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• Incredble low disk performance on HP DL385 G7

  - by 3molo

  Hi, As a test of the Opteron processor family, I bought a HP DL385 G7 6128 with HP Smart Array P410i Controller - no memory. The machine has 20GB ram 2x146GB 15k rpm SAS + 2x250GB SATA2, both in Raid 1 configurations. I run Vmware ESXi 4.1. Problem: Even with one virtual machine only, tried Linux 2.6/Windows server 2008/Windows 7, the VMs' feel really sluggish. With windows 7, the vmware converter installation even timed out. Tried both SATA and SAS disks and SATA disks are nearly unsusable, while SAS disks feels extremely slow.I can't see a lot of disk activity in the infrastructure client, but I haven't been looking for causes or even tried diagnostics because I have a feeling that it's either because of the cheap raid controller - or simply because of the lack of memory for it. Despite the problems, I continued and installed a virtual machine that serves a key function, so it's not easy to take it down and run diagnostics. Would very much like to know what you guys have to say of it, is it more likely to be a problem with the controller/disks or is it low performance because of budget components? Thanks in advance,

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• Teach Your Kid to Code Coming to Philly.NET

  - by Steve Michelotti

  Originally posted on: http://geekswithblogs.net/michelotti/archive/2014/05/20/teach-your-kid-to-code-coming-to-philly.net.aspxTomorrow night (Wednesday, May 21) my son and I will be at Philly.NET presenting Teach Your Kid to Code. Bring your kid out to Philly.NET with you for a fun evening! After our first talk, I’ll then be giving an introduction to TypeScript. Of any presentation I’ve ever given, this is my favorite: Have you ever wanted a way to teach your kid to code? For that matter, have you ever wanted to simply be able to explain to your kid what you do for a living? Putting things in a context that a kid can understand is not as easy as it sounds. If you are someone curious about these concepts, this is a “can’t miss” presentation that will be co-presented by Justin Michelotti (6th grader) and his father. Bring your kid with you to Philly.NET for this fun and educational session. We will show tools you may not have been aware of like SmallBasic and Kodu – we’ll even throw in a little Visual Studio and JavaScript. Concepts such as variables, conditionals, loops, and functions will be covered while we introduce object oriented concepts without any of the confusing words. Kids are not required for entry!

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• How to justify rewriting/revamping legacy software in a business case?

  - by sxthomson

  I work for a great little software company which makes good revenue from our main software package. The problem for me is that it's almost unmaintainable. It's written in Delphi 7 (has upgraded versions over time) and has been worked on by a lot of developers over the past 20 or so years. The software lacks any meaningful architecture - there's no object orientation whatsoever, horrible amounts of cyclical dependencies and an over-reliance on global variables to name just a few things. Another huge thing for me is Delphi 7 does NOT support 64-bit. The problem here for me is that my management team don't care about technical things, they want to know why they should care. Obviously that's expected, so what I'm asking here is for some guidance, or tales, or pitfalls about this kind of thing. There's a few things I would love to include, namely for me, the length of time taken to debug/write a feature in "legacy" code, versus coherent, well structured OO code. Does anyone know of any blog posts or the like where this is talked about? For us in the company this is a huge reason. Despite being decent developers we feel like writing a new feature is just piling more rubbish on top. On top of that, even for me who has a decent level of understanding of the code, changing things is infuriating - a small change can have a ridiculous domino effect. Anyone have any experiences they'd like to share?

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• Software raid 0 with six disks performance

  - by user134880

  I have some problems with disk performance. I have 6 x WD 500Gb RE4 disks. Each disk gives 135Mb/sec throughput. All measurements are made with hdparm with options "-tT" (I know that it is just synthetic test, but I need some start point to make measurements). I have controller with Sil3124 x 4 ports PCI Express 1x So... RAID0 on controller with 2 disks gives 200Mb/s - ok, pcie limit. RAID0 on motherboard with 2 disks gives 270Mb/s - niceeee :) RAID0 on contorller with 4 disks gives 200Mb/s - ok, pcie limit. RAID0 on controller with 4 disks + 1 disks on motherboard = 340Mb/s ... :( RAID0 on controller with 4 disks + 2 disks on motherboard = 300Mb/s .... why? Any ideas? Maybe need more cpu power? Now there is Pentium D Dual core 2.8Ghz, 4Gb RAM. It is dedicated box for storage.. no other activity.

