Search Results

Search found 10693 results on 428 pages for 'max requests'.

Page 364/428 | < Previous Page | 360 361 362 363 364 365 366 367 368 369 370 371  | Next Page >

  • JDBC transaction dead-lock solution required?

    - by user49767
    It's a scenario described my friend and challenged to find solution. He is using Oracle database and JDBC connection with read committed as transaction isolation level. In one of the transaction, he updates a record and executes selects statement and commits the transaction. when everything happening within single thread, things are fine. But when multiple requests are handled, dead-lock happens. Thread-A updates a record. Thread B updates another record. Thread-A issues select statement and waits for Thread-B's transaction to complete the commit operation. Thread-B issues select statement and waits for Thread-A's transaction to complete the commit operation. Now above causes dead-lock. Since they use command pattern, the base framework allows to issue commit only once (at the end of all the db operation), so they are unable to issue commit immediately after select statement. My argument was Thread-A supposed to select all the records which are committed and hence should not be issue. But he said that Thread-A will surely wait till Thread-B commits the record. is that true? What are all the ways, to avoid the above issue? is it possible to change isolation-level? (without changing underlying java framework) Little information about base framework, it is something similar to Struts action, their each and every request handled by one action, transaction begins before execution and commits after execution.

    Read the article

  • How to handle images better in Android

    - by primal
    In the microblogging application I am developing I wish to show an user image beside each post in the timeline. The images are small in size(max 50*50 dip) and are not more than 10 in number. I've two approaches in my mind. 1) Allow user to chose an image from Gallery on signing up. Send the image to the server and on subsequent signups load the image from the server. I'm worried whether this approach is doing too much unnecessary work. 2) The same method is same as above in first step but this time the image is not send to the server but a key value associated with the image is sent to the server. On subsequent signups, after obtaining the key from the server the specific image is loaded from gallery. I am not sure whether the second approach is possible. Any corrections on this aspect would be much appreciated. Also, Is it possible to store an image in SharedPreferences? Any new approach to handle this problem better are welcome.

    Read the article

  • How to Specify Columntype in fluent nHibernate?

    - by Bipul
    I have a class CaptionItem public class CaptionItem { public virtual int SystemId { get; set; } public virtual int Version { get; set; } protected internal virtual IDictionary<string, string> CaptionValues {get; private set;} } I am using following code for nHibernate mapping Id(x => x.SystemId); Version(x => x.Version); Cache.ReadWrite().IncludeAll(); HasMany(x => x.CaptionValues) .KeyColumn("CaptionItem_Id") .AsMap<string>(idx => idx.Column("CaptionSet_Name"), elem => elem.Column("Text")) .Not.LazyLoad() .Cascade.Delete() .Table("CaptionValue") .Cache.ReadWrite().IncludeAll(); So in database two tables get created. One CaptionValue and other CaptionItem. In CaptionItem table has three columns 1. CaptionItem_Id int 2. Text nvarchar(255) 3. CaptionSet_Name nvarchar(255) Now, my question is how can I make the columnt type of Text to nvarchar(max)? Thanks in advance.

    Read the article

  • Consolidate multiple site files into single location

    - by seengee
    We have a custom PHP/MySQL CMS running on Linux/Apache thats rolled out to multiple sites (20+) on the same server. Each site uses exactly the same CMS files with a few files for each site being customised. The customised files for each site are: /library/mysql_connect.php /public_html/css/* /public_html/ftparea/* /public_html/images/* There's also a couple of other random files inside /public_html/includes/ that are unique to each site. Other than this each site on the server uses the exact same files. Each site sitting within /home/username/. There is obviously a massive amount of replication here as each time we want to deploy a system update we need to update to each user account. Given the common site files are all stored in SVN it would make far more sense if we were able to simply commit to SVN and deploy to a single location direct from there. Unfortunately, making a major architecture change at this stage could be problematic. In my mind the ideal scenario would mean creating an account like /home/commonfiles/ and each site using these common files unless an account specific file exists, for example a request is made to /home/user/public_html/index.php but as this file doesnt exist the request is then redirected to /home/commonfiles/public_html/index.php. I know that generally this approach is possible, similar to how Zend Framework (and probably others) redirect all requests that dont match a specific file to index.php. I'm just not sure about how exactly to go about implementing it and whether its actually advisable. Would really welcome any input/ideas people have got. Thanks.

