Search Results

Search found 13151 results on 527 pages for 'performance counters'.

Page 460/527 | < Previous Page | 456 457 458 459 460 461 462 463 464 465 466 467  | Next Page >

  • Maximum page fetch with maximum bandwith

    - by Ehsan
    Hi I want to create an application like a spider I've implement fetching page as the following code in multi-thread application but there is two problem 1) I want to use my maximum bandwidth to send/receive request, how should I config my request to do so (Like Download Accelerator application and the like) cause I heard the normal application will use 66% of the available bandwidth. 2) I don't know what exactly HttpWebRequest.KeepAlive do, but as its name implies I think i can create a connection to a website and without closing the connection sending another request to that web site using existing connection. does it boost performance or Im wrong ?? public PageFetchResult Fetch() { PageFetchResult fetchResult = new PageFetchResult(); try { HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(URLAddress); HttpWebResponse resp = (HttpWebResponse)req.GetResponse(); Uri requestedURI = new Uri(URLAddress); Uri responseURI = resp.ResponseUri; string resultHTML = ""; byte[] reqHTML = ResponseAsBytes(resp); if (!string.IsNullOrEmpty(FetchingEncoding)) resultHTML = Encoding.GetEncoding(FetchingEncoding).GetString(reqHTML); else if (!string.IsNullOrEmpty(resp.CharacterSet)) resultHTML = Encoding.GetEncoding(resp.CharacterSet).GetString(reqHTML); req.Abort(); resp.Close(); fetchResult.IsOK = true; fetchResult.ResultHTML = resultHTML; } catch (Exception ex) { fetchResult.IsOK = false; fetchResult.ErrorMessage = ex.Message; } return fetchResult; }

    Read the article

  • Non-blocking TCP buffer issues.

    - by Poni
    Hi! I think I'm in a problem. I have two TCP apps connected to each other which use winsock I/O completion ports to send/receive data (non-blocking sockets). Everything works just fine until there's a data transfer burst. The sender starts sending incorrect/malformed data. I allocate the buffers I'm sending on the stack, and if I understand correctly, that's a wrong to do, because these buffers should remain as I sent them until I get the "write complete" notification from IOCP. Take this for example: void some_function() { char cBuff[1024]; // filling cBuff with some data WSASend(...); // sending cBuff, non-blocking mode // filling cBuff with other data WSASend(...); // again, sending cBuff // ..... and so forth! } If I understand correctly, each of these WSASend() calls should have its own unique buffer, and that buffer can be reused only when the send completes. Correct? Now, what strategies can I implement in order to maintain a big sack of such buffers, how should I handle them, how can I avoid performance penalty, etc'? And, if I am to use buffers that means I should copy the data to be sent from the source buffer to the temporary one, thus, I'd set SO_SNDBUF on each socket to zero, so the system will not re-copy what I already copied. Are you with me? Please let me know if I wasn't clear.

    Read the article

  • My OpenCL kernel is slower on faster hardware.. But why?

    - by matdumsa
    Hi folks, As I was finishing coding my project for a multicore programming class I came up upon something really weird I wanted to discuss with you. We were asked to create any program that would show significant improvement in being programmed for a multi-core platform. I’ve decided to try and code something on the GPU to try out OpenCL. I’ve chosen the matrix convolution problem since I’m quite familiar with it (I’ve parallelized it before with open_mpi with great speedup for large images). So here it is, I select a large GIF file (2.5 MB) [2816X2112] and I run the sequential version (original code) and I get an average of 15.3 seconds. I then run the new OpenCL version I just wrote on my MBP integrated GeForce 9400M and I get timings of 1.26s in average.. So far so good, it’s a speedup of 12X!! But now I go in my energy saver panel to turn on the “Graphic Performance Mode” That mode turns off the GeForce 9400M and turns on the Geforce 9600M GT my system has. Apple says this card is twice as fast as the integrated one. Guess what, my timing using the kick-ass graphic card are 3.2 seconds in average… My 9600M GT seems to be more than two times slower than the 9400M.. For those of you that are OpenCL inclined, I copy all data to remote buffers before starting, so the actual computation doesn’t require roundtrip to main ram. Also, I let OpenCL determine the optimal local-worksize as I’ve read they’ve done a pretty good implementation at figuring that parameter out.. Anyone has a clue? edit: full source code with makefiles here http://www.mathieusavard.info/convolution.zip cd gimage make cd ../clconvolute make put a large input.gif in clconvolute and run it to see results

