Search Results

Search found 25579 results on 1024 pages for 'complex event processing'.

Page 751/1024 | < Previous Page | 747 748 749 750 751 752 753 754 755 756 757 758  | Next Page >

• Do you like Twisted?

  - by Luca

  I use Python Twisted for web development, and I don't like it? I know async programming is a great idea, I know there are may async web servers now, I know it's the only way to solve some problems you'd have with threads but I don't like. The problem is that, you're forced to program in a twisted way. So, the architecture you have in mind, very often have to be modified to fit the way twisted works. The architecture have to follow the technology, I don't think this is good. When we use callback in javascript, we don't have too many difficulties: things are usually simpler, we use a callback in response to an Ajax call. But in a server web app things are, very often, a bit more complex. Writing chain of callbacks don't seem to me a wonderful way of programming. The code is not simple, and so it is difficult to understand and to maintain. Writing twisted code we very often lost the linear intuitive idea of the algorithm we wanted to implement, especially when things grow in complexity. What's your point of view?

  Read the article

• Starting a process in one HTTP call and getting results in another

  - by KillianDS

  Hi, I'm writing a very simple testing framework for my application, the design isn't perfect, but I don't have time to write something more complex. Essentially, I have a client and server-application, on my server I want a small python web server to start the server application with given test sequences on a GET or POST call. Also, the application prints some testdata to stderr which I'd like to catch and return in another HTTP call. At the moment I have this: from subprocess import Popen, PIPE from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer p = None class MyHandler(BaseHTTPRequestHandler): def do_GET(self): global p if self.path.endswith("start/"): p = Popen(["./bin/Release/simplex264","BBB-360","127.0.0.1"], stderr=PIPE) print 'started' return elif self.path.endswith("getResults/"): self.wfile.write(p.stderr.read()) return self.send_error(404,'File Not Found: %s' % self.path) def main(): try: server = HTTPServer(('localhost', 9876), MyHandler) print 'Started server...' server.serve_forever() except KeyboardInterrupt: print 'Shutting down...' server.socket.close() if __name__ == '__main__': main() Which 'works', except for one part, when I try to open http://localhost:9876/start/, it does not return before the process ended. However, the 'started' appears in my shell immediately (I added this because I thought the Popen call would only return after execution). I do not know the perfect inner workings of Popen and BaseHTTPRequestHandler however and do not really know where it goes wrong. Is there any way to make this work asynchronously?

  Read the article

• Detecting Connection Speed / Bandwidth in .net/WCF

  - by Mystagogue

  I'm writing both client and server code using WCF, where I need to know the "perceived" bandwidth of traffic between the client and server. I could use ping statistics to gather this information separately, but I wonder if there is a way to configure the channel stack in WCF so that the same statistics can be gathered simultaneously while performing my web service invocations. This would be particularly useful in cases where ICMP is disabled (e.g. ping won't work). In short, while making my regular business-related web service calls (REST calls to be precise), is there a way to collect connection speed data implicitly? Certainly I could time the web service round trip, compared to the size of data used in the round-trip, to give me an idea of throughput - but I won't know how much of that perceived bandwidth was network related, or simply due to server-processing latency. I could perhaps solve that by having the server send back a time delta, representing server latency, so that the client can compute the actual network traffic time. If a more sophisticated approach is not available, that might be my answer...

  Read the article

• I can't figure out why this fps counter is inaccurate.

  - by rmetzger

  I'm trying to track frames per second in my game. I don't want the fps to show as an average. I want to see how the frame rate is affected when I push keys and add models etc. So I am using a variable to store the current time and previous time, and when they differ by 1 second, then I update the fps. My problem is that it is showing around 33fps but when I move the mouse around really fast, the fps jumps up to 49fps. Other times, if I change a simple line of code elsewhere not related to the frame counter, or close the project and open it later, the fps will be around 60. Vsync is on so I can't tell if the mouse is still effecting the fps. Here is my code which is in an update function that happens every frame: FrameCount++; currentTime = timeGetTime (); static unsigned long prevTime = currentTime; TimeDelta = (currentTime - prevTime) / 1000; if (TimeDelta > 1.0f) { fps = FrameCount / TimeDelta; prevTime = currentTime; FrameCount = 0; TimeDelta = 0; } Here are the variable declarations: int FrameCount; double fps, currentTime, prevTime, TimeDelta, TimeElapsed; Please let me know what is wrong here and how to fix it, or if you have a better way to count fps. Thanks!!!!!! I am using DirectX 9 btw but I doubt that is relevant, and I am using PeekMessage. Should I be using an if else statement instead? Here is my message processing loop: MSG msg; ZeroMemory (&msg, sizeof (MSG)); while (msg.message != WM_QUIT) { if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) { TranslateMessage (&msg); DispatchMessage (&msg); } Update (); RenderFrame (); }