    Read the article

  • Application Design: Single vs. Multiple Hits to the DB

    - by shyneman
    I'm building a service that performs a set of configured activities based on the type of request that it receives. Each activity involves going to the database and retrieving/updating some kind of information. The logic for each activity can be generalized and re-used across different request types. The activities may need to participate in a transaction for the duration of the servicing the request. One option, I'm considering is having each activity maintain its own access to DAL/database. This fully encapsulates the activity into a stand-alone re-usable piece, but hitting the database multiple times for one request doesn't seem like a viable option. I don't really know how to easily implement the concept of a transaction across the multiple activities here either. The second option is to encapsulate ALL the activities into one big activity and hit the database once. But this does not allow re-use and configuration of these activities for different requests. Does anyone have any suggestions and input about what should be the best way to approach my problem? Thanks for any help.

    Read the article

  • I'm trying to grasp the concept of creating a program that uses a SQL Server database, but I'm used

    - by Sergio Tapia
    How can I make a program use a SQL Server database, and have that program work on whatever computer it's installed on. If you've been following my string of questions today, you'd know that I'm making an open source and free Help Desk suite for small and medium businesses. The client application. The client application is a Windows Forms app. On installation and first launch on every client machine, it'll ask for the address of the main Help Desk server. The server. Here I plan to handle all incoming help requests, show them to the IT guys, and provide WCF services for the Client application to consume. My dilemma lies in that, I know how to make the program run on my local machine; but I'm really stumped on how to make this work for everyone who wants to download and install the server bit on their Windows Server. Would I have to make an SQL Script and have it run on the MS SQL server when a user wants to install the 'server' application? Many thanks to all for your valuable time and effort to teach me. It's really really appreciated. :) Edit: To clarify, each business will have their server completely separate from me. I will have no access whatsoever to them nor will they be in any way connected to me. (I don't know why I should clarify this :P ) So, assuming the have ABSOLUTELY NO DATABASE SERVER installed; what can I do?

    Read the article

  • CakePHP 1.26: Bug in 'Security' component?

    - by Steve
    Okay, for those of you who may have read this earlier, I've done a little research and completely revamped my question. I've been having a problem where my form requests get blackholed by the Security component, although everything works fine when the Security component is disabled. I've traced it down to a single line in a form: <?php echo $form->create('Audition');?> <fieldset> <legend><?php __('Edit Audition');?></legend> <?php echo $form->input('ensemble'); echo $form->input('position'); echo $form->input('aud_date'); // The following line works fine... echo $form->input('owner'); // ...but the following line blackholes when Security included // and the form is submitted: // echo $form->input('owner', array('disabled'=>'disabled'); ?> </fieldset> <?php echo $form->end('Submit');?> (I've commented out the offending line for clarity) I think I'm following the rules by using the form helper; as far as I can tell, this is a bug in the Security component, but I'm too much of a CakePHP n00b to know for sure. I'd love to get some feedback, and if it's a real bug, I'll submit it to the CakePHP team. I'd also love to know if I'm just being dumb and missing something obvious here.

    Read the article

  • Can you catch exceeded allocated memory error before it kills the script?

    - by kristovaher
    The thing is that I want to catch memory problems before they happen. I have a system that gets rows from database and casts the returned associative array to a variable, but I never know what the size of the database result is is or how much memory it will take once the database request is made. This means that my software can fail simply because memory is exceeded. But I want to avoid that somehow. One of the ways is to obviously make database requests that are smaller, but what if this is not possible or what if I do not know the size of data that is returned from database? Is it possible to 'catch' situations where memory use is exceeded in PHP? Something like this: $requestOk=memory_test(function(){ return doSomething(); }); if($requestOk){ // Memory seems fine // $requestOk now has the value from memory_test() function } else { // Function would have exceeded memory } I just find it problematic that my script can just die at any moment because of memory issues. From what I know, try-catch cannot be used here because it is a fatal error. Any help would be appreciated!

    Read the article

  • Want to display a 3D model on the iPhone: how to get started?