    Read the article

  • video streaming infrastructure

    - by alchemical
    We would like to set-up a live video-chat web site and are looking for basic architectural advice and/or a recomendation for a particular framework to use. Here are the basic features of the site: Most streams will be broadcast live from a single person with a web cam, etc., and viewed by typically 1-10 people, although there could be up to 100+ viewers on the high side. Audio and video do not have to be super-high quality, but do need to be "good enough". The main point is to convey the basic info in the video (and audio). If occasionally the frame-rate drops low and then goes back to normal fairly soon, we could live with that. Budget is an issue, so we are in general looking for a lower cost solution that will give us most of what we need in temers of performance and quality. We are looking at Peer1 for co-lo. The rest of our web site will be .Net / Windows platform. We are open to looking at any platform for the best streaming solution, although our technical expertise is currently more on the Windows side.

    Read the article

  • Which Javascript framework (jQuery vs Dojo vs ... )?

    - by cletus
    There are a few Javascript frameworks/toolets out there, such as: jQuery; Dojo; Prototype; YUI; MooTools; ExtJS; SmartClient; and others I'm sure. It certainly seems that jQuery is ascendant in terms of mindshare at the moment. For example, Microsoft (ASP.NET MVC) and Nokia will use it. I also found this this performance comparison of Dojo, jQuery, MooTools and Prototype (Edit: Updated Comparison), which looks highly favourable to Dojo and jQuery. Now my previous experience with Javascript has been the old school HTML + Javascript most of us have done and RIA frameworks like Google Web Toolkit ("GWT") and Ext-GWT, which were a fairly low-stress entry into the Ajax world for someone from a Java background, such as myself. But, after all this, I find myself leaning towards the more PHP + Ajax type solution, which just seems that much more lightweight. So I've been looking into jQuery and I really like it's use of commands, the use of fluent interfaces and method chaining, it's cross-browser CSS selector superset, the fact that it's lightweight and extensible, the brevity of the syntax, unobtrusive Javascript and the plug-in framework. Now obviously many of these aren't unique to jQuery but on the basis that some things are greater than their sum of parts, it just seems that it all fits together and works well. So jQuery seems to have a lot going for it and it looks to the frontrunner for what I choose to concentrate on. Is there anything else I should be aware of or any particular reasons not to choose it or to choose something else? EDIT: Just wanted to add this trend comparison of Javascript frameworks.

    Read the article

  • How to invalidate cache when benchmarking?

    - by Michael Buen
    I have this code, that when swapping the order of UsingAs and UsingCast, their performance also swaps. using System; using System.Diagnostics; using System.Linq; using System.IO; class Test { const int Size = 30000000; static void Main() { object[] values = new MemoryStream[Size]; UsingAs(values); UsingCast(values); Console.ReadLine(); } static void UsingCast(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = 0; foreach (object o in values) { if (o is MemoryStream) { var m = (MemoryStream)o; sum += (int)m.Length; } } sw.Stop(); Console.WriteLine("Cast: {0} : {1}", sum, (long)sw.ElapsedMilliseconds); } static void UsingAs(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = 0; foreach (object o in values) { if (o is MemoryStream) { var m = o as MemoryStream; sum += (int)m.Length; } } sw.Stop(); Console.WriteLine("As: {0} : {1}", sum, (long)sw.ElapsedMilliseconds); } } Outputs: As: 0 : 322 Cast: 0 : 281 When doing this... UsingCast(values); UsingAs(values); ...Results to this: Cast: 0 : 322 As: 0 : 281 When doing just this... UsingAs(values); ...Results to this: As: 0 : 322 When doing just this: UsingCast(values); ...Results to this: Cast: 0 : 322 Aside from running them independently, how to invalidate the cache so the second code being benchmarked won't receive the cached memory of first code? Benchmarking aside, just loved the fact that modern processors do this caching magic :-)

    Read the article

  • Pitfalls and practical Use-Cases: Toplink, Hibernate, Eclipse Link, Ibatis ...