  Read the article

• Browser performance when combining image resizing with animated movement

  - by Steve Reichgut

  I have been tasked with the job of converting a Flash animation into HTML. The animation is rather complex and requires the need to move multiple images (9) from location (x,y) to location (x2,y2) while simultaneously increasing the image size from 215px wide to 930px wide. While doing some initial testing of this animation with just 1-2 images, I noticed a lot of choppiness in FF handling of this animation. To try and isolate the problem, I removed the dynamic resizing of the animation and just moved it from point A to point B. What was interesting was that I saw the same behavior when simply moving a 930px image that was resized down to 215px (via the CSS width or inline width properties). When I try the same animation with a different image that is actually 215px wide, it performed smoothly. I then tried the same animation with the original 930px wide image (with no resizing) and it performed well also. This makes me wonder if the browser is having to "resize" the image down to 215px each time it is moved which is causing the choppiness. Is this a correct assumption? If so, is there any other way to optimize the animation to allow for simultaneous image resizing and image movement? Notes: 1) One optimization I have done is to position the images absolutely in order to minimize the reflow process. 2) I have tested the animation using both jQuery and the fX animation framework.

  Read the article

• Upload using python script takes very long on one laptop as compared to another

  - by Engr Am

  I have a python 2.7 code which uses STORBINARY function for uploading files to an ftp server and RETRBINARY for downloading from this server. However, the issue is the upload is taking a very long time on three laptops from different brands as compared to a Dell laptop. The strange part is when I manually upload any file, it takes the same time on all the systems. The manual upload rate and upload rate with the python script is the same on the Dell Laptop. However, on every other brand of laptop (I have tried with IBM, Toshiba, Fujitsu-Siemens) the python script has a very low upload rate than the manual attempt. Also, on all these other laptops, the upload rate using the python script is the same (1Mbit/s) while the manual upload rate is approx. 8 Mbit/s. I have tried to vary the filesize for the upload to no avail. TCP Optimizer improved the download rate on all the systems but had no effect on the upload rate. Download rate using this script on all the systems is fine and same as the manual download rate. I have checked the server and it has more than 90% free space. The network connection is the same for all the laptops, and I try uploading only with one laptop at a time. All the laptops have almost the same system configurations, same operating system and approximately the same free drive space. If anything the Dell laptop is a little less in terms of processing power and RAM than 2 of the others, but I suppose this has no effect as I have checked many times to see how much was the CPU usage and network usage during these uploads and downloads, and I am sure that no other virus or program has been eating up my bandwidth. Here is the code ('ftp' and 'file_path' are inputs to the function): path,filename=os.path.split(file_path) filesize=os.path.getsize(file_path) deffilesize=(filesize/1024)/1024 f = open(file_path, "rb") upstart = time.clock() print ftp.storbinary("STOR "+filename, f) upende = time.clock()-upstart outname="Upload " f.close() return upende, deffilesize, outname

  Read the article

• Cast errors with IXmlSerializable

  - by Nathan

  I am trying to use the IXmlSerializable interface to deserialize an Object (I am using it because I need specific control over what gets deserialized and what does not. See my previous question for more information). However, I'm stumped as to the error message I get. Below is the error message I get (I have changed some names for clarity): An unhandled exception of type 'System.InvalidCastException' occurred in App.exe Additional information: Unable to cast object of type 'System.Xml.XmlNode[]' to type 'MyObject'. MyObject has all the correct methods defined for the interface, and regardless of what I put in the method body for ReadXml() I still get this error. It doesn't matter if it has my implementation code or if it's just blank. I did some googling and found an error that looks similar to this involving polymorphic objects that implement IXmlSerializable. However, my class does not inherit from any others (besides Object). I suspected this may be an issue because I never reference XmlNode any other time in my code. Microsoft describes a solution to the polymorphism error: https://connect.microsoft.com/VisualStudio/feedback/details/422577/incorrect-deserialization-of-polymorphic-type-that-implements-ixmlserializable?wa=wsignin1.0#details The code the error occurs at is as follows. The object to be read back in is an ArrayList of "MyObjects" IO::FileStream ^fs = gcnew IO::FileStream(filename, IO::FileMode::Open); array<System::Type^>^ extraTypes = gcnew array<System::Type^>(1); extraTypes[0] = MyObject::typeid; XmlSerializer ^xmlser = gcnew XmlSerializer(ArrayList::typeid, extraTypes); System::Object ^obj; obj = xmlser->Deserialize(fs); fs->Close(); ArrayList ^al = safe_cast<ArrayList^>(obj); MyObject ^objs; for each(objs in al) //Error occurs here { //do some processing } Thanks for reading and for any help.

