Search Results

Search found 8219 results on 329 pages for 'less'.

Page 274/329 | < Previous Page | 270 271 272 273 274 275 276 277 278 279 280 281  | Next Page >

  • Create a Remote Git Repository from an Existing XCode Repository

    - by codeWithoutFear
    Introduction Distributed version control systems (VCS’s), like Git, provide a rich set of features for managing source code.  Many development tools, including XCode, provide built-in support for various VCS’s.  These tools provide simple configuration with limited customization to get you up and running quickly while still providing the safety net of basic version control. I hate losing (and re-doing) work.  I have OCD when it comes to saving and versioning source code.  Save early, save often, and commit to the VCS often.  I also hate merging code.  Smaller and more frequent commits enable me to minimize merge time and effort as well. The work flow I prefer even for personal exploratory projects is: Make small local changes to the codebase to create an incrementally improved (and working) system. Commit these changes to the local repository.  Local repositories are quick to access, function even while offline, and provides the confidence to continue making bold changes to the system.  After all, I can easily recover to a recent working state. Repeat 1 & 2 until the codebase contains “significant” functionality and I have connectivity to the remote repository. Push the accumulated changes to the remote repository.  The smaller the change set, the less likely extensive merging will be required.  Smaller is better, IMHO. The remote repository typically has a greater degree of fault tolerance and active management dedicated to it.  This can be as simple as a network share that is backed up nightly or as complex as dedicated hardware with specialized server-side processing and significant administrative monitoring. XCode’s out-of-the-box Git integration enables steps 1 and 2 above.  Time Machine backups of the local repository add an additional degree of fault tolerance, but do not support collaboration or take advantage of managed infrastructure such as on-premises or cloud-based storage. Creating a Remote Repository These are the steps I use to enable the full workflow identified above.  For simplicity the “remote” repository is created on the local file system.  This location could easily be on a mounted network volume. Create a Test Project My project is called HelloGit and is located at /Users/Don/Dev/HelloGit.  Be sure to commit all outstanding changes.  XCode always leaves a single changed file for me after the project is created and the initial commit is submitted. Clone the Local Repository We want to clone the XCode-created Git repository to the location where the remote repository will reside.  In this case it will be /Users/Don/Dev/RemoteHelloGit. Open the Terminal application. Clone the local repository to the remote repository location: git clone /Users/Don/Dev/HelloGit /Users/Don/Dev/RemoteHelloGit Convert the Remote Repository to a Bare Repository The remote repository only needs to contain the Git database.  It does not need a checked out branch or local files. Go to the remote repository folder: cd /Users/Don/Dev/RemoteHelloGit Indicate the repository is “bare”: git config --bool core.bare true Remove files, leaving the .git folder: rm -R * Remove the “origin” remote: git remote rm origin Configure the Local Repository The local repository should reference the remote repository.  The remote name “origin” is used by convention to indicate the originating repository.  This is set automatically when a repository is cloned.  We will use the “origin” name here to reflect that relationship. Go to the local repository folder: cd /Users/Don/Dev/HelloGit Add the remote: git remote add origin /Users/Don/Dev/RemoteHelloGit Test Connectivity Any changes made to the local Git repository can be pushed to the remote repository subject to the merging rules Git enforces. Create a new local file: date > date.txt /li> Add the new file to the local index: git add date.txt Commit the change to the local repository: git commit -m "New file: date.txt" Push the change to the remote repository: git push origin master Now you can save, commit, and push/pull to your OCD hearts’ content! Code without fear! --Don

    Read the article

  • Sprinkle Some Magik on that Java Virtual Machine

    - by Jim Connors
    GE Energy, through its Smallworld subsidiary, has been providing geospatial software solutions to the utility and telco markets for over 20 years.  One of the fundamental building blocks of their technology is a dynamically-typed object oriented programming language called Magik.  Like Java, Magik source code is compiled down to bytecodes that run on a virtual machine -- in this case the Magik Virtual Machine. Throughout the years, GE has invested considerable engineering talent in the support and maintenance of this virtual machine.  At the same time vast energy and resources have been invested in the Java Virtual Machine. The question for GE has been whether to continue to make that investment on its own or to leverage massive effort provided by the Java community? Utilizing the Java Virtual Machine instead of maintaining its own virtual machine would give GE more opportunity to focus on application solutions.   At last count, there are dozens, perhaps hundreds of examples of programming languages that have been hosted atop the Java Virtual Machine.  Prior to the release of Java 7, that effort, although certainly possible, was generally less than optimal for languages like Magik because of its dynamic nature.  Java, as a statically typed language had little use for this capability.  In the quest to be a more universal virtual machine, Java 7, via JSR-292, introduced a new bytecode called invokedynamic.  In short, invokedynamic affords a more flexible method call mechanism needed by dynamic languages like Magik. With this new capability GE Energy has succeeded in hosting their Magik environment on top of the Java Virtual Machine.  So you may ask, why would GE wish to do such a thing?  The benefits are many: Competitors to GE Energy claimed that the Magik environment was proprietary.  By utilizing the Java Virtual Machine, that argument gets put to bed.  JVM development is done in open source, where contributions are made world-wide by all types of organizations and individuals. The unprecedented wealth of class libraries and applications written for the Java platform are now opened up to Magik/JVM platform as first class citizens. In addition, the Magik/JVM solution vastly increases the developer pool to include the 9 million Java developers -- the largest developer community on the planet. Applications running on the JVM showed substantial performance gains, in some cases as much as a 5x speed up over the original Magik platform. Legacy Magik applications can still run on the original platform.  They can be seamlessly migrated to run on the JVM by simply recompiling the source code. GE can now leverage the huge Java community.  Undeniably the best virtual machine ever created, hundreds if not thousands of world class developers continually improve, poke, prod and scrutinize all aspects of the Java platform.  As enhancements are made, GE automatically gains access to these. As Magik has little in the way of support for multi-threading, GE will benefit from current and future Java offerings (e.g. lambda expressions) that aim to further facilitate multi-core/multi-threaded application development. As the JVM is available for many more platforms, it broadens the reach of Magik, including the potential to run on a class devices never envisioned just a few short years ago.  For example, Java SE compatible runtime environments are available for popular embedded ARM/Intel/PowerPC configurations that could theoretically host this software too. As compared to other JVM language projects, the Magik integration differs in that it represents a serious commercial entity betting a sizable part of its business on the success of this effort.  Expect to see announcements not only from General Electric, but other organizations as they realize the benefits of utilizing the Java Virtual Machine.

    Read the article

  • Cloud Backup: Getting the Users' Backs Up

    - by Tony Davis
    On Wednesday last week, Microsoft announced that as of July 1, all data transfers into its Microsoft Azure cloud will be free (though you have to pay for transferring data out). On Thursday last week, SQL Azure in Western Europe went down. It was a relatively short outage, but since SQL Azure currently provides no easy way to take a standard backup of a database and store it locally, many people had no recourse but to wait patiently for their cloud-based app to resume. It seems that Microsoft are very keen encourage developers to move their data onto their cloud, but are developers ready to do it, given that such basic backup capabilities are lacking? Recently on Simple-Talk, Mike Mooney described a perfect use case for the Microsoft Cloud. They had a simple web-based application with a SQL Server backend; they could move the application to Windows Azure, and the data into SQL Azure and in the process free themselves from much of the hassle surrounding management and scaling of the hardware, network and so on. It was a great fit and yet it nearly didn't happen; lack of support for the BACKUP command almost proved a show-stopper. Of course, backups of Azure databases are always and have always been taken automatically, for disaster recovery purposes, but these are strictly on-cloud copies and as of now it is not possible to use them to them to restore a database to a particular point in time. It seems that none of those clever Microsoft people managed to predict the need to perform basic backups of Azure databases so that copies could be stored locally, outside the Azure universe. At the very least, as Mike points out, performing a local backup before a new deployment is more or less mandatory. Microsoft did at least note the sound of gnashing teeth and, as a stop-gap measure, offered SQL Azure Database Copy which basically allows you to create an online clone of your database, but this doesn't allow for storing local archives of the data. To that end MS has provided SQL Azure Import/Export, to package up and export a database and its data, using BACPACs. These BACPACs do not guarantee transactional consistency; for example, if a child table is modified after the parent is copied, then the copied database will be in inconsistent state (meaning, to add to the fun, BACPACs need to be created from a database copy). In any event, widespread problems with BACPAC's evil cousin, the DACPAC have been well-documented, and it seems likely that many will also give BACPAC the bum's rush. Finally, in a TechEd 2011 presentation tagged "SQL Azure Advanced Administration", it was announced that "backup and restore" were coming in the next SQL Azure CTP. And yet this still doesn't mean that we'll get simple backups as DBAs know and love them. What it does mean, at least, is the ability to restore any given database to a point in time within a 2-week window. For the time being, if you want a local copy of your data and don't want to brave the BACPAC, one is left with SSIS or BCP, creative use of schema and data comparison tools, or use of SQL Azure Backup (currently in beta) in order to perform this simple but vital task. Cheers, Tony.

