with a different set of the data (or rows). Due to some reasons, one or more of the threads lag behind, creating the CXPACKET Wait Stat. There is an organizer/coordinator thread (thread 0), which takes waits for all the threads to complete and gathers result together to present on the client’s side. The organizer thread has to wait for the all the threads to finish before it can move ahead. The Wait by this organizer thread for slow threads to complete is called CXPACKET wait. Note that not all the CXPACKET wait types are bad. You might experience a case when it totally makes sense. There might also be cases when this is unavoidable. If you remove this particular wait type for any query, then that query may run slower because the parallel operations are disabled for the query. Reducing CXPACKET wait: We cannot discuss about reducing the CXPACKET wait without talking about the server workload type. OLTP: On Pure OLTP system, where the transactions are smaller and queries are not long but very quick usually, set the “Maximum Degree of Parallelism” to 1 (one). This way it makes sure that the query never goes for parallelism and does not incur more engine overhead. EXEC sys.sp_configure N'cost threshold for parallelism', N'1' GO RECONFIGURE WITH OVERRIDE GO Data-warehousing / Reporting server: As queries will be running for long time, it is advised to set the “Maximum Degree of Parallelism” to 0 (zero). This way most of the queries will utilize the parallel processor, and long running queries get a boost in their performance due to multiple processors. EXEC sys.sp_configure N'cost threshold for parallelism', N'0' GO RECONFIGURE WITH OVERRIDE GO Mixed System (OLTP & OLAP): Here is the challenge. The right balance has to be found. I have taken a very simple approach. I set the “Maximum Degree of Parallelism” to 2, which means the query still uses parallelism but only on 2 CPUs. However, I keep the “Cost Threshold for Parallelism” very high. This way, not all the queries will qualify for parallelism but only the query with higher cost will go for parallelism. I have found this to work best for a system that has OLTP queries and also where the reporting server is set up. Here, I am setting ‘Cost Threshold for Parallelism’ to 25 values (which is just for illustration); you can choose any value, and you can find it out by experimenting with the system only. In the following script, I am setting the ‘Max Degree of Parallelism’ to 2, which indicates that the query that will have a higher cost (here, more than 25) will qualify for parallel query to run on 2 CPUs. This implies that regardless of the number of CPUs, the query will select any two CPUs to execute itself. EXEC sys.sp_configure N'cost threshold for parallelism', N'25' GO EXEC sys.sp_configure N'max degree of parallelism', N'2' GO RECONFIGURE WITH OVERRIDE GO Read all the post in the Wait Types and Queue series. Additionally a must read comment of Jonathan Kehayias. Note: The information presented here is from my experience and I no way claim it to be accurate. I suggest you all to read the online book for further clarification. All the discussion of Wait Stats over here is generic and it varies from system to system. It is recommended that you test this on the development server before implementing on the production server. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: DMV, Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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  • Spolskism or Twitterism: A Doctor writes...

    - by Phil Factor
    "I never realized I had a problem. I just 'twittered' because it was a social thing to do. All my mates were doing it. It made me feel good to have 'followers'; it bolstered my self-esteem. Of course, you don't think of the long-term effects on your work and on the way you think. There's no denying that it impairs your judgment…" Yes, this story is typical. Hundreds of people are waking up to the long term effects of twittering, and seeking help. Dave, who wishes to remain anonymous, told our reporter… "I started using Twitter at work. Just a few minutes now and then, throughout the day. A lot of my colleagues were doing it and I thought 'Well, that's cool; it must be part of what I should be doing at work'. Soon, I was avidly reading every twitter that came my way, and counting the minutes between my own twitters. I tried to kid myself that it was all about professional development and getting other people to help you with work-related problems, but in truth I had become addicted to the buzz of the social network. The worse thing was that it made me seem busy even when I was really just frittering my time away. Inevitably, I started to get behind with my real work." Experts have identified the syndrome and given it a name: 'Twitterism', sometimes referred to as 'Spolskism', after the person who first drew attention to the pernicious damage to well-being that the practice caused, and who had the courage to take the pledge of rejecting it. According to one expert… "The occasional Twitter does little harm to the participant, and can be an adaptive way of dealing with stress. Unfortunately, it rarely stops there. The addictive qualities of the practice have put a strain on the caring professions who are faced with a flood of people making that first bold step to seeking help". Dave is one of those now seeking help for his addiction… "I had lost touch with reality. Even though I twittered my work colleagues constantly, I found I actually spoke to them less and less. Even when out socializing, I would frequently disengage from the conversation, in order to twitter. I stopped blogging. I stopped responding to emails; the only way to reach me was through the world of Twitter. Unfortunately, my denial about the harm that twittering was doing to me, my friends, and my work-colleagues was so strong that I truly couldn't see that I had a problem." Like other addictions, the help and support of others who are 'taking the cure' is important. There is a common bond between those who have 'been through hell and back' and are once more able to experience the joys of actually conversing and socializing, rather than the false comfort of solitary 'twittering'. Complete abstinence is essential to the cure. Most of those who risk even an occasional twitter face a headlong slide back into 'binge' twittering. Tom, another twitterer who has managed to kick the habit explains… "My twittering addiction now seems more like a bad dream. You get to work, and switch on the PC. You say to yourself, just open up the browser, just for a minute, just to see what people are saying on Twitter. The next thing you know, half the day has gone by. The worst thing is that when you're addicted, you get good at covering up the habit; I spent so much time looking at the screen and typing on the keyboard, people just assumed I was working hard.I know that I must never forget what it was like then, and what it's like now that I've kicked the habit. I now have more time for productive work and a real social life." Like many addictions, Spolskism has its most detrimental effects on family, friends and workmates, rather than the addict. So often nowadays, we hear the sad stories of Twitter-Widows; tales of long lonely evenings spent whilst their partners are engrossed in their twittering into their 'mobiles' or indulging in their solitary spolskistic habits in privacy, under cover of 'having to do work at home'. Workmates suffer too, when the addicts even take their laptops or mobiles into meetings in order to 'twitter' with their fellow obsessives, even stooping to complain to their followers how boring the meeting is. No; The best advice is to leave twittering to the birds. You know it makes sense.

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  • Auto DOP and Concurrency

    - by jean-pierre.dijcks
    After spending some time in the cloud, I figured it is time to come down to earth and start discussing some of the new Auto DOP features some more. As Database Machines (the v2 machine runs Oracle Database 11.2) are effectively selling like hotcakes, it makes some sense to talk about the new parallel features in more detail. For basic understanding make sure you have read the initial post. The focus there is on Auto DOP and queuing, which is to some extend the focus here. But now I want to discuss the concurrency a little and explain some of the relevant parameters and their impact, specifically in a situation with concurrency on the system. The goal of Auto DOP The idea behind calculating the Automatic Degree of Parallelism is to find the highest possible DOP (ideal DOP) that still scales. In other words, if we were to increase the DOP even more  above a certain DOP we would see a tailing off of the performance curve and the resource cost / performance would become less optimal. Therefore the ideal DOP is the best resource/performance point for that statement. The goal of Queuing On a normal production system we should see statements running concurrently. On a Database Machine we typically see high concurrency rates, so we need to find a way to deal with both high DOP’s and high concurrency. Queuing is intended to make sure we Don’t throttle down a DOP because other statements are running on the system Stay within the physical limits of a system’s processing power Instead of making statements go at a lower DOP we queue them to make sure they will get all the resources they want to run efficiently without trashing the system. The theory – and hopefully – practice is that by giving a statement the optimal DOP the sum of all statements runs faster with queuing than without queuing. Increasing the Number of Potential Parallel Statements To determine how many statements we will consider running in parallel a single parameter should be looked at. That parameter is called PARALLEL_MIN_TIME_THRESHOLD. The default value is set to 10 seconds. So far there is nothing new here…, but do realize that anything serial (e.g. that stays under the threshold) goes straight into processing as is not considered in the rest of this post. Now, if you have a system where you have two groups of queries, serial short running and potentially parallel long running ones, you may want to worry only about the long running ones with this parallel statement threshold. As an example, lets assume the short running stuff runs on average between 1 and 15 seconds in serial (and the business is quite happy with that). The long running stuff is in the realm of 1 – 5 minutes. It might be a good choice to set the threshold to somewhere north of 30 seconds. That way the short running queries all run serial as they do today (if it ain’t broken, don’t fix it) and allows the long running ones to be evaluated for (higher degrees of) parallelism. This makes sense because the longer running ones are (at least in theory) more interesting to unleash a parallel processing model on and the benefits of running these in parallel are much more significant (again, that is mostly the case). Setting a Maximum DOP for a Statement Now that you know how to control how many of your statements are considered to run in parallel, lets talk about the specific degree of any given statement that will be evaluated. As the initial post describes this is controlled by PARALLEL_DEGREE_LIMIT. This parameter controls the degree on the entire cluster and by default it is CPU (meaning it equals Default DOP). For the sake of an example, let’s say our Default DOP is 32. Looking at our 5 minute queries from the previous paragraph, the limit to 32 means that none of the statements that are evaluated for Auto DOP ever runs at more than DOP of 32. Concurrently Running a High DOP A basic assumption about running high DOP statements at high concurrency is that you at some point in time (and this is true on any parallel processing platform!) will run into a resource limitation. And yes, you can then buy more hardware (e.g. expand the Database Machine in Oracle’s case), but that is not the point of this post… The goal is to find a balance between the highest possible DOP for each statement and the number of statements running concurrently, but with an emphasis on running each statement at that highest efficiency DOP. The PARALLEL_SERVER_TARGET parameter is the all important concurrency slider here. Setting this parameter to a higher number means more statements get to run at their maximum parallel degree before queuing kicks in.  PARALLEL_SERVER_TARGET is set per instance (so needs to be set to the same value on all 8 nodes in a full rack Database Machine). Just as a side note, this parameter is set in processes, not in DOP, which equates to 4* Default DOP (2 processes for a DOP, default value is 2 * Default DOP, hence a default of 4 * Default DOP). Let’s say we have PARALLEL_SERVER_TARGET set to 128. With our limit set to 32 (the default) we are able to run 4 statements concurrently at the highest DOP possible on this system before we start queuing. If these 4 statements are running, any next statement will be queued. To run a system at high concurrency the PARALLEL_SERVER_TARGET should be raised from its default to be much closer (start with 60% or so) to PARALLEL_MAX_SERVERS. By using both PARALLEL_SERVER_TARGET and PARALLEL_DEGREE_LIMIT you can control easily how many statements run concurrently at good DOPs without excessive queuing. Because each workload is a little different, it makes sense to plan ahead and look at these parameters and set these based on your requirements.