    - by Martin K.
    I worked a lot with Hibernate as my JPA implementation. In most cases it works fine! But I have also seen a lot of pitfalls: Remoting with persisted Objects is difficult, because Hibernate replaces the Java collections with its own collection implementation. So the every client must have the Hibernate .jar libraries. You have to take care on LazyLoading exceptions etc. One way to get around this problem is the use of webservices. Dirty checking is done against the Database without any lock. "Delayed SQL", causes that the data access isn't ACID compliant. (Lost data...) Implict Updates So we don't know if an object is modified or not (commit causes updates). Are there similar issues with Toplink, Eclipse Link and Ibatis? When should I use them? Have they a similar performance? Are there reasons to choose Eclipse Link/Toplink... over Hibernate?

    Read the article

  • Application passwords and SQLite security

    - by Bryan
    I have been searching on google for information regarding application passwords and SQLite security for some time, and nothing that I have found has really answered my questions. Here is what I am trying to figure out: 1) My application is going to have an optional password activity that will be called when the application is first opened. My questions for this are a) If I store the password via android preference or SQLite database, how can I ensure security and privacy for the password, and b) how should password recovery be handled? Regarding b) from above, I have thought about requiring an email address when the password feature is enabled, and also a password hint question for use when requesting password recovery. Upon successfully answering the hint question, the password is then emailed to the email address that was submitted. I am not completely confident in the security and privacy of the email method, especially if the email is sent when the user is connected to an open, public wireless network. 2) My application will be using an SQLite database, which will be stored on the SD card if the user has one. Regardless of whether it is stored on the phone or the SD card, what options do I have for data encryption, and how does that affect the application performance? Thanks in advance for time taken to answer these questions. I think that there may be other developers struggling with the same concerns.

    Read the article

  • Several Small, Specific, MySQL Query Cache Questions

    - by Robbie
    I've look all over the web and in the questions asked here about MySQL caching and most of them seem very non-specific about a couple of questions that I have about performance and MySQL query caching. Specifically I want answers to these questions, assume for all questions that I have the query cache enabled and it is of type 2, or "DEMAND": Is the query cache per table, per database, or per server? Meaning if I have the cache size set to X and have T tables and D databases will I be caching TX, DX, or X amount of data? If I have table T1 which I regularly use the SQL_CACHE hint on for SELECT queries and table T2 which I never do, when I query T2 with a SELECT query will it check through the cache first before performing the query? *Note: I don't want to use the SQL_NO_CACHE for all T2 queries.* Assume the same situation as in question 2. If I alter (INSERT, DELETE) table T2 will any processing be done on the cache? For answers to 2 and 3, is this processing time negligible if T2 is constantly being altered and is the target of a majority of my SELECT queries?

    Read the article

  • Sorting GridView Formed With Data Set

    - by nani
    Following Code is for Sorting GridView Formed With DataSet Source: http://www.highoncoding.com/Articles/176_Sorting_GridView_Manually_.aspx But it is not displaying any output. There is no problem in sql connection. I am unable to trace the error, please help me. Thank You. public partial class _Default : System.Web.UI.Page { private const string ASCENDING = " ASC"; private const string DESCENDING = " DESC"; private DataSet GetData() { SqlConnection cnn = new SqlConnection("Server=localhost;Database=Northwind;Trusted_Connection=True;"); SqlDataAdapter da = new SqlDataAdapter("SELECT TOP 5 firstname,lastname,hiredate FROM EMPLOYEES", cnn); DataSet ds = new DataSet(); da.Fill(ds); return ds; } public SortDirection GridViewSortDirection { get { if (ViewState["sortDirection"] == null) ViewState["sortDirection"] = SortDirection.Ascending; return (SortDirection)ViewState["sortDirection"]; } set { ViewState["sortDirection"] = value; } } protected void GridView1_Sorting(object sender, GridViewSortEventArgs e) { string sortExpression = e.SortExpression; if (GridViewSortDirection == SortDirection.Ascending) { GridViewSortDirection = SortDirection.Descending; SortGridView(sortExpression, DESCENDING); } else { GridViewSortDirection = SortDirection.Ascending; SortGridView(sortExpression, ASCENDING); } } private void SortGridView(string sortExpression, string direction) { // You can cache the DataTable for improving performance DataTable dt = GetData().Tables[0]; DataView dv = new DataView(dt); dv.Sort = sortExpression + direction; GridView1.DataSource = dv; GridView1.DataBind(); } } aspx page asp:GridView ID="GridView1" runat="server" AllowSorting="True" OnSorting="GridView1_Sorting" /asp:GridView

    Read the article

  • Is it possible that a single-threaded program is executed simultaneously on more than one CPU core?