    Read the article

  • Grid pathfinding with a lot of entities

    - by Vee
    I'd like to explain this problem with a screenshot from a released game, DROD: Gunthro's Epic Blunder, by Caravel Games. The game is turn-based and tile-based. I'm trying to create something very similar (a clone of the game), and I've got most of the fundamentals done, but I'm having trouble implementing pathfinding. Look at the screenshot. The guys in yellow are friendly, and want to kill the roaches. Every turn, every guy in yellow pathfinds to the closest roach, and every roach pathfinds to the closest guy in yellow. By closest I mean the target with the shortest path, not a simple distance calculation. All of this without any kind of slowdown when loading the level or when passing turns. And all of the entities change position every turn. Also (not shown in screenshot), there can be doors that open and close and change the level's layout. Impressive. I've tried implementing pathfinding in my clone. First attempt was making every roach find a path to a yellow guy every turn, using a breadth-first search algorithm. Obviously incredibly slow with more than a single roach, and would get exponentially slower with more than a single yellow guy. Second attempt was mas making every yellow guy generate a pathmap (still breadth-first search) every time he moved. Worked perfectly with multiple roaches and a single yellow guy, but adding more yellow guys made the game slow and unplayable. Last attempt was implementing JPS (jump point search). Every entity would individually calculate a path to its target. Fast, but with a limited number of entities. Having less than half the entities in the screenshot would make the game slow. And also, I had to get the "closest" enemy by calculating distance, not shortest path. I've asked on the DROD forums how they did it, and a user replied that it was breadth-first search. The game is open source, and I took a look at the source code, but it's C++ (I'm using C#) and I found it confusing. I don't know how to do it. Every approach I tried isn't good enough. And I believe that DROD generates global pathmaps, somehow, but I can't understand how every entity find the best individual path to other entities that move every turn. What's the trick? This is a reply I just got on the DROD forums: Without having looked at the code I'd wager it's two (or so) pathmaps for the whole room: One to the nearest enemy, and one to the nearest friendly for every tile. There's no need to make a separate pathmap for every entity when the overall goal is "move towards nearest enemy/friendly"... just mark every tile with the number of moves it takes to the nearest target and have the entity chose the move that takes it to the tile with the lowest number. To be honest, I don't understand it that well.

    Read the article

  • Production Access Denied! Who caused this rule anyways?

    - by Matt Watson
    One of the biggest challenges for most developers is getting access to production servers. In smaller dev teams of less than about 5 people everyone usually has access. Then you hire developer #6, he messes something up in production... and now nobody has access. That is how it always starts in small dev teams. I think just about every rule of life there is gets created this way. One person messes it up for the rest of us. Rules are then put in place to try and prevent it from happening again.Breaking the rules is in our nature. In this example it is for good cause and a necessity to support our applications and troubleshoot problems as they arise. So how do developers typically break the rules? Some create their own method to collect log files off servers so they can see them. Expensive log management programs can collect log files, but log files alone are not enough. Centralizing where important errors are logged to is common. Some lucky developers are given production server access by the IT operations team out of necessity. Wait. That's not fair to all developers and knowingly breaks the company rule!  When customers complain or the system is down, the rules go out the window. Commonly lead developers get production access because they are ultimately responsible for supporting the application and may be the only person who knows how to fix it. The problem with only giving lead developers production access is it doesn't scale from a support standpoint. Those key employees become the go to people to help solve application problems, but they also become a bottleneck. They end up spending up to half of their time every day helping resolve application defects, performance problems, or whatever the fire of the day is. This actually the last thing you want your lead developers doing. They should be working on something more strategic like major enhancements to the product. Having production access can actually be a curse if you are the guy stuck hunting down log files all day. Application defects are good tasks for junior developers. They can usually handle figuring out simple application problems. But nothing is worse than being a junior developer who can't figure out those problems and the back log of them grows and grows. Some of them require production server access to verify a deployment was done correctly, verify config settings, view log files, or maybe just restart an application. Since the junior developers don't have access, they end up bugging the developers who do have access or they track down a system admin to help. It can take hours or days to see server information that would take seconds or minutes if they had access of their own. It is very frustrating to the developer trying to solve the problem, the system admin being forced to help, and most importantly your customers who are not happy about the situation. This process is terribly inefficient. Production database access is also important for solving application problems, but presents a lot of risk if developers are given access. They could see data they shouldn't.  They could write queries on accident to update data, delete data, or merely select every record from every table and bring your database to its knees. Since most of the application we create are data driven, it can be very difficult to track down application bugs without access to the production databases.Besides it being against the rule, why don't all developers have access? Most of the time it comes down to security, change of control, lack of training, and other valid reasons. Developers have been known to tinker with different settings to try and solve a problem and in the process forget what they changed and made the problem worse. So it is a double edge sword. Don't give them access and fixing bugs is more difficult, or give them access and risk having more bugs or major outages being created!Matt WatsonFounder, CEOStackifyAgile Support for Agile Developers

    Read the article

  • Managing game state / 'what to update' within an XNA game 'screen'

    - by codinghands
    Note - having read through other GDev questions suggested when writing this question I'm confident this isn't a dupe. Of course, it's 3am and I'm likely wrong, so please mod as such if so. I'm trying to figure out how best to manage state within my game screens - please bare with me though! At the moment I'm using a heavily modified version of the fantastic game state management example on the XNA site available here. This is working perfectly for my 'Screens' - 'IntroScreen' with some shiny logos, 'TitleScreen' and a 'MenuScreen' stacked on top for the title and menu, 'PlayScreen' for the actual gameplay, etc. Each screen has the a bunch of sprites, and an 'Update' and 'Draw', managed by a 'ScreenManager'. In addition to the above, and as suggested as an answer to my other question here, most screens have a 'GameProcessQueue' class full of 'GameProcess'es which lets me do just about anything (animations, youbetcha!), in any order, in sequence or parallel. Why mention all this? When I talk about managing game state I'm thinking more for complex scenarios within a 'Screen'. 'TitleScreen', 'MenuScreen' and the like are all relatively simple. 'Play Screen' less so. How do people manage the different 'states' within the screen (or whatever you call it) that 'does' gameplay? (for me, the 'PlayScreen') I've thought about the following: Enum of different states in the Screen, 'activeState' enum-type variable, switching on the enum in the Screen Update() loop to determine what Screen Update 'sub'-function is called. I can see this getting hairy pretty fast though as screens get more complex and with the 'PlayScreen' becoming a behemoth mega-class. 'State' class with Update loop - a Screen can have any number of 'States', 1+ of which are 'active'. Screen update loop calls update on all active states. States themselves know which screen they belong to, and may even belong to a 'StateManager' which handles transitioning from one state to the next. Once a state is over it's removed from the ScreenState list. The Screen doesn't need a bunch of GameProcessQueues, each State has its own. Abstract Screen further to be more flexible - I can see the similarities between what I've got (game 'Screens' handled by a ScreenManager) and what I want (states within a screen, and a mechanism to manage them). However at the moment I see 'Screens' as high level and very distinct ('PlayScreen' with baddies != 'MenuScreen' with 4 words and event handlers), where as my proposed 'States' are more intrinsically tied to a specific screen with complex requirements. I think. This is for a turn-based board game, so it's easier to define things as a discrete series of steps (IntroAnimation - P1Turn - P2Turn - P1Turn ... - GameOver - .... Obviously with an open-world RPG things are very different, but any advice in this scenario is appreciated. If I'm just going OOP-crazy please say so. Similarly I'm concious there's a huge amount on this site re: state management. But as my first 'serious' game after a couple of false starts I'd like to get this right, and would rather be harassed and modded down than never ask :)

    Read the article

  • database design help for game / user levels / progress

    - by sprugman
    Sorry this got long and all prose-y. I'm creating my first truly gamified web app and could use some help thinking about how to structure the data. The Set-up Users need to accomplish tasks in each of several categories before they can move up a level. I've got my Users, Tasks, and Categories tables, and a UserTasks table which joins the three. ("User 3 has added Task 42 in Category 8. Now they've completed it.") That's all fine and working wonderfully. The Challenge I'm not sure of the best way to track the progress in the individual categories toward each level. The "business" rules are: You have to achieve a certain number of points in each category to move up. If you get the number of points needed in Cat 8, but still have other work to do to complete the level, any new Cat 8 points count toward your overall score, but don't "roll over" into the next level. The number of Categories is small (five currently) and unlikely to change often, but by no means absolutely fixed. The number of points needed to level-up will vary per level, probably by a formula, or perhaps a lookup table. So the challenge is to track each user's progress toward the next level in each category. I've thought of a few potential approaches: Possible Solutions Add a column to the users table for each category and reset them all to zero each time a user levels-up. Have a separate UserProgress table with a row for each category for each user and the number of points they have. (Basically a Many-to-Many version of #1.) Add a userLevel column to the UserTasks table and use that to derive their progress with some kind of SUM statement. Their current level will be a simple int in the User table. Pros & Cons (1) seems like by far the most straightforward, but it's also the least flexible. Perhaps I could use a naming convention based on the category ids to help overcome some of that. (With code like "select cats; for each cat, get the value from Users.progress_{cat.id}.") It's also the one where I lose the most data -- I won't know which points counted toward leveling up. I don't have a need in mind for that, so maybe I don't care about that. (2) seems complicated: every time I add or subtract a user or a category, I have to maintain the other table. I foresee synchronization challenges. (3) Is somewhere in between -- cleaner than #2, but less intuitive than #1. In order to find out where a user is, I'd have mildly complex SQL like: SELECT categoryId, SUM(points) from UserTasks WHERE userId={user.id} & countsTowardLevel={user.level} groupBy categoryId Hmm... that doesn't seem so bad. I think I'm talking myself into #3 here, but would love any input, advice or other ideas. P.S. Sorry for the cross-post. I wrote this up on SO and then remembered that there was a game dev-focused one. Curious to see if I get different answers one place than the other....