    - by JeremyReimer
    I want to display and rotate a single 3D model, preferably textured, on the iPhone. Doesn't have to zoom in and out, or have a background, or anything. I have the following: an iPhone a MacBook the iPhone SDK Blender My knowledge base: I can make 3D models in various 3D programs (I'm most comfortable with 3D Studio Max, which I once took a course on, but I've used others) General knowledge of procedural programming from years ago (QuickBasic - I'm old!) Beginner's knowledge of object-oriented programming from going through simple Java and C# tutorials (Head Start C# book and my wife's intro to OOP course that used Java) I have managed to display a 3D textured model and spin it using a tutorial in C# I got off the net (I didn't just copy and paste, I understand basically how it works) and the XNA game development library, using Visual Studio on Windows. What I do not know: Much about Objective C Anything about OpenGL or OpenGL ES, which the iPhone apparently uses Anything about XCode My main problem is that I don't know where to start! All the iPhone books I found seem to be about creating GUI applications, not OpenGL apps. I found an OpenGL book but I don't know how much, if any, applies to iPhone development. And I find the Objective C syntax somewhat confusing, with the weird nested method naming, things like "id" that don't make sense, and the scary thought that I have to do manual memory management. Where is the best place to start? I couldn't find any tutorials for this sort of thing, but maybe my Google-Fu is weak. Or maybe I should start with learning Objective C? I know of books like Aaron Hillgrass', but I've also read that they are outdated and much of the sample code doesn't work on the iPhone SDK, plus it seems geared towards the Model-View-Controller paradigm which doesn't seem that suited for 3D apps. Basically I'm confused about what my first steps should be.

    Read the article

  • PHP check http referer for form submitted by AJAX, secure?

    - by Michael Mao
    Hi all: This is the first time I am working for a front-end project that requires server-side authentication for AJAX requests. I've encountered problems like I cannot make a call of session_start as the beginning line of the "destination page", cuz that would get me a PHP Warning : Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at C:\xampp\htdocs\comic\app\ajaxInsert Book.php:1) in C:\xampp\htdocs\comic\app\common.php on line 10 I reckon this means I have to figure out a way other than checking PHP session variables to authenticate the "caller" of this PHP script, and this is my approach : I have a "protected" PHP page, which must be used as the "container" of my javascript that posts the form through jQuery $.ajax(); method In my "receiver" PHP script, what I've got is: <?php define(BOOKS_TABLE, "books"); define(APPROOT, "/comic/"); define(CORRECT_REFERER, "/protected/staff/addBook.php"); function isRefererCorrect() { // the following line evaluates the relative path for the referer uri, // Say, $_SERVER['HTTP_REFERER'] returns "http://localhost/comic/protected/staff/addBook.php" // Then the part we concern is just this "/protected/staff/addBook.php" $referer = substr($_SERVER['HTTP_REFERER'], 6 + strrpos($_SERVER['HTTP_REFERER'], APPROOT)); return (strnatcmp(CORRECT_REFERER, $referer) == 0) ? true : false; } //http://stackoverflow.com/questions/267546/correct-http-header-for-json-file header('Content-type: application/json charset=UTF-8'); header('Cache-Control: no-cache, must-revalidate'); echo json_encode(array ( "feedback"=>"ok", "info"=>isRefererCorrect() )); ?> My code works, but I wonder is there any security risks in this approach? Can someone manipulate the post request so that he can pretend that the caller javascript is from the "protected" page? Many thanks to any hints or suggestions.

    Read the article

  • architecture and tools for a remote control application?

    - by slothbear
    I'm working on the design of a remote control application. From my iPhone or a web browser, I'll send a few commands. Soon my home computer will perform the commands and send back results. I know there are remote desktop apps, but I want something programmable, something simpler, and something that I wrote. My current direction is to use Amazon Simple Queue Service (SQS) as the message bus. The iPhone places some messages in a queue. My local Java/JRuby program notices the messages on the queue, performs the work and sends back status via a different queue. This will be a very low-volume application. At $1.00 for a million requests (plus a handful of data transfer charges), Amazon SQS looks a lot more affordable than having my own server of any type. And super reliable, that's important for me too. Are there better/standard toolkits or architectures for this kind of remote control? Cost is not a big issue, but I prefer the tons I learn by doing it myself. I'm moderately concerned about security, but doubt it will be a problem. The list of commands recognized will be very short, and only recognized in specific contexts. No "erase hard drive" stuff. update: I'll probably distribute these programs to some other people who want the same function, but who don't have Amazon SQS accounts. For now, they'll use anonymous access to my queues, with random 80-character queue names.

