Search Results

Search found 6023 results on 241 pages for 'grid computing'.

Page 56/241 | < Previous Page | 52 53 54 55 56 57 58 59 60 61 62 63  | Next Page >

  • How to Profile R Code that Includes SNOW Cluster

    - by James
    Hi, I have a nested loop that I'm using foreach, DoSNOW, and a SNOW socket cluster to solve for. How should I go about profiling the code to make sure I'm not doing something grossly inefficient. Also is there anyway to measure the data flows going between the master and nodes in a Snow cluster? Thanks, James

    Read the article

  • Should I persist images on EBS or S3?

    - by javanes
    I am migrating my Java,Tomcat, Mysql server to AWS EC2. I have already attached EBS volume for storing MySql data. In my web application people may upload images. So I should persist them. There are 2 alternatives in my mind: Save uploaded images to EBS volume. Use the S3 service. The followings are my notes, please be skeptic about them, as my expertise is not on servers, but software development. EBS plus: S3 storage is more expensive. (0.15 $/Gb 0.1$/Gb) S3 plus: Serving statics from EBS may influence my web server's performance negatively. Is this true? Does Serving images affect server performance notably? For S3 my server will not be responsible for serving statics. S3 plus: Serving statics from EBS may result I/O cost, probably it will be minor. EBS plus: People say EBS is faster. S3 plus: People say S3 is more safe for persistence. EBS plus: No need to learn API, it is straight forward to save the images to EBS volume. Namely I can not decide, will be happy if you guide. Thanks

    Read the article

  • Gluster strange issue with shared mount point like seprate mount.

    - by Satish
    I have two nodes and for experiment i have install glusterfs and create volume and successfully mounted on own node, but if i create file in node1 it is not showing in node2, look like both behaving like they are separate. node1 10.101.140.10:/nova-gluster-vol 2.0G 820M 1.2G 41% /mnt node2 10.101.140.10:/nova-gluster-vol 2.0G 33M 2.0G 2% /mnt volume info split brian $ sudo gluster volume heal nova-gluster-vol info split-brain Gathering Heal info on volume nova-gluster-vol has been successful Brick 10.101.140.10:/brick1/sdb Number of entries: 0 Brick 10.101.140.20:/brick1/sdb Number of entries: 0 test node1 $ echo "TEST" > /mnt/node1 $ ls -l /mnt/node1 -rw-r--r-- 1 root root 5 Oct 27 17:47 /mnt/node1 node2 (file isn't there, while they are shared mount) $ ls -l /mnt/node1 ls: cannot access /mnt/node1: No such file or directory What i am missing??

    Read the article

  • Validate DataGridColumn cell's individually

    - by Joshua Fox
    How can I validate the cells in a DataGridColumn individually? The validation is configured per-row. For example FIELD VALUE TYPE age 13 Integer height 13x3 Integer registered true Boolean temperature 98.G6 Float In this case, of course 13x3 and 98.G6 would be invalid. Writing a Validator is no problem, and I can grab the TYPE from the data provider object, but now do I get individual access to the GUI cells so I can give the Validator a source which is an individual cell, set the errorString on an individual cell.

    Read the article

  • Is there any way to delete an HttpOnly cookie from C# Selenium tests?

    - by BenA
    I have a set of C# Selenium tests that need to delete a cookie that has the HttpOnly flag set. Unfortunately the DefaultSelenium.GetCookie() and DefaultSelenium.DeleteCookie() commands aren't able to access the cookie, because it has that HttpOnly flag set. I've confirmed this by removing the flag by hand, and checking that subsequent calls to either of those methods are then happily able to manipulate the cookie in question. Is there any other way to do this via the Selenium .NET client driver? All ideas welcome!

    Read the article

  • Build farms using ccnet

    - by Grzenio
    Is it possible to use CruiseControl.Net to set up a build farm? We currently have 4 different build machines building different things at different times and have a bit of a headache to manually balance the load somehow. I would prefer to designate one of them to be the master build machine, which would delegate work to the other ones when they are free.