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• How to visualize code?

  - by gablin

  I've mostly only had to read my own code. As such, I've had no need to visualize the code as I already know how each and every class and module communicate with one another. But the few times I've had to read someone else's code - let us now assume we are talking about at least one larger module which contains several internal classes - I've almost always found myself wishing "This would have been so much easier to understand if I could just visualize it!" So what are the common methods or tools for enabling this? Which do you use, and why do you prefer them over the others? I've heard stuff like UML, module and class diagrams, but I imagine there are more. Furthermore, any of these is most likely better than anything I can devise on my own. EDIT: For those who answer with "Use pen and paper and just draw it": This isn't very helpful unless you explain this further. What exactly am I supposed to draw? A box for each class? Should I include the public methods? What about its fields? How should I draw connections that explain how one class uses another? What about modules? What if the language isn't object-oriented but functional or logical, or even just imperative (C, for instance)? What about global variables and functions? Is there an already-standardized way of drawing this, or do I need to think up of a method of my own? You get the drift.

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• High-performance Academic Server [closed]

  - by PHPsmith

  Suppose I want to build a server for the university's academic interests. The server is dedicated only to a site, where users (students and lecturers) just view and fill the academic data. But at a time (e.g. once a semester), about 12,000 students will access the site simultaneously. Due to limitation of resources, I have to build the server using free software (except for the operating system Windows 7, the university has been prepared). The hardware is also limited to the usual 4-core computers (eg, Ivy Bridge Intel Core i7-3770) with approximately 16GB of memory (DDR3 1600 MHz), equipped with an RJ-45 port (Intel 82 579 Gigabit Ethernet). With all these limitations, I have to choose the software (web server, database, etc) are appropriate for this purpose is achieved. I decided to create a site in PHP. Please help me by answering the following questions based on your expertise. (my prime candidate software to consider after googling) Web server which is faster & stable & secure, when implemented and optimized for PHP? And why? (nginx) PHP accelerator which is faster & stable & compatible with the selected web server? And why? (APC with Zend Optimizer+) Database which is faster & stable & secure, when implemented and optimized for selected web server and selected PHP accelerator? (MySQL) Are there any errors that have been or will be happening from my condition is? If there is, please enlighten me? Is there anything else I need to know in order to achieve this goal? If there is, please enlighten me? I understand that the performance also depends on the implementation of source-code program, so I assume it will create a site with the best efficiency (e.g. using AJAX).

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• Encapsulating code in F# (Part 2)

  - by MarkPearl

  In part one of this series I showed an example of encapsulation within a local definition. This is useful to know so that you are aware of the scope of value holders etc. but what I am more interested in is encapsulation with regards to generating useful F# code libraries in .Net, this is done by using Namespaces and Modules. Lets have a look at some C# code first… using System; namespace EncapsulationNS { public class EncapsulationCLS { public static void TestMethod() { Console.WriteLine("Hello"); } } } Pretty simple stuff… now the F# equivalent…. namespace EncapsulationNS module EncapsulationMDL = let TestFunction = System.Console.WriteLine("Hello") ()   Even easier… lets look at some specifics about F# namespaces… Namespaces are open. meaning you can have multiple source files and assemblies can contribute to the same namespace. So, Namespaces are a great way to group modules together, so the question needs to be asked, what role do modules play. For me, the F# module is in many ways similar to the vb6 days of modules. In vb6 modules were separate files and simply allowed us to group certain methods together. I find it easier to visualize F# modules this way than to compare them to the C# classes. However that being said one is not restricted to one module per file – there is flexibility to have multiple modules in one code file however with my limited F# experience I would still recommend using the file as the standard level of separating modules as it is very easy to then find your way around a solution. An important note about interop with F# and other .Net languages. I wrote a blog post a while back about a very basic F# to C# interop. If I were to reference an F# library in a C# project (for instance ‘TestFunction’), in C# it would show this method as a static method call, meaning I would not have to instantiate an instance of the module.