  Read the article

• Ajax heavy JS apps using excessive amounts of memory over time.

  - by Shane Reustle

  I seem to have some pretty large memory leaks in an app that I am working on. The app itself is not very complex. Every 15 seconds, the page requests approx 40kb of JSON from the server, and draws a table on the page using it. It is cheaper to draw the table over because the data is usually always new. I am attaching a few events to the table, approx 5 per line, 30 lines in the table. I used jQuery's .html() method to put the new html into the container and overwrite the existing. I do this specifically so that jQuery's special cleanup functions go in and attempt to detach all events on the elements in the element that it is overwriting. I then also delete the large variables of html once they are sent to the DOM using delete my_var. I have checked for circular references and attached events that are never cleared a few times, but never REALLY dug into it. I was wondering if someone could give me a few pointers on how to optimize a very heavy app like this. I just picked up "High Performance Javascript" by Nicholas Zakas, but didn't have much time to get into it yet. To give an idea on how much memory this is using, after 4~ hours, it is using about 420,000k on chrome, and much more on Firefox or IE. Thanks!

  Read the article

• How would i down-sample a .wav file then reconstruct it using nyquist? - in MATLAB

  - by Andrew

  This is all done in MATLAB 2010 My objective is to show the results of: undersampling, nyquist rate/ oversampling First i need to downsample the .wav file to get an incomplete/ or impartial data stream that i can then reconstuct. Heres the flow chart of what im going to be doing So the flow is analog signal - sampling analog filter - ADC - resample down - resample up - DAC - reconstruction analog filter what needs to be achieved: F= Frequency F(Hz=1/s) E.x. 100Hz = 1000 (Cyc/sec) F(s)= 1/(2f) Example problem: 1000 hz = Highest frequency 1/2(1000hz) = 1/2000 = 5x10(-3) sec/cyc or a sampling rate of 5ms This is my first signal processing project using matlab. what i have so far. % Fs = frequency sampled (44100hz or the sampling frequency of a cd) [test,fs]=wavread('test.wav'); % loads the .wav file left=test(:,1); % Plot of the .wav signal time vs. strength time=(1/44100)*length(left); t=linspace(0,time,length(left)); plot(t,left) xlabel('time (sec)'); ylabel('relative signal strength') **%this is were i would need to sample it at the different frequecys (both above and below and at) nyquist frequency.*I think.*** soundsc(left,fs) % shows the resaultant audio file , which is the same as original ( only at or above nyquist frequency however) Can anyone tell me how to make it better, and how to do the sampling at verious frequencies?

  Read the article

• Get Json and output to text file undecoded

  - by Gary

  Hi, I want to fetch json script and write it to a txt file undecoded, exactly how it was originally. I do have a script that I use that I am modifying but unsure what to commands to use. This script decodes, which is what I want to advoid. //Get Age list($bstat,$bage,$bdata) = explode("\t",check_file('./advise/roadsnow.txt',60*2+15)); //Test Age if ( $bage > $CacheMaxAge ) { //echo "The if statement evaluated to true so get new file and reset $bage"; $bage="0"; $file = file_get_contents('http://somesite.jsontxt'); $out = (json_decode($file)); $report = wordwrap($out->mainText, 100, "\n"); //$valid = $out->validTo; //write the data to a text file called roadsnow.txt $myFile = "./advise/roadsnow.txt"; $fh = fopen($myFile, 'w') or die("can't open file"); $stringData = $report; fwrite($fh, $stringData); } else { //echo the test evaluated to false; file is not stale so read local cache //print "we are at the read local cache"; $stringData = file_get_contents("./advise/roadsnow.txt"); } // if/else is done carry on with processing //Format file $data = $stringData