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  • XNA Notes 005

    - by George Clingerman
    Another week and another crazy amount of activity going on in the XNA community. I’m fairly certain I missed over half of it. In fact, if I am missing things, make sure to email me and I’ll try and make sure I catch it next week! ([email protected]). Also, if you’ve got any advice, things you like/don’t like about the way these XNA Notes are going let me know. I always appreciate feedback (currently spammers are leaving me the nicest comments so you guys have work to do!) Without further ado, here’s this week’s notes! Time Critical XNA News The XNA Team Blob reminds us that February 7th is the last day to submit XNA 3.1 games to peer review! http://blogs.msdn.com/b/xna/archive/2011/01/31/7-days-left-to-submit-xna-gs-3-1-games-on-app-hub.aspx XNA MVPS Chris Williams kicks off the marketing campaign for our book http://geekswithblogs.net/cwilliams/archive/2011/01/28/143680.aspx Catalin Zima posts the comparison cheat sheet for why Angry Birds is different than Chickens Can’t Fly http://www.amusedsloth.com/2011/02/comparison-cheat-sheet-for-chickens-cant-fly-and-angry-birds/ Jim Perry congratulates the developers selected by Game Developer Magazine for Best Xbox LIVE Indie Games of 2010 http://machxgames.com/blog/?p=24 @NemoKrad posts his XNAKUUG talks for all to enjoy http://twitter.com/NemoKrad/statuses/33142362502864896 http://xna-uk.net/blogs/randomchaos/archive/2011/02/03/xblig-uk-2011-january-amp-february-talk.aspx George  (that’s me!) preps for his XNA talk coming up on the 8th http://twitter.com/clingermangw/statuses/32669550554124288 http://www.portlandsilverlight.net/Meetings/Details/15 XNA Developers FireFly posts the last tutorial in his XNA Tower Defense tutorial series http://forums.create.msdn.com/forums/p/26442/451460.aspx#451460 http://xnatd.blogspot.com/2011/01/tutorial-14-polishing-game.html @fredericmy posts the main difference when porting a game from Windows Phone 7 to Xbox 360 http://fairyengine.blogspot.com/2011/01/main-differences-when-porting-game-from.html @ElementCy creates a pretty rad video of a MineCraft type terrain created using XNA http://www.youtube.com/watch?v=Waw1f7wnl9I Andrew Russel gets the first XNA badge on gamedev.stackexchange http://twitter.com/_AndrewRussell/statuses/32322877004972032 http://gamedev.stackexchange.com/badges?tab=tags And his funding for ExEn has passed $7000 only $3000 to go http://twitter.com/_AndrewRussell/statuses/33042412804771840 Subodh Pushpak blogs about his Windows Phone 7 XNA talk http://geekswithblogs.net/subodhnpushpak/archive/2011/02/01/windows-phone-7-silverlight--xna-development-talk.aspx Slyprid releases the latest version of Transmute and needs more people to test http://twitter.com/slyprid/statuses/32452488418299904 http://forgottenstarstudios.com/ SpynDoctorGames celebrates the 1 year anniversary of Your Doodles Are Bugged! Congrats! http://twitter.com/SpynDoctorGames/statuses/32511689068908544 Noogy (creator of Dust the Elysian Tail) prepares his conversion to XNA 4.0 http://twitter.com/NoogyTweet/statuses/32522008449253376 @philippedasilva posts about the Indiefreaks Game Framework v0.2.0.0 Input management system http://twitter.com/philippedasilva/statuses/32763393957957632 http://indiefreaks.com/2011/02/02/behind-smart-input-system-feature/ Mommy’s Best Games debates what to do about High Scores with their new update http://mommysbest.blogspot.com/2011/02/high-score-shake-up.html @BinaryTweedDeej want to know if there’s anything the community needs to make XNA games for the PC. Give him some feedback! http://twitter.com/BinaryTweedDeej/status/32895453863354368 @mikebmcl promises to write us all a book (I can’t wait to read it!) http://twitter.com/mikebmcl/statuses/33206499102687233 @werezompire is going to live, LIVE, thanks to all the generosity and support from the community! http://twitter.com/werezompire/statuses/32840147644977153 Xbox LIVE Indie Games (XBLIG) Making money in Xbox 360 indie game development. Is it possible? http://www.bitmob.com/articles/making-money-in-xbox-360-indie-game-development-is-it-possible @AlejandroDaJ posts some thoughts abut the bitmob article http://twitter.com/AlejandroDaJ/statuses/31068552165330944 http://www.apathyworks.com/blog/view.php?id=00215 Kobun gets my respect as an XBLIG champion. I’m not sure who Kobun is, but if you’ve every read through the comment sections any time Kotaku writes about XBLIGs you’ll see a lot of confusion, disinformation in there. Kobun has been waging a secret war battling that lack of knowledge and he does it well. Also he’s running a pretty kick ass site for Xbox LIVE Indie Game reviews http://xboxindies.teamkobun.com/ @radiangames releases his last Xbox LIVE Indie Game...for now http://bit.ly/gMK6lE Playing Avaglide with the Kinect controller http://www.youtube.com/watch?v=UqAYbHww53o http://www.joystiq.com/2011/01/30/kinect-hacks-take-to-the-skies-with-avaglide/ Luke Schneider of Radiangames interviewed in Edge magazine http://www.next-gen.biz/features/radiangames-venture Digital Quarters posts thoughts on why XBLIG’s online requirement kills certain genres http://digitalquarters.blogspot.com/2011/02/thoughts-why-xbligs-online-requirement.html Mommy’s Best Games shares the news that several XBLIGs were featured in the March 2011 issue of Famitsu 360 http://forums.create.msdn.com/forums/p/33455/451487.aspx#451487 NaviFairy continues with his Indie-Game-A-Day http://gaygamer.net/2011/02/indie_game_a_day_epic_dungeon.html http://gaygamer.net/2011/02/indie_game_a_day_break_limit_r.html and more every day...that’s kind of the point! Keep your eye on this series! VVGTV continues with it’s awesome reviews/promotions for XBLIGs http://vvgtv.com/ http://vvgtv.com/2011/02/03/iredia-atrams-secret-xblig-review-2/ http://vvgtv.com/2011/02/02/poopocalypse-coming-soon-to-xblig/ ….and even more, you get the point. Magicka is an Indie Game doing really well on Steam AND it’s made using XNA http://www.magickagame.com/ http://twitter.com/Magickagame/statuses/32712762580799488 GameMarx reviews Antipole http://www.gamemarx.com/reviews/73/antipole-is-vvvvvvery-good.aspx Armless Octopus review Alpha Squad http://www.armlessoctopus.com/2011/01/28/xbox-indie-review-alpha-squad/ An interesting article about Kodu that Jim Perry found http://twitter.com/MachXGames/statuses/32848044105924608 http://www.develop-online.net/news/36915/10-year-old-Jordan-makes-games-The-UK-needs-more-like-her XNA Game Development Sgt. Conker posts about the Natur beta, a new book and whether you can make money with XBLIG http://www.sgtconker.com/ http://www.sgtconker.com/2011/01/a-new-book-on-the-block-and-a-new-natur-beta/ http://www.sgtconker.com/2011/01/making-money-in-xbox-360-indie-game-development-is-it-possible/ Tips for setting up SVN http://bit.ly/fKxgFh @bsimser found tons of royalty free music and soundfx for your XNA Games http://twitter.com/bsimser/statuses/31426632933711872 Post on the new features in the next Sunburn Editor http://www.synapsegaming.com/blogs/fivesidedbarrel/archive/2011/01/28/new-editor-features-prefabs-components-and-more.aspx @jasons_novaleaf posts source code for light pre-pass optimizations for #xna http://twitter.com/jasons_novaleaf/statuses/33348855403642880 http://jcoluna.wordpress.com/2011/02/01/xna-4-0-light-pre-pass-optimization-round-one/ I’ve been learning about doing an A.I. for turn based games and this article was a great resource. http://www.gamasutra.com/view/feature/1535/designing_ai_algorithms_for_.php?print=1

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  • Replication - between pools in the same system

    - by Steve Tunstall
    OK, I fully understand that's it's been a LONG time since I've blogged with any tips or tricks on the ZFSSA, and I'm way behind. Hey, I just wrote TWO BLOGS ON THE SAME DAY!!! Make sure you keep scrolling down to see the next one too, or you may have missed it. To celebrate, for the one or two of you out there who are still reading this, I got something for you. The first TWO people who make any comment below, with your real name and email so I can contact you, will get some cool Oracle SWAG that I have to give away. Don't get excited, it's not an iPad, but it pretty good stuff. Only the first two, so if you already see two below, then settle down. Now, let's talk about Replication and Migration.  I have talked before about Shadow Migration here: https://blogs.oracle.com/7000tips/entry/shadow_migrationShadow Migration lets one take a NFS or CIFS share in one pool on a system and migrate that data over to another pool in the same system. That's handy, but right now it's only for file systems like NFS and CIFS. It will not work for LUNs. LUN shadow migration is a roadmap item, however. So.... What if you have a ZFSSA cluster with multiple pools, and you have a LUN in one pool but later you decide it's best if it was in the other pool? No problem. Replication to the rescue. What's that? Replication is only for replicating data between two different systems? Who told you that? We've been able to replicate to the same system now for a few code updates back. These instructions below will also work just fine if you're setting up replication between two different systems. After replication is complete, you can easily break replication, change the new LUN into a primary LUN and then delete the source LUN. Bam. Step 1- setup a target system. In our case, the target system is ourself, but you still have to set it up like it's far away. Go to Configuration-->Services-->Remote Replication. Click the plus sign and setup the target, which is the ZFSSA you're on now. Step 2. Now you can go to the LUN you want to replicate. Take note which Pool and Project you're in. In my case, I have a LUN in Pool2 called LUNp2 that I wish to replicate to Pool1.  Step 3. In my case, I made a Project called "Luns" and it has LUNp2 inside of it. I am going to replicate the Project, which will automatically replicate all of the LUNs and/or Filesystems inside of it.  Now, you can also replicate from the Share level instead of the Project. That will only replicate the share, and not all the other shares of a project. If someone tells you that if you replicate a share, it always replicates all the other shares also in that Project, don't listen to them.Note below how I can choose not only the Target (which is myself), but I can also choose which Pool to replicate it to. So I choose Pool1.  Step 4. I did not choose a schedule or pick the "Continuous" button, which means my replication will be manual only. I can now push the Manual Replicate button on my Actions list and you will see it start. You will see both a barber pole animation and also an update in the status bar on the top of the screen that a replication event has begun. This also goes into the event log.  Step 5. The status bar will also log an event when it's done. Step 6. If you go back to Configuration-->Services-->Remote Replication, you will see your event. Step 7. Done. To see your new replica, go to the other Pool (Pool1 for me), and click the "Replica" area below the words "Filesystems | LUNs" Here, you will see any replicas that have come in from any of your sources. It's a simple matter from here to break the replication, which will change this to a "Local" LUN, and then delete the original LUN back in Pool2. Ok, that's all for now, but I promise to give out more tricks sometime in November !!! There's very exciting stuff coming down the pipe for the ZFSSA. Both new hardware and new software features that I'm just drooling over. That's all I can say, but contact your local sales SC to get a NDA roadmap talk if you want to hear more.   Happy Halloween,Steve 

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  • Getting Started with Prism (aka Composite Application Guidance for WPF and Silverlight)

    - by dotneteer
    Overview Prism is a framework from the Microsoft Patterns and Practice team that allow you to create WPF and Silverlight in a modular way. It is especially valuable for larger projects in which a large number of developers can develop in parallel. Prism achieves its goal by supplying several services: · Dependency Injection (DI) and Inversion of control (IoC): By using DI, Prism takes away the responsibility of instantiating and managing the life time of dependency objects from individual components to a container. Prism relies on containers to discover, manage and compose large number of objects. By varying the configuration, the container can also inject mock objects for unit testing. Out of the box, Prism supports Unity and MEF as container although it is possible to use other containers by subclassing the Bootstrapper class. · Modularity and Region: Prism supplies the framework to split application into modules from the application shell. Each module is a library project that contains both UI and code and is responsible to initialize itself when loaded by the shell. Each window can be further divided into regions. A region is a user control with associated model. · Model, view and view-model (MVVM) pattern: Prism promotes the user MVVM. The use of DI container makes it much easier to inject model into view. WPF already has excellent data binding and commanding mechanism. To be productive with Prism, it is important to understand WPF data binding and commanding well. · Event-aggregation: Prism promotes loosely coupled components. Prism discourages for components from different modules to communicate each other, thus leading to dependency. Instead, Prism supplies an event-aggregation mechanism that allows components to publish and subscribe events without knowing each other. Architecture In the following, I will go into a little more detail on the services provided by Prism. Bootstrapper In a typical WPF application, application start-up is controls by App.xaml and its code behind. The main window of the application is typically specified in the App.xaml file. In a Prism application, we start a bootstrapper in the App class and delegate the duty of main window to the bootstrapper. The bootstrapper will start a dependency-injection container so all future object instantiations are managed by the container. Out of box, Prism provides the UnityBootstrapper and MefUnityBootstrapper abstract classes. All application needs to either provide a concrete implementation of one of these bootstrappers, or alternatively, subclass the Bootstrapper class with another DI container. A concrete bootstrapper class must implement the CreateShell method. Its responsibility is to resolve and create the Shell object through the DI container to serve as the main window for the application. The other important method to override is ConfigureModuleCatalog. The bootstrapper can register modules for the application. In a more advance scenario, an application does not have to know all its modules at compile time. Modules can be discovered at run time. Readers to refer to one of the Open Modularity Quick Starts for more information. Modules Once modules are registered with or discovered by Prism, they are instantiated by the DI container and their Initialize method is called. The DI container can inject into a module a region registry that implements IRegionViewRegistry interface. The module, in its Initialize method, can then call RegisterViewWithRegion method of the registry to register its regions. Regions Regions, once registered, are managed by the RegionManager. The shell can then load regions either through the RegionManager.RegionName attached property or dynamically through code. When a view is created by the region manager, the DI container can inject view model and other services into the view. The view then has a reference to the view model through which it can interact with backend services. Service locator Although it is possible to inject services into dependent classes through a DI container, an alternative way is to use the ServiceLocator to retrieve a service on demard. Prism supplies a service locator implementation and it is possible to get an instance of the service by calling: ServiceLocator.Current.GetInstance<IServiceType>() Event aggregator Prism supplies an IEventAggregator interface and implementation that can be injected into any class that needs to communicate with each other in a loosely-coupled fashion. The event aggregator uses a publisher/subscriber model. A class can publishes an event by calling eventAggregator.GetEvent<EventType>().Publish(parameter) to raise an event. Other classes can subscribe the event by calling eventAggregator.GetEvent<EventType>().Subscribe(EventHandler, other options). Getting started The easiest way to get started with Prism is to go through the Prism Hands-On labs and look at the Hello World QuickStart. The Hello World QuickStart shows how bootstrapper, modules and region works. Next, I would recommend you to look at the Stock Trader Reference Implementation. It is a more in depth example that resemble we want to set up an application. Several other QuickStarts cover individual Prism services. Some scenarios, such as dynamic module discovery, are more advanced. Apart from the official prism document, you can get an overview by reading Glen Block’s MSDN Magazine article. I have found the best free training material is from the Boise Code Camp. To be effective with Prism, it is important to understands key concepts of WPF well first, such as the DependencyProperty system, data binding, resource, theme and ICommand. It is also important to know your DI container of choice well. I will try to explorer these subjects in depth in the future. Testimony Recently, I worked on a desktop WPF application using Prism. I had a wonderful experience with Prism. The Prism is flexible enough even in the presence of third party controls such as Telerik WPF controls. We have never encountered any significant obstacle.