    - by Wolfgang Plaschg
    When I run a single-threaded program that i have written on my quad core Intel i can see in the Windows Task Manager that actually all four cores of my CPU are more or less active. One core is more active than the other three, but there is also activity on those. There's no other program (besided the OS kernel of course) running that would be plausible for that activitiy. And when I close my program all activity an all cores drops down to nearly zero. All is left is a little "noise" on the cores, so I'm pretty sure all the visible activity comes directly or indirectly (like invoking system routines) from my program. Is it possible that the OS or the cores themselves try to balance some code or execution on all four cores, even it's not a multithreaded program? Do you have any links that documents this technique? Some infos to the program: It's a console app written in Qt, the Task Manager states that only one thread is running. Maybe Qt uses threads, but I don't use signals or slots, nor any GUI. Link to Task Manager screenshot: http://img97.imageshack.us/img97/6403/taskmanager.png This question is language agnostic and not tied to Qt/C++, i just want to know if Windows or Intel do to balance also single-threaded code on all cores. If they do, how does this technique work? All I can think of is, that kernel routines like reading from disk etc. is scheduled on all cores, but this won't improve performance significantly since the code still has to run synchronous to the kernel api calls. EDIT Do you know any tools to do a better analysis of single and/or multi-threaded programs than the poor Windows Task Manager?

    Read the article

  • Registry access error when Migrating ASP.NET application to IIS7

    - by fande455
    I'm running windows 7 64-bit and iis7. I'm trying to setup a web application that was previously in iis6 on XP. It's giving me the error below. I've added the network service user to the Performance Monitor Users group to no avail. Access to the registry key 'Global' is denied. 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.UnauthorizedAccessException: Access to the registry key 'Global' is denied. ASP.NET is not authorized to access the requested resource. Consider granting access rights to the resource to the ASP.NET request identity. ASP.NET has a base process identity (typically {MACHINE}\ASPNET on IIS 5 or Network Service on IIS 6) that is used if the application is not impersonating. If the application is impersonating via , the identity will be the anonymous user (typically IUSR_MACHINENAME) or the authenticated request user. To grant ASP.NET access to a file, right-click the file in Explorer, choose "Properties" and select the Security tab. Click "Add" to add the appropriate user or group. Highlight the ASP.NET account, and check the boxes for the desired access.

    Read the article

  • Problem with Binding Multiple Objects on WPF

    - by Diego Modolo Ribeiro
    Hi, I'm developing a user control called SearchBox, that will act as a replacer for ComboBox for multiple records, as the performance in ComboBox is low for this scenario, but I'm having a big binding problem. I have a base control with a DependencyProperty called SelectedItem, and my SearchControl shows that control so that the user can select the record. The SearchControl also has a DependencyProperty called SelectedItem on it, and it is being updated when the user selects something on the base control, but the UI, wich has the SearchControl, is not being updated. I used a null converter so that I could see if the property was updating, but it's not. Below is some of the code: This is the UI: <NectarControles:MaskedSearchControl x:Name="teste" Grid.Row="0" Grid.Column="1" Height="21" ItemsSource="{Binding C001_Lista}" DisplayMember="C001_Codigo" Custom:CustomizadorTextBox.CodigoCampo="C001_Codigo" ViewType="{x:Type C001:C001_Search}" ViewModelType="{x:Type C001_ViewModel:C001_ViewModel}" SelectedItem="{Binding Path=Instancia.C001_Holding, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, Converter={StaticResource DebuggingConverter}}"> </NectarControles:MaskedSearchControl> This is the relevante part of the SearchControl: Binding selectedItemBinding = new Binding("SelectedItem"); selectedItemBinding.Source = this.SearchControlBase; selectedItemBinding.Mode = BindingMode.TwoWay; selectedItemBinding.UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged; this.SetBinding(SelectedItemProperty, selectedItemBinding); ... public System.Data.Objects.DataClasses.IEntityWithKey SelectedItem { get { return (System.Data.Objects.DataClasses.IEntityWithKey)GetValue(SelectedItemProperty); } set { SetValue(SelectedItemProperty, value); if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("SelectedItem")); } } Please someone help me... Tks...