    Read the article

  • Save result of for loop in a vector

    - by hendrik
    i think I'm just too tired to see the mistake. i wrote a function to get the maximal value for two data sets from a for loop plot_zu <- function(x) {for (i in 1:x){ z=data_raw[grep(a[i], data_raw$Gene.names),] b=data_raw_ace[grep(a[i], data_raw_ace$Gene.names),] p<-vector("numeric", length(1:length(a))) p[i]<-max(z$t_test_diff) return(p)} } so picture: a is a vector of names and the data set (data_raw(_ace)) are filtered by it. In the end i would like to have all maxima values of column t_test_diff in a vector. After that i want to add the t_test_diff column values from data_raw_ace also. So the problem is, that i get this: [1] 1.210213 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 [8] 0.000000 0.000000 So there is a problem with brackets or something but i cannot see it ( first value fits). Sorry for no good example but i think it is understandable and an easy to solve question. If im to dumb to explain my problem right, i will add an example. !! Thx a lot !! grateful Hendrik

    Read the article

  • WordPress: Related Posts by Tags, but in the Same Categories

    - by Norbert
    I'm using the script below to get related posts by tags, but noticed that if I have a picture of a bird tagged white and a table also tagged white, the table will show up in the related posts section of the bird. Is there a way to only get posts that match at least one of the categories, so bird and table won't be related, unless they share one category? I tried setting an category__in array inside $args, but no luck! <?php $tags = wp_get_post_tags($post->ID); if ($tags) { $tag_ids = array(); foreach($tags as $individual_tag) $tag_ids[] = $individual_tag->term_id; $args=array( 'tag__in' => $tag_ids, 'post__not_in' => array($post->ID), 'showposts'=>6, // Number of related posts that will be shown. 'caller_get_posts'=>1 ); $my_query = new wp_query($args); if( $my_query->have_posts() ) { while ($my_query->have_posts()) { $my_query->the_post(); ?> <?php if ( get_post_meta($post->ID, 'Image', true) ) { ?> <a style="text-decoration: none;" href="<?php the_permalink(); ?>"> <img style="max-height: 125px; margin: 15px 10px; vertical-align: middle;" src="<?php bloginfo('template_directory'); ?>/scripts/timthumb.php?src=<?php echo get_post_meta($post->ID, "Image", $single = true); ?>&w=125&zc=1" alt="" /> </a> <?php } ?> <?php } } } ?>

    Read the article

  • Finding users whose birtday is today with JPA

    - by Jeduan Cornejo
    Hi, I have a table with users and are trying to get a list with the people who have birthday today so the app can send an email. The User is defined as @Entity public class User { @Size(max = 30) @NotNull private String name; [...] @Temporal(TemporalType.DATE) @DateTimeFormat(style = "S-") protected Date birthday; } and I've got a method which returns the people which were born today like so @SuppressWarnings("unchecked") public static List<User> findUsersWithBirthday() { List<User> users = entityManager().createQuery("select u from User u where u.birthday = :date") .setParameter("date", new Date(), TemporalType.DATE) .getResultList(); return users; } This is fine and all for finding people which were born today, however tha's not really that useful, so I've been struggling for a way to find all the users that were born today, independent of the year. Using MySQL there's functions I can use like select month(curdate()) as month, dayofmonth(curdate()) as day However I've been struggling to find a JPA equivalent to that. I'm using Spring 3.0.1 and Hibernate 3.3.2

    Read the article

  • Rate Limit Calls To Api Using Cache

    - by namtax
    Hi I am using coldfusion to call the last.fm api, using a cfc bundle sourced from here I am concerned about going over the request limit, which is 5 requests per originating IP address per second, averaged over a 5 minute period. The cfc bundle has a central component which calls all the other components, which are split up into sections like "artist", "track" etc...This central component "lastFmApi.cfc." is initiated in my application, and persisted for the lifespan of the application // Application.cfc example <cffunction name="onApplicationStart"> <cfset var apiKey = '[your api key here]' /> <cfset var apiSecret = '[your api secret here]' /> <cfset application.lastFm = CreateObject('component', 'org.FrankFusion.lastFm.lastFmApi').init(apiKey, apiSecret) /> </cffunction> Now if I want to call the api through a handler/controller, for example my artist handler...I can do this <cffunction name="artistPage" cache="5 mins"> <cfset qAlbums = application.lastFm.user.getArtist(url.artistName) /> </cffunction> I am a bit confused towards caching, but am caching each call to the api in this handler for 5 mins, but does this make any difference, because each time someone hits a new artist page wont this still count as a fresh hit against the api? Wondering how best to tackle this Thanks