  Read the article

• jQuery not support rich:hotKey in jsf tag

  - by eswaramoorthy-nec

  Hi, i have used rich:hotKey for h:inputText in my jsp page. And also i wrote jQuery for get the textBox value. When i use jquery, that time rich:kotKey not worked sample.jsp <%@page contentType="text/html" pageEncoding="UTF-8"%> <%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %> <%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %> <%@ taglib uri="http://richfaces.org/a4j" prefix="a4j" %> <%@ taglib uri="http://richfaces.org/rich" prefix="rich"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <f:view> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>JSP Page</title> <script type="text/javascript" src="../../resource/js/jquery.min.js"/> <script type="text/javascript"> function typedName() { //Get The value using styleClass id var userName = jQuery.trim($('.textBox').val()); alert("Name is : " + userName); } // If i am not use above typedName() script and load src, then // the following testButton() clicked script perfectly worked. function testButton() { alert("Test Button Clicked"); } </script> </head> <body> <h:form> <rich:panel> <h:outputText value="Enter your Name : "/> <h:inputText id="textBox" styleClass="textBox" value ="" />&nbsp; <a4j:commandButton id="nameButton" value="NameButton" onclick="typedName();"/><br> <a4j:commandButton id="testButton" value="TestButton" onclick="testButton();" /> <%--HotKey for text Box and focus to testButton --%> <rich:hotKey key="return" selector="#textBox" handler="#{rich:element('testButton')}.click(); event.stopPropagation();event.preventDefault(); return false;"/> </rich:panel> </h:form> </body> </f:view> If i am not include the jquery, then that time i hit the enter button from text box, then automatically called testButton() script. If i include the Jquery, then rich:hotkey not work. I am also Used , var $J = jQuery.noConflict(); . But this time also not work jQuery. I hope help me about this. Thanks for your effort.

  Read the article

• Using SetParent to steal the main window of another process but keeping the message loops separate

  - by insta

  Background: My coworker and I are maintaining a million-line legacy application we inherited. Its frontend is written in VB6, and as we're devoting almost all of our resources to converting it to C#, we are looking for quick & dirty solutions to our specific problem. The application behaves in a plugin-ish manner. There are up to 20ish separate ActiveX controls that can be loaded at once in a grid-style layout. The problem is that the ActiveX controls do all of their processing on their own UI thread, and as a lot of it is blocking waiting on network access, the UI gets very soupy. When our hosting C# app loads these controls, it becomes unresponsive because of how many controls are chewing up UI resources doing nothing. To top it off, the controls are fragile and will crash at the slightest provocation. When they are hosted in the main C# app, it creates serious instability. The best my coworker and I have come up with so far is starting a process per ActiveX control. This process, which we call the proxy, is another winforms app. It uses named pipes to communicate with the hosting process. The hosting process creates a window, loads an ActiveX control of our choice (via some reflections & AxHost magic), and tells the main process what its window handle is via the named pipe. The main process uses a combination of SetParent, and SetWindowPos to move the proxy application into itself to emulate a plugin. Size updates are sent via the named pipe. This works well enough until the ActiveX application does some sort of lengthy process and we click around on the main window while it's working. For awhile the main window is responsive, but eventually it becomes unresponsive as the child window waits for its UI thread. How can we keep the child windows on their own complete thread while still getting the benefits of SetParent? (please let me know if anything isn't clear!)

  Read the article

• Which tools to use and how to find file descriptors leaking from Glassfish?

  - by cclark

  We release new code to production every week and Glassfish hasn't had any problems. This weekend we had to move racks at our hosting provider. There were not any code changes (they just powered off, moved, re-racked and powered on) but we're on a new network infrastructure and suddenly we're leaking file descriptors like a sieve. So I'm guessing there is some sort of connection attempting to be made which now fails due to a network change. I'm running Glassfish v2ur2-b04/AS9.1_02 on RHEL4 with an embedded IMQ instance. After the move I started seeing: [#|2010-04-25T05:34:02.783+0000|SEVERE|sun-appserver9.1|javax.enterprise.system.container.web|_ThreadID=33;_ThreadName=SelectorThread-?4848;_RequestID=c4de6f6d-c1d6-416d-ac6e-49750b1a36ff;|WEB0756: Caught exception during HTTP processing. java.io.IOException: Too many open files at sun.nio.ch.ServerSocketChannelImpl.accept0(Native Method) ... [#|2010-04-25T05:34:03.327+0000|WARNING|sun-appserver9.1|javax.enterprise.system.stream.err|_ThreadID=34;_ThreadName=Timer-1;_RequestID=d27e1b94-d359-4d90-a6e3-c7ec49a0f383;|java.lang.NullPointerException at com.sun.jbi.management.system.AutoAdminTask.pollAutoDirectory(AutoAdminTask.java:1031) Using lsof I check the number of file descriptors and I see quite a few entries which look like: java 18510 root 8556u sock 0,4 1555182 can't identify protocol java 18510 root 8557u sock 0,4 1555320 can't identify protocol java 18510 root 8558u sock 0,4 1555736 can't identify protocol java 18510 root 8559u sock 0,4 1555883 can't identify protocol If I do a count of open file descriptors every minute I see it growing by 12 every minute. I have no idea what these sockets are. I've undeployed my application so there is only a plain Glassfish instance running and I still see it leaking 12 file descriptors a minute. So I think this leak is in Glassfish or potentially IMQ. What approach should I take to tracking down these sockets of unknown protocol? What tools can I use (or flags can I pass to lsof) to get more information about where to look? thanks, chuck