    Read the article

  • Ask the Readers: Would You Be Willing to Give Windows Up and Use a Different O.S.?

    - by Asian Angel
    When it comes to computers, Windows definitely rules the desktop in comparison to other operating systems. What we would like to know this week is if you would actually be willing to give up using Windows altogether and move to a different operating system on your computers. Note: This week’s Ask the Readers post is posing a hypothetical situation, so please refrain from starting arguments or a flame war in the comments. Good reasoned discussion is always welcome. There is no doubt that Windows is the dominant operating system in use today. Everywhere you go or look it is easy to find computers with Windows installed such as at work, home, the library, government offices, and more. For many people it is the operating system that they know and are comfortable with, which makes changing to a different operating system less appealing. Adding to the preference for Windows (or dependency based on your view) is the custom software that many businesses use on a daily basis. Throw in the high volume of people who depend on and use Microsoft Office as a standard for their business documents and it is little wonder that Windows is so dominant. So what would you use if you did decide to take a break from or permanently move away from Windows? If your choice is Linux then you have a large and wonderful variety of distributions to choose from based on what you want out of your system. Want a distribution that is easy to work with? You could choose Ubuntu, Linux Mint, or others that are engineered to be ready to go “out of the box”. Like a challenge? Perhaps Arch Linux is more your style. One of the most attractive features of all about Linux is the price…it is very hard to beat free! Maybe Mac OS X sounds like the perfect choice. It has a certain mystique and elegance associated with it and many OS X fans refuse to use anything else if given a choice. Then there is the soon to be released Chrome OS with its’ emphasis on cloud computing. This is a system that is definitely focused on being as low-maintenance and hassle-free as possible. Quick on, quick off, minimalist, and made to be portable. All of the system’s updates will occur automatically leaving you free to work and play in the cloud. But it does have its’ limitations…no installing all of those custom apps that you love using on Windows or other systems…it is literally all about the browsing window and web apps. So there you have it. If the opportunity presented itself would you, could you give Windows up and use a different operating system? Would it be easy or hard for you to do? Perhaps it would not really matter so long as you could do what you needed or wanted to do on a computer. And maybe this is the perfect time to try something new and find out…that new favorite operating system could be just an install disc away. Let us know your thoughts in the comments! How-To Geek Polls require Javascript. Please Click Here to View the Poll. Latest Features How-To Geek ETC The Complete List of iPad Tips, Tricks, and Tutorials The 50 Best Registry Hacks that Make Windows Better The How-To Geek Holiday Gift Guide (Geeky Stuff We Like) LCD? LED? Plasma? The How-To Geek Guide to HDTV Technology The How-To Geek Guide to Learning Photoshop, Part 8: Filters Improve Digital Photography by Calibrating Your Monitor The Brothers Mario – Epic Gangland Style Mario Brothers Movie Trailer [Video] Score Awesome Games on the Cheap with the Humble Indie Bundle Add a Colorful Christmas Theme to Your Windows 7 Desktop This Windows Hack Changes the Blue Screen of Death to Red Edit Images Quickly in Firefox with Pixlr Grabber Zoho Writer, Sheet, and Show Now Available in Chrome Web Store

    Read the article

  • Exploring TCP throughput with DTrace

    - by user12820842
    One key measure to use when assessing TCP throughput is assessing the amount of unacknowledged data in the pipe. This is sometimes termed the Bandwidth Delay Product (BDP) (note that BDP is often used more generally as the product of the link capacity and the end-to-end delay). In DTrace terms, the amount of unacknowledged data in bytes for the connection is the different between the next sequence number to send and the lowest unacknoweldged sequence number (tcps_snxt - tcps_suna). According to the theory, when the number of unacknowledged bytes for the connection is less than the receive window of the peer, the path bandwidth is the limiting factor for throughput. In other words, if we can fill the pipe without the peer TCP complaining (by virtue of its window size reaching 0), we are purely bandwidth-limited. If the peer's receive window is too small however, the sending TCP has to wait for acknowledgements before it can send more data. In this case the round-trip time (RTT) limits throughput. In such cases the effective throughput limit is the window size divided by the RTT, e.g. if the window size is 64K and the RTT is 0.5sec, the throughput is 128K/s. So a neat way to visually determine if the receive window of clients may be too small should be to compare the distribution of BDP values for the server versus the client's advertised receive window. If the BDP distribution overlaps the send window distribution such that it is to the right (or lower down in DTrace since quantizations are displayed vertically), it indicates that the amount of unacknowledged data regularly exceeds the client's receive window, so that it is possible that the sender may have more data to send but is blocked by a zero-window on the client side. In the following example, we compare the distribution of BDP values to the receive window advertised by the receiver (10.175.96.92) for a large file download via http. # dtrace -s tcp_tput.d ^C BDP(bytes) 10.175.96.92 80 value ------------- Distribution ------------- count -1 | 0 0 | 6 1 | 0 2 | 0 4 | 0 8 | 0 16 | 0 32 | 0 64 | 0 128 | 0 256 | 3 512 | 0 1024 | 0 2048 | 9 4096 | 14 8192 | 27 16384 | 67 32768 |@@ 1464 65536 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 32396 131072 | 0 SWND(bytes) 10.175.96.92 80 value ------------- Distribution ------------- count 16384 | 0 32768 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 17067 65536 | 0 Here we have a puzzle. We can see that the receiver's advertised window is in the 32768-65535 range, while the amount of unacknowledged data in the pipe is largely in the 65536-131071 range. What's going on here? Surely in a case like this we should see zero-window events, since the amount of data in the pipe regularly exceeds the window size of the receiver. We can see that we don't see any zero-window events since the SWND distribution displays no 0 values - it stays within the 32768-65535 range. The explanation is straightforward enough. TCP Window scaling is in operation for this connection - the Window Scale TCP option is used on connection setup to allow a connection to advertise (and have advertised to it) a window greater than 65536 bytes. In this case the scaling shift is 1, so this explains why the SWND values are clustered in the 32768-65535 range rather than the 65536-131071 range - the SWND value needs to be multiplied by two since the reciever is also scaling its window by a shift factor of 1. Here's the simple script that compares BDP and SWND distributions, fixed to take account of window scaling. #!/usr/sbin/dtrace -s #pragma D option quiet tcp:::send / (args[4]-tcp_flags & (TH_SYN|TH_RST|TH_FIN)) == 0 / { @bdp["BDP(bytes)", args[2]-ip_daddr, args[4]-tcp_sport] = quantize(args[3]-tcps_snxt - args[3]-tcps_suna); } tcp:::receive / (args[4]-tcp_flags & (TH_SYN|TH_RST|TH_FIN)) == 0 / { @swnd["SWND(bytes)", args[2]-ip_saddr, args[4]-tcp_dport] = quantize((args[4]-tcp_window)*(1 tcps_snd_ws)); } And here's the fixed output. # dtrace -s tcp_tput_scaled.d ^C BDP(bytes) 10.175.96.92 80 value ------------- Distribution ------------- count -1 | 0 0 | 39 1 | 0 2 | 0 4 | 0 8 | 0 16 | 0 32 | 0 64 | 0 128 | 0 256 | 3 512 | 0 1024 | 0 2048 | 4 4096 | 9 8192 | 22 16384 | 37 32768 |@ 99 65536 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 3858 131072 | 0 SWND(bytes) 10.175.96.92 80 value ------------- Distribution ------------- count 512 | 0 1024 | 1 2048 | 0 4096 | 2 8192 | 4 16384 | 7 32768 | 14 65536 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 1956 131072 | 0