    Read the article

  • django-cms lighttpd redirect domain to url

    - by Robert
    Hello, I am using djano-cms for my site, but instead of language alias /en/ /de/ I need to use another domain. I would like to avoid running multiple django instances, and instead I would like to use lighttpd redirects if possible. I would like requests coming to domain2.com getting data from domain.com/en . The best would be if the user entering: domain2.com/offer got transparently data from domain.com/en/offer Tried many solutions with url.redirect, url.rewrite but none seems to work as desired. Also tried with: http://stackoverflow.com/questions/261904/matching-domains-with-regex-for-lighttpd-mod-evhost-www-domain-com-domain-com but that didn't work. Please help. This is my lighttpd configuration. $HTTP["host"] == "^domain2\.com" { url.redirect = ("^/(.*)" => "http://domain.com/en/$1") } $HTTP["host"] =~ "^domain\.com" { server.document-root = "/var/www/django/projects/domain/" accesslog.filename = "/var/log/lighttpd/domain.log-access.log" server.errorlog = "/var/log/lighttpd/www.domain-error.log" fastcgi.server = ( "/domain-service.fcgi" => ( "main" => ( "socket" => "/tmp/django-domain.sock", "check-local" => "disable", ) ), ) alias.url = ( "/media/" => "/var/www/django/projects/domain/media/", ) url.rewrite-once = ( "^(/site_media.*)$" => "$1", "^(/media.*)$" => "$1", "^/favicon\.ico$" => "/media/favicon.ico", "^(/.*)$" => "/domain-service.fcgi$1", } Thanks

    Read the article

  • Rack, FastCGI, Lighttpd configuration

    - by zacsek
    Hi! I want to run a simple application using Rack, FastCGI and Lighttpd, but I cannot get it working. I get the following error: /usr/lib/ruby/1.8/rack/handler/fastcgi.rb:23:in `initialize': Address already in use - bind(2) (Errno::EADDRINUSE) from /usr/lib/ruby/1.8/rack/handler/fastcgi.rb:23:in `new' from /usr/lib/ruby/1.8/rack/handler/fastcgi.rb:23:in `run' from /www/test.rb:7 Here is the application: #!/usr/bin/ruby app = Proc.new do |env| [200, {'Content-Type' => 'text/plain'}, "Hello World!"] end require 'rack' Rack::Handler::FastCGI.run app, :Port => 4000 ... and the lighttpd.conf: server.modules += ( "mod_access", "mod_accesslog", "mod_fastcgi" ) server.port = 80 server.document-root = "/www" mimetype.assign = ( ".html" => "text/html", ".txt" => "text/plain", ".jpg" => "image/jpeg", ".png" => "image/png" ) index-file.names = ( "test.rb" ) fastcgi.debug = 1 fastcgi.server = ( ".rb" => (( "host" => "127.0.0.1", "port" => 4000, "bin-path" => "/www/test.rb", "check-local" => "disable", "max-procs" => 1 )) ) Can someone help me? What am I doing wrong?

    Read the article

  • Node & Redis: Crucial Design Issues in Production Mode

    - by Ali
    This question is a hybrid one, being both technical and system design related. I'm developing the backend of an application that will handle approx. 4K request per second. We are using Node.js being super fast and in terms of our database struction we are using MongoDB, with Redis being a layer between Node and MongoDB handling volatile operations. I'm quite stressed because we are expecting concurrent requests that we need to handle carefully and we are quite close to launch. However I do not believe I've applied the correct approach on redis. I have a class Student, and they constantly change stages(such as 'active', 'doing homework','in lesson' etc. Thus I created a Redis DB for each state. (1 for being 'active', 2 for being 'doing homework'). Above I have the structure of the 'active' students table; xa5p - JSON stringified object #1 pQrW - JSON stringified object #2 active_student_table - {{studentId:'xa5p'}, {studentId:'pQrW'}} Since there is no 'select all keys method' in Redis, I've been suggested to use a set such that when I run command 'smembers' I receive the keys and later on do 'get' for each id in order to find a specific user (lets say that age older than 15). I've been also suggested that in fact I used never use keys in production mode. My question is, no matter how 'conceptual' it is, what specific things I should avoid doing in Node & Redis in production stage?. Are they any issues related to my design? Students must be objects and I sure can list them in a list but I haven't done yet. Is it that crucial in production stage?