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  • MVVM Light V4 preview 2 (BL0015) #mvvmlight

    - by Laurent Bugnion
    Over the past few weeks, I have worked hard on a few new features for MVVM Light V4. Here is a second early preview (consider this pre-alpha if you wish). The features are unit-tested, but I am now looking for feedback and there might be bugs! Bug correction: Messenger.CleanupList is now thread safe This was an annoying bug that is now corrected: In some circumstances, an exception could be thrown when the Messenger’s recipients list was cleaned up (i.e. the “dead” instances were removed). The method is called now and then and the exception was thrown apparently at random. In fact it was really a multi-threading issue, which is now corrected. Bug correction: AllowPartiallyTrustedCallers prevents EventToCommand to work This is a particularly annoying regression bug that was introduced in BL0014. In order to allow MVVM Light to work in XBAPs too, I added the AllowPartiallyTrustedCallers attribute to the assemblies. However, we just found out that this causes issues when using EventToCommand. In order to allow EventToCommand to continue working, I reverted to the previous state by removing the AllowPartiallyTrustedCallers attribute for now. I will work with my friends at Microsoft to try and find a solution. Stay tuned. Bug correction: XML documentation file is now generated in Release configuration The XML documentation file was not generated for the Release configuration. This was a simple flag in the project file that I had forgotten to set. This is corrected now. Applying EventToCommand to non-FrameworkElements This feature has been requested in order to be able to execute a command when a Storyboard is completed. I implemented this, but unfortunately found out that EventToCommand can only be added to Storyboards in Silverlight 3 and Silverlight 4, but not in WPF or in Windows Phone 7. This obviously limits the usefulness of this change, but I decided to publish it anyway, because it is pretty damn useful in Silverlight… Why not in WPF? In WPF, Storyboards added to a resource dictionary are frozen. This is a feature of WPF which allows to optimize certain objects for performance: By freezing them, it is a contract where we say “this object will not be modified anymore, so do your perf optimization on them without worrying too much”. Unfortunately, adding a Trigger (such as EventTrigger) to an object in resources does not work if this object is frozen… and unfortunately, there is no way to tell WPF not to freeze the Storyboard in the resources… so there is no way around that (at least none I can see. In Silverlight, objects are not frozen, so an EventTrigger can be added without problems. Why not in WP7? In Windows Phone 7, there is a totally different issue: Adding a Trigger can only be done to a FrameworkElement, which Storyboard is not. Here I think that we might see a change in a future version of the framework, so maybe this small trick will work in the future. Workaround? Since you cannot use the EventToCommand on a Storyboard in WPF and in WP7, the workaround is pretty obvious: Handle the Completed event in the code behind, and call the Command from there on the ViewModel. This object can be obtained by casting the DataContext to the ViewModel type. This means that the View needs to know about the ViewModel, but I never had issues with that anyway. New class: NotifyPropertyChanged Sometimes when you implement a model object (for example Customer), you would like to have it implement INotifyPropertyChanged, but without having all the frills of a ViewModelBase. A new class named NotifyPropertyChanged allows you to do that. This class is a simple implementation of INotifyPropertyChaned (with all the overloads of RaisePropertyChanged that were implemented in BL0014). In fact, ViewModelBase inherits NotifyPropertyChanged. ViewModelBase does not implement IDisposable anymore The IDisposable interface and the Dispose method had been marked obsolete in the ViewModelBase class already in V3. Now they have been removed. Note: By this, I do not mean that IDisposable is a bad interface, or that it shouldn’t be used on viewmodels. In the contrary, I know that this interface is very useful in certain circumstances. However, I think that having it by default on every instance of ViewModelBase was sending a wrong message. This interface has a strong meaning in .NET: After Dispose has been executed, the instance should not be used anymore, and should be ready for garbage collection. What I really wanted to have on ViewModelBase was rather a simple cleanup method, something that can be executed now and then during runtime. This is fulfilled by the ICleanup interface and its Cleanup method. If your ViewModels need IDisposable, you can still use it! You will just have to implement the interface on the class itself, because it is not available on ViewModelBase anymore. What’s next? I have a couple exciting new features implemented already but that need more testing before they go live… Just stay tuned and by MIX11 (12-14 April 2011), we should see at least a major addition to MVVM Light Toolkit, as well as another smaller feature which is pretty cool nonetheless More about this later! Happy Coding Laurent   Laurent Bugnion (GalaSoft) Subscribe | Twitter | Facebook | Flickr | LinkedIn

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  • Red Gate does Byte Night 2012

    - by red(at)work
    On the 5th of October 2012, a team of nine plucky Red Gaters braved the howling wind and the driving rain to sleep outside. No tents or mattresses were allowed – all we took for protection were sleeping bags, groundsheets, plastic sacks and Colin’s enormous fishing umbrella (a godsend in umbrella-y disguise). Why would we do such a thing? For Byte Night, an annual tech sector sleepout in support of Action for Children, who tackle the causes as well as the consequences of youth homelessness. Byte Night encourages technology professionals to do for one night a year what thousands of young people have to do every night – sleep rough.  We signed up for Byte Night in the warm, heady midst of the British summer, thinking it couldn’t possibly be all that bad. Even on the night itself – before the rain began to fall, sat in the comfort and warmth of a company canteen, drinking wine and eating chill and preparing to win the pub quiz – we were excited and optimistic about the night that lay ahead of us. All of that changed as soon as we stepped out into one of the worst rainstorms of the year. Brian, the team’s birthday boy, describes it best: Picture the scene: it’s 3 am on a Friday. I’m lying outside, fully clothed in a sleeping bag, wearing a raincoat, trussed up inside a large plastic pocket, on a ground sheet beneath a giant umbrella, wedged so tightly between two of my colleagues that I can’t move my arms. I’m wide awake, staring up at the grey sky beyond the edge of the umbrella; a limp, flickering white glow hints at a moon somewhere behind the drifting clouds. I haven’t slept since we first moved outside at 11 pm. Outside. Did I mention we were outside? I’m hung over. I need the loo. But there is no way on earth that I’m getting out of this sleeping bag. It’s cold. It’s raining. Not just raining, but chucking it down. It’s been doing this non-stop since 10pm. The rain sounds like a hyperactive drummer on the fishing umbrella, and the noise is loud and relentless. Puddles of water are forming all over the groundsheet, and, despite being ensconced inside the plastic pouch, I am wet. The fishing umbrella is protecting me from the worst of the driving rain, but not all of me is under it, and five hours of rain is no match for it. Everything is wet. My left side has become horribly damp. My trainers, which I placed next to my sleeping bag, are now completely soaked through. Mmm. That’ll be fun in the morning. My head is next to Colin’s head on one side, and a multi-pack of McCoy’s cheddar and onion crisps on the other. Don’t ask about the tub of hummus. That’s somewhere down by my ankles, abandoned to the night. Jess, who is lying next to me, rolls over onto her side. A mini waterfall cascades from her rain-pouch onto my face. Bah. I continue to stare into the heavens, willing the dawn to hurry up. Something lands on my face. It’s a mosquito. Great. Midnight, when this still seemed like fun – when we opened some champagne and my colleagues presented me with a caterpillar birthday cake, when everyone was drunk and jolly and full of stoic resolve – feels like a long time ago. Did I mention that today is my birthday? The remains of the caterpillar cake endure the same fate as the hummus, left out in the rain like a metaphor for sadness. It’s getting colder. I can see my breath. Silence has descended on the group, apart from the rustle of plastic. And the rain, obviously. Someone snores, and I envy whoever it is the sweet escape of sleep. I try to wriggle a bit further down inside my sleeping bag, but it doesn’t want to be wriggled into. Only 3 hours till dawn. 180 minutes. I begin to count them off, one at a time.  All nine of us got to go home in the morning, but thousands of children across the UK don’t have that luxury. If you’d like to sponsor the Red Gate Byte Night team, our JustGiving page can be found here.   Chris, before the outside bit actually happened. More photos from Byte Night Cambridge 2012 can be found here.

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  • Supporting users if they're not on your site

    - by Roger Hart
    Have a look at this Read Write Web article, specifically the paragraph in bold and the comments. Have a wry chuckle, or maybe weep for the future of humanity - your call. Then pause, and worry about information architecture. The short story: Read Write Web bumps up the Google rankings for "Facebook login" at the same time as Facebook makes UI changes, and a few hundred users get confused and leave comments on Read Write Web complaining about not being able to log in to their Facebook accounts.* Blindly clicking the first Google result is not a navigation behaviour I'd anticipated for folks visiting big names sites like Facebook. But then, I use Launchy and don't know where any of my files are, depend on Firefox auto-complete, view Facebook through my IM client, and don't need a map to find my backside with both hands. Not all our users behave in the same way, which means not all of our architecture is within our control, and people can get to your content in all sorts of ways. Even if the Read Write Web episode is a prank of some kind (there are, after all, plenty of folks who enjoy orchestrated trolling) it's still a useful reminder. Your users may take paths through and to your content you cannot control, and they are unlikely to deconstruct their assumptions along the way. I guess the meaningful question is: can you still support those users? If they get to you from Google instead of your front door, does what they find still make sense? Does your information architecture still work if your guests come in through the bathroom window? Ok, so here they broke into the house next door - you can't be expected to deal with that. But the rest is well worth thinking about. Other off-site interaction It's rarely going to be as funny as the comments at Read Write Web, but your users are going to do, say, and read things they think of as being about you and your products, in places you don't control. That's good. If you pay attention to it, you get data. Your users get a better experience. There are easy wins, too. Blogs, forums, social media &c. People may look for and find help with your product on blogs and forums, on Twitter, and what have you. They may learn about your brand in the same way. That's fine, it's an interaction you can be part of. It's time-consuming, certainly, but you have the option. You won't get a blogger to incorporate your site navigation just in case your users end up there, but you can be there when they do. Again, Anne Gentle, Gordon McLean and others have covered this in more depth than I could. Direct contact Sales people, customer care, support, they all talk to people. Are they sending links to your content? if so, which bits? Do they know about all of it? Do they have the content they need to support them - messaging that funnels sales, FAQ that are realistically frequent, detailed examples of things people want to do, that kind of thing. Are they sending links because users can't find the good stuff? Are they sending précis of your content, or re-writes, or brand new stuff? If so, does that mean your content isn't up to scratch, or that you've got content missing? Direct sales/care/support interactions are enormously valuable, and can help you know what content your users find useful. You can't have a table of contents or a "See also" in a phonecall, but your content strategy can support more interactions than browsing. *Passing observation about Facebook. For plenty if folks, it is  the internet. Its services are simple versions of what a lot of people use the internet for, and they're aggregated into one stop. Flickr, Vimeo, Wordpress, Twitter, LinkedIn, and all sorts of games, have Facebook doppelgangers that are not only friendlier to entry-level users, they're right there, behind only one layer of authentication. As such, it could own a lot of interaction convention. Heavy users may well not be tech-savvy, and be quite change averse. That doesn't make this episode not dumb, but I'm happy to go easy on 'em.

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  • Frameskipping in Android gameloop causing choppy sprites (Open GL ES 2.0)

    - by user22241
    I have written a simple 2d platform game for Android and am wondering how one deals with frame-skipping? Are there any alternatives? Let me explain further. So, my game loop allows for the rendering to be skipped if game updates and rendering do not fit into my fixed time-slice (16.667ms). This allows my game to run at identically perceived speeds on different devices. And this works great, things do run at the same speed. However, when the gameloop skips a render call for even one frame, the sprite glitches. And thinking about it, why wouldn't it? You're seeing a sprite move say, an average of 10 pixels every 1.6 seconds, then suddenly, there is a pause of 3.2ms, and the sprite then appears to jump 20 pixels. When this happens 3 or 4 times in close succession, the result is very ugly and not something I want in my game. Therfore, my question is how does one deal with these 'pauses' and 'jumps' - I've read every article on game loops I can find (see below) and my loops are even based off of code from these articles. The articles specifically mention frame skipping but they don't make any reference to how to deal with visual glitches that result from it. I've attempted various game-loops. My loop must have a mechanism in-place to allow rendering to be skipped to keep game-speed constant across multiple devices (or alternative, if one exists) I've tried interpolation but this doesn't eliminate this specific problem (although it looks like it may mitigate the issue slightly as when it eventually draws the sprite it 'moves it back' between the old and current positions so the 'jump' isn't so big. I've also tried a form of extrapolation which does seem to keep things smooth considerably, but I find it to be next to completely useless because it plays havoc with my collision detection (even when drawing with a 'display only' coordinate - see extrapolation-breaks-collision-detection) I've tried a loop that uses Thread.sleep when drawing / updating completes with time left over, no frame skipping in this one, again fairly smooth, but runs differently on different devices so no good. And I've tried spawning my own, third thread for logic updates, but this, was extremely messy to deal with and the performance really wasn't good. (upon reading tons of forums, most people seem to agree a 2 thread loops ( so UI and GL threads) is safer / easier). Now if I remove frame skipping, then all seems to run nice and smooth, with or without inter/extrapolation. However, this isn't an option because the game then runs at different speeds on different devices as it falls behind from not being able to render fast enough. I'm running logic at 60 Ticks per second and rendering as fast as I can. I've read, as far as I can see every article out there, I've tried the loops from My Secret Garden and Fix your timestep. I've also read: Against the grain deWITTERS Game Loop Plus various other articles on Game-loops. A lot of the others are derived from the above articles or just copied word for word. These are all great, but they don't touch on the issues I'm experiencing. I really have tried everything I can think of over the course of a year to eliminate these glitches to no avail, so any and all help would be appreciated. A couple of examples of my game loops (Code follows): From My Secret Room public void onDrawFrame(GL10 gl) { //Rre-set loop back to 0 to start counting again loops=0; while(System.currentTimeMillis() > nextGameTick && loops < maxFrameskip) { SceneManager.getInstance().getCurrentScene().updateLogic(); nextGameTick += skipTicks; timeCorrection += (1000d / ticksPerSecond) % 1; nextGameTick += timeCorrection; timeCorrection %= 1; loops++; } extrapolation = (float)(System.currentTimeMillis() + skipTicks - nextGameTick) / (float)skipTicks; render(extrapolation); } And from Fix your timestep double t = 0.0; double dt2 = 0.01; double currentTime = System.currentTimeMillis()*0.001; double accumulator = 0.0; double newTime; double frameTime; @Override public void onDrawFrame(GL10 gl) { newTime = System.currentTimeMillis()*0.001; frameTime = newTime - currentTime; if ( frameTime > (dt*5)) //Allow 5 'skips' frameTime = (dt*5); currentTime = newTime; accumulator += frameTime; while ( accumulator >= dt ) { SceneManager.getInstance().getCurrentScene().updateLogic(); previousState = currentState; accumulator -= dt; } interpolation = (float) (accumulator / dt); render(interpolation); }

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  • HttpModule Init method is called several times - why?