  Read the article

• Why does jquery leak memory so badly?

  - by Thomas Lane

  This is kind of a follow-up to a question I posted last week: http://stackoverflow.com/questions/2429056/simple-jquery-ajax-call-leaks-memory-in-ie I love the jquery syntax and all of its nice features, but I've been having trouble with a page that automatically updates table cells via ajax calls leaking memory. So I created two simple test pages for experimenting. Both pages do an ajax call every .1 seconds. After each successful ajax call, a counter is incremented and the DOM is updated. The script stops after 1000 cycles. One uses jquery for both the ajax call and to update the DOM. The other uses the Yahoo API for the ajax and does a document.getElementById(...).innerHTML to update the DOM. The jquery version leaks memory badly. Running in drip (on XP Home with IE7), it starts at 9MB and finishes at about 48MB, with memory growing linearly the whole time. If I comment out the line that updates the DOM, it still finishes at 32MB, suggesting that even simple DOM updates leak a significant amount of memory. The non-jquery version starts and finishes at about 9MB, regardless of whether it updates the DOM. Does anyone have a good explanation of what is causing jquery to leak so badly? Am I missing something obvious? Is there a circular reference that I'm not aware of? Or does jquery just have some serious memory issues? Here is the source for the leaky (jquery) version: <html> <head> <script type="text/javascript" src="http://www.google.com/jsapi"></script> <script type="text/javascript"> google.load('jquery', '1.4.2'); </script> <script type="text/javascript"> var counter = 0; leakTest(); function leakTest() { $.ajax({ url: '/html/delme.x', type: 'GET', success: incrementCounter }); } function incrementCounter(data) { if (counter<1000) { counter++; $('#counter').text(counter); setTimeout(leakTest,100); } else $('#counter').text('finished.'); } </script> </head> <body> <div>Why is memory usage going up?</div> <div id="counter"></div> </body> </html> And here is the non-leaky version: <html> <head> <script type="text/javascript" src="http://yui.yahooapis.com/2.8.0r4/build/yahoo/yahoo-min.js"></script> <script type="text/javascript" src="http://yui.yahooapis.com/2.8.0r4/build/event/event-min.js"></script> <script type="text/javascript" src="http://yui.yahooapis.com/2.8.0r4/build/connection/connection_core-min.js"></script> <script type="text/javascript"> var counter = 0; leakTest(); function leakTest() { YAHOO.util.Connect.asyncRequest('GET', '/html/delme.x', {success:incrementCounter}); } function incrementCounter(o) { if (counter<1000) { counter++; document.getElementById('counter').innerHTML = counter; setTimeout(leakTest,100); } else document.getElementById('counter').innerHTML = 'finished.' } </script> </head> <body> <div>Memory usage is stable, right?</div> <div id="counter"></div> </body> </html>

  Read the article

• SQL to CodeIgniter Array Missing Data Issue

  - by SamD

  $query = $this->db->query("SELECT t1.numberofbets, t1.profit, t2.seven_profit, t3.28profit, user.user_id, username, password, email, balance, user.date_added, activation_code, activated FROM user LEFT JOIN (SELECT user_id, SUM(amount_won) AS profit, count(tip_id) AS numberofbets FROM tip GROUP BY user_id) as t1 ON user.user_id = t1.user_id LEFT JOIN (SELECT user_id, SUM(amount_won) AS seven_profit FROM tip WHERE date_settled > '$seven_daystime' GROUP BY user_id) as t2 ON user.user_id = t2.user_id LEFT JOIN (SELECT user_id, SUM(amount_won) AS 28profit FROM tip WHERE date_settled > '$twoeight_daystime' GROUP BY user_id) as t3 ON user.user_id = t3.user_id where activated = 1 GROUP BY user.user_id ORDER BY user.date_added DESC"); return $query->result_array(); The query works fine running it in phpMyAdmin and returns complete results (in image attached). However, printing the array in CodeIgniter, it has no value for one field ,seven_profit, where it is there in the SQL query ran in phpMyAdmin, just the discrepancy in this one field, from sql to php array... I just can’t see why, when printing the array, that one field, which should have value of 26, contains nothing? Any ideas? I changed the field name from starting with a number in attempt to fix it, but no difference. I know this is complex and looks horrible, any help or just people coming across something similar would be great to know about, thanks. Sam

  Read the article

• Why execution of a portion of code loaded from external file is not halted by the OS?