    Read the article

  • Doctrine - get the offset of an object in a collection (implementing an infinite scroll)

    - by dan
    I am using Doctrine and trying to implement an infinite scroll on a collection of notes displayed on the user's browser. The application is very dynamic, therefore when the user submits a new note, the note is added to the top of the collection straightaway, besides being sent (and stored) to the server. Which is why I can't use a traditional pagination method, where you just send the page number to the server and the server will figure out the offset and the number of results from that. To give you an example of what I mean, imagine there are 20 notes displayed, then the user adds 2 more notes, therefore there are 22 notes displayed. If I simply requests "page 2", the first 2 items of that page will be the last two items of the page currently displayed to the user. Which is why I am after a more sophisticated method, which is the one I am about to explain. Please consider the following code, which is part of the server code serving an AJAX request for more notes: // $lastNoteDisplayedId is coming from the AJAX request $lastNoteDisplayed = $repository->findBy($lastNoteDisplayedId); $allNotes = $repository->findBy($filter, array('createdAt' => 'desc')); $offset = getLastNoteDisplayedOffset($allNotes, $lastNoteDisplayedId); // retrieve the page to send back so that it can be appended to the listing $notesPerPage = 30 $notes = $repository->findBy( array(), array('createdAt' => 'desc'), $notesPerPage, $offset ); $response = json_encode($notes); return $response; Basically I would need to write the method getLastNoteDisplayedOffset, that given the whole set of notes and one particoular note, it can give me its offset, so that I can use it for the pagination of the previous Doctrine statement. I know probably a possible implementation would be: getLastNoteDisplayedOffset($allNotes, $lastNoteDisplayedId) { $i = 0; foreach ($allNotes as $note) { if ($note->getId() === $lastNoteDisplayedId->getId()) { break; } $i++; } return $i; } I would prefer not to loop through all notes because performance is an important factor. I was wondering if Doctrine has got a method itself or if you can suggest a different approach.

    Read the article

  • HTTP Handler error when downloading files - SSL

    - by Chiefy
    Ok big problem as this is affecting two projects on our new server. We have a file that is downloaded by users, the files are downloaded using a HTTPHandler. Since moving the site to the server and setting SSL the downloads have stopped working and we get an error message "Unable to download DownloadDocument.ashx" from site". DownloadDocument.ashx is the handler page that is set in the web.config and the button that goes there is a hyperlink with the id of the document as a querystring. Ive read the article on http://support.microsoft.com/kb/316431 and read a few other requests on this site but nothing seems to be working. This problem only happens in IE and works fine when I run it on the server in http instead of https. public override void HandleRequest(HttpContext context) { Guid guid = new Guid(context.Request.QueryString["ID"]); DataTable dt = Documents.GetDocument(guid); if (dt != null) { context.Response.Cache.SetCacheability(HttpCacheability.Private); context.Response.AddHeader("content-disposition", string.Format("attachment; filename={0}", dt.Rows[0]["DocumentName"].ToString())); context.Response.AddHeader("Content-Transfer-Encoding", "binary"); context.Response.AddHeader("Content-Length", ((byte[])dt.Rows[0]["Document"]).Length.ToString()); context.Response.ContentType = string.Format("application/{0}", dt.Rows[0]["Extension"].ToString().Remove(0, 1)); context.Response.Buffer = true; context.Response.BinaryWrite((byte[])dt.Rows[0]["Document"]); context.Response.Flush(); context.Response.End(); } } The above is my current code for the request. Ive used the base handler on http://haacked.com/archive/2005/03/17/AnAbstractBoilerplateHttpHandler.aspx. Any ideas on what this might be and how we can fix it. Thanks in advance for all responses.

    Read the article

  • Event feed implementation - will it scale?

    - by SlappyTheFish
    Situation: I am currently designing a feed system for a social website whereby each user has a feed of their friends' activities. I have two possible methods how to generate the feeds and I would like to ask which is best in terms of ability to scale. Events from all users are collected in one central database table, event_log. Users are paired as friends in the table friends. The RDBMS we are using is MySQL. Standard method: When a user requests their feed page, the system generates the feed by inner joining event_log with friends. The result is then cached and set to timeout after 5 minutes. Scaling is achieved by varying this timeout. Hypothesised method: A task runs in the background and for each new, unprocessed item in event_log, it creates entries in the database table user_feed pairing that event with all of the users who are friends with the user who initiated the event. One table row pairs one event with one user. The problems with the standard method are well known – what if a lot of people's caches expire at the same time? The solution also does not scale well – the brief is for feeds to update as close to real-time as possible The hypothesised solution in my eyes seems much better; all processing is done offline so no user waits for a page to generate and there are no joins so database tables can be sharded across physical machines. However, if a user has 100,000 friends and creates 20 events in one session, then that results in inserting 2,000,000 rows into the database. Question: The question boils down to two points: Is this worst-case scenario mentioned above problematic, i.e. does table size have an impact on MySQL performance and are there any issues with this mass inserting of data for each event? Is there anything else I have missed?