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• JEditorPane Code Completion

  - by Geertjan

  Code completion in a JEditorPane: Unfortunately, a lot of this solution depends on the Java Editor support in the IDE. Therefore, to use it, in its current state, you'll need lots of Java Editor related JARs even though your own application probably doesn't include a Java Editor. A key thing one needs to do is implement the NetBeans Code Completion API, using the related tutorial in the NetBeans Platform Learning Trail, but register the CompletionProvider as follows: @MimeRegistration(mimeType = "text/x-dialog-binding", service = CompletionProvider.class) Then in the TopComponent, include this code, which will bind all the completion providers in the above location, i.e., text/x-dialog-binding, to the JEditorPane: EditorKit kit = CloneableEditorSupport.getEditorKit("text/x-java"); jEditorPane1.setEditorKit(kit); FileObject fob; try {     fob = FileUtil.getConfigRoot().createData("tmp.java");     DataObject dob = DataObject.find(fob);     jEditorPane1.getDocument().putProperty(             Document.StreamDescriptionProperty,             dob);     DialogBinding.bindComponentToFile(fob, 0, 0, jEditorPane1);     jEditorPane1.setText("Egypt"); } catch (IOException ex) {     Exceptions.printStackTrace(ex); } Not a perfect solution, a bit hacky, with a high overheard, but a start nonetheless. Someone should look in the NetBeans sources to see how this actually works and then create a generic solution that is not tied to the Java Editor.

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• Where did I write that code ?

  - by Tarun Arora

  Every been in that situation when you desperately need to find that code you checked into TFS a few days back but just can’t remember what team project, what branch, what solution or what file you checked it into. Well you are not alone… Only if there was a way to efficiently search for files and text with in TFS. It is possible… You need to get your hands on Agent Ransack… This is a stand a lone tool that does not integrate with TFS but gives you the capability to search through text files effortlessly. Agent Ransack searches through files, text or otherwise, fast and efficiently. When searching the contents of files for code, or other text, Agent Ransack displays the text found so you can quickly browse the results without having to separately open each file! Agent Ransack is free for both Personal and Commercial use and can be Download from here.   Set the Look In directory of the Ransack search tool to your TFS Workspace and type the text you would like to scan for, you can limit the search by narrowing down the filter path or the name of the file. Found text is shown with highlighted keywords so you don't need to waste time opening each file looking for the right information.         The regular expression wizard helps you build regular expressions for complex pattern matching searches         You even have the option of searching by modified, created or last accessed date          Export your results to a file for importing into other apps or for sharing with others          Agent Ransack also provides search support for popular Office formats including Office 2007 and OpenOffice Next time you are looking for that illusive line of code whether it is a method declaration, function call, or algorithm that you checked into TFS, use Agent Ransack for a quick search.

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• Task-It Source Code

  Download Source Code I've received many questions about when the source code for the Task-It application will be released. Well, the time has finally come. I haven't been able to release this sooner due to the flurry of releases that have been coming out lately. Silverlight 4, WCF RIA Services, and even our Q1 Rad Controls. Each time I got the latest bits I ran into issues (either bugs or visual issues) in the Task-It that needed to be fixed. Having said that, the app is far from perfect. There are still some bugs lurking and things that need to be fixed up visually (especially the RadGridView filtering popup), but the main purpose of this app is to show the RadControls for Silverlight 4 in the context of a real-world application, and I don't want to keep delaying the release of the source code. Minimum requirements To run the app you will need the latest Silverlight bits. Silverlight 4 RTM, VS2010 and the ...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• how to use rsa in application i found code but dont know how to implement [closed]

  - by Smart Guy

  HOW TO I USE THIS RSA http://xtrace.blogspot.com/2012/03/rsa-demo-example.html?showComment=1349091173502#c199333123405145467 TUTOTIAL CODE IN MY LOGIN CODE BELOW I found code but dnt know how to implement public class LoginScreen extends Activity implements OnClickListener{ public void onCreate(Bundle icicle) { super.onCreate(icicle); setContentView(R.layout.login.xml); TextView lblMobileNo = (TextView)findViewById(R.id.lblMobileNo); lblMobileNo.setTextColor(getResources().getColor(R.color.text_color_red)); mobile = (EditText)findViewById(R.id.txtMobileNo); TextView lblPinNo = (TextView)findViewById(R.id.lblPinNo); lblPinNo.setTextColor(getResources().getColor(R.color.text_color_red)); pin = (EditText)findViewById(R.id.txtPinNo); btnLogin = (Button)findViewById(R.id.btnLogin); btnClear = (Button)findViewById(R.id.btnClear); btnLogin.setOnClickListener(new OnClickListener() { public void onClick(View view) { postLoginData(); } }); btnClear.setOnClickListener(new OnClickListener() { public void onClick(View v) { cleartext(); } }); /* btnClear.setOnClickListener(new OnClickListener() { public void onClick(View arg0) { } }); */ } public void postLoginData() { Intent i = new Intent(this.getApplicationContext(),NEWCLASS.class); Bundle bundle = new Bundle(); bundle.putString("mno", mobile.getText().toString()); bundle.putString("pinno", pin.getText().toString()); i.putExtras(bundle); startActivity(i); } } @Override public void onClick(View v) { } public void cleartext() { { pin.setText("") ; mobile.setText(""); } } }