    - by MartinF
    I was creating a http module and while debugging I noticed something which at first (at least) seemed like weird behaviour. When i set a breakpoint in the init method of the httpmodule i can see that the http module init method is being called several times even though i have only started up the website for debugging and made one single request (sometimes it is hit only 1 time, other times as many as 10 times). I know that I should expect several instances of the HttpApplication to be running and for each the http modules will be created, but when i request a single page it should be handled by a single http application object and therefore only fire the events associated once, but still it fires the events several times for each request which makes no sense - other than it must have been added several times within that httpApplication - which means it is the same httpmodule init method which is being called every time and not a new http application being created each time it hits my break point (see my code example at the bottom etc.). What could be going wrong here ? is it because i am debugging and set a breakpoint in the http module? It have noticed that it seems that if i startup the website for debugging and quickly step over the breakpoint in the httpmodule it will only hit the init method once and the same goes for the eventhandler. If I instead let it hang at the breakpoint for a few seconds the init method is being called several times (seems like it depends on how long time i wait before stepping over the breakpoint). Maybe this could be some build in feature to make sure that the httpmodule is initialised and the http application can serve requests , but it also seems like something that could have catastrophic consequences. This could seem logical, as it might be trying to finish the request and since i have set the break point it thinks something have gone wrong and try to call the init method again ? soo it can handle the request ? But is this what is happening and is everything fine (i am just guessing), or is it a real problem ? What i am specially concerned about is that if something makes it hang on the "production/live" server for a few seconds a lot of event handlers are added through the init and therefore each request to the page suddenly fires the eventhandler several times. This behaviour could quickly bring any site down. I have looked at the "original" .net code used for the httpmodules for formsauthentication and the rolemanagermodule etc but my code isnt any different that those modules uses. My code looks like this. public void Init(HttpApplication app) { if (CommunityAuthenticationIntegration.IsEnabled) { FormsAuthenticationModule formsAuthModule = (FormsAuthenticationModule) app.Modules["FormsAuthentication"]; formsAuthModule.Authenticate += new FormsAuthenticationEventHandler(this.OnAuthenticate); } } here is an example how it is done in the RoleManagerModule from the .NET framework public void Init(HttpApplication app) { if (Roles.Enabled) { app.PostAuthenticateRequest += new EventHandler(this.OnEnter); app.EndRequest += new EventHandler(this.OnLeave); } } Do anyone know what is going on? (i just hope someone out there can tell me why this is happening and assure me that everything is perfectly fine) :) UPDATE: I have tried to narrow down the problem and so far i have found that the Init method being called is always on a new object of my http module (contary to what i thought before). I seems that for the first request (when starting up the site) all of the HttpApplication objects being created and its modules are all trying to serve the first request and therefore all hit the eventhandler that is being added. I cant really figure out why this is happening. If i request another page all the HttpApplication's created (and their moduless) will again try to serve the request causing it to hit the eventhandler multiple times. But it also seems that if i then jump back to the first page (or another one) only one HttpApplication will start to take care of the request and everything is as expected - as long as i dont let it hang at a break point. If i let it hang at a breakpoint it begins to create new HttpApplication's objects and starts adding HttpApplications (more than 1) to serve/handle the request (which is already in process of being served by the HttpApplication which is currently stopped at the breakpoint). I guess or hope that it might be some intelligent "behind the scenes" way of helping to distribute and handle load and / or errors. But I have no clue. I hope some out there can assure me that it is perfectly fine and how it is supposed to be?

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  • Monitoring almost anything with BizTalk 360

    - by Michael Stephenson
    When you work in an integration environment it is common that you will find yourself in a situation where you integrate with some unusual applications or have some unusual dependencies. That is the nature of integration. When you work with BizTalk one of the common problems is that BizTalk often is the place where problems with applications you integrate with are highlighted and these external applications may have poor monitoring solutions. Fortunately if you are a working with a customer who uses BizTalk 360 then it contains a feature called the "Web Endpoint Manager". Typically the web endpoint manager is used to monitor web services that you integrate with and will ping them at appropriate times to make sure they return the expected HTTP status code. When you have an usual situation where you want to monitor something which is key to the success to your solution but you find yourself having to consider a significant custom solution to monitor the external dependency then the Web Endpoint Manager could be your friend. The endpoint manager monitors a url and checks for a certain status code. This means that you can create your own aspx web page and then make BizTalk 360 monitor this web page. Behind the web page you could write any code you wished. An example of this is architecture is shown in the below diagram.     In the custom web page you would implement some custom code to do whatever it is that you want to monitor. In the below code snippet you can see how the Page_Load default method is doing some kind of check then depending on the result of the check it returns a certain HTTP code. protected void Page_Load(object sender, EventArgs e) { var result = CheckSomething();   if (result == "Success") Response.StatusCode = 202; else if (result == "DatabaseError") Response.StatusCode = 510; else if (result == "SystemError") Response.StatusCode = 512; else Response.StatusCode = 513;   }   In BizTalk 360 you would go into the Monitor and Notify tab and then to BizTalk Environment which gives you access to the Web Endpoint Manager. You need an alarm setup which configures how the endpoint will be checked. I'm not going to go through the details of creating the alarm as this is already documented in the BizTalk 360 documentation. One point to note is that in the example I am using I setup a threshold alarm which means that the url is checked about every minute and if there is an error that persists for a period of time then the alarm will raise the alert notification. In my example I configured the alarm to fire if the error persisted for 3 minutes. The below picture shows accessing the endpoint manager.   In the web endpoint manager you would then configure your endpoint to monitor and the HTTP response code which indicates all is working fine. The below picture shows this. I now have my endpoint monitoring setup and BizTalk 360 should be checking my custom endpoint to see that it is available. If I wanted to manually sanity check that the endpoints I have registered are working fine then clicking the Refresh button will show if they are all good or not. If my custom ASP.net page which is checking my dependency gets a problem you will see in the endpoint manager that the status code does not match the expected return code and your endpoints will display in red and you can see the problem. The below picture shows this. If I use specific HTTP response codes for the errors the custom ASP.net page might encounter I can easily interpret these to know what the problem is. Using the alarms and notifications with BizTalk 360 it means when your endpoint goes into an error state you can easily configure email or SMS notifications from BizTalk 360 to tell you that your endpoint is having problems and you can use BizTalk 360 to help correlate what the problem is to allow you to investigate further. Below you can see the email which tells me my endpoint is not working.   When everything returns to normal you will see the status is now fixed and you will see a situation like below where you can see the WebEndpoints are now green and the return code matches what is expected.   Conclusion As you can see it is really easy to plug your own custom ASP.net page into the BizTalk 360 web endpoint monitoring feature. This extension then gives you the power to really extend the monitoring to almost anything you want as long as you can write some .net code to check that the dependency is available and working. It would be interesting to hear of any ideas people have around things they would monitor with this extension. More details on the end point monitor can be found on the following link: http://www.biztalk360.com/tour/monitoring_notifications

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  • DBCC CHECKDB (BatmanDb, REPAIR_ALLOW_DATA_LOSS) &ndash; Are you Feeling Lucky?

    - by David Totzke
    I’m currently working for a client on a PowerBuilder to WPF migration.  It’s one of those “I could tell you, but I’d have to kill you” kind of clients and the quick-lime pits are currently occupied by the EMC tech…but I’ve said too much already. At approximately 3 or 4 pm that day users of the Batman[1] application here in Gotham[1] started to experience problems accessing the application.  Batman[2] is a document management system here that also integrates with the ERP system.  Very little goes on here that doesn’t involve Batman in some way.  The errors being received seemed to point to network issues (TCP protocol error, connection forcibly closed by the remote host etc…) but the real issue was much more insidious. Connecting to the database via SSMS and performing selects on certain tables underlying the application areas that were having problems started to reveal the issue.  You couldn’t do a SELECT * FROM MyTable without it bombing and giving the same error noted above.  A run of DBCC CHECKDB revealed 14 tables with corruption.  One of the tables with issues was the Document table.  Pretty central to a “document management” system.  Information was obtained from IT that a single drive in the SAN went bad in the night.  A new drive was in place and was working fine.  The partition that held the Batman database is configured for RAID Level 5 so a single drive failure shouldn’t have caused any trouble and yet, the database is corrupted.  They do hourly incremental backups here so the first thing done was to try a restore.  A restore of the most recent backup failed so they worked backwards until they hit a good point.  This successful restore was for a backup at 3AM – a full day behind.  This time also roughly corresponds with the time the SAN started to report the drive failure.  The plot thickens… I got my hands on the output from DBCC CHECKDB and noticed a pattern.  What’s sad is that nobody that should have noticed the pattern in the DBCC output did notice.  There was a rush to do things to try and recover the data before anybody really understood what was wrong with it in the first place.  Cooler heads must prevail in these circumstances and some investigation should be done and a plan of action laid out or you could end up making things worse[3].  DBCC CHECKDB also told us that: repair_allow_data_loss is the minimum repair level for the errors found by DBCC CHECKDB Yikes.  That means that the database is so messed up that you’re definitely going to lose some stuff when you repair it to get it back to a consistent state.  All the more reason to do a little more investigation into the problem.  Rescuing this database is preferable to having to export all of the data possible from this database into a new one.  This is a fifteen year old application with about seven hundred tables.  There are TRIGGERS everywhere not to mention the referential integrity constraints to deal with.  Only fourteen of the tables have an issue.  We have a good backup that is missing the last 24 hours of business which means we could have a “do-over” of yesterday but that’s not a very palatable option either. All of the affected tables had TEXT columns and all of the errors were about LOB data types and orphaned off-row data which basically means TEXT, IMAGE or NTEXT columns.  If we did a SELECT on an affected table and excluded those columns, we got all of the rows.  We exported that data into a separate database.  Things are looking up.  Working on a copy of the production database we then ran DBCC CHECKDB with REPAIR_ALLOW_DATA_LOSS and that “fixed” everything up.   The allow data loss option will delete the bad rows.  This isn’t too horrible as we have all of those rows minus the text fields from out earlier export.  Now I could LEFT JOIN to the exported data to find the missing rows and INSERT them minus the TEXT column data. We had the restored data from the good 3AM backup that we could now JOIN to and, with fingers crossed, recover the missing TEXT column information.  We got lucky in that all of the affected rows were old and in the end we didn’t lose anything.  :O  All of the row counts along the way worked out and it looks like we dodged a major bullet here. We’ve heard back from EMC and it turns out the SAN firmware that they were running here is apparently buggy.  This thing is only a couple of months old.  Grrr…. They dispatched a technician that night to come and update it .  That explains why RAID didn’t save us. All-in-all this could have been a lot worse.  Given the root cause here, they basically won the lottery in not losing anything. Here are a few links to some helpful posts on the SQL Server Engine blog.  I love the title of the first one: Which part of 'REPAIR_ALLOW_DATA_LOSS' isn't clear? CHECKDB (Part 8): Can repair fix everything? (in fact, read the whole series) Ta da! Emergency mode repair (we didn’t have to resort to this one thank goodness)   Dave Just because I can…   [1] Names have been changed to protect the guilty. [2] I'm Batman. [3] And if I'm the coolest head in the room, you've got even bigger problems...