    Read the article

  • Strategies for serializing an object for auditing/logging purpose in .NET?

    - by Jiho Han
    Let's say I have an application that processes messages. Messages are just objects in this case that implements IMessage interface which is just a marker. In this app, if a message fails to process, then I want to log it, first of all for auditing and troubleshooting purposes. Secondly I might want to use it for re-processing. Ideally, I want the message to be serialized into a format that is human-readable. The first candidate is XML although there are others like JSON. If I were to serialize the messages as XML, I want to know whether the message object is XML-serializable. One way is to reflect on the type and to see if it has a parameter-less constructor and the other is to require IXmlSerializable interface. I'm not too happy with either of these approaches. There is a third option which is to try to serialize it and catch exceptions. This doesn't really help - I want to, in some way, stipulate that IMessage (or a derived type) should be xml-serializable. The reflection route has obvious disadvantages such as security, performance, etc. IXmlSerializable route locks down my messages to one format, when in the future, I might want to change the serialization format to be JSON. The other thing is even the simplest objects now must implement ReadXml and WriteXml methods. Is there a route that involves the least amount of work that lets me serialize an arbitrary object (as long as it implements the marker interface) into XML but not lock future messages into XML?

    Read the article

  • Is Annotation in Javascript? If not, how to switch between debug/productive modes in declarative way

    - by Michael Mao
    Hi all: This is but a curious question. I cannot find any useful links from Google so it might be better to ask the gurus here. The point is: is there a way to make "annotation" in javascript source code so that all code snippets for testing purpose can be 'filtered out' when project is deployed from test field into the real environment? I know in Java, C# or some other languages, you can assign an annotation just above the function name, such as : // it is good to remove the annoying warning messages @SuppressWarnings("unchecked") public class Tester extends TestingPackage { ... } Basically I've got a lot of testing code that prints out something into FireBug console. I don't wanna manually "comment out" them because the guy that is going to maintain the code might not be aware of all the testing functions, so he/she might just miss one function and the whole thing can be brought down to its knees. One other thing, we might use a minimizer to "shrink" the source code into "human unreadable" code and boost up performance (just like jQuery.min), so trying to match testing section out of the mess is not possible for plain human eyes in the future. Any suggestion is much appreciated.

    Read the article

  • Writing a JMS Publisher without "public static void main"

    - by The Elite Gentleman
    Hi guys, Every example I've seen on the web, e.g. http://www.codeproject.com/KB/docview/jms_to_jms_bridge_activem.aspx, creates a publisher and subscriber with a public static void main method. I don't think that'll work for my web application. I'm learning JMS and I've setup Apache ActiveMQ to run on JBoss 5 and Tomcat 6 (with no glitches). I'm writing a messaging JMS service that needs to send email asynchronously. I've already written a JMS subscriber that receives the message (the class inherits MessageListener). My question is simple: How do I write a publisher that will so that my web applications can call it? Does it have to be published somewhere? My thought is to create a publisher with a no-attribute constructor (in there) and get the MessageQueue Factory, etc. from the JNDI pool (in the constructor). Is my idea correct? How do I subscribe my subscriber to the Queue Receiver? (So far, the subscriber has no constructor, and if I write a constructor, do I always subscribe myself to the Queue receiver?) Thanks for your help, sorry if my terminology is not up to scratch, there are too many java terminologies that I get lost sometimes (maybe a java GPS will do! :-) ) PS Is there a tutorial out there that explains how to write a "better" (better can mean anything, but in my case it's all about performance in high demand requests) JMS Publisher and Subscriber that I can run on Application Server such as JBoss or Glassfish? Don't forget that the JMS application will needs a "guarantee" uptime as many applications will use this.