    Read the article

  • Different Editors for one column in EditorGridPanel ExtJS

    - by Sloane
    Hi, I am trying to show/load different editor on different rows of a editorgridpanel. Like a textbox on one row combobox/superboxselect on another and it could be any order, random. The conditions which dictate which editor will be shown reside in the database. Please tell me if this is possible and if so, how do i go about it.. I have tried pulling the conditions asynchronously which are pulled on a click event for the respective column, but calling it async causes problems. Please advise

    Read the article

  • Distributed Message Ordering

    - by sbanwart
    I have an architectural question on handling message ordering. For purposes of this question, the transport is irrelevant, so I'm not going to specify one. Say we have three systems, a website, a CRM and an ERP. For this example, the ERP will be the "master" system in terms of data ownership. The website and the CRM can both send a new customer message to the ERP system. The ERP system then adds a customer and publishes the customer with the newly assigned account number so that the website and CRM can add the account number to their local customer records. This is a pretty straight forward process. Next we move on to placing orders. The account number is required in order for the CRM or website to place an order with the ERP system. However the CRM will permit the user to place an order even if the customer lacks an account number. (For this example assume we can't modify the CRM behavior) This creates the possibility that a user could create a new customer, and place an order before the account number gets updated in the CRM. What is the best way to handle this scenario? Would it be best to send the order message sans account number and let it go to an error queue? Would it be better to have the CRM endpoint hold the message and wait until the account number is updated in the CRM? Maybe something completely different that I haven't thought of? Thanks in advance for any help.

    Read the article

  • cloud and existing enterprise applications technologies

    - by maxxxee
    What is the significance of new cloud platforms and databases like Microsoft Azure and Amazon EC2? Is it a replacement for enterprise application platforms like .net or JEE in a cloud environment? Is it neccessary to use these or other cloud specific platforms, or can we implement .net or JEE on a cloud based environment?

    Read the article

  • Cloud Database Service Latency/Performance

    - by Gcoop
    Hi All, I am running a heavy traffic site and our server is beginning to get to its limits, at the moment the entire LAMP stack is on one box (not ideal). I would like to move the database onto it's own box or onto a cloud service, but from my previous experience moving the database off the same box as the webserver increases the latency of reads quite dramatically slowing down the site. Is using a cloud service for this going to overcome this problem, because as far as I can tell its essentially the same situation (as moving it onto a separate box in my control)? In which case why is there so much popularity around cloud based database services at the moment? Are cloud based database services so quick that the latency of reads is so low that its almost like having it on the same box in the same datacentre?

    Read the article

  • RackSpace Cloud Strips $_SESSION if URL Has Certain File Extensions

    - by macinjosh
    The Situation I am creating a video training site for a client on the RackSpace Cloud using the traditional LAMP stack (RackSpace's cloud has both Windows and LAMP stacks). The videos and other media files I'm serving on this site need to be protected as my client charges money for access to them. There is no DRM or funny business like that, essentially we store the files outside of the web root and use PHP to authenticate user's before they are able to access the files by using mod_rewrite to run the request through PHP. So let's say the user requests a file at this URL: http://www.example.com/uploads/preview_image/29.jpg I am using mod_rewrite to rewrite that url to: http://www.example.com/files.php?path=%2Fuploads%2Fpreview_image%2F29.jpg Here is a simplified version of the files.php script: <?php // Setups the environment and sets $logged_in // This part requires $_SESSION require_once('../../includes/user_config.php'); if (!$logged_in) { // Redirect non-authenticated users header('Location: login.php'); } // This user is authenticated, continue $content_type = "image/jpeg"; // getAbsolutePathForRequestedResource() takes // a Query Parameter called path and uses DB // lookups and some string manipulation to get // an absolute path. This part doesn't have // any bearing on the problem at hand $file_path = getAbsolutePathForRequestedResource($_GET['path']); // At this point $file_path looks something like // this: "/path/to/a/place/outside/the/webroot" if (file_exists($file_path) && !is_dir($file_path)) { header("Content-Type: $content_type"); header('Content-Length: ' . filesize($file_path)); echo file_get_contents($file_path); } else { header('HTTP/1.0 404 Not Found'); header('Status: 404 Not Found'); echo '404 Not Found'; } exit(); ?> The Problem Let me start by saying this works perfectly for me. On local test machines it works like a charm. However once deployed to the cloud it stops working. After some debugging it turns out that if a request to the cloud has certain file extensions like .JPG, .PNG, or .SWF (i.e. extensions of typically static media files.) the request is routed to a cache system called Varnish. The end result of this routing is that by the time this whole process makes it to my PHP script the session is not present. If I change the extension in the URL to .PHP or if I even add a query parameter Varnish is bypassed and the PHP script can get the session. No problem right? I'll just add a meaningless query parameter to my requests! Here is the rub: The media files I am serving through this system are being requested through compiled SWF files that I have zero control over. They are generated by third-party software and I have no hope of adding or changing the URLs that they request. Are there any other options I have on this? Update: I should note that I have verified this behavior with RackSpace support and they have said there is nothing they can do about it.