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  • Windows Workflow Foundation (WF) and things I wish were more intuitive

    - by pjohnson
    I've started using Windows Workflow Foundation, and so far ran into a few things that aren't incredibly obvious. Microsoft did a good job of providing a ton of samples, which is handy because you need them to get anywhere with WF. The docs are thin, so I've been bouncing between samples and downloadable labs to figure out how to implement various activities in a workflow. Code separation or not? You can create a workflow and activity in Visual Studio with or without code separation, i.e. just a .cs "Component" style object with a Designer.cs file, or a .xoml XML markup file with code behind (beside?) it. Absence any obvious advantage to one or the other, I used code separation for workflows and any complex custom activities, and without code separation for custom activities that just inherit from the Activity class and thus don't have anything special in the designer. So far, so good. Workflow Activity Library project type - What's the point of this separate project type? So far I don't see much advantage to keeping your custom activities in a separate project. I prefer to have as few projects as needed (and no fewer). The Designer's Toolbox window seems to find your custom activities just fine no matter where they are, and the debugging experience doesn't seem to be any different. Designer Properties - This is about the designer, and not specific to WF, but nevertheless something that's hindered me a lot more in WF than in Windows Forms or elsewhere. The Properties window does a good job of showing you property values when you hover the mouse over the values. But they don't do the same to find out what a control's type is. So maybe if I named all my activities "x1" and "x2" instead of helpful self-documenting names like "listenForStatusUpdate", then I could easily see enough of the type to determine what it is, but any names longer than those and all I get of the type is "System.Workflow.Act" or "System.Workflow.Compone". Even hitting the dropdown doesn't expand any wider, like the debugger quick watch "smart tag" popups do when you scroll through members. The only way I've found around this in VS 2008 is to widen the Properties dialog, losing precious designer real estate, then shrink it back down when you're done to see what you were doing. Really? WF Designer - This is about the designer, and I believe is specific to WF. I should be able to edit the XML in a .xoml file, or drag and drop using the designer. With WPF (at least in VS 2010 Ultimate), these are side by side, and changes to one instantly update the other. With WF, I have to right-click on the .xoml file, choose Open With, and pick XML Editor to edit the text. It looks like this is one way where WF didn't get the same attention WPF got during .NET Fx 3.0 development. Service - In the WF world, this is simply a class that talks to the workflow about things outside the workflow, not to be confused with how the term "service" is used in every other context I've seen in the Windows and .NET world, i.e. an executable that waits for events or requests from a client and services them (Windows service, web service, WCF service, etc.). ListenActivity - Such a great concept, yet so unintuitive. It seems you need at least two branches (EventDrivenActivity instances), one for your positive condition and one for a timeout. The positive condition has a HandleExternalEventActivity, and the timeout has a DelayActivity followed by however you want to handle the delay, e.g. a ThrowActivity. The timeout is simple enough; wiring up the HandleExternalEventActivity is where things get fun. You need to create a service (see above), and an interface for that service (this seems more complex than should be necessary--why not have activities just wire to a service directly?). And you need to create a custom EventArgs class that inherits from ExternalDataEventArgs--you can't create an ExternalDataEventArgs event handler directly, even if you don't need to add any more information to the event args, despite ExternalDataEventArgs not being marked as an abstract class, nor a compiler error nor warning nor any other indication that you're doing something wrong, until you run it and find that it always times out and get to check every place mentioned here to see why. Your interface and service need an event that consumes your custom EventArgs class, and a method to fire that event. You need to call that method from somewhere. Then you get to hope that you did everything just right, or that you can step through code in the debugger before your Delay timeout expires. Yes, it's as much fun as it sounds. TransactionScopeActivity - I had the bright idea of putting one in as a placeholder, then filling in the database updates later. That caused this error: The workflow hosting environment does not have a persistence service as required by an operation on the workflow instance "[GUID]". ...which is about as helpful as "Object reference not set to an instance of an object" and even more fun to debug. Google led me to this Microsoft Forums hit, and from there I figured out it didn't like that the activity had no children. Again, a Validator on TransactionScopeActivity would have pointed this out to me at design time, rather than handing me a nearly useless error at runtime. Easily enough, I disabled the activity and that fixed it. I still see huge potential in my work where WF could make things easier and more flexible, but there are some seriously rough edges at the moment. Maybe I'm just spoiled by how much easier and more intuitive development elsewhere in the .NET Framework is.

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  • Responsible BI for Excel, Even for Older Versions

    - by andrewbrust
    On Wednesday, I will have the honor of co-presenting, for both The Data Warehouse Institute (TDWI) and the New York Technology Council. on the subject of Excel and BI. My co-presenter will be none other than Bill Baker, who was a Microsoft Distinguished Engineer and, essentially, the father of BI at that company.  Details on the events are here and here. We'll be talking about PowerPivot, of course, but that's not all. Probably even more important than any one product, will be our discussion of whether the usual characterization of Excel as the nemesis of IT, the guilty pleasure of business users and the antithesis of formal BI is really valid and/or hopelessly intractable. Without giving away our punchline, I'll tell you that we are much more optimistic than that. There are huge upsides to Excel and while there are real dangers to using it in the BI space, there are standards and practices you can employ to ensure Excel is used responsibly. And when those practices are followed, Excel becomes quite powerful indeed. One of the keys to this is using Excel as a data consumer rather than data storage mechanism. Caching data in Excel is OK, but only if that data is (a) not modified and (b) configured for automated periodic refresh. PowerPivot meets both criteria -- it stores a read-only copy of your data in the form of a model, and once workbook containing a PowerPivot model is published to SharePoint, it can be configured for scheduled data refresh, on the server, requiring no user intervention whatsoever. Data refresh is a bit like hard drive backup: it will only happen reliably if it's automated, and super-easy to configure. PowerPivot hits a real home run here (as does Windows Home Server for PC backup, but I digress). The thing about PowerPivot is that it's an add-in for Excel 2010. What if you're not planning to go to that new version for quite a while? What if you’ve just deployed Office 2007 in your organization? What if you're still on Office 2003, or an even earlier version? What can you do immediately to share data responsibly and easily? As it turns out, there's a feature in Excel that's been around for quite a while, that can help: Web Queries.  The Web Query feature was introduced, ostensibly, to allow Excel to pull data in from Internet Web pages…for example, data in a stock quote history table will come in nicely, as will any data in a Web page that is displayed in an HTML table.  To use the feature In Excel 2007 or 2010, click the Data Tab or the ribbon and click the “From Web” button towards the left; in older versions use the corresponding option in  the menu or  toolbars.  Next, paste a URL into the resulting dialog box and tap Enter or click the Go button.  A preview of the Web page will come up, and the dialog will allow you to select the specific table within the page whose data you’d like to import.  Here’s an example: Now just click the table, click the Import button, and the Import Data dialog appears.  You can simply click OK to bring in your data or you can first click the Properties… button and configure the data import to be refreshed at an interval in minutes that you select.  Now your data’s in the spreadsheet and ready to worked with: Your data may be vulnerable to modification, but if you’ve set up the data refresh, any accidental or malicious changes will be corrected in time anyway. The thing about this feature is that it’s most useful not for public Web pages, but for pages behind the firewall.  In effect, the Web Query feature provides an incredibly easy way to consume data in Excel that’s “published” from an application.  Users just need a URL.  They don’t need to know server and database names and since the data is read-only, providing credentials may be unnecessary, or can be handled using integrated security.  If that’s not good enough, the Web Query can be saved to a special .iqy file, which can be edited to provide POST parameter data. The only requirement is that the data must be provided in an HTML table, with the first row providing the column names.  From an ASP.NET project, it couldn’t be easier: a simple bound GridView control is totally compatible.  Use a data source control with it, and you don’t even have to write any code.  Users can link to pages that are part of an application’s UI, or developers can create pages that are specially designed for the purpose of providing an interface to the Web Query import feature.  And none of this is Microsoft- or .NET-specific.  You can create pages in any language you want (PHP comes to mind) that output the result set of a query in HTML table format, and then consume that data in a Web Query.  Then build PivotTables and charts on the data, and in Excel 2007 or 2010 you can use conditional formatting to create scorecards and dashboards. This strategy allows you to create pages that function quite similarly to the OData XML feeds rendered when .NET developers create an “Astoria” WCF Data Service.  And while it’s cool that PowerPivot and Excel 2010 can import such OData feeds, it’s good to know that older versions of Excel can function in a similar fashion, and can consume data produced by virtually any Web development platform. As a final matter, instead of just telling you that “older versions” of Excel support this feature, I’ll be more specific.  To discover what the first version of Excel was to support Web queries, go to http://bit.ly/OldSchoolXL.

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  • Simple Preferred time control using silverlight 3.

    - by mohanbrij
    Here I am going to show you a simple preferred time control, where you can select the day of the week and the time of the day. This can be used in lots of place where you may need to display the users preferred times. Sample screenshot is attached below. This control is developed using Silverlight 3 and VS2008, I am also attaching the source code with this post. This is a very basic example. You can download and customize if further for your requirement if you want. I am trying to explain in few words how this control works and what are the different ways in which you can customize it further. File: PreferredTimeControl.xaml, in this file I have just hardcoded the controls and their positions which you can see in the screenshot above. In this example, to change the start day of the week and time, you will have to go and change the design in XAML file, its not controlled by your properties or implementation classes. You can also customize it to change the start day of the week, Language, Display format, styles, etc, etc. File: PreferredTimeControl.xaml.cs, In this control using the code below, first I am taking all the checkbox from my form and store it in the Global Variable, which I can use across my page. List<CheckBox> checkBoxList; #region Constructor public PreferredTimeControl() { InitializeComponent(); GetCheckboxes();//Keep all the checkbox in List in the Load itself } #endregion #region Helper Methods private List<CheckBox> GetCheckboxes() { //Get all the CheckBoxes in the Form checkBoxList = new List<CheckBox>(); foreach (UIElement element in LayoutRoot.Children) { if (element.GetType().ToString() == "System.Windows.Controls.CheckBox") { checkBoxList.Add(element as CheckBox); } } return checkBoxList; } Then I am exposing the two methods which you can use in the container form to get and set the values in this controls. /// <summary> /// Set the Availability on the Form, with the Provided Timings /// </summary> /// <param name="selectedTimings">Provided timings comes from the DB in the form 11,12,13....37 /// Where 11 refers to Monday Morning, 12 Tuesday Morning, etc /// Here 1, 2, 3 is for Morning, Afternoon and Evening respectively, and for weekdays /// 1,2,3,4,5,6,7 where 1 is for Monday, Tuesday, Wednesday, Thrusday, Friday, Saturday and Sunday respectively /// So if we want Monday Morning, we can can denote it as 11, similarly for Saturday Evening we can write 36, etc /// </param> public void SetAvailibility(string selectedTimings) { foreach (CheckBox chk in checkBoxList) { chk.IsChecked = false; } if (!String.IsNullOrEmpty(selectedTimings)) { string[] selectedString = selectedTimings.Split(','); foreach (string selected in selectedString) { foreach (CheckBox chk in checkBoxList) { if (chk.Tag.ToString() == selected) { chk.IsChecked = true; } } } } } /// <summary> /// Gets the Availibility from the selected checkboxes /// </summary> /// <returns>String in the format of 11,12,13...41,42...31,32...37</returns> public string GetAvailibility() { string selectedText = string.Empty; foreach (CheckBox chk in GetCheckboxes()) { if (chk.IsChecked == true) { selectedText = chk.Tag.ToString() + "," + selectedText; } } return selectedText; }   In my example I am using the matrix format for Day and Time, for example Monday=1, Tuesday=2, Wednesday=3, Thursday = 4, Friday = 5, Saturday = 6, Sunday=7. And Morning = 1, Afternoon =2, Evening = 3. So if I want to represent Morning-Monday I will have to represent it as 11, Afternoon-Tuesday as 22, Morning-Wednesday as 13, etc. And in the other way to set the values in the control I am passing the values in the control in the same format as preferredTimeControl.SetAvailibility("11,12,13,16,23,22"); So this will set the checkbox value for Morning-Monday, Morning-Tuesday, Morning-Wednesday, Morning-Saturday, Afternoon of Tuesday and Afternoon of Wednesday. To implement this control, first I have to import this control in xmlns namespace as xmlns:controls="clr-namespace:PreferredTimeControlApp" and finally put in your page wherever you want, <Grid x:Name="LayoutRoot" Style="{StaticResource LayoutRootGridStyle}"> <Border x:Name="ContentBorder" Style="{StaticResource ContentBorderStyle}"> <controls:PreferredTimeControl x:Name="preferredTimeControl"></controls:PreferredTimeControl> </Border> </Grid> And in the code behind you can just include this code: private void InitializeControl() { preferredTimeControl.SetAvailibility("11,12,13,16,23,22"); } And you are ready to go. For more details you can refer to my code attached. I know there can be even simpler and better way to do this. Let me know if any other ideas. Sorry, Guys Still I have used Silverlight 3 and VS2008, as from the system I am uploading this is still not upgraded, but still you can use the same code with Silverlight 4 and VS2010 without any changes. May be just it will ask you to upgrade your project which will take care of rest. Download Source Code.   Thanks ~Brij

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  • SQLAuthority News – #TechEdIn – TechEd India 2012 Memories and Photos