    Read the article

  • Controlling server configurations with IPS

    - by barts
    I recently received a customer question regarding how they best could control which packages and which versions were used on their production Solaris 11 servers.  They had considered pointing each server at its own software repository - a common initial approach.  A simpler method leverages one of dependency mechanisms we introduced with Solaris 11, but is not immediately obvious to most people. Typically, most internal IT departments qualify particular versions for production use.  What this customer wanted to do was insure that their operations staff only installed internally qualified versions of Solaris on their servers.  The easiest way of doing this is to leverage the 'incorporate' type of dependency in a small package defined for each server type.  From the reference " Packaging and Delivering Software With the Image Packaging System in Oracle® Solaris 11.1":  The incorporate dependency specifies that if the given package is installed, it must be at the given version, to the given version accuracy. For example, if the dependent FMRI has a version of 1.4.3, then no version less than 1.4.3 or greater than or equal to 1.4.4 satisfies the dependency. Version 1.4.3.7 does satisfy this example dependency. The common way to use incorporate dependencies is to put many of them in the same package to define a surface in the package version space that is compatible. Packages that contain such sets of incorporate dependencies are often called incorporations. Incorporations are typically used to define sets of software packages that are built together and are not separately versioned. The incorporate dependency is heavily used in Oracle Solaris to ensurethat compatible versions of software are installed together. An example incorporate dependency is: depend type=incorporate fmri=pkg:/driver/network/ethernet/[email protected],5.11-0.175.0.0.0.2.1 So, to make sure only qualified versions are installed on a server, create a package that will be installed on the machines to be controlled.  This package will contain an incorporate dependency on the "entire" package, which controls the various components used to be build Solaris.  Every time a new version of Solaris has been qualified for production use, create a new version of this package specifying the new version of "entire" that was qualified.  Once this new control package is available in the repositories configured on the production server, the pkg update command will update that system to the specified version.  Unless a new version of the control package is made available, pkg update will report that no updates are available since no version of the control package can be installed that satisfies the incorporate constraint. Note that if desired, the same package can be used to specify which packages must be present on the system by adding either "require" or "group" dependencies; the latter permits removal of some of the packages, the former does not.  More details on this can be found in either the section 5 pkg man page or the previously mentioned reference document. This technique of using package dependencies to constrain system configuration leverages the SAT solver which is at the heart of IPS, and is basic to how we package Solaris itself.  

    Read the article

  • Handling "related" work within a single agile work item

    - by Tesserex
    I'm on a project team of 4 devs, myself included. We've been having a long discussion on how to handle extra work that comes up in the course of a single work item. This extra work is usually things that are slightly related to the task, but not always necessary to accomplish the goal of the item (that may be an opinion). Examples include but are not limited to: refactoring of the code changed by the work item refactoring code neighboring the code changed by the item re-architecting the larger code area around the ticket. For example if an item has you changing a single function, you realize the entire class now could be redone to better accommodate this change. improving the UI on a form you just modified When this extra work is small we don't mind. The problem is when this extra work causes a substantial extension of the item beyond the original feature point estimation. Sometimes a 5 point item will actually take 13 points of time. In one case we had a 13 point item that in retrospect could have been 80 points or more. There are two options going around in our discussion for how to handle this. We can accept the extra work in the same work item, and write it off as a mis-estimation. Arguments for this have included: We plan for "padding" at the end of the sprint to account for this sort of thing. Always leave the code in better shape than you found it. Don't check in half-assed work. If we leave refactoring for later, it's hard to schedule and may never get done. You are in the best mental "context" to handle this work now, since you're waist deep in the code already. Better to get it out of the way now and be more efficient than to lose that context when you come back later. We draw a line for the current work item, and say that the extra work goes into a separate ticket. Arguments include: Having a separate ticket allows for a new estimation, so we aren't lying to ourselves about how many points things really are, or having to admit that all of our estimations are terrible. The sprint "padding" is meant for unexpected technical challenges that are direct barriers to completing the ticket requirements. It is not intended for side items that are just "nice-to-haves". If you want to schedule refactoring, just put it at the top of the backlog. There is no way for us to properly account for this stuff in an estimation, since it seems somewhat arbitrary when it comes up. A code reviewer might say "those UI controls (which you actually didn't modify in this work item) are a bit confusing, can you fix that too?" which is like an hour, but they might say "Well if this control now inherits from the same base class as the others, why don't you move all of this (hundreds of lines of) code into the base and rewire all this stuff, the cascading changes, etc.?" And that takes a week. It "contaminates the crime scene" by adding unrelated work into the ticket, making our original feature point estimates meaningless. In some cases, the extra work postpones a check-in, causing blocking between devs. Some of us are now saying that we should decide some cut off, like if the additional stuff is less than 2 FP, it goes in the same ticket, if it's more, make it a new ticket. Since we're only a few months into using Agile, what's the opinion of all the more seasoned Agile veterans around here on how to handle this?

    Read the article

  • Additional new material WebLogic Community

    - by JuergenKress
    Virtual Developer Conference On Demand - Register Updated Book: WebLogic 12c: Distinctive Recipes - Architecture, Development, Administration by Oracle ACE Director Frank Munz - Blog | YouTube Webcast: Migrating from GlassFish to WebLogic - Replay Reliance Commercial Finance Accelerates Time-to-Market, Improves IT Staff Productivity by 70% - Blog | Oracle Magazine Retrieving WebLogic Server Name and Port in ADF Application by Andrejus Baranovskis, Oracle Ace Director - Blog Using Oracle WebLogic 12c with NetBeans IDEOracle ACE Director Markus Eisele walks you through installing and configuring all the necessary components, and helps you get started with a simple Hello World project. Read the article. Video: Oracle A-Team ADF Mobile Persistence SampleThis video by Oracle Fusion Middleware A-Team architect Steven Davelaar demonstrates how to use the ADF Mobile Persistence Sample JDeveloper extension to generate a fully functional ADF Mobile application that reads and writes data using an ADF BC SOAP web service. Watch the video. Java ME 8 ReleaseDownload Java ME today! This release is an implementation of the Java ME 8 standards JSR 360 (CLDC 8) and JSR 361 (MEEP 8), and includes support of alignment with Java SE 8 language features and APIs, an enhanced services-enabled application platform, the ability to "right-size" the platform to address a wide range of target devices, and more. Learn more Download Java ME SDK 8It includes application development support for Oracle Java ME Embedded 8 platforms and includes plugins for NetBeans 8. See the Java ME 8 Developer Tools Documentation to learn JavaOne 2014 Early Bird RateRegister early to save $400 off the onsite price. With the release of Java 8 this year, we have exciting new sessions and an interactive demo space! NetBeans IDE 8.0 Patch UpdateThe NetBeans Team has released a patch for NetBeans IDE 8.0. Download it today to get fixes that enhance stability and performance. Java 8 Questions ForumFor any questions about this new release, please join the conversation on the Java 8 Questions Forum. Java ME 8: Getting Started with Samples and Demo CodeLearn in few steps how to get started with Java ME 8! The New Java SE 8 FeaturesJava SE 8 introduces enhancements such as lambda expressions that enable you to write more concise yet readable code, better utilize multicore systems, and detect more errors at compile time. See What's New in JDK 8 and the new Java SE 8 documentation portal. Pay Less for Java-Related Books!Save 20% on all new Oracle Press books related to Java. Download the free preview sampler for the Java 8 book written by Herbert Schildt, Maurice Naftain, Henrik Ebbers and J.F. DiMarzio. New book: EJB 3 in Action, Second Edition WebLogic 12c Does WebSockets Getting Started by C2B2 Video: Building Robots with Java Embedded Video: Nighthacking TV Watch presentations by Stephen Chin and community members about Java SE, Java Embedded, Java EE, Hadoop, Robots and more. Migrating the Spring Pet Clinic to Java EE 7 Trip report : Jozi JUG Java Day in Johannesburg How to Build GlassFish 4 from Source 4,000 posts later : The Aquarium WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Wiki Technorati Tags: WebLogic,WebLogic Community,Oracle,OPN,Jürgen Kress