    Read the article

  • what is file verification system for php project or licence checking the configuration files

    - by Jayapal Chandran
    Hi, My colleague asked me a question like "license check to config file". when i searched i got this http://www.google.com/search?q=file+verification+system&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a and in the result i got this http://integrit.sourceforge.net/texinfo/integrit.html but could not grasp much of its idea. Here is my thoughts... Our project is written in codeigniter. The project owner is providing it to their customer. The owner is a business partner with that concept. Besides, the owner needs control of the project code so that the customer will not break rules with him like changing the code or moving it go another server or validity. So the owner needs a system to enable disable the site. Let me give an example... owner.com will have an admin panel where he can either disable or enable the client.com. when he disables the client.com should display a custom message instead of loading the files. client.com is written i a way that i will process requests from owner.com and also the other way round. so, here i want a list of the concepts with which we can implement the ownership and control over client.com any suggestions, links, references, answers will be helpful. If i am missing something in my question i will update my question according to your comments if any so that the users can give in their idea without confusing of what i had asked. THX

    Read the article

  • Set size of JTable in JScrollPane and in JPanel with the size of the JFrame

    - by user1761818
    I want the table with the same width as the frame and also when I resize the frame the table need to be resized too. I think setSize() of JTable doesn't work correctly. Can you help me? import java.awt.Color; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTable; import javax.swing.SwingUtilities; public class Main extends JFrame { public Main() { setSize(400, 600); String[] columnNames = {"A", "B", "C"}; Object[][] data = { {"Moni", "adsad", 2}, {"Jhon", "ewrewr", 4}, {"Max", "zxczxc", 6} }; JTable table = new JTable(data, columnNames); JScrollPane tableSP = new JScrollPane(table); int A = this.getWidth(); int B = this.getHeight(); table.setSize(A, B); JPanel tablePanel = new JPanel(); tablePanel.add(tableSP); tablePanel.setBackground(Color.red); add(tablePanel); setTitle("Marks"); setLocationRelativeTo(null); setDefaultCloseOperation(EXIT_ON_CLOSE); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { public void run() { Main ex = new Main(); ex.setVisible(true); } }); } }

    Read the article

  • Using PHP to get the source code of a URL I must be logged in to reach

    - by Maxwell
    I am trying to write a PHP script that will get the source code of a page in my Amazon account. However, to reach that page, I must be logged in. From what I understand, I should be able to accomplish this by posting the correct request headers, and then capturing the HTML response. Is that correct? If so, I'd really appreciate it if someone could explain to me how exactly I would do this. If it's not right, I'd love to hear the correct way of doing it! I've used Firebug to get the request and response headers I need. It's just a matter of what to do with them now. I read elsewhere on this site that you can't send a request with the PHP post method, and that perhaps using cURL is the way to go. I really know nothing about cURL, so the more info the better. Also, feel free to point me to some useful tutorials on this topic. Thanks! Max

    Read the article

  • Passing information safely between Wicket and Hibernate in long running conversations

    - by Peter Tillemans
    We are using Wicket with Hibernate in the background. As part of out UI we have quite long running conversations spanning multiple requests before the updated information is written back to the database. To avoid getting hibernate errors with detached objects we are now using value objects to transfer info from the service layer to Wicket. However we now end up with an explosion of almost the same objects : e.g. Answer (mapped entity saved in hibernate) AnswerVO (immutable value object) AnswerModel (A mutable bean in the session domain) IModel wrapped Wicket Model and usually this gets wrapped in a CompoundPropertyModel This plumbing becomes exponentially worse when collections to other objects are involved in the objects. There has to be a better way to organize this. Can anyone share tips to make this less onerous? Maybe make the value objects mutable so we can remove the need for a seaprate backing bean in Wicket? Use the entity beans but absolutely make dead-certain they are detached from hibernate. (easier said than done)? Some other tricks or patterns?

    Read the article

< Previous Page | 360 361 362 363 364 365 366 367 368 369 370 371  | Next Page >