    Read the article

  • Best approach to storing image pixels in bottom-up order in Java

    - by finnw
    I have an array of bytes representing an image in Windows BMP format and I would like my library to present it to the Java application as a BufferedImage, without copying the pixel data. The main problem is that all implementations of Raster in the JDK store image pixels in top-down, left-to-right order whereas BMP pixel data is stored bottom-up, left-to-right. If this is not compensated for, the resulting image will be flipped vertically. The most obvious "solution" is to set the SampleModel's scanlineStride property to a negative value and change the band offsets (or the DataBuffer's array offset) to point to the top-left pixel, i.e. the first pixel of the last line in the array. Unfortunately this does not work because all of the SampleModel constructors throw an exception if given a negative scanlineStride argument. I am currently working around it by forcing the scanlineStride field to a negative value using reflection, but I would like to do it in a cleaner and more portable way if possible. e.g. is there another way to fool the Raster or SampleModel into arranging the pixels in bottom-up order but without breaking encapsulation? Or is there a library somewhere that will wrap the Raster and SampleModel, presenting the pixel rows in reverse order? I would prefer to avoid the following approaches: Copying the whole image (for performance reasons. The code must process hundreds of large (= 1Mpixels) images per second and although the whole image must be available to the application, it will normally access only a tiny (but hard-to-predict) portion of the image.) Modifying the DataBuffer to perform coordinate transformation (this actually works but is another "dirty" solution because the buffer should not need to know about the scanline/pixel layout.) Re-implementing the Raster and/or SampleModel interfaces from scratch (but I have a hunch that I will be unable to avoid this.)

    Read the article

  • Design: Website calling a webservice on the same machine

    - by Chris L
    More of a design/conceptual question. At work the decision was made to have our data access layer be called through webservices. So our website would call the webservices for any/all data to and from the database. Both the website & the webservices will be on the same machine(so no trip across the wire), but the database is on a separate machine(so that would require a trip across the wire regardless). This is all in-house, the website, webservice, and database are all within the same company(AFAIK, the webservices won't be reused by another other party). To the best of my knowledge: the website will open a port to the webservices, and the webservices will in turn open another port and go across the wire to the database server to get/submit the data. The trip across the wire can't be avoided, but I'm concerned about the webservices standing in the middle. I do agree there needs to be distinct layers between the functionality(such as business layer, data access layer, etc...), but this seems overly complex to me. I'm also sensing there will be some performance problems down the line. Seems to me it would be better to have the (DAL)assemblies referenced directly within the solution, thus negating the first port to port connection. Any thoughts(or links) both for and against this idea would be appreciated P.S. We're a .NET shop(migrating from vb to C# 3.5)

    Read the article

  • Need help choosing database server

    - by The Pretender
    Good day everyone. Recently I was given a task to develop an application to automate some aspects of stocks trading. While working on initial architecture, the database dilemma emerged. What I need is a fast database engine which can process huge amounts of data coming in very fast. I'm fairly experienced in general programming, but I never faced a task of developing a high-load database architecture. I developed a simple MSSQL database schema with several many-to-many relationships during one of my projects, but that's it. What I'm looking for is some advice on choosing the most suitable database engine and some pointers to various manuals or books which describe high-load database development. Specifics of the project are as follows: OS: Windows NT family (Server 2008 / 7) Primary platform: .NET with C# Database structure: one table to hold primary items and two or three tables with foreign keys to the first table to hold additional information. Database SELECT requirements: Need super-fast selection by foreign keys and by combination of foreign key and one of the columns (presumably DATETIME) Database INSERT requirements: The faster the better :) If there'll be significant performance gain, some parts can be written in C++ with managed interfaces to the rest of the system. So once again: given all that stuff I just typed, please give me some advice on what the best database for my project is. Links or references to some manuals and books on the subject are also greatly appreciated. EDIT: I'll need to insert 3-5 rows in 2 tables approximately once in 30-50 milliseconds and I'll need to do SELECT with 0-2 WHERE clauses queries with similar rate.

    Read the article

  • DNS-Based Environment Determination

    - by zvolkov
    Found the following here. The questions is: where can I find more details on how exactly implement this on Windows? Any guide or how-to anybody? Or maybe you can provide your invaluable suggestions? Specifically, how do I make so that "all QA servers would first resolve entries in qa.example.com first and then if that lookup failed they would try example.com" (I'm a dev, not a DNS specialist, but our IT Support has refused to help on this:() Use DNS Based Environment Determination for your servers. Do this by initially splitting your top level domain into a number of sub domains depending on their function, and then creating DNS Service Names in each of the sub domains pointing to the relevant server for that service. Based on the list above we would then have: * clientdb.prod.example.com for Production * clientdb.perf.example.com for Performance Testing * clientdb.qa.example.com for QA * clientdb.dev.example.com for Development Servers then resolve entries in their relevant sub domain by function. That is, all QA servers would first resolve entries in qa.example.com first and then if that lookup failed they would try example.com. This allows you to have a single configuration entry for your client database hostname (clientdb) that would resolve correctly in all environments. This technique has the added advantage of still having global services defined in a common top level domain. Here's one related (but not equivalent) SO question: http://stackoverflow.com/questions/774490/dns-resolving-based-on-client-ip This seems to be related to Providing "split horizon" DNS service. Reading that, I see that I will probably need separate DNS Server for each environment. Is this true or does Windows support some form of "tagging" the records to be visible depending on the requestor's IP? Also, cross-posted on ServerFault