    Read the article

  • Ti Launchpad

    - by raysmithequip
    Just thought I would get a couple of notes up here for reference to anyone that is interested...it is now Feb 2011 and I have not been posting here enough to remember this blog. Back in Nov 2010 I ordered the Ti launchpad msp430, it is a little target board kit replete with a mini USB cable, two very inexpensive programmable mcu's and a couple of pin headers with a couple of led's on board, a spi connector some on board jumpers and two programmable micro switches....all for less than $5.00...INCLUDING SHIPPING!!....not bad when the ardruino's are running around 20.00 for the target board, atmega328 and cable off of eBay...I wont even mention the microchip pic right now.  Naw, for $5.00 the Ti launchpad kit is about the cheapest fun around...if-uns your a geek that is... Well, the launchpad was backordered for almost two months, came like Xmas eve in fact...I had almost forgotten it!! And really, it was way late and not my idea of an Xmas present for myself.  That would of been the web expressions 4 I bought a few weeks back.  With all the holidays, I did not even look at it till last week, in fact I passed the wrapped board around at my local ham club meeting during points of personal privilege....some oh's and ahhs but mostly duhs...I actually ordered it to avoid downloading the huge code compressor studio 4 (CCS) that was supposed to be included on the cd.  No cd.  I had already downloaded IAR  another programming IDE for these little micro bugs. In my spare time I toyed with IAR and the launchpad board but after about two days of playing delete the driver with windows I decided to just download CCS 4, the code limited version, and give that a shot......CCS 4, is a good rewrite from the earlier versions, it is based on Eclipse as an IDE and includes the drivers for the msp430 target board I received in the kit.  Once installed I quickly configured the debugger for the target chip which was already plugged into the dip socket at the factory, msp430G2131 from he drop down list and clicked ok...I was in!! The CCS4 is full of bells and whistles compared to the IAR, which I would of preferred for the simplicity.  But the code compressor studio really does have it all!!..the code limited version is free, and of all things will give you java script editor box.  The whole layout in debugger mode reminds me of any modern programmer IDE...I mean sure give me Tex anytime but you simply must admire all the boxes and options included in the GUI.  It was a simple matter to check the assembly code in the flash and ram memory that came preloaded for the launchpad kit.  Assembly.  I am right now looking for my old assembly textbooks...sure I remember how to use mov and add etc but a couple of the commands are a little more than vague anymore.  Still, these little mcu's are about 50 cents each and might just work in a couple of projects I have lined up for the near future.  I may document the code here.  Luckily, I plan to write the code in c++ for the main project but if it has to be assembly, no prob.  For reference, the program that came already on the 2131 in the kit was a temperature indicator that alternately flashed red and green leds and changed the intensity of either depending on whether the temp was rising or falling...neat.  Neat enough that it might be worthwhile banging out a little GUI in windows 7 to test the new user device system calls, maybe put a temp gauge widget up on the desktop...just to keep from getting bored.  If you see some assembly code on this blog, you know I was doing something with one of the many mcu's out there.....thats all for now, more to follow...a bit later, of course.

    Read the article

  • Why are you doing this? [closed]

    - by NIcholas Lawson
    I am working on a story that I am going to be querying to several magazines in my hometown about this work that is being done by the AXR group. This is a group of people who have networked online and are working on developing a higher level syntax structure than CSS and HTML currently offer. I am covering this is as a story because I see potential in this as a human interest story in cosmopolitan society. I have been asked by the group to pose this question to you and would appreciate any and all comments you would have on the following ... To AXR: So when does the internet become finished? At what point does a computer scientist say to himself ... my job here is finished ... the internet is complete? When is the internet ready to be more about the display of content than the uploading of new websites or computer tech? You are embarking on upon a sixty year project every day you work with this internet, what drives you? Why are you spending your hard earned hours working on the code to this computer? I spend thirty hours a week online because I love the writing and I know what would make the internet better ... ease of use ... i know it is difficult to program but I see some very elegant solutions online ... in this early inception phase of your programming development for this HSS prototype ... I would like to know why I do not see you programmers asking questions such as ... What would make the end user's life the easiest when using this code? I know you can solve the problem but an evolution forward would be simple, not simple to a computer scientist but simple to use for a career janitor ... if you could solve the problem of alleviating the stress at using a the computer you could get better content out of the computer ... right now the main problem is that the best content is in the hands of the people least likely to use the computer and the more simple you make the computer to use ... the better the content collection will be in the long run ... That is not what I want to talk about though ... why are you writing code when you could be writing stories? I know the computer is worthless without content so I build content, I know the book is worthless without the combinations of words in them, i know the television is worthless without the television news anchor or the actor, what I want to know from you folks in a very journalistic sense is why are you even bothering to bother to write code for a machine that has only made our lives i would dare say less interesting. why are you feeding the beast your time when you could be writing stories or being an actor or musician or auto mechanic ... why code? why this machine? what do you love about it? what do you hate about it? what do you wonder about it? I want to know so that starting out I know how to further shape my questions with axr ... i want the full story ... i want the real answers ... and i want to know why you are doing this, it would make for great writing if you could elucidate on this point.

    Read the article

  • RPi and Java Embedded GPIO: Big Data and Java Technology

    - by hinkmond
    Java Embedded and Big Data go hand-in-hand, especially as demonstrated by prototyping on a Raspberry Pi to show how well the Java Embedded platform can perform on a small embedded device which then becomes the proof-of-concept for industrial controllers, medical equipment, networking gear or any type of sensor-connected device generating large amounts of data. The key is a fast and reliable way to access that data using Java technology. In the previous blog posts you've seen the integration of a static electricity sensor and the Raspberry Pi through the GPIO port, then accessing that data through Java Embedded code. It's important to point out how this works and why it works well with Java code. First, the version of Linux (Debian Wheezy/Raspian) that is found on the RPi has a very convenient way to access the GPIO ports through the use of Linux OS managed file handles. This is key in avoiding terrible and complex coding using register manipulation in C code, or having to program in a less elegant and clumsy procedural scripting language such as python. Instead, using Java Embedded, allows a fast way to access those GPIO ports through those same Linux file handles. Java already has a very easy to program way to access file handles with a high degree of performance that matches direct access of those file handles with the Linux OS. Using the Java API java.io.FileWriter lets us open the same file handles that the Linux OS has for accessing the GPIO ports. Then, by first resetting the ports using the unexport and export file handles, we can initialize them for easy use in a Java app. // Open file handles to GPIO port unexport and export controls FileWriter unexportFile = new FileWriter("/sys/class/gpio/unexport"); FileWriter exportFile = new FileWriter("/sys/class/gpio/export"); ... // Reset the port unexportFile.write(gpioChannel); unexportFile.flush(); // Set the port for use exportFile.write(gpioChannel); exportFile.flush(); Then, another set of file handles can be used by the Java app to control the direction of the GPIO port by writing either "in" or "out" to the direction file handle. // Open file handle to input/output direction control of port FileWriter directionFile = new FileWriter("/sys/class/gpio/gpio" + gpioChannel + "/direction"); // Set port for input directionFile.write("in"); // Or, use "out" for output directionFile.flush(); And, finally, a RandomAccessFile handle can be used with a high degree of performance on par with native C code (only milliseconds to read in data and write out data) with low overhead (unlike python) to manipulate the data going in and out on the GPIO port, while the object-oriented nature of Java programming allows for an easy way to construct complex analytic software around that data access functionality to the external world. RandomAccessFile[] raf = new RandomAccessFile[GpioChannels.length]; ... // Reset file seek pointer to read latest value of GPIO port raf[channum].seek(0); raf[channum].read(inBytes); inLine = new String(inBytes); It's Big Data from sensors and industrial/medical/networking equipment meeting complex analytical software on a small constraint device (like a Linux/ARM RPi) where Java Embedded allows you to shine as an Embedded Device Software Designer. Hinkmond

    Read the article

  • ArchBeat Link-o-Rama Top 10 for October 7-13, 2012

    - by Bob Rhubart
    The Top 10 items shared via the OTN ArchBeat Facebook page for the week of October 7-13, 2012. OOW12: Oracle Business Process Management/Oracle ADF Integration Best Practices | Andrejus Baranovskis The Oracle OpenWorld presentations keep coming! Oracle ACE Director Andrejus Baranovskis shares the slides from "Oracle Business Process Management/Oracle ADF Integration Best Practices," co-presented with Danilo Schmiedel from Opitz Consulting. Oracle's Analytics, Engineered Systems, and Big Data Strategy | Mark Rittman Part 1 of 3 in Oracle ACE Director Mark Rittman's series on Oracle Exalytics, Oracle R Enterprise and Endeca. Adaptive ADF/WebCenter template for the iPad | Maiko Rocha Oracle Fusion Middleware A-Team member Maiko Rocha responds to a a customer request for information about how to create an adaptive iPad template for their WebCenter Portal application, "a specific template to streamline their workflow on the iPad." Following the Thread in OSB | Antony Reynolds Antony Reynolds recently led an Oracle Service Bus POC in which his team needed to get high throughput from an OSB pipeline. "Imagine our surprise when, on stressing the system, we saw it lock up, with large numbers of blocked threads." He shares the details of the problem and the solution in this extensive technical post. WebCenter Sites Gadget Development Concepts Quickstart | John Brunswick What are Gadgets? "At their most basic level they can be thought of as lightweight portlets that run largely on the client side of an architecture," says John Brunswick. "Gadgets provide a cross-platform container to run reusable UI modules that generally expose dynamic information to an end user, allowing for some level of end user customization." Oracle Fusion Middleware Security: OAM and OIM 11g Academies Looking for technical how-to content covering Oracle Access Manager and Oracle Identity Manager? The people behind the Oracle Middleware Security blog have indexed relevant blog posts into what they call Academies. "These indexes contain the articles we've written that we believe provide long lasting guidance on OAM and OIM. Posts covered in these series include articles on key aspects of OAM and OIM 11g, best practice architectural guidance, integrations, and customizations." Fusion Applications Technical Tips | Naveen Nahata "Setting memory parameters for Admin and Managed servers of various domains in Fusion Applications can be, let us say, a little daunting," says Oracle Fusion Middleware A-Team member Naveen Nahata. "While all this may look complicated and intimidating, it is actually relatively simple once you understand how it all works." Updated Agenda for OTN Architect Day Los Angeles (Oct 25) In less than two weeks Oracle Architect Day rolls into Los Angeles, with a full slate of sessions devoted to cloud computing, engineered systems, and SOA. Follow the link for the updated event agenda. ORCLville: OOW 2012 - A Not So Brief Recap Oracle ACE Director Floyd Teter, an Applications & Apps Technology specialists, shares his personal, frank, and and extensive recap or Oracle OpenWorld 2012. SOA Suite create partition in Enterprise Manager | Peter Paul van de Beek "In Oracle SOA Suite 10g, or more specific BPEL 10g, one could group functionality in domains," says Peter Paul van de Beek. "This feature has been away in the early versions of SOA Suite 11g. They have returned in more recent version and can be used for all SCA composites (instead of BPEL only). Nowadays these 10g domains are called partitions." Thought for the Day "I strive for an architecture from which nothing can be taken away." — Helmut Jahn Source: BrainyQuote.com

    Read the article

  • Working and Studying in Oracle, how I balance my time....