    - by pinaldave
    TechEd India 2012 was held in Bangalore last March 21 to 23, 2012. Just like every year, this event is bigger, grander and inspiring. Pinal Dave at TechEd India 2012 Family Event Every single year, TechEd is a special affair for my entire family.  Four months before the start of TechEd, I usually start to build the mental image of the event. I start to think  about various things. For the most part, what excites me most is presenting a session and meeting friends. Seriously, I start thinking about presenting my session 4 months earlier than the event!  I work on my presentation day and night. I want to make sure that what I present is accurate and that I have experienced it firsthand. My wife and my daughter also contribute to my efforts. For us, TechEd is a family event, and the two of them feel equally responsible as well. They give up their family time so I can bring out the best content for the Community. Pinal, Shaivi and Nupur at TechEd India 2012 Guinea Pigs (My Experiment Victims) I do not rehearse my session, ever. However, I test my demo almost every single day till the last moment that I have to present it already. I sometimes go over the demo more than 2-3 times a day even though the event is more than a month away. I have two “guinea pigs”: 1) Nupur Dave and 2) Vinod Kumar. When I am at home, I present my demos to my wife Nupur. At times I feel that people often backup their demo, but in my case, I have backup demo presenters. In the office during lunch time, I present the demos to Vinod. I am sure he can walk my demos easily with eyes closed. Pinal and Vinod at TechEd India 2012 My Sessions I’ve been determined to present my sessions in a real and practical manner. I prefer to present the subject that I myself would be eager to attend to and sit through if I were an audience. Just keeping that principle in mind, I have created two sessions this year. SQL Server Misconception and Resolution Pinal and Vinod at TechEd India 2012 We believe all kinds of stuff – that the earth is flat, or that the forbidden fruit is apple, or that the big bang theory explains the origin of the universe, and so many other things. Just like these, we have plenty of misconceptions in SQL Server as well. I have had this dream of co-presenting a session with Vinod Kumar for the past 3 years. I have been asking him every year if we could present a session together, but we never got it to work out, until this year came. Fortunately, we got a chance to stand on the same stage and present a single subject.  I believe that Vinod Kumar and I have an excellent synergy when we are working together. We know each other’s strengths and weakness. We know when the other person will speak and when he will keep quiet. The reason behind this synergy is that we have worked on 2 Video Learning Courses (SQL Server Indexes and SQL Server Questions and Answers) and authored 1 book (SQL Server Questions and Answers) together. Crowd Outside Session Hall This session was inspired from the “Laurel and Hardy” show so we performed a role-playing of those famous characters. We had an excellent time at the stage and, for sure, the audience had a wonderful time, too. We had an extremely large audience for this session and had a great time interacting with them. Speed Up! – Parallel Processes and Unparalleled Performance Pinal Dave at TechEd India 2012 I wanted to approach this session at level 400 and I was very determined to do so. The biggest challenge I had was that this was a total of 60 minutes of session and the audience profile was very generic. I had to present at level 100 as well at 400. I worked hard to tune up these demos. I wanted to make sure that my messages would land perfectly to the minds of the attendees, and when they walk out of the session, they could use the knowledge I shared on their servers. After the session, I felt an extreme satisfaction as I received lots of positive feedback at the event. At one point, so many people rushed towards me that I was a bit scared that the stage might break and someone would get injured. Fortunately, nothing like that happened and I was able to shake hands with everybody. Pinal Dave at TechEd India 2012 Crowd rushing to Pinal at TechEd India 2012 Networking This is one of the primary reasons many of us visit the annual TechEd event. I had a fantastic time meeting SQL Server enthusiasts. Well, it was a terrific time meeting old friends, user group members, MVPs and SQL Enthusiasts. I have taken many photographs with lots of people, but I have received a very few back. If you are reading this blog and have a photo of us at the event, would you please send it to me so I could keep it in my memory lane? SQL Track Speaker: Jacob and Pinal at TechEd India 2012 SQL Community: Pinal, Tejas, Nakul, Jacob, Balmukund, Manas, Sudeepta, Sahal at TechEd India 2012 Star Speakers: Amit and Balmukund at TechEd India 2012 TechED Rockstars: Nakul, Tejas and Pinal at TechEd India 2012 I guess TechEd is a mix of family affair and culture for me! Hamara TechEd (Our TechEd) Please tell me which photo you like the most! Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Author Visit, SQLAuthority News, SQLServer, T SQL, Technology Tagged: TechEd, TechEdIn

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  • Scripting out Contained Database Users

    - by Argenis
      Today’s blog post comes from a Twitter thread on which @SQLSoldier, @sqlstudent144 and @SQLTaiob were discussing the internals of contained database users. Unless you have been living under a rock, you’ve heard about the concept of contained users within a SQL Server database (hit the link if you have not). In this article I’d like to show you that you can, indeed, script out contained database users and recreate them on another database, as either contained users or as good old fashioned logins/server principals as well. Why would this be useful? Well, because you would not need to know the password for the user in order to recreate it on another instance. I know there is a limited number of scenarios where this would be necessary, but nonetheless I figured I’d throw this blog post to show how it can be done. A more obscure use case: with the password hash (which I’m about to show you how to obtain) you could also crack the password using a utility like hashcat, as highlighted on this SQLServerCentral article. The Investigation SQL Server uses System Base Tables to save the password hashes of logins and contained database users. For logins it uses sys.sysxlgns, whereas for contained database users it leverages sys.sysowners. I’ll show you what I do to figure this stuff out: I create a login/contained user, and then I immediately browse the transaction log with, for example, fn_dblog. It’s pretty obvious that only two base tables touched by the operation are sys.sysxlgns, and also sys.sysprivs – the latter is used to track permissions. If I connect to the DAC on my instance, I can query for the password hash of this login I’ve just created. A few interesting things about this hash. This was taken on my laptop, and I happen to be running SQL Server 2014 RTM CU2, which is the latest public build of SQL Server 2014 as of time of writing. In 2008 R2 and prior versions (back to 2000), the password hashes would start with 0x0100. The reason why this changed is because starting with SQL Server 2012 password hashes are kept using a SHA512 algorithm, as opposed to SHA-1 (used since 2000) or Snefru (used in 6.5 and 7.0). SHA-1 is nowadays deemed unsafe and is very easy to crack. For regular SQL logins, this information is exposed through the sys.sql_logins catalog view, so there is really no need to connect to the DAC to grab an SID/password hash pair. For contained database users, there is (currently) no method of obtaining SID or password hashes without connecting to the DAC. If we create a contained database user, this is what we get from the transaction log: Note that the System Base Table used in this case is sys.sysowners. sys.sysprivs is used as well, and again this is to track permissions. To query sys.sysowners, you would have to connect to the DAC, as I mentioned previously. And this is what you would get: There are other ways to figure out what SQL Server uses under the hood to store contained database user password hashes, like looking at the execution plan for a query to sys.dm_db_uncontained_entities (Thanks, Robert Davis!) SIDs, Logins, Contained Users, and Why You Care…Or Not. One of the reasons behind the existence of Contained Users was the concept of portability of databases: it is really painful to maintain Server Principals (Logins) synced across most shared-nothing SQL Server HA/DR technologies (Mirroring, Availability Groups, and Log Shipping). Often times you would need the Security Identifier (SID) of these logins to match across instances, and that meant that you had to fetch whatever SID was assigned to the login on the principal instance so you could recreate it on a secondary. With contained users you normally wouldn’t care about SIDs, as the users are always available (and synced, as long as synchronization takes place) across instances. Now you might be presented some particular requirement that might specify that SIDs synced between logins on certain instances and contained database users on other databases. How would you go about creating a contained database user with a specific SID? The answer is that you can’t do it directly, but there’s a little trick that would allow you to do it. Create a login with a specified SID and password hash, create a user for that server principal on a partially contained database, then migrate that user to contained using the system stored procedure sp_user_migrate_to_contained, then drop the login. CREATE LOGIN <login_name> WITH PASSWORD = <password_hash> HASHED, SID = <sid> ; GO USE <partially_contained_db>; GO CREATE USER <user_name> FROM LOGIN <login_name>; GO EXEC sp_migrate_user_to_contained @username = <user_name>, @rename = N’keep_name’, @disablelogin = N‘disable_login’; GO DROP LOGIN <login_name>; GO Here’s how this skeleton would look like in action: And now I have a contained user with a specified SID and password hash. In my example above, I renamed the user after migrated it to contained so that it is, hopefully, easier to understand. Enjoy!

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  • Get and Set property accessors are ‘actually’ methods

    - by nmarun
    Well, they are ‘special’ methods, but they indeed are methods. See the class below: 1: public class Person 2: { 3: private string _name; 4:  5: public string Name 6: { 7: get 8: { 9: return _name; 10: } 11: set 12: { 13: if (value == "aaa") 14: { 15: throw new ArgumentException("Invalid Name"); 16: } 17: _name = value; 18: } 19: } 20:  21: public void Save() 22: { 23: Console.WriteLine("Saving..."); 24: } 25: } Ok, so a class with a field, a property with the get and set accessors and a method. Now my calling code says: 1: static void Main() 2: { 3: try 4: { 5: Person person1 = new Person 6: { 7: Name = "aaa", 8: }; 9:  10: } 11: catch (Exception ex) 12: { 13: Console.WriteLine(ex.Message); 14: Console.WriteLine(ex.StackTrace); 15: Console.WriteLine("--------------------"); 16: } 17: } When the code is run, you’ll get the following exception message displayed: Now, you see the first line of the stack trace where it says that the exception was thrown in the method set_Name(String value). Wait a minute, we have not declared any method with that name in our Person class. Oh no, we actually have. When you create a property, this is what happens behind the screen. The CLR creates two methods for each get and set property accessor. Let’s look at the signature once again: set_Name(String value) This also tells you where the ‘value’ keyword comes from in our set property accessor. You’re actually wiring up a method parameter to a field. 1: set 2: { 3: if (value == "aaa") 4: { 5: throw new ArgumentException("Invalid Name"); 6: } 7: _name = value; 8: } Digging deeper on this, I ran the ILDasm tool and this is what I see: We see the ‘free’ constructor (named .ctor) that the compiler gives us, the _name field, the Name property and the Save method. We also see the get_Name and set_Name methods. In order to compare the Save and the set_Name methods, I double-clicked on the two methods and this is what I see: The ‘.method’ keyword tells that both Save and set_Name are both methods (no guessing there!). Seeing the set_Name method as a public method did kinda surprise me. So I said, why can’t I do a person1.set_Name(“abc”) since it is declared as public. This cannot be done because the get_Name and set_Name methods have an extra attribute called ‘specialname’. This attribute is used to identify an IL (Intermediate Language) token that can be treated with special care by the .net language. So the thumb-rule is that any method with the ‘specialname’ attribute cannot be generally called / invoked by the user (a simple test using intellisense proves this). Their functionality is exposed through other ways. In our case, this is done through the property itself. The same concept gets extended to constructors as well making them special methods too. These so-called ‘special’ methods can be identified through reflection. 1: static void ReflectOnPerson() 2: { 3: Type personType = typeof(Person); 4:  5: MethodInfo[] methods = personType.GetMethods(); 6:  7: for (int i = 0; i < methods.Length; i++) 8: { 9: Console.Write("Method: {0}", methods[i].Name); 10: // Determine whether or not each method is a special name. 11: if (methods[i].IsSpecialName) 12: { 13: Console.Write(" has 'SpecialName' attribute"); 14: } 15: Console.WriteLine(); 16: } 17: } Line 11 shows the ‘IsSpecialName’ boolean property. So a method with a ‘specialname’ attribute gets mapped to the IsSpecialName property. The output is displayed as: Wuhuuu! There they are.. our special guests / methods. Verdict: Getting to know the internals… helps!