    Read the article

  • Does Firefox on OS X Lion make use of Full Page Zoom for the touchpad? How to customize behavior?

    - by Steven Lu
    I really like the smooth pinch-zoom of Safari using the touchpad, but the two-finger scroll on Firefox is so much better than the scrolling performance in Safari. So I really like to use Firefox, but then I miss out on two-finger-double-tap to zoom to paragraph width, and the smooth pinch gesture zoom. What I'm wondering is if it is possible to write a Firefox Extension to improve the update rate of the full-page zoom in Firefox that is already functioning via the touchpad pinch gesture. I feel like it is specifically programmed to zoom at certain zoom levels: 100%, 120%, 150% (these are guesses of mine) but I think it would be great if I can get some more control there to make it work more like the zoom functionality in Safari. Also the two-finger-double-tap on a paragraph or element to zoom to it would be really awesome as well. https://developer.mozilla.org/en/Full_page_zoom This seems to indicate (if "full page zoom" is what I think it is) that an extension has the ability to zoom to an arbitrary scale factor, but what remains is to find out if it is possible to obtain or hook the touchpad pinch gesture. Update: I have updated the toolkit.zoomManager.zoomValues option in about:config to include more zoom levels: .3,.5,.67,.8,.9,1,1.01,1.02,1.03,1.04,1.05,1.06,1.07,1.08,1.09,1.1,1.2,1.33,1.5,1.7,2,2.4,3 Notice how I inserted a bunch of entries between 1 and 1.1. But it isn't switching between them any faster (why would it?) so it's less usable than before because of waiting for it to respond fast enough. It's clear that re-rendering the page at a different zoom level requires time and in order for the zoom to be dynamic, some kind of screen capture and scale effect must be performed (which is what Safari does). I guess such a thing is probably doable but I don't think I could pull it off. :-/

    Read the article

  • Can you force a crash if a write occurs to a given memory location with finer than page granularity?

    - by Joseph Garvin
    I'm writing a program that for performance reasons uses shared memory (alternatives have been evaluated, and they are not fast enough for my task, so suggestions to not use it will be downvoted). In the shared memory region I am writing many structs of a fixed size. There is one program responsible for writing the structs into shared memory, and many clients that read from it. However, there is one member of each struct that clients need to write to (a reference count, which they will update atomically). All of the other members should be read only to the clients. Because clients need to change that one member, they can't map the shared memory region as read only. But they shouldn't be tinkering with the other members either, and since these programs are written in C++, memory corruption is possible. Ideally, it should be as difficult as possible for one client to crash another. I'm only worried about buggy clients, not malicious ones, so imperfect solutions are allowed. I can try to stop clients from overwriting by declaring the members in the header they use as const, but that won't prevent memory corruption (buffer overflows, bad casts, etc.) from overwriting. I can insert canaries, but then I have to constantly pay the cost of checking them. Instead of storing the reference count member directly, I could store a pointer to the actual data in a separate mapped write only page, while keeping the structs in read only mapped pages. This will work, the OS will force my application to crash if I try to write to the pointed to data, but indirect storage can be undesirable when trying to write lock free algorithms, because needing to follow another level of indirection can change whether something can be done atomically. Is there any way to mark smaller areas of memory such that writing them will cause your app to blow up? Some platforms have hardware watchpoints, and maybe I could activate one of those with inline assembly, but I'd be limited to only 4 at a time on 32-bit x86 and each one could only cover part of the struct because they're limited to 4 bytes. It'd also make my program painful to debug ;)