    - by anca.rosu
    Hi, my name is Laura. I am working as an Intern within Executive Administration at Oracle Denmark, whilst studying Information Management at Copenhagen Business school. I have recently handeding a paper on Information Systems which gave me exposure to Oracle. Once completing this paper I came across a job posting on my University’s intranet site and I applied directly online. When I submitted my application for the job offer, I wondered about what language I should use for the application form, as the job posting was in Danish, but the contact person and number looked Irish. I therefore chose English. Later that same day, Fiona, one of Oracle’s Graduates Recruitment Consultants based in Ireland, contacted me. This shows how global Oracle truly is. I went for my face-to-face interview in Oracle Denmark with Charlotte, one of the team managers. I spent 5 minutes waiting in the lobby, just looking around, thinking to myself, I really want to work here. The atmosphere seemed so pleasant with a relaxed approach between colleagues, employees and guests. The interview took about an hour, but we touched on a lot of different subjects. The profile I got of Oraclewas that this is a place where you are encouraged to think for yourself, and you are given the freedom to use your ideas. Later that evening, Fiona called and offered me the job. I was very happy. At Oracle Denmark we have 4 different zones: a Quiet Zone, a Project Zone, a Dialogue Zone and a Call Zone. Everyday when you arrive you consider what will be the most productive for the day’s task, and you take your toolbox and go find a desk in the zone you have decided on. It is therefore very unusual to be next to the same person two days in a row. At Oracle, people are located all over the world, and everybody has team members, colleagues or leaders in other countries, or even other time zones. Initially,I was worried about how I would adapt to this approach but I soon realized I had nothing to worry about and now I appreciate working this way. My colleagues have been very supportive and they have openly welcomed me into my new role. I typically work two days a week and have three days at University. During exam periods, I have the flexibility to work less hours and focus on the exams, in return for putting in more hours at work when needed. The first time I had to ask for time off before handing in a paper, my boss looked at me and said, ”Of course! Your education is the most important!” I hope that by sharing my experiences with you, I can inspire or encourage you to consider Oracle as a potential employer, where you can grow both professionally and personally. If you have any questions related to this article feel free to contact  [email protected].  You can find our job opportunities via http://campus.oracle.com Technorati Tags: Intern,Oracle Denmark,Information Systems,Business school,Copenhagen,Graduates Recruitment,Ireland,Quiet Zone,Project Zone,Dialogue Zone,Call Zone,University,flexibility

    Read the article

  • Organization &amp; Architecture UNISA Studies &ndash; Chap 6

    - by MarkPearl
    Learning Outcomes Discuss the physical characteristics of magnetic disks Describe how data is organized and accessed on a magnetic disk Discuss the parameters that play a role in the performance of magnetic disks Describe different optical memory devices Magnetic Disk The way data is stored on and retried from magnetic disks Data is recorded on and later retrieved form the disk via a conducting coil named the head (in many systems there are two heads) The writ mechanism exploits the fact that electricity flowing through a coil produces a magnetic field. Electric pulses are sent to the write head, and the resulting magnetic patterns are recorded on the surface below with different patterns for positive and negative currents The physical characteristics of a magnetic disk   Summarize from book   The factors that play a role in the performance of a disk Seek time – the time it takes to position the head at the track Rotational delay / latency – the time it takes for the beginning of the sector to reach the head Access time – the sum of the seek time and rotational delay Transfer time – the time it takes to transfer data RAID The rate of improvement in secondary storage performance has been considerably less than the rate for processors and main memory. Thus secondary storage has become a bit of a bottleneck. RAID works on the concept that if one disk can be pushed so far, additional gains in performance are to be had by using multiple parallel components. Points to note about RAID… RAID is a set of physical disk drives viewed by the operating system as a single logical drive Data is distributed across the physical drives of an array in a scheme known as striping Redundant disk capacity is used to store parity information, which guarantees data recoverability in case of a disk failure (not supported by RAID 0 or RAID 1) Interesting to note that the increase in the number of drives, increases the probability of failure. To compensate for this decreased reliability RAID makes use of stored parity information that enables the recovery of data lost due to a disk failure.   The RAID scheme consists of 7 levels…   Category Level Description Disks Required Data Availability Large I/O Data Transfer Capacity Small I/O Request Rate Striping 0 Non Redundant N Lower than single disk Very high Very high for both read and write Mirroring 1 Mirrored 2N Higher than RAID 2 – 5 but lower than RAID 6 Higher than single disk Up to twice that of a signle disk for read Parallel Access 2 Redundant via Hamming Code N + m Much higher than single disk Highest of all listed alternatives Approximately twice that of a single disk Parallel Access 3 Bit interleaved parity N + 1 Much higher than single disk Highest of all listed alternatives Approximately twice that of a single disk Independent Access 4 Block interleaved parity N + 1 Much higher than single disk Similar to RAID 0 for read, significantly lower than single disk for write Similar to RAID 0 for read, significantly lower than single disk for write Independent Access 5 Block interleaved parity N + 1 Much higher than single disk Similar to RAID 0 for read, lower than single disk for write Similar to RAID 0 for read, generally  lower than single disk for write Independent Access 6 Block interleaved parity N + 2 Highest of all listed alternatives Similar to RAID 0 for read; lower than RAID 5 for write Similar to RAID 0 for read, significantly lower than RAID 5  for write   Read page 215 – 221 for detailed explanation on RAID levels Optical Memory There are a variety of optical-disk systems available. Read through the table on page 222 – 223 Some of the devices include… CD CD-ROM CD-R CD-RW DVD DVD-R DVD-RW Blue-Ray DVD Magnetic Tape Most modern systems use serial recording – data is lade out as a sequence of bits along each track. The typical recording used in serial is referred to as serpentine recording. In this technique when data is being recorded, the first set of bits is recorded along the whole length of the tape. When the end of the tape is reached the heads are repostioned to record a new track, and the tape is again recorded on its whole length, this time in the opposite direction. That process continued back and forth until the tape is full. To increase speed, the read-write head is capable of reading and writing a number of adjacent tracks simultaneously. Data is still recorded serially along individual tracks, but blocks in sequence are stored on adjacent tracks as suggested. A tape drive is a sequential access device. Magnetic tape was the first kind of secondary memory. It is still widely used as the lowest-cost, slowest speed member of the memory hierarchy.

    Read the article

  • Impressions of Pivotal Tracker

    Pivotal Tracker is a free, online agile project management system. Ive been using it recently to better communicate to customers about the current state of our project. In Pivotal Tracker, the unit of work is a story and stories are arranged into iterations or delivery cycles. Stories can be any level of granularity you want, but the idea is to use stories to communicate clearly to customers, so you dont want to write a novel. You especially dont want to write a list of detailed programming tasks. A good story for a point of sale system might be: Allow managers to override the price of an item while ringing up a customer. A less useful story: Script out the process of adding a manager flag to the user table and stage that script into the deploy directory. Stories are estimated using a point scale, by default 1, 2 or 3. Iterations are then automatically laid out by combining enough tasks to fill the point total for that period of time. You have to start with a guess on how many points your team can do in an iteration, then adjust with real data as you complete iterations. This is basic agile methodology, but where Pivotal Tracker adds value is that it automatically and graphically lays out iterations for you on your project site. This makes communication and planning easy. Compiling release notes is no longer painful as it has been clear from the outset what work is going on. While I much prefer Pivotal Trackers customer facing interface over what we used previously (TFS), I see a couple of gaps. First, I have not able to make much headway with the reporting tools. Despite my complaints about TFS, it can produce some nice reports. Second, its not clear where if at all, Id keep track of purely internal tasks. Im talking about server maintenance, cleaning up source control, checking back on some code which you never quite felt right about. Theres no purpose in cluttering up an iteration backlog with these items, but if you dont track them, you lose them. Im not sure what a good answer for that is. One gap I thought Id see, which I dont, is more granular dev tasks. If Im implementing a story, Ill write out the steps and track my progress, but really, those steps arent useful to anybody but me. The only time Ive found that level of detail really useful is when my tasks are defined at too high a level anyway or when Im working with someone who needs more coaching and might not be able to finish a story in time without some scaffolding to get them going. You can learn more about Pivotal Tracker at: http://www.pivotaltracker.com/learnmore.   --- Relevant Links --- A good intro to stories: http://www.agilemodeling.com/artifacts/userStory.htmDid you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