    Read the article

  • cheap way to scale a rails application

    - by VP
    I have an application, that is becoming big, but until now, its not giving me a good revenue. That means, short money to re-invest on that. In this scenario, i found a way to make a "cheap distributed rails" deployment. I've got 4 VPS. All of them are in the same physical server. I added a load balance server running HAproxy in one dedicated VPS. There i pointed my virtual ip address where my domain name is associated. Behind this HAproxy i have more two VPS running my rails APP, passenger and memcache. Both apps servers are looking to the same database server, my 4th VPS. So with $44/month, i mounted a distributed environment. It won't be my final choice, but now, that the budget is short, is that a good way to deploy a rails application? Any pros or cons? It worth my $44/month?

    Read the article

  • Why isn't Hadoop implemented using MPI?

    - by artif
    Correct me if I'm wrong, but my understanding is that Hadoop does not use MPI for communication between different nodes. What are the technical reasons for this? I could hazard a few guesses, but I do not know enough of how MPI is implemented "under the hood" to know whether or not I'm right. Come to think of it, I'm not entirely familiar with Hadoop's internals either. I understand the framework at a conceptual level (map/combine/shuffle/reduce and how that works at a high level) but I don't know the nitty gritty implementation details. I've always assumed Hadoop was transmitting serialized data structures (perhaps GPBs) over a TCP connection, eg during the shuffle phase. Let me know if that's not true.

    Read the article

  • Are functional programming languages good for practical tasks?

    - by Clueless
    It seems to me from my experimenting with Haskell, Erlang and Scheme that functional programming languages are a fantastic way to answer scientific questions. For example, taking a small set of data and performing some extensive analysis on it to return a significant answer. It's great for working through some tough Project Euler questions or trying out the Google Code Jam in an original way. At the same time it seems that by their very nature, they are more suited to finding analytical solutions than actually performing practical tasks. I noticed this most strongly in Haskell, where everything is evaluated lazily and your whole program boils down to one giant analytical solution for some given data that you either hard-code into the program or tack on messily through Haskell's limited IO capabilities. Basically, the tasks I would call 'practical' such as Aceept a request, find and process requested data, and return it formatted as needed seem to translate much more directly into procedural languages. The most luck I have had finding a functional language that works like this is Factor, which I would liken to a reverse-polish-notation version of Python. So I am just curious whether I have missed something in these languages or I am just way off the ball in how I ask this question. Does anyone have examples of functional languages that are great at performing practical tasks or practical tasks that are best performed by functional languages?

    Read the article

  • C++ Numerical truncation error

    - by Andrew
    Hello everyone, sorry if dumb but could not find an answer. #include <iostream> using namespace std; int main() { double a(0); double b(0.001); cout << a - 0.0 << endl; for (;a<1.0;a+=b); cout << a - 1.0 << endl; for (;a<10.0;a+=b); cout << a - 10.0 << endl; cout << a - 10.0-b << endl; return 0; } Output: 0 6.66134e-16 0.001 -1.03583e-13 Tried compiling it with MSVC9, MSVC10, Borland C++ 2010. All of them arrive in the end to the error of about 1e-13. Is it normal to have such a significant error accumulation over only a 1000, 10000 increments?