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• Optimize Apache performance

  - by Phliplip

  I'm looking for ways to optimize our current web server hosted in-house. I'm trying to supply as much relevant information below. Please let me know if you would require additional information in order to assist. Server is running 1 single website, which is an online pizza ordering platform built on Zend Framework (ver1). On traffic stats from the last month aprox 6.000 pageloads per day, concentrated mainly around dinnertime. Around 1500 loads/hour peaks in that period. We recently upgraded from a 2/2mbit aDSL-line to 100/100mbit fiber, and we still have performance issues at dinner time. We assumed the 2mbit was the issue. Website is pretty snappy in low-load periods. Hardware CPU: Intel(R) Xeon(R) CPU 5160 @ 3.00GHz (3000.13-MHz K8-class CPU) Mem: 328M Active, 4427M Inact, 891M Wired, 244M Cache, 623M Buf, 33M Free Swap: 16G Total, 468K Used, 16G Free (6GB physical, 16GB swap) Filesystem Type Size Used Avail Capacity Mounted on /dev/ad7s1a ufs 4.8G 768M 3.7G 17% / devfs devfs 1.0K 1.0K 0B 100% /dev /dev/ad7s1g ufs 176G 5.2G 157G 3% /home /dev/ad7s1e ufs 4.8G 2.8M 4.5G 0% /tmp /dev/ad7s1f ufs 19G 3.5G 14G 19% /usr /dev/ad7s1d ufs 4.8G 550M 3.9G 12% /var Server OS FreeBSD 8.2-RELEASE Software apache-2.2.17 php5-5.3.8 mysql-server-5.5 Apache footprint (example, taken from # top) 31140 www 1 45 0 377M 41588K lockf 2 0:00 0.00% httpd 31122 www 1 44 0 375M 35416K lockf 2 0:00 0.00% httpd 31109 www 1 44 0 375M 38188K lockf 2 0:00 0.00% httpd 31113 www 1 44 0 375M 35188K lockf 2 0:00 0.00% httpd Apache is using the prefork MPM, APC (Alternative PHP Cache). SSL module is loaded, but not utilized (as in don't really work, thus not used). There is a file containing settings for MPM modules, but as i see it's not included in the httpd.conf file, the include line is commented out. Thus i would guess that the prefork MPM is working of default values too. Here are some other Apache conf values that i found - which are included in https.conf Timeout 300 KeepAlive On MaxKeepAliveRequests 100 KeepAliveTimeout 5 UseCanonicalName Off HostnameLookups Off

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• share code between check and process methods

  - by undu

  My job is to refactor an old library for GIS vector data processing. The main class encapsulates a collection of building outlines, and offers different methods for checking data consistency. Those checking functions have an optional parameter that allows to perform some process. For instance: std::vector<Point> checkIntersections(int process_mode = 0); This method tests if some building outlines are intersecting, and return the intersection points. But if you pass a non null argument, the method will modify the outlines to remove the intersection. I think it's pretty bad (at call site, a reader not familiar with the code base will assume that a method called checkSomething only performs a check and doesn't modifiy data) and I want to change this. I also want to avoid code duplication as check and process methods are mostly similar. So I was thinking to something like this: // a private worker std::vector<Point> workerIntersections(int process_mode = 0) { // it's the equivalent of the current checkIntersections, it may perform // a process depending on process_mode } // public interfaces for check and process std::vector<Point> checkIntersections() /* const */ { workerIntersections(0); } std::vector<Point> processIntersections(int process_mode /*I have different process modes*/) { workerIntersections(process_mode); } But that forces me to break const correctness as workerIntersections is a non-const method. How can I separate check and process, avoiding code duplication and keeping const-correctness?