    Read the article

  • iPhone OpenGL and NSTimer issues

    - by Kyle
    I have an NSTimer that runs at 60hz. With an OpenGL scene loaded and rendering, my game can get 60fps, solid, all day long.. Then if I go and recompile the app, or reload it, it will get 40fps. Same resources loaded. I've been running into this problem for years, and I just want to know why. It's crazy, and I want to know if I should just abandon this stupid Timer. Conditions are not different on my 3GS between loads. It will just get 40fps sometimes. Obviously the clockrate is not different between loads, so the performance figures should be constant given a constant scene. Here is a log of my framerates: A good load: :-) FrameRate: 61 FrameRate: 61 FrameRate: 61 FrameRate: 60 FrameRate: 60 FrameRate: 61 FrameRate: 60 FrameRate: 60 FrameRate: 61 FrameRate: 60 FrameRate: 61 Now, I'll go ahead and do nothing, recompile, and run: FrameRate: 43 FrameRate: 50 FrameRate: 45 FrameRate: 48 FrameRate: 40 FrameRate: 45 FrameRate: 42 FrameRate: 41 FrameRate: 42 FrameRate: 44 FrameRate: 41 FrameRate: 46 ^- Massive difference visually. What the flying heck could cause this? SAME area of the scene, SAME camera setup. No variables are different.

    Read the article

  • Mysqli query only works on localhost, not webserver

    - by whamo
    Hello. I have changed some of my old queries to the Mysqli framework to improve performance. Everything works fine on localhost but when i upload it to the webserver it outputs nothing. After connecting I check for errors and there are none. I also checked the php modules installed and mysqli is enabled. I am certain that it creates a connection to the database as no errors are displayed. (when i changed the database name string it gave the error) There is no output from the query on the webserver, which looks like this: $mysqli = new mysqli("server", "user", "password"); if (mysqli_connect_errno()) { printf("Can't connect Errorcode: %s\n", mysqli_connect_error()); exit; } // Query used $query = "SELECT name FROM users WHERE id = ?"; if ($stmt = $mysqli->prepare("$query")) { // Specify parameters to replace '?' $stmt->bind_param("d", $id); $stmt->execute(); // bind variables to prepared statement $stmt->bind_result($_userName); while ($stmt->fetch()) { echo $_userName; } $stmt-close(); } } //close connection $mysqli-close(); As I said this code works perfectly on my localserver just not online. Checked the error logs and there is nothing so everything points to a good connection. All the tables exists as well etc. Anyone any ideas because this one has me stuck! Also, if i get this working, will all my other queries still work? Or will i need to make them use the mysqli framework as well? Thanks in advance.

    Read the article

  • Which non-clustered index should I use?

    - by Junior Mayhé
    Here I am studying nonclustered indexes on SQL Server Management Studio. I've created a table with more than 1 million records. This table has a primary key. CREATE TABLE [dbo].[Customers]( [CustomerId] [int] IDENTITY(1,1) NOT NULL, [CustomerName] [varchar](100) NOT NULL, [Deleted] [bit] NOT NULL, [Active] [bit] NOT NULL, CONSTRAINT [PK_Customers] PRIMARY KEY CLUSTERED ( [CustomerId] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] This is the query I'll be using to see what execution plan is showing: SELECT CustomerName FROM Customers Well, executing this command with no additional non-clustered index, it leads the execution plan to show me: I/O cost = 3.45646 Operator cost = 4.57715 Now I'm trying to see if it's possible to improve performance, so I've created a non-clustered index for this table: 1) First non-clustered index CREATE NONCLUSTERED INDEX [IX_CustomerID_CustomerName] ON [dbo].[Customers] ( [CustomerId] ASC, [CustomerName] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO Executing again the select against Customers table, the execution plan shows me: I/O cost = 2.79942 Operator cost = 3.92001 It seems better. Now I've deleted this just created non-clustered index, in order to create a new one: 2) First non-clustered index CREATE NONCLUSTERED INDEX [IX_CustomerIDIncludeCustomerName] ON [dbo].[Customers] ( [CustomerId] ASC ) INCLUDE ( [CustomerName]) WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO With this new non-clustered index, I've executed the select statement again and the execution plan shows me the same result: I/O cost = 2.79942 Operator cost = 3.92001 So, which non-clustered index should I use? Why the costs are the same on execution plan for I/O and Operator? Am I doing something wrong or this is expected? thank you

    Read the article

< Previous Page | 456 457 458 459 460 461 462 463 464 465 466 467  | Next Page >