    Read the article

  • PVM terminates after Adding Host

    - by Tyug
    On Ubuntu 9.10 using PVM 3.4.5-12 (the PVM package when you use apt-get) The program terminates after adding a host. laptop> pvm pvm> add bowtie-slave add bowtie-slave terminated laptop> Current Configuration only $PVM_RSH = bin/usr/ssh I can ssh perfectly fine into the slave without a password, and run commands on it. Any ideas? Thanks in advance! Here are the sample logs: Laptop log [t80040000] 02/11 10:23:32 laptop (127.0.1.1:xxxxx) LINUX 3.4.5 [t80040000] 02/11 10:23:32 ready Thu Feb 11 10:23:32 2010 [t80040000] 02/11 10:23:32 netoutput() sendto: errno=22 [t80040000] 02/11 10:23:32 em=0x2c24f0 [t80040000] 02/11 10:23:32 [49/à][6e/à][76/à][61/à][6c/à][69/à][64/à][20/à][61/à][72/à] [t80040000] 02/11 10:23:32 netoutput() sendto: Invalid argument [t80040000] 02/11 10:23:32 pvmbailout(0) bowtie-log [t80080000] 02/11 10:23:25 bowtie-slave (xxx.x.x.xxx:xxxxx) LINUX64 3.4.5 [t80080000] 02/11 10:23:25 ready Thu Feb 11 10:23:25 2010 [t80080000] 02/11 10:28:26 work() run = STARTUP, timed out waiting for master [t80080000] 02/11 10:28:26 pvmbailout(0)

    Read the article

  • open source gossip-based membership protocol?

    - by Aaron
    I am looking for a library which I can plug into a distributed application which implements any gossip-based membership protocol. Such a library would allow me to send/receive membership lists, merge received membership lists, etc... Even better would be if the library implemented a protocol with performance O(logn) performance guarantees. Does anyone know of any open source library like this? It doesn't need to meet all of the aforementioned requirements; even something partially implemented would be helpful.

    Read the article

  • mvc contrib pager question - AsPagination

    - by csetzkorn
    Hi, I might be wrong but is the AsPagination method not very inefficient as it sucks all the data from a repository first to initialise TotalItems etc.? So paging is not used to make the data access more efficient. I have not found any examples which use a repository and 'true' paging (i.e. uses TOP etc. in the atcual SQL). How do I use the Pager if I have a repository method with this signature: IList GetData(int? page, out int TotalItems) Any feedback would be very much appreciated. Thanks. Christian

    Read the article

  • Problems with objectatasource,giving attributes like delete insert and update

    - by kamal
    After going to the process of adding the various attributes like insert,delete and update.But when i run it through the browser ,editing works but updating and deleting doesn't !(for the update and shows the same thing for delete,my friends think i need to use codes to repair the problems,can you help me please.it shows this: Server Error in '/WebSite3' Application. ObjectDataSource 'ObjectDataSource1' could not find a non-generic method 'Update' that has parameters: First_name, Surname, Original_author_id, First name, original_author id. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.InvalidOperationException: ObjectDataSource 'ObjectDataSource1' could not find a non-generic method 'Update' that has parameters: First_name, Surname, Original_author_id, First name, original_author id. Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. Stack Trace: [InvalidOperationException: ObjectDataSource 'ObjectDataSource1' could not find a non-generic method 'Update' that has parameters: First_name, Surname, Original_author_id, First name, original_author id.] System.Web.UI.WebControls.ObjectDataSourceView.GetResolvedMethodData(Type type, String methodName, IDictionary allParameters, DataSourceOperation operation) +1119426 System.Web.UI.WebControls.ObjectDataSourceView.ExecuteUpdate(IDictionary keys, IDictionary values, IDictionary oldValues) +1008 System.Web.UI.DataSourceView.Update(IDictionary keys, IDictionary values, IDictionary oldValues, DataSourceViewOperationCallback callback) +92 System.Web.UI.WebControls.GridView.HandleUpdate(GridViewRow row, Int32 rowIndex, Boolean causesValidation) +907 System.Web.UI.WebControls.GridView.HandleEvent(EventArgs e, Boolean causesValidation, String validationGroup) +704 System.Web.UI.WebControls.GridView.OnBubbleEvent(Object source, EventArgs e) +95 System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +37 System.Web.UI.WebControls.GridViewRow.OnBubbleEvent(Object source, EventArgs e) +123 System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +37 System.Web.UI.WebControls.LinkButton.OnCommand(CommandEventArgs e) +118

    Read the article

< Previous Page | 52 53 54 55 56 57 58 59 60 61 62 63  | Next Page >