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• Performance of external USB disk with ESXi5

  - by PeterMmm

  I have a new HP DL120 G7 server with ESXi5. One VM is a Win2003 instalation and I have an external USB2.0 drive attached by USB Controller and USB Device. I copy a 4GB file from external USB to server disk. In the VM that takes up to 10 minutes. On a native Win2003 that takes aprox. 3 minutes. I have no explaination for that diference: In any case the bottleneck is the USB connection, much slower than the disks (SAS, RAID1). If the USB connection on the VM would be USB1.1 and not USB2.0 it would take much more time. (The disk performance between server partitions on the VM is correct. - see update) Could be that my native box is extremely fast and the VM is the normal case. ??? Update I try with passtrough and a first run copy the same data in aprox. 7 minutes. Still 2 times slower than the native connection. I also did another messure and the copy between partitions on the same VM takes 3 minutes.

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• I’m new to C++ and unsure about how to improve this code [migrated]

  - by Laian Alsabbagh

  The purpose of the following code is to get a random number of 100 nodes and to distribute these nodes randomly in range 500*500 …(X,Y).. this was the first step #include<iostream> #include <fstream> #include<cmath> using namespace std; int main() { const int x = 0, y = 1; int nodes[100][2]; ofstream myfile; myfile.open ("example.txt"); myfile << "Writing this to a file.\n"; for (int i=0; i<100 ;i++) { nodes[i][x] = rand() % 501; nodes[i][y] = rand() % 501; myfile <<nodes[i][x]<<" "<<nodes[i][y]; } myfile.close(); } now the next step is to improve this code to distribute these nodes in order ( "Imust divide both xy_coordinates as : x= 0-100-200-300-400-500 & y=0-100-200-300-400-500) next is to distribute the nodes (regardless number of nodes) in order range Starting from (0,100 )….(100,100)..(100,200)…….untile i reach the last point (500,500),, ") I’m really confused of how to do it correctly I start to think to define 2 dimensional array , and then to define 2 for loops enter code here Int no_nodes=100; Int XY_coordinate [500][500]; For (int i=0;i<no_nodes; i++) { For (int j=0;j<no_nodes; j++)

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• c# WinForms ReportViewer Performance issue using RefreshReport() and ServerReport.SetParameters()

  - by mdk

  Hi All, Currently I am writing a c# client application that uses the WinForms ReportViewer Control to display reports from a remote server. I am having performance troubles with the ReportViewer Control, to be specific with the 2 methods reportViewer.ServerReport.SetParameters() and reportViewer.RefreshReport() – they both take a really long time to complete and not just on the very first call, but on each subsequent call as well. SetParameters() takes 20 to 40 seconds (they vary greatly in time, some execute event okay fast) and RefreshReport() is a bit faster but still takes ages. I don’t think the server is the culprit, as the same report viewed using the browser renders pretty fast, about a second tops. The report in question doesn't matter as well. When I break into the process and take a look at the call stack, I see a call to Socket.DoConnect. So I thought that’s a good reason to start using fiddler and I installed it, disabled caching and fired up the app again to see which call takes that long to connect, but the performance issue was gone. By using a proxy I am having the same performance as the webbrowser. FYI: I am using NTLM authentication in the following way: reportViewer.ServerReport.ReportServerCredentials.NetworkCredentials = new NetworkCredentials() { Username = ... } I don’t have a strong webbackground, so I guess my question is: What should this tell me / What should I be looking into? (Btw: Adding fiddler to my installation package is not the solution I am looking for :)) I am grateful for any pointers. Take care, -Martin

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• emacs tramp performance

  - by Oleg Pavliv

  Is there a way to improve emacs tramp performance? For me it's faster to open an external ftp client (filezilla), transfer files to the local disk and open them in an external editor (notepad) than open them with emacs. I use emacs23.1 under windows xp. I tried different tramp-default-method (telnet, pscp, ftp), all of them have the same performance. Profiling results with elp-instrument-package are the following (I opened 3 remote files of 1.5 MB each one) tramp-file-name-handler 1461 350.41599999 0.2398466803 tramp-sh-file-name-handler 1461 350.02699999 0.2395804243 tramp-send-command 227 179.63400000 0.7913392070 tramp-send-command-and-check 205 177.77600000 0.8672000000 tramp-wait-for-regexp 227 176.47800000 0.7774361233 tramp-wait-for-output 226 176.40000000 0.7805309734 tramp-barf-unless-okay 18 133.46699999 7.4148333333 tramp-handle-insert-file-contents 3 132.046 44.015333333 tramp-handle-file-local-copy 3 131.281 43.760333333 tramp-accept-process-output 2375 112.95100000 0.0475583157 So, actual file transfer takes 132 sec, about 1/3 of total time. Why does it spend so much time in tramp-sh-file-name-handler? I tried to advice a function tramp-sh-file-name-handler to store and return cached results but it does not work, probably this function has some side effects. Any ideas how to improve tramp performance? (I use emacs 23.1 under WindowsXP)