    Read the article

  • No external microphone Acer AO722

    - by Leeghwater
    The ACER AO722 comes with an external mic input, and this input is not recognised by Alsa mixer or Sound (in System Settings). There are various comments on this problem, but no real solutions. For example External Mic not working but Internal Mic works on an Acer Aspiron AO722. Using the internal mic is not an option, as I need to use skype professionally. I have tried everything in alsamixer (accessible through the Terminal Ctrl+Alt+t, command: alsamixer), and in Sound (under System Settings). I have also installed Pulseaudio. But to no avail. The headset is working normally under Skype in Windows. My AO722 came with Windows 7 on it, so I have installed Skype there too. My headset has separate connectors for ears and mic, and these go into the respective output and input on the right side of the laptop. This location: http://bernaerts.dyndns.org/linux/202-ubuntu-acer-ao722 sounds like an effective solution but it is for Ubuntu Natty 11.04. The solution suggested sounds drastic to me: replace the kernel 2.6.38-13 with version 2.6.38-12. I use Ubuntu 12.04, and my kernel is 3.2.0-30-generic-pae. Question: could I try this solution with Ubuntu 12.04? Is this a risky thing to do? I have found harware work around this problem. The audio output seems to be a combi output with also a microphone connection. I have made an adapter for this output. I used a 4 contacts 3,5 mm audio jack plug. To this plug I have soldered 2 female (common stereo) connectors, one for ears and one for the mic of my headset. The 4 contacts jack, which goes into the laptop (in audio OUTput) is wired as follows: tip = hot audio right; first sleeve after tip = hot audio left; second sleeve = common earth (for both ears and microphone); the 3rd sleeve = microphone signal input. In the connector which I could buy, the 3rd sleeve is not so much a sleeve, but part of the metal base of the connector; normally you would expect this one to be connect to earth. But connecting the mic signal to it works. Maybe ready made adapters of this kind and even headsets with a combi jack can simply be purchased; I didn't check. When I plug in the 4 contacts jack, Sound and Alsamixer immediately recognise an external microphone (even if no mic is connected to the adapter). In Sound, under the Input tab, 'Settings for internal microphone' changes into 'Setting for microphone'. The microphone comes through loud and clear, however there is a constant noise in the background. Others have reported this too. If I disconnect the external mic from the adapter, or shortcircuit the external microphone, the noise gets less but does not disappear. Therefore, it is not background noise from the room, but it comes from the computer itself. However, if you talk directly in the microphone of the headset, the noise level is acceptable for VOIP. The headset of my mobile phone Nokia C1 mobile comes wwith a 4 contacts combi 3,5mm jack plug. However, this one works (ear and mic) with the AO722 only if not inserted fully. Possibly the wiring of this headset jack is different. I cannot find detailed specs of the AO722, and don't know whether the audio 'output' was actually designed as a combi input/output. I have seen that at least one other AO model has a combi connector only. In any case, I do not believe that connecting your headset in this way will harm your computer. I would still appreciate a software solution. This must be possible, because the proper microphone input connector works under MS Windows.

    Read the article

  • NFJS Central Iowa Software Symposium Des Moines Trip Report

    - by reza_rahman
    As some of you may be aware, I recently joined the well-respected US based No Fluff Just Stuff (NFJS) Tour. If you work in the US and still don't know what the No Fluff Just Stuff (NFJS) Tour is, you are doing yourself a very serious disfavor. NFJS is by far the cheapest and most effective way to stay up to date through some world class speakers and talks. Following the US cultural tradition of old-fashioned roadshows, NFJS is basically a set program of speakers and topics offered at major US cities year round. The NFJS Central Iowa Software Symposium was held August 8 - 10 in Des Moines. The attendance at the event and my sessions was moderate by comparison to some of the other shows. It is one of the few events of it's kind that take place this part the country so it is extremely important. I had five talks total over two days, more or less back-to-back. The first one was my JavaScript + Java EE 7 talk titled "Using JavaScript/HTML5 Rich Clients with Java EE 7". This talk is basically about aligning EE 7 with the emerging JavaScript ecosystem (specifically AngularJS). The slide deck for the talk is here: JavaScript/HTML5 Rich Clients Using Java EE 7 from Reza Rahman The demo application code is posted on GitHub. The code should be a helpful resource if this development model is something that interests you. Do let me know if you need help with it but the instructions should be fairly self-explanatory. I am delivering this material at JavaOne 2014 as a two-hour tutorial. This should give me a little more bandwidth to dig a little deeper, especially on the JavaScript end. The second talk (on the second day) was our flagship Java EE 7/8 talk. Currently the talk is basically about Java EE 7 but I'm slowly evolving the talk to transform it into a Java EE 8 talk as we move forward. The following is the slide deck for the talk: JavaEE.Next(): Java EE 7, 8, and Beyond from Reza Rahman The next talk I delivered was my Cargo Tracker/Java EE + DDD talk. This talk basically overviews DDD and describes how DDD maps to Java EE using code examples/demos from the Cargo Tracker Java EE Blue Prints project. Applied Domain-Driven Design Blue Prints for Java EE from Reza Rahman The third was my talk titled "Using NoSQL with ~JPA, EclipseLink and Java EE". The talk covers an interesting gap that there is surprisingly little material on out there. The talk has three parts -- a birds-eye view of the NoSQL landscape, how to use NoSQL via a JPA centric facade using EclipseLink NoSQL, Hibernate OGM, DataNucleus, Kundera, Easy-Cassandra, etc and how to use NoSQL native APIs in Java EE via CDI. The slides for the talk are here: Using NoSQL with ~JPA, EclipseLink and Java EE from Reza Rahman The JPA based demo is available here, while the CDI based demo is available here. Both demos use MongoDB as the data store. Do let me know if you need help getting the demos up and running. I finishd off the event with a talk titled Building Java HTML5/WebSocket Applications with JSR 356. The talk introduces HTML 5 WebSocket, overviews JSR 356, tours the API and ends with a small WebSocket demo on GlassFish 4. The slide deck for the talk is posted below. Building Java HTML5/WebSocket Applications with JSR 356 from Reza Rahman The demo code is posted on GitHub: https://github.com/m-reza-rahman/hello-websocket. My next NFJS show is the Greater Atlanta Software Symposium on September 12 - 14. Here's my tour schedule so far, I'll keep you up-to-date as the tour goes forward: September 12 - 14, Atlanta. September 19 - 21, Boston. October 17 - 19, Seattle. I hope you'll take this opportunity to get some updates on Java EE as well as the other useful content on the tour?

    Read the article

  • A more elegant way of embedding a SOAP security header in Silverlight 4

    - by Your DisplayName here!
    The current situation with Silverlight is, that there is no support for the WCF federation binding. This means that all security token related interactions have to be done manually. Requesting the token from an STS is not really the bad part, sending it along with outgoing SOAP messages is what’s a little annoying. So far you had to wrap all calls on the channel in an OperationContextScope wrapping an IContextChannel. This “programming model” was a little disruptive (in addition to all the async stuff that you are forced to do). It seems that starting with SL4 there is more support for traditional WCF extensibility points – especially IEndpointBehavior, IClientMessageInspector. I never read somewhere that these are new features in SL4 – but I am pretty sure they did not exist in SL3. With the above mentioned interfaces at my disposal, I thought I have another go at embedding a security header – and yeah – I managed to make the code much prettier (and much less bizarre). Here’s the code for the behavior/inspector: public class IssuedTokenHeaderInspector : IClientMessageInspector {     RequestSecurityTokenResponse _rstr;       public IssuedTokenHeaderInspector(RequestSecurityTokenResponse rstr)     {         _rstr = rstr;     }       public void AfterReceiveReply(ref Message reply, object correlationState)     { }       public object BeforeSendRequest(ref Message request, IClientChannel channel)     {         request.Headers.Add(new IssuedTokenHeader(_rstr));                  return null;     } }   public class IssuedTokenHeaderBehavior : IEndpointBehavior {     RequestSecurityTokenResponse _rstr;       public IssuedTokenHeaderBehavior(RequestSecurityTokenResponse rstr)     {         if (rstr == null)         {             throw new ArgumentNullException();         }           _rstr = rstr;     }       public void ApplyClientBehavior(       ServiceEndpoint endpoint, ClientRuntime clientRuntime)     {         clientRuntime.MessageInspectors.Add(new IssuedTokenHeaderInspector(_rstr));     }       // rest omitted } This allows to set up a proxy with an issued token header and you don’t have to worry anymore with embedding the header manually with every call: var client = GetWSTrustClient();   var rst = new RequestSecurityToken(WSTrust13Constants.KeyTypes.Symmetric) {     AppliesTo = new EndpointAddress("https://rp/") };   client.IssueCompleted += (s, args) => {     _proxy = new StarterServiceContractClient();     _proxy.Endpoint.Behaviors.Add(new IssuedTokenHeaderBehavior(args.Result));   };   client.IssueAsync(rst); Since SL4 also support the IExtension<T> interface, you can also combine this with Nicholas Allen’s AutoHeaderExtension.