  - by menjaraz

  I've harnessed a project released on internet a long time ago. Here comes the details, all irrelevant things being stripped off for sake of concision and clarity. A binary file whose content is descibed below HEX DUMP: 55 89 E5 83 EC 08 C7 45 FC 00 00 00 00 8B 45 FC 3B 45 10 72 02 EB 19 8B 45 FC 8B 55 0C 01 C2 8B 45 FC 03 45 08 8A 00 88 02 8D 45 FC FF 00 EB DD C6 45 FA 00 83 7D 10 01 76 6C 80 7D FA 00 74 02 EB 64 C6 45 FA 01 C7 45 FC 00 00 00 00 8B 45 10 48 39 45 FC 72 02 EB E2 8B 45 FC 8B 4D 0C 01 C1 8B 45 FC 03 45 0C 8D 50 01 8A 01 3A 02 73 30 8B 45 FC 03 45 0C 8A 00 88 45 FB 8B 45 FC 8B 55 0C 01 C2 8B 45 FC 03 45 0C 40 8A 00 88 02 8B 45 FC 03 45 0C 8D 50 01 8A 45 FB 88 02 C6 45 FA 00 8D 45 FC FF 00 EB A7 C9 C2 0C 00 90 90 90 90 90 90 is loaded into memory and executed using the following method snippet var MySrcArray, MyDestArray: array [1 .. 15] of Byte; // ... MyBuffer: Pointer; TheProc: procedure; SortIt: procedure(ASrc, ADest: Pointer; ASize: LongWord); stdcall; begin // Initialization of MySrcArray with random Bytes and display here ... // Instructions of loading of the binary file into MyBuffer using merely **GetMem** here ... @SortIt := MyBuffer; try SortIt(@MySrcArray, @MyDestArray, 15); // Display of MyDestArray (The outcome of the processing !) except // Invalid code error handling end; // Cleaning code here ... end; works like a charm on my box. My Question: How comes it works without using VirtualAlloc and/or VirtualProtect?

  Read the article

• Sharing storage between servers

  - by El Yobo

  I have a PHP based web application which is currently only using one webserver but will shortly be scaling up to another. In most regards this is pretty straightforward, but the application also stores a lot of files on the filesystem. It seems that there are many approaches to sharing the files between the two servers, from the very simple to the reasonably complex. These are the options that I'm aware of Simple network storage NFS SMB/CIFS Clustered filesystems Lustre GFS/GFS2 GlusterFS Hadoop DFS MogileFS What I want is for a file uploaded via one webserver be immediately available if accessed through the other. The data is extremely important and absolutely cannot be lost, so whatever is implemented needs to a) never lose data and b) have very high availability (as good as, or better, than a local filesystem). It seems like the clustered filesystems will also provide faster data access than local storage (for large files) but that isn't of vita importance at the moment. What would you recommend? Do you have any suggestions to add or anything specifically to look out for with the above options? Any suggestions on how to manage backup of data on the clustered filesystems?

  Read the article

• Yet another "What is this code doing"-type of Perl code

  - by Mike

  I have inherited some code from a guy whose favorite past time was to shorten every line to its absolute minimum (and sometimes only to make it look cool). His code is hard to understand but I managed to understand (and rewrite) most of it. Now I have stumbled on a piece of code which, no matter how hard I try, I cannot understand. my @heads = grep {s/\.txt$//} OSA::Fast::IO::Ls->ls($SysKey,'fo','osr/tiparlo',qr{^\d+\.txt$}) || (); my @selected_heads = (); for my $i (0..1) { $selected_heads[$i] = int rand scalar @heads; for my $j (0..@heads-1) { last if (!grep $j eq $_, @selected_heads[0..$i-1]); $selected_heads[$i] = ($selected_heads[$i] + 1) % @heads; #WTF? } my $head_nr = sprintf "%04d", $i; OSA::Fast::IO::Cp->cp($SysKey,'',"osr/tiparlo/$heads[$selected_heads[$i]].txt","$recdir/heads/$head_nr.txt"); OSA::Fast::IO::Cp->cp($SysKey,'',"osr/tiparlo/$heads[$selected_heads[$i]].cache","$recdir/heads/$head_nr.cache"); } From what I can understand, this is supposed to be some kind of randomizer, but I never saw a more complex way to achieve randomness. Or are my assumptions wrong? At least, that's what this code is supposed to do. Select 2 random files and copy them. === NOTES === The OSA Framework is a Framework of our own. They are named after their UNIX counterparts and do some basic testing so that the application does not need to bother with that.