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• Difference in performance between Stax and DOM parsing

  - by Fazal

  I have been using DOM for a long time and as such DOM parsing performance wise has been pretty good. Even when dealing with XML of about 4-7 MB the parsing has been fast. The issue we face with DOM is the memory footprint which become huge as soon as we start dealing with large XMLs. Lately I tried moving to Stax (Streaming parsers for XML) which are supposed top be second generation parsers (reading about Stax it said its the fastest parser now). When I tried stax parser for large XML for about 4MB memory footprint definitely reduced drastically but time take to parse entire XML and create java object out of it increased almost by 5 times over DOM. I used sjsxp.jar implementation of Stax. I can deuce to some extent logically that performance may not be extremely good due to streaming nature of the parser but a reduction of 5 time (e.g. DOM takes about 8 seconds to build object for this XML, whereas Stax parsing took about 40 seconds on average) is definitely not going to be acceptable. Am I missing some point here completely as I am not able to come to terms with these performance numbers

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• Writing to a log4net FileAppender with multiple threads performance problems

  - by Wayne

  TickZoom is a very high performance app which uses it's own parallelization library and multiple O/S threads for smooth utilization of multi-core computers. The app hits a bottleneck where users need to write information to a LogAppender from separate O/S threads. The FileAppender uses the MinimalLock feature so that each thread can lock and write to the file and then release it for the next thread to write. If MinimalLock gets disabled, log4net reports errors about the file being already locked by another process (thread). A better way for log4net to do this would be to have a single thread that takes care of writing to the FileAppender and any other threads simply add their messages to a queue. In that way, MinimalLock could be disabled to greatly improve performance of logging. Additionally, the application does a lot of CPU intensive work so it will also improve performance to use a separate thread for writing to the file so the CPU never waits on the I/O to complete. So the question is, does log4net already offer this feature? If so, how do you do enable threaded writing to a file? Is there another, more advanced appender, perhaps? If not, then since log4net is already wrapped in the platform, that makes it possible to implement a separate thread and queue for this purpose in the TickZoom code. Sincerely, Wayne

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• Performance degrades for more than 2 threads on Xeon X5355

  - by zoolii

  Hi All, I am writing an application using boost threads and using boost barriers to synchronize the threads. I have two machines to test the application. Machine 1 is a core2 duo (T8300) cpu machine (windows XP professional - 4GB RAM) where I am getting following performance figures : Number of threads :1 , TPS :21 Number of threads :2 , TPS :35 (66 % improvement) further increase in number of threads decreases the TPS but that is understandable as the machine has only two cores. Machine 2 is a 2 quad core ( Xeon X5355) cpu machine (windows 2003 server with 4GB RAM) and has 8 effective cores. Number of threads :1 , TPS :21 Number of threads :2 , TPS :27 (28 % improvement) Number of threads :4 , TPS :25 Number of threads :8 , TPS :24 As you can see, performance is degrading after 2 threads (though it has 8 cores). If the program has some bottle neck , then for 2 thread also it should have degraded. Any idea? , Explanations ? , Does the OS has some role in performance ? - It seems like the Core2duo (2.4GHz) scales better than Xeon X5355 (2.66GHz) though it has better clock speed. Thank you -Zoolii

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• Hibernate 3.5.0 causes extreme performance problems

  - by user303396

  I've recently updated from hibernate 3.3.1.GA to hibernate 3.5.0 and I'm having a lot of performance issues. As a test, I added around 8000 entities to my DB (which in turn cause other entities to be saved). These entities are saved in batches of 20 so that the transactions aren't too large for performance reasons. When using hibernate 3.3.1.GA all 8000 entities get saved in about 3 minutes. When using hibernate 3.5.0 it starts out slower than with hibernate 3.3.1. But it gets slower and slower. At around 4,000 entities, it sometimes takes 5 minutes just to save a batch of 20. If I then go to a mysql console and manually type in an insert statement from the mysql general query log, half of them run perfect in 0.00 seconds. And half of them take a long time (maybe 40 seconds) or timeout with "ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction" from MySQL. Has something changed in hibernate's transaction management in version 3.5.0 that I should be aware of? The ONLY thing I changed to experience these unusable performance issues is replace the following hibernate 3.3.1.GA jar files: com.springsource.org.hibernate-3.3.1.GA.jar, com.springsource.org.hibernate.annotations-3.4.0.GA.jar, com.springsource.org.hibernate.annotations.common-3.3.0.ga.jar, com.springsource.javassist-3.3.0.ga.jar with the new hibernate 3.5.0 release hibernate3.jar and javassist-3.9.0.GA.jar. Thanks.