    Read the article

  • Heterogeneous Datacenter Management with Enterprise Manager 12c

    - by Joe Diemer
    The following is a Guest Blog, contributed by Bryce Kaiser, Product Manager at Blue MedoraWhen I envision a perfect datacenter, it would consist of technologies acquired from a single vendor across the entire server, middleware, application, network, and storage stack - Apps to Disk - that meets your organization’s every IT requirement with absolute best-of-breed solutions in every category.   To quote a familiar motto, your datacenter would consist of "Hardware and Software, Engineered to Work Together".  In almost all cases, practical realities dictate something far less than the IT Utopia mentioned above.   You may wish to leverage multiple vendors to keep licensing costs down, a single vendor may not have an offering in the IT category you need, or your preferred vendor may quite simply not have the solution that meets your needs.    In other words, your IT needs dictate a heterogeneous IT environment.  Heterogeneity, however, comes with additional complexity. The following are two pretty typical challenges:1) No End-to-End Visibility into the Enterprise Wide Application Deployment. Each vendor solution which is added to an infrastructure may bring its own tooling creating different consoles for different vendor applications and platforms.2) No Visibility into Performance Bottlenecks. When multiple management tools operate independently, you lose diagnostic capabilities including identifying cross-tier issues with database, hung-requests, slowness, memory leaks and hardware errors/failures causing DB/MW issues. As adoption of Oracle Enterprise Manager (EM) has increased, especially since the release of Enterprise Manager 12c, Oracle has seen an increase in the number of customers who want to leverage their investments in EM to manage non-Oracle workloads.  Enterprise Manager provides a single pane of glass view into their entire datacenter.  By creating a highly extensible framework via the Oracle EM Extensibility Development Kit (EDK), Oracle has provided the tooling for business partners such as my company Blue Medora as well as customers to easily fill gaps in the ecosystem and enhance existing solutions.  As mentioned in the previous post on the Enterprise Manager Extensibility Exchange, customers have access to an assortment of Oracle and Partner provided solutions through this Exchange, which is accessed at http://www.oracle.com/goto/emextensibility.  Currently, there are over 80 Oracle and partner provided plug-ins across the EM 11g and EM 12c versions.  Blue Medora is one of those contributing partners, for which you will find 3 of our solutions including our flagship plugin for VMware.  Let's look at Blue Medora’s VMware plug-in as an example to what I'm trying to convey.  Here is a common situation solved by true visibility into your entire stack:Symptoms•    My database is bogging down, however the database appears okay internally.  Maybe it’s starved for resources?•    My OS tooling is showing everything is “OK”.  Something doesn’t add up. Root cause•    Through the VMware plugin we can see the problem is actually on the virtualization layer Solution•    From within Enterprise Manager  -- the same tool you use for all of your database tuning -- we can overlay the data of the database target, host target, and virtual machine target for a true picture of the true root cause. Here is the console view: Perhaps your monitoring conditions are more specific to your environment.  No worries, Enterprise Manager still has you covered.  With Metric Extensions you have the “Next Generation” of User-Defined Metrics, which easily bring the power of your existing management scripts into a single console while leveraging the proven Enterprise Manager framework. Simply put, Oracle Enterprise manager boasts a growing ecosystem that provides the single pane of glass for your entire datacenter from the database and beyond.  Bryce can be contacted at [email protected]

    Read the article

  • Doubts about several best practices for rest api + service layer

    - by TheBeefMightBeTough
    I'm going to be starting a project soon that exposes a restful api for business intelligence. It may not be limited to a restful api, so I plan to delegate requests to a service layer that then coordinates multiple domain objects (each of which have business logic local to the object). The api will likely have many calls as it is a long-term project. While thinking about the design, I recalled a few best practices. 1) Use command objects at the controller layer (I'm using Spring MVC). 2) Use DTOs at the service layer. 3) Validate in both the controller and service layer, though for different reasons. I have my doubts about these recommendations. 1) Using command objects adds a lot of extra single-purpose classes (potentially one per request). What exactly is the benefit? Annotation based validation can be done using this approach, sure. What if I have two requests that take the same parameters, but have different validation requirements? I would have to have two different classes with exactly the same members but different annotations? Bleh. 2) I have heard that using DTOs is preferable to parameters because it makes for more maintainable code down the road (say, e.g., requirements change and the service parameters need to be altered). I don't quite understand this. Shouldn't an api be more-or-less set in stone? I would understand that in the early phases of a project (or, especially, an entire company) the domain itself will not be well understood, and thus core domain objects may change along with the apis that manipulate these objects. At this point however the number of api methods should be small and their dependents few, so changes to the methods could easily be tolerated from a maintainability standpoint. In a large api with many methods and a substantial domain model, I would think having a DTO for potentially each domain object would become unwieldy. Am I misunderstanding something here? 3) I see validation in the controller and service layer as redundant in most cases. Why would I validate that parameters are not null and are in general well formed in the controller if the service is going to do exactly the same (and more). Couldn't I just do all the validation in the service and throw a runtime exception with a list of bad parameters then catch that in the controller to make the error messages more presentable? Better yet, couldn't I just make the error messages user-friendly in the service and let the exception trickle up to a global handler (ControllerAdvice in spring, for example)? Is there something wrong with either of these approaches? (I do see a use case for controller validation if the input does not map one-to-one with the service input, but since the controllers are for a rest api and not forms, the api parameters will probably map directly to service parameters.) I do also have a question about unchecked vs checked exceptions. Namely, I'm not really sure why I'd ever want to use a checked exception. Every time I have seen them used they just get wrapped into general exceptions (DomainException, SystemException, ApplicationException, w/e) to reduce the signature length of methods, or devs catch Exception rather than dealing with the App1Exception, App2Exception, Sys1Exception, Sys2Exception. I don't see how either of these practices is very useful. Why not just use unchecked exceptions always and catch the ones you actually do care about? You could just document what unchecked exceptions the method throws.

    Read the article

  • Easy Made Easier - Networking

    - by dragonfly
        In my last post, I highlighted the feature of the Appliance Manager Configurator to auto-fill some fields based on previous field values, including host names based on System Name and sequential IP addresses from the first IP address entered. This can make configuration a little faster and a little less subject to data entry errors, particularly if you are doing the configuration on the Oracle Database Appliance itself.     The Oracle Database Appliance Appliance Manager Configurator is available for download here. But why would you download it, if it comes pre-installed on the Oracle Database Appliance? A common reason for customers interested in this new Engineered System is to get a good idea of how easy it is to configure. Beyond that, you can save the resulting configuration as a file, and use it on an Oracle Database Appliance. This allows you to verify the data entered in advance, and in the comfort of your office. In addition, the topic of this post is another strong reason to download and use the Appliance Manager Configurator prior to deploying your Oracle Database Appliance.     The most common source of hiccups in deploying an Oracle Database Appliance, based on my experiences with a variety of customers, involves the network configuration. It is during Step 11, when network validation occurs, that these come to light, which is almost half way through the 24 total steps, and can be frustrating, whether it was a typo, DNS mis-configuration or IP address already in use. This is why I recommend as a best practice taking advantage of the Appliance Manager Configurator prior to deploying an Oracle Database Appliance.     Why? Not only do you get the benefit of being able to double check your entries before you even start on the Oracle Database Appliance, you can also take advantage of the Network Validation step. This is the final step before you review all the data and can save it to a text file. It can be skipped, if you aren't ready or are not connected to the network that the Oracle Database Appliance will be on. My recommendation, though, is to run the Appliance Manager Configurator on your laptop, enter the data or re-load a previously saved file of the data, and then connect to the network that the Oracle Database Appliance will be on. Now run the Network Validation. It will check to make sure that the host names you entered are in DNS and do resolve to the IP addresses you specifiied. It will also ping the IP Addresses you specified, so that you can verify that no other machine is already using them (yes, that has happened at customer sites).     After you have completed the validation, as seen in the screen shot below, you can review the results and move on to saving your settings to a file for use on your Oracle Database Appliance, or if there are errors, you can use the Back button to return to the appropriate screen and correct the data. Once you are satisfied with the Network Validation, just check the Skip/Ignore Network Validation checkbox at the top of the screen, then click Next. Is the Network Validation in the Appliance Manager Configurator required? No, but it can save you time later. I should also note that the Network Validation screen is not part of the Appliance Manager Configurator that currently ships on the Oracle Database Appliance, so this is the easiest way to verify your network configuration.     I hope you are finding this series of posts useful. My next post will cover some aspects of the windowing environment that gets run by the 'startx' command on the Oracle Database Appliance, since this is needed to run the Appliance Manager Configurator via a direct connected monitor, keyboard and mouse, or via the ILOM. If it's been a while since you've used an OpenWindows environment, you'll want to check it out.

    Read the article

< Previous Page | 270 271 272 273 274 275 276 277 278 279 280 281  | Next Page >