  Read the article

• Making Javascript and HTML5 games

  - by Jeff Meatball Yang

  A long time ago (Netscape 4-era), I wrote Javascript-based games: Pong, Minesweeper, and John Conway's Life among them. I'm getting back into it, and want to get my hands even dirtier. I have a few games in mind: Axis & Allies clone, with rugged maps and complex rules. Tetris clone, possibly with real-time player-vs-player or player-vs-computer mode Breakout clone, with a couple weapons and particle velocities In all of these, I have only a few objectives: Use JavaScript and HTML 5 - it should run on Chrome, Safari, or maybe an iPad. Start small and simple, then build-up features. Learn something new about game design and implementation. So my questions are: How would you implement these games? Do you have any technology recommendations? If you've written these games, what was the hardest part? N.B. I also want to start from first-principles - if you recommend a framework/library, I would appreciate some theory or implementation details behind it. These games are different enough that I should learn something new from each one.

  Read the article

• Should frontend and backend handled by different controllers?

  - by DR

  In my previous learning projects I always used a single controller, but know I wonder if that is good practice or even always possible. In all RESTful Rails tutorials the controllers have a show, an edit and an index view. If an authorized user is logged on, the edit view becomes available and the index view shows additional data manipulation controls, like a delete button or a link to the edit view. Now I have a Rails application which falls exactly into this pattern, but the index view is not reusable: The normal user sees a flashy index page with lots of pictures, complex layout, no Javascript requirement, ... The Admin user index has a completly different minimalistic design, jQuery table and lots of additional data, ... Now I'm not sure how to handle this case. I can think of the following: Single controller, single view: The view is split into two large blocks/partials using an if statement. Single controller, two views: index and index_admin. Two different controllers: BookController and BookAdminController None of this solutions seems perfect, but for now I'm inclined to use the 3rd option. What's the preferred way to do this?

  Read the article

• Best way to detect similar email addresses?

  - by Chris

  I have a list of ~20,000 email addresses, some of which I know to be fraudulent attempts to get around a "1 per e-mail" limit. ([email protected], [email protected], [email protected], etc...). I want to find similar email addresses for evaluation. Currently I'm using a levenshtein algorithm to check each e-mail against the others in the list and report any with an edit distance of less than 2. However, this is painstakingly slow. Is there a more efficient approach? The test code I'm using now is: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.IO; using System.Threading; namespace LevenshteinAnalyzer { class Program { const string INPUT_FILE = @"C:\Input.txt"; const string OUTPUT_FILE = @"C:\Output.txt"; static void Main(string[] args) { var inputWords = File.ReadAllLines(INPUT_FILE); var outputWords = new SortedSet<string>(); for (var i = 0; i < inputWords.Length; i++) { if (i % 100 == 0) Console.WriteLine("Processing record #" + i); var word1 = inputWords[i].ToLower(); for (var n = i + 1; n < inputWords.Length; n++) { if (i == n) continue; var word2 = inputWords[n].ToLower(); if (word1 == word2) continue; if (outputWords.Contains(word1)) continue; if (outputWords.Contains(word2)) continue; var distance = LevenshteinAlgorithm.Compute(word1, word2); if (distance <= 2) { outputWords.Add(word1); outputWords.Add(word2); } } } File.WriteAllLines(OUTPUT_FILE, outputWords.ToArray()); Console.WriteLine("Found {0} words", outputWords.Count); } } }