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  • Oracle Social Network Developer Challenge Winners

    - by kellsey.ruppel
    Originally posted by Jake Kuramoto on The Apps Lab blog. Now that OpenWorld 2012 has wrapped, I have time to tell you all about what happened. Maybe you recall that Noel (@noelportugal) and I were running a modified hackathon during the show, the Oracle Social Network Developer Challenge. Without further ado, congratulations to Dimitri Gielis (@dgielis) and Martin Giffy D’Souza (@martindsouza) on their winning entry, an integration between Oracle APEX and Oracle Social Network that integrates feedback and bug submission with Oracle Social Network Conversations, allowing developers, end-users and project leaders to view and discuss the feedback on their APEX applications from within Oracle Social Network. Update: Bob Rhubart of OTN (@brhubart) interviewed Dimitri and Martin right after their big win. Money quote from Dimitri when asked what he’d buy with the $500 in Amazon gift cards, “Oracle Social Network.” Nice one. In their own words: In the developers perspective it’s important to get feedback soon, so after a first iteration and end-users start to test, they can give feedback of the application. Previously it stopped there, and it was up to the developer to communicate further with email, phone etc. With OSN every feedback and communication gets logged and other people can see the discussion immediately as well. For the end users perspective he can now communicate in a more efficient way to not only the developers, but also between themselves. Maybe many end-users (in different locations) would like to change some behaviour, by using OSN they can see the entry somebody put in with a screenshot and they can just start to chat about it. Some key technical end users can have lighten the tasks of the development team by looking at the feedback first and start to communicate with their peers. For the project manager he has now the ability to really see what communication has taken place in certain areas and can make decisions on that. Later, if things come up again, he can always go back in OSN and see what was said at that moment in time. Integrating OSN in the APEX applications enhances the user experience, makes the lives of the developers easier and gives a better overview to project managers. Incidentally, you may already know Dimitri and Martin, since both are Oracle Ace Directors. I ran into Martin at the Ace Director briefings Friday before the conference started, and at that point, he wasn’t sure he’d have time to enter the Challenge. After some coaxing, he and Dimitri agreed to give it a go and banged out their entry on Tuesday night, or more accurately, very early Wednesday morning, the day of the Challenge judging. I think they said it took them about four hours of hardcore coding to get it done, very much like a traditional hackathon, which is essentially a code sprint from idea to finished product. Here are some screenshots of the workflow they built. #gallery-1 { margin: auto; } #gallery-1 .gallery-item { float: left; margin-top: 10px; text-align: center; width: 33%; } #gallery-1 img { border: 2px solid #cfcfcf; } #gallery-1 .gallery-caption { margin-left: 0; } I love this idea, i.e. closing the loop between web developers and users, a very common pain point, and so did our judges. Speaking of, special thanks to our panel of three judges: Reggie Bradford (@reggiebradford), serial entrepreneur, founder of Vitrue and SVP of Cloud Product Development at Oracle Robert Hipps (@roberthipps), VP of Development for Oracle Social Network and my former boss Roland Smart (@rsmartx), VP of Social Marketing and the brains behind the Oracle Social Developer Community Finally, thanks to everyone who made this possible, including: The three other teams from HarQen (@harqen), TEAM Informatics (@teaminformatics) and Fishbowl Solutions (@fishbowle20) featuring Friend of the ‘Lab John Sim (@jrsim_uix), who finished and presented entries. I’ll be posting the details of their work this week. The one guy who finished an entry, but couldn’t make the judging, Bex Huff (@bex). Bex rallied from a hospitalization due to an allergic reaction during the show; he’s fine, don’t worry. I’ll post details of his work next week, too. The 40-plus people who registered to compete in the Challenge. Noel for all his hard work, sample code, and flying monkey target, more on that to come. The Oracle Social Network development team for supporting this event. Everyone in legal and the beta program office for their help. And finally, the Oracle Technology Network (@oracletechnet) for hosting the event and providing countless hours of operational and moral support. Sorry if I’ve missed some people, since this was a huge team effort. This event was a big success, and we plan to do similar events in the future. Stay tuned to this channel for more. 

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  • What Counts For a DBA: Simplicity

    - by Louis Davidson
    Too many computer processes do an apparently simple task in a bizarrely complex way. They remind me of this strip by one of my favorite artists: Rube Goldberg. In order to keep the boss from knowing one was late, a process is devised whereby the cuckoo clock kisses a live cuckoo bird, who then pulls a string, which triggers a hat flinging, which in turn lands on a rod that removes a typewriter cover…and so on. We rely on creating automated processes to keep on top of tasks. DBAs have a lot of tasks to perform: backups, performance tuning, data movement, system monitoring, and of course, avoiding being noticed.  Every day, there are many steps to perform to maintain the database infrastructure, including: checking physical structures, re-indexing tables where needed, backing up the databases, checking those backups, running the ETL, and preparing the daily reports and yes, all of these processes have to complete before you can call it a day, and probably before many others have started that same day. Some of these tasks are just naturally complicated on their own. Other tasks become complicated because the database architecture is excessively rigid, and we often discover during “production testing” that certain processes need to be changed because the written requirements barely resembled the actual customer requirements.   Then, with no time to change that rigid structure, we are forced to heap layer upon layer of code onto the problematic processes. Instead of a slight table change and a new index, we end up with 4 new ETL processes, 20 temp tables, 30 extra queries, and 1000 lines of SQL code.  Report writers then need to build reports and make magical numbers appear from those toxic data structures that are overly complex and probably filled with inconsistent data. What starts out as a collection of fairly simple tasks turns into a Goldbergian nightmare of daily processes that are likely to cause your dinner to be interrupted by the smartphone doing the vibration dance that signifies trouble at the mill. So what to do? Well, if it is at all possible, simplify the problem by either going into the code and refactoring the complex code to simple, or taking all of the processes and simplifying them into small, independent, easily-tested steps.  The former approach usually requires an agreement on changing underlying structures that requires countless mind-numbing meetings; while the latter can generally be done to any complex process without the same frustration or anger, though it will still leave you with lots of steps to complete, the ability to test each step independently will definitely increase the quality of the overall process (and with each step reporting status back, finding an actual problem within the process will be definitely less unpleasant.) We all know the principle behind simplifying a sequence of processes because we learned it in math classes in our early years of attending school, starting with elementary school. In my 4 years (ok, 9 years) of undergraduate work, I remember pretty much one thing from my many math classes that I apply daily to my career as a data architect, data programmer, and as an occasional indentured DBA: “show your work”. This process of showing your work was my first lesson in simplification. Each step in the process was in fact, far simpler than the entire process.  When you were working an equation that took both sides of 4 sheets of paper, showing your work was important because the teacher could see every step, judge it, and mark it accordingly.  So often I would make an error in the first few lines of a problem which meant that the rest of the work was actually moving me closer to a very wrong answer, no matter how correct the math was in the subsequent steps. Yet, when I got my grade back, I would sometimes be pleasantly surprised. I passed, yet missed every problem on the test. But why? While I got the fact that 1+1=2 wrong in every problem, the teacher could see that I was using the right process. In a computer process, the process is very similar. We take complex processes, show our work by storing intermediate values, and test each step independently. When a process has 100 steps, each step becomes a simple step that is tested and verified, such that there will be 100 places where data is stored, validated, and can be checked off as complete. If you get step 1 of 100 wrong, you can fix it and be confident (that if you did your job of testing the other steps better than the one you had to repair,) that the rest of the process works. If you have 100 steps, and store the state of the process exactly once, the resulting testable chunk of code will be far more complex and finding the error will require checking all 100 steps as one, and usually it would be easier to find a specific needle in a stack of similarly shaped needles.  The goal is to strive for simplicity either in the solution, or at least by simplifying every process down to as many, independent, testable, simple tasks as possible.  For the tasks that really can’t be done completely independently, minimally take those tasks and break them down into simpler steps that can be tested independently.  Like working out division problems longhand, have each step of the larger problem verified and tested.

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  • T-SQL Tuesday #21 - Crap!

    - by Most Valuable Yak (Rob Volk)
    Adam Machanic's (blog | twitter) ever popular T-SQL Tuesday series is being held on Wednesday this time, and the topic is… SHIT CRAP. No, not fecal material.  But crap code.  Crap SQL.  Crap ideas that you thought were good at the time, or were forced to do due (doo-doo?) to lack of time. The challenge for me is to look back on my SQL Server career and find something that WASN'T crap.  Well, there's a lot that wasn't, but for some reason I don't remember those that well.  So the additional challenge is to pick one particular turd that I really wish I hadn't squeezed out.  Let's see if this outline fits the bill: An ETL process on text files; That had to interface between SQL Server and an AS/400 system; That didn't use SSIS (should have) or BizTalk (ummm, no) but command-line scripting, using Unix utilities(!) via: xp_cmdshell; That had to email reports and financial data, some of it sensitive Yep, the stench smell is coming back to me now, as if it was yesterday… As to why SSIS and BizTalk were not options, basically I didn't know either of them well enough to get the job done (and I still don't).  I also had a strict deadline of 3 days, in addition to all the other responsibilities I had, so no time to learn them.  And seeing how screwed up the rest of the process was: Payment files from multiple vendors in multiple formats; Sent via FTP, PGP encrypted email, or some other wizardry; Manually opened/downloaded and saved to a particular set of folders (couldn't change this); Once processed, had to be placed BACK in the same folders with the original archived; x2 divisions that had to run separately; Plus an additional vendor file in another format on a completely different schedule; So that they could be MANUALLY uploaded into the AS/400 system (couldn't change this either, even if it was technically possible) I didn't feel so bad about the solution I came up with, which was naturally: Copy the payment files to the local SQL Server drives, using xp_cmdshell Run batch files (via xp_cmdshell) to parse the different formats using sed, a Unix utility (this was before Powershell) Use other Unix utilities (join, split, grep, wc) to process parsed files and generate metadata (size, date, checksum, line count) Run sqlcmd to execute a stored procedure that passed the parsed file names so it would bulk load the data to do a comparison bcp the compared data out to ANOTHER text file so that I could grep that data out of the original file Run another stored procedure to import the matched data into SQL Server so it could process the payments, including file metadata Process payment batches and log which division and vendor they belong to Email the payment details to the finance group (since it was too hard for them to run a web report with the same data…which they ran anyway to compare the emailed file against…which always matched, surprisingly) Email another report showing unmatched payments so they could manually void them…about 3 months afterward All in "Excel" format, using xp_sendmail (SQL 2000 system) Copy the unmatched data back to the original folder locations, making sure to match the file format exactly (if you've ever worked with ACH files, you'll understand why this sucked) If you're one of the 10 people who have read my blog before, you know that I love the DOS "for" command.  Like passionately.  Like fairy-tale love.  So my batch files were riddled with for loops, nested within other for loops, that called other batch files containing for loops.  I think there was one section that had 4 or 5 nested for commands.  It was wrong, disturbed, and completely un-maintainable by anyone, even myself.  Months, even a year, after I left the company I got calls from someone who had to make a minor change to it, and they called me to talk them out of spraying the office with an AK-47 after looking at this code.  (for you Star Trek TOS fans) The funniest part of this, well, one of the funniest, is that I made the deadline…sort of, I was only a day late…and the DAMN THING WORKED practically unchanged for 3 years.  Most of the problems came from the manual parts of the overall process, like forgetting to decrypt the files, or missing/late files, or saved to the wrong folders.  I'm definitely not trying to toot my own horn here, because this was truly one of the dumbest, crappiest solutions I ever came up with.  Fortunately as far as I know it's no longer in use and someone has written a proper replacement.  Today I would knuckle down and do it in SSIS or Powershell, even if it took me weeks to get it right. The real lesson from this crap code is to make things MAINTAINABLE and UNDERSTANDABLE.  sed scripting regular expressions doesn't fit that criteria in any way.  If you ever find yourself under pressure to do something fast at all costs, DON'T DO IT.  Stop and consider long-term maintainability, not just for yourself but for others on your team.  If you can't explain the basic approach in under 5 minutes, it ultimately won't succeed.  And while you may love to leave all that crap behind, it may follow you anyway, and you'll step in it again.   P.S. - if you're wondering about all the manual stuff that couldn't be changed, it was because the entire process had gone through Six Sigma, and was deemed the best possible way.  Phew!  Talk about stink!

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  • R Package Installation with Oracle R Enterprise