  Read the article

• User preferences using SQL and JavaScript

  - by Shyam

  Hi, I am using Server Side JavaScript - yes, I am actually using Server Side JavaScript. To complexify things even more, I use Oracle as a backend database (10g). With some crazy XSLT and mutant-like HTML generation, I can build really fancy web forms - yes, I am aware of Rails and other likewise frameworks and I choose the path of horror instead. I have no JQuery or other fancy framework at my disposal, just plain ol' JavaScript that should be supported by the underlying engine called Mozilla Rhino. Yes, it is insane and I love it. So, I have a bunch of tables at my disposal and some of them are filled with associative keys that link to values. As I am a people pleaser, I want to add some nifty user-preference driven solutions. My users have all an unique user_id and this user_id is available during the entire session. My initial idea is to have a user preference table, where I have "three" columns: user_id, feature and pref_string. Using a delimiter, such as : or - (haven't thought about a suitable one yet), I could like store a bunch of preferences as a list and store its elements inside an array using the .split-method (similar like the PHP-explode function). The feature column could be like the table name or some identifier for the "feature" i want to link preferences too. I hate hardcoding objects, especially as I want to be able to back these up and reuse this functionality application-wide. Of course I would love better ideas, just keep in mind I cannot just add a library that easily. These preferences could be like "joined" to the table, so I can query it and use its values. I hope it doesn't sounds too complex, because well.. its basically something really simple I need. Thanks!

  Read the article

• why doesn't winmain set the errorlevel?

  - by Brian R. Bondy

  int APIENTRY _tWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow) { MessageBox(NULL, _T("This should return 90 no?"), _T("OK"), MB_OK); return 90; } Why does the above program correctly display the message box, but does not set the error level? I compile this program to the name a.exe. Then from command prompt I type: c:\> a.exe (message box is displayed, I press ok) c:\> echo %ERRORLEVEL% 0 I get the same results if I do exit(90); right before the return. It still says 0. I also tried to start the program via CreateProcess and obtain the result with GetExitCodeProcess but it also returns 0 to me. I did error checking to ensure it was all started correctly. I originally seen this problem in a more complex program. But made this simple program to verify the problem. Results are the same, both programs that have WinMain return 0 always. I tried both x64, x86 and unicode and MBCS compiling options. All give 0 as an error level/status code.

  Read the article

• Rhino Mocks Partial Mock

  - by dotnet crazy kid

  I am trying to test the logic from some existing classes. It is not possible to re-factor the classes at present as they are very complex and in production. What I want to do is create a mock object and test a method that internally calls another method that is very hard to mock. So I want to just set a behaviour for the secondary method call. But when I setup the behaviour for the method, the code of the method is invoked and fails. Am I missing something or is this just not possible to test without re-factoring the class? I have tried all the different mock types (Strick,Stub,Dynamic,Partial ect.) but they all end up calling the method when I try to set up the behaviour. using System; using MbUnit.Framework; using Rhino.Mocks; namespace MMBusinessObjects.Tests { [TestFixture] public class PartialMockExampleFixture { [Test] public void Simple_Partial_Mock_Test() { const string param = "anything"; //setup mocks MockRepository mocks = new MockRepository(); var mockTestClass = mocks.StrictMock<TestClass>(); //record beahviour *** actualy call into the real method stub *** Expect.Call(mockTestClass.MethodToMock(param)).Return(true); //never get to here mocks.ReplayAll(); //this is what i want to test Assert.IsTrue(mockTestClass.MethodIWantToTest(param)); } public class TestClass { public bool MethodToMock(string param) { //some logic that is very hard to mock throw new NotImplementedException(); } public bool MethodIWantToTest(string param) { //this method calls the if( MethodToMock(param) ) { //some logic i want to test } return true; } } } }

  Read the article

• How to cache pages using background jobs ?

  - by Alexandre

  Definitions: resource = collection of database records, regeneration = processing these records and outputting the corresponding html Current flow: Receive client request Check for resource in cache If not in cache or cache expired, regenerate Return result The problem is that the regeneration step can tie up a single server process for 10-15 seconds. If a couple of users request the same resource, that could result in a couple of processes regenerating the exact same resource simultaneously, each taking up 10-15 seconds. Wouldn't it be preferrable to have the frontend signal some background process saying "Hey, regenerate this resource for me". But then what would it display to the user? "Rebuilding" is not acceptable. All resources would have to be in cache ahead of time. This could be a problem as the database would almost be duplicated on the filesystem (too big to fit in memory). Is there a way to avoid this? Not ideal, but it seems like the only way out. But then there's one more problem. How to keep the same two processes from requesting the regeneration of a resource at the same time? The background process could be regenerating the resource when a frontend asks for the regeneration of the same resource. I'm using PHP and the Zend Framework just in case someone wants to offer a platform-specific solution. Not that it matters though - I think this problem applies to any language/framework. Thanks!

  Read the article

< Previous Page | 747 748 749 750 751 752 753 754 755 756 757 758  | Next Page >