    - by Sherry LaMonica-Oracle
    Normal 0 false false false EN-US X-NONE X-NONE Programming languages give developers the opportunity to write reusable functions and to bundle those functions into logical deployable entities. In R, these are called packages. R has thousands of such packages provided by an almost equally large group of third-party contributors. To allow others to benefit from these packages, users can share packages on the CRAN system for use by the vast R development community worldwide. R's package system along with the CRAN framework provides a process for authoring, documenting and distributing packages to millions of users. In this post, we'll illustrate the various ways in which such R packages can be installed for use with R and together with Oracle R Enterprise. In the following, the same instructions apply when using either open source R or Oracle R Distribution. In this post, we cover the following package installation scenarios for: R command line Linux shell command line Use with Oracle R Enterprise Installation on Exadata or RAC Installing all packages in a CRAN Task View Troubleshooting common errors 1. R Package Installation BasicsR package installation basics are outlined in Chapter 6 of the R Installation and Administration Guide. There are two ways to install packages from the command line: from the R command line and from the shell command line. For this first example on Oracle Linux using Oracle R Distribution, we’ll install the arules package as root so that packages will be installed in the default R system-wide location where all users can access it, /usr/lib64/R/library.Within R, using the install.packages function always attempts to install the latest version of the requested package available on CRAN:R> install.packages("arules")If the arules package depends upon other packages that are not already installed locally, the R installer automatically downloads and installs those required packages. This is a huge benefit that frees users from the task of identifying and resolving those dependencies.You can also install R from the shell command line. This is useful for some packages when an internet connection is not available or for installing packages not uploaded to CRAN. To install packages this way, first locate the package on CRAN and then download the package source to your local machine. For example:$ wget http://cran.r-project.org/src/contrib/arules_1.1-2.tar.gz Then, install the package using the command R CMD INSTALL:$ R CMD INSTALL arules_1.1-2.tar.gzA major difference between installing R packages using the R package installer at the R command line and shell command line is that package dependencies must be resolved manually at the shell command line. Package dependencies are listed in the Depends section of the package’s CRAN site. If dependencies are not identified and installed prior to the package’s installation, you will see an error similar to:ERROR: dependency ‘xxx’ is not available for package ‘yyy’As a best practice and to save time, always refer to the package’s CRAN site to understand the package dependencies prior to attempting an installation. If you don’t run R as root, you won’t have permission to write packages into the default system-wide location and you will be prompted to create a personal library accessible by your userid. You can accept the personal library path chosen by R, or specify the library location by passing parameters to the install.packages function. For example, to create an R package repository in your home directory: R> install.packages("arules", lib="/home/username/Rpackages")or$ R CMD INSTALL arules_1.1-2.tar.gz --library=/home/username/RpackagesRefer to the install.packages help file in R or execute R CMD INSTALL --help at the shell command line for a full list of command line options.To set the library location and avoid having to specify this at every package install, simply create the R startup environment file .Renviron in your home area if it does not already exist, and add the following piece of code to it:R_LIBS_USER = "/home/username/Rpackages" 2. Setting the RepositoryEach time you install an R package from the R command line, you are asked which CRAN mirror, or server, R should use. To set the repository and avoid having to specify this during every package installation, create the R startup command file .Rprofile in your home directory and add the following R code to it:cat("Setting Seattle repository")r = getOption("repos") r["CRAN"] = "http://cran.fhcrc.org/"options(repos = r)rm(r) This code snippet sets the R package repository to the Seattle CRAN mirror at the start of each R session. 3. Installing R Packages for use with Oracle R EnterpriseEmbedded R execution with Oracle R Enterprise allows the use of CRAN or other third-party R packages in user-defined R functions executed on the Oracle Database server. The steps for installing and configuring packages for use with Oracle R Enterprise are the same as for open source R. The database-side R engine just needs to know where to find the R packages.The Oracle R Enterprise installation is performed by user oracle, which typically does not have write permission to the default site-wide library, /usr/lib64/R/library. On Linux and UNIX platforms, the Oracle R Enterprise Server installation provides the ORE script, which is executed from the operating system shell to install R packages and to start R. The ORE script is a wrapper for the default R script, a shell wrapper for the R executable. It can be used to start R, run batch scripts, and build or install R packages. Unlike the default R script, the ORE script installs packages to a location writable by user oracle and accessible by all ORE users - $ORACLE_HOME/R/library.To install a package on the database server so that it can be used by any R user and for use in embedded R execution, an Oracle DBA would typically download the package source from CRAN using wget. If the package depends on any packages that are not in the R distribution in use, download the sources for those packages, also.  For a single Oracle Database instance, replace the R script with ORE to install the packages in the same location as the Oracle R Enterprise packages. $ wget http://cran.r-project.org/src/contrib/arules_1.1-2.tar.gz$ ORE CMD INSTALL arules_1.1-2.tar.gzBehind the scenes, the ORE script performs the equivalent of setting R_LIBS_USER to the value of $ORACLE_HOME/R/library, and all R packages installed with the ORE script are installed to this location. For installing a package on multiple database servers, such as those in an Oracle Real Application Clusters (Oracle RAC) or a multinode Oracle Exadata Database Machine environment, use the ORE script in conjunction with the Exadata Distributed Command Line Interface (DCLI) utility.$ dcli -g nodes -l oracle ORE CMD INSTALL arules_1.1-1.tar.gz The DCLI -g flag designates a file containing a list of nodes to install on, and the -l flag specifies the user id to use when executing the commands. For more information on using DCLI with Oracle R Enterprise, see Chapter 5 in the Oracle R Enterprise Installation Guide.If you are using an Oracle R Enterprise client, install the package the same as any R package, bearing in mind that you must install the same version of the package on both the client and server machines to avoid incompatibilities. 4. CRAN Task ViewsCRAN also maintains a set of Task Views that identify packages associated with a particular task or methodology. Task Views are helpful in guiding users through the huge set of available R packages. They are actively maintained by volunteers who include detailed annotations for routines and packages. If you find one of the task views is a perfect match, you can install every package in that view using the ctv package - an R package for automating package installation. To use the ctv package to install a task view, first, install and load the ctv package.R> install.packages("ctv")R> library(ctv)Then query the names of the available task views and install the view you choose.R> available.views() R> install.views("TimeSeries") 5. Using and Managing R packages To use a package, start up R and load packages one at a time with the library command.Load the arules package in your R session. R> library(arules)Verify the version of arules installed.R> packageVersion("arules")[1] '1.1.2'Verify the version of arules installed on the database server using embedded R execution.R> ore.doEval(function() packageVersion("arules"))View the help file for the apropos function in the arules packageR> ?aproposOver time, your package repository will contain more and more packages, especially if you are using the system-wide repository where others are adding additional packages. It’s good to know the entire set of R packages accessible in your environment. To list all available packages in your local R session, use the installed.packages command:R> myLocalPackages <- row.names(installed.packages())R> myLocalPackagesTo access the list of available packages on the ORE database server from the ORE client, use the following embedded R syntax: R> myServerPackages <- ore.doEval(function() row.names(installed.packages()) R> myServerPackages 6. Troubleshooting Common ProblemsInstalling Older Versions of R packagesIf you immediately upgrade to the latest version of R, you will have no problem installing the most recent versions of R packages. However, if your version of R is older, some of the more recent package releases will not work and install.packages will generate a message such as: Warning message: In install.packages("arules") : package ‘arules’ is not availableThis is when you have to go to the Old sources link on the CRAN page for the arules package and determine which version is compatible with your version of R.Begin by determining what version of R you are using:$ R --versionOracle Distribution of R version 3.0.1 (--) -- "Good Sport" Copyright (C) The R Foundation for Statistical Computing Platform: x86_64-unknown-linux-gnu (64-bit)Given that R-3.0.1 was released May 16, 2013, any version of the arules package released after this date may work. Scanning the arules archive, we might try installing version 0.1.1-1, released in January of 2014:$ wget http://cran.r-project.org/src/contrib/Archive/arules/arules_1.1-1.tar.gz$ R CMD INSTALL arules_1.1-1.tar.gzFor use with ORE:$ ORE CMD INSTALL arules_1.1-1.tar.gzThe "package not available" error can also be thrown if the package you’re trying to install lives elsewhere, either another R package site, or it’s been removed from CRAN. A quick Google search usually leads to more information on the package’s location and status.Oracle R Enterprise is not in the R library pathOn Linux hosts, after installing the ORE server components, starting R, and attempting to load the ORE packages, you may receive the error:R> library(ORE)Error in library(ORE) : there is no package called ‘ORE’If you know the ORE packages have been installed and you receive this error, this is the result of not starting R with the ORE script. To resolve this problem, exit R and restart using the ORE script. After restarting R and ">running the command to load the ORE packages, you should not receive any errors.$ ORER> library(ORE)On Windows servers, the solution is to make the location of the ORE packages visible to R by adding them to the R library paths. To accomplish this, exit R, then add the following lines to the .Rprofile file. On Windows, the .Rprofile file is located in R\etc directory C:\Program Files\R\R-<version>\etc. Add the following lines:.libPaths("<path to $ORACLE_HOME>/R/library")The above line will tell R to include the R directory in the Oracle home as part of its search path. When you start R, the path above will be included, and future R package installations will also be saved to $ORACLE_HOME/R/library. This path should be writable by the user oracle, or the userid for the DBA tasked with installing R packages.Binary package compiled with different version of RBy default, R will install pre-compiled versions of packages if they are found. If the version of R under which the package was compiled does not match your installed version of R you will get an error message:Warning message: package ‘xxx’ was built under R version 3.0.0The solution is to download the package source and build it for your version of R.$ wget http://cran.r-project.org/src/contrib/Archive/arules/arules_1.1-1.tar.gz$ R CMD INSTALL arules_1.1-1.tar.gzFor use with ORE:$ ORE CMD INSTALL arules_1.1-1.tar.gzUnable to execute files in /tmp directoryBy default, R uses the /tmp directory to install packages. On security conscious machines, the /tmp directory is often marked as "noexec" in the /etc/fstab file. This means that no file under /tmp can ever be executed, and users who attempt to install R package will receive an error:ERROR: 'configure' exists but is not executable -- see the 'R Installation and Administration Manual’The solution is to set the TMP and TMPDIR environment variables to a location which R will use as the compilation directory. For example:$ mkdir <some path>/tmp$ export TMPDIR= <some path>/tmp$ export TMP= <some path>/tmpThis error typically appears on Linux client machines and not database servers, as Oracle Database writes to the value of the TMP environment variable for several tasks, including holding temporary files during database installation. 7. Creating your own R packageCreating your own package and submitting to CRAN is for advanced users, but it is not difficult. The procedure to follow, along with details of R's package system, is detailed in the Writing R Extensions manual.

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  • BizTalk Envelopes explained

    - by Robert Kokuti
    Recently I've been trying to get some order into an ESB-BizTalk pub/sub scenario, and decided to wrap the payload into standardized envelopes. I have used envelopes before in a 'light weight' fashion, and I found that they can be quite useful and powerful if used systematically. Here is what I learned. The Theory In my experience, Envelopes are often underutilised in a BizTalk solution, and quite often their full potential is not well understood. Here I try to simplify the theory behind the Envelopes within BizTalk.   Envelopes can be used to attach additional data to the ‘real’ data (payload). This additional data can contain all routing and processing information, and allows treating the business data as a ‘black box’, possibly compressed and/or encrypted etc. The point here is that the infrastructure does not need to know anything about the business data content, just as a post man does not need to know the letter within the envelope. BizTalk has built-in support for envelopes through the XMLDisassembler and XMLAssembler pipeline components (these are part of the XMLReceive and XMLSend default pipelines). These components, among other things, perform the following: XMLDisassembler Extracts the payload from the envelope into the Message Body Copies data from the envelope into the message context, as specified by the property schema(s) associated by the envelope schema. Typically, once the envelope is through the XMLDisassembler, the payload is submitted into the Messagebox, and the rest of the envelope data are copied into the context of the submitted message. The XMLDisassembler uses the Property Schemas, referenced by the Envelope Schema, to determine the name of the promoted Message Context element.   XMLAssembler Wraps the Message Body inside the specified envelope schema Populates the envelope values from the message context, as specified by the property schema(s) associated by the envelope schema. Notice that there are no requirements to use the receiving envelope schema when sending. The sent message can be wrapped within any suitable envelope, regardless whether the message was originally received within an envelope or not. However, by sharing Property Schemas between Envelopes, it is possible to pass values from the incoming envelope to the outgoing envelope via the Message Context. The Practice Creating the Envelope Add a new Schema to the BizTalk project:   Envelopes are defined as schemas, with the <Schema> Envelope property set to Yes, and the root node’s Body XPath property pointing to the node which contains the payload. Typically, you’d create an envelope structure similar to this: Click on the <Schema> node and set the Envelope property to Yes. Then, click on the Envelope node, and set the Body XPath property pointing to the ‘Body’ node:   The ‘Body’ node is a Child Element, and its Data Structure Type is set to xs:anyType.  This allows the Body node to carry any payload data. The XMLReceive pipeline will submit the data found in the Body node, while the XMLSend pipeline will copy the message into the Body node, before sending to the destination. Promoting Properties Once you defined the envelope, you may want to promote the envelope data (anything other than the Body) as Property Fields, in order to preserve their value in the message context. Anything not promoted will be lost when the XMLDisassembler extracts the payload from the Body. Typically, this means you promote everything in the Header node. Property promotion uses associated Property Schemas. These are special BizTalk schemas which have a flat field structure. Property Schemas define the name of the promoted values in the Message Context, by combining the Property Schema’s Namespace and the individual Field names. It is worth being systematic when it comes to naming your schemas, their namespace and type name. A coherent method will make your life easier when it comes to referencing the schemas during development, and managing subscriptions (filters) in BizTalk Administration. I developed a fairly coherent naming convention which I’ll probably share in another article. Because the property schema must be flat, I recommend creating one for each level in the envelope header hierarchy. Property schemas are very useful in passing data between incoming as outgoing envelopes. As I mentioned earlier, in/out envelopes do not have to be the same, but you can use the same property schema when you promote the outgoing envelope fields as you used for the incoming schema.  As you can reference many property schemas for field promotion, you can pick data from a variety of sources when you define your outgoing envelope. For example, the outgoing envelope can carry some of the incoming envelope’s promoted values, plus some values from the standard BizTalk message context, like the AdapterReceiveCompleteTime property from the BizTalk message-tracking properties. The values you promote for the outgoing envelope will be automatically populated from the Message Context by the XMLAssembler pipeline component. Using the Envelope Receiving Enveloped messages are automatically recognized by the XMLReceive pipeline, or any other custom pipeline which includes the XMLDisassembler component. The Body Path node will become the Message Body, while the rest of the envelope values will be added to the Message context, as defined by the Property Shemas referenced by the Envelope Schema. Sending The Send Port’s filter expression can use the promoted properties from the incoming envelope. If you want to enclose the sent message within an envelope, the Send Port XMLAssembler component must be configured with the fully qualified envelope name:   One way of obtaining the fully qualified envelope name is copy it off from the envelope schema property page: The full envelope schema name is constructed as <Name>, <Assembly> The outgoing envelope is populated by the XMLAssembler pipeline component. The Message Body is copied to the specified envelope’s Body Path node, while the rest of the envelope fields are populated from the Message Context, according to the Property Schemas associated with the Envelope Schema. That’s all for now, happy enveloping!

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