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• Static Vs Non-Static Method Performance C#

  - by dotnetguts

  Hello All, I have few global methods declared in public class in my asp.net web application. I have habbit of declaring all global methods in public class in following format public static string MethodName(parameters) { } I want to know how it would impact on performance point of view? 1) Which one is Better? Static Method or Non-Static Method? 2) Reason why it is better? Following link shows Non-Static methods are good because, static methods are using locks to be Thread-safe. The always do internally a Monitor.Enter() and Monitor.exit() to ensure Thread-safety. http://bytes.com/topic/c-sharp/answers/231701-static-vs-non-static-function-performance And Following link shows Static Methods are good static methods are normally faster to invoke on the call stack than instance methods. There are several reasons for this in the C# programming language. Instance methods actually use the 'this' instance pointer as the first parameter, so an instance method will always have that overhead. Instance methods are also implemented with the callvirt instruction in the intermediate language, which imposes a slight overhead. Please note that changing your methods to static methods is unlikely to help much on ambitious performance goals, but it can help a tiny bit and possibly lead to further reductions. http://dotnetperls.com/static-method I am little confuse which one to use? Thanks

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• MS SQL - High performance data inserting with stored procedures

  - by Marks

  Hi. Im searching for a very high performant possibility to insert data into a MS SQL database. The data is a (relatively big) construct of objects with relations. For security reasons i want to use stored procedures instead of direct table access. Lets say i have a structure like this: Document MetaData User Device Content ContentItem[0] SubItem[0] SubItem[1] SubItem[2] ContentItem[1] ... ContentItem[2] ... Right now I think of creating one big query, doing somehting like this (Just pseudo-code): EXEC @DeviceID = CreateDevice ...; EXEC @UserID = CreateUser ...; EXEC @DocID = CreateDocument @DeviceID, @UserID, ...; EXEC @ItemID = CreateItem @DocID, ... EXEC CreateSubItem @ItemID, ... EXEC CreateSubItem @ItemID, ... EXEC CreateSubItem @ItemID, ... ... But is this the best solution for performance? If not, what would be better? Split it into more querys? Give all Data to one big stored procedure to reduce size of query? Any other performance clue? I also thought of giving multiple items to one stored procedure, but i dont think its possible to give a non static amount of items to a stored procedure. Since 'INSERT INTO A VALUES (B,C),(C,D),(E,F) is more performant than 3 single inserts i thought i could get some performance here. Thanks for any hints, Marks

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• Unable to build my c++ code with g++ 4.6.3

  - by Mriganka

  I am facing multiple issues with building my c++ code on Ubuntu 12.04. This code was building and running fine on RH Enterprise. I am using g++ 4.6.3. Here's the output of g++ -v. g++ -v Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/lib/gcc/i686-linux-gnu/4.6/lto-wrapper Target: i686-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.6.3-1ubuntu5' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.6 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.6 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable-objc-gc --enable-targets=all --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=i686-linux-gnu --host=i686-linux-gnu --target=i686-linux-gnu Thread model: posix gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) Here's a sample of my code: #include "Word.h" #include < string> using namespace std; pthread_mutex_t Word::_lock = PTHREAD_MUTEX_INITIALIZER; Word::Word(): _occurrences(1) { memset(_buf, 0, 25); } Word::Word(char *str): _occurrences(1) { memset(_buf, 0, 25); if (str != NULL) { strncpy(_buf, str, strlen(str)); } } g++ -c -ansi or g++ -c -std=c++98 or g++ -c -std=c++03, none of these options are able to build the code correctly. I get the following compilation errors: mriganka@ubuntu:~/WordCount$ make g++ -c -g -ansi Word.cpp -o Word.o Word.cpp: In constructor ‘Word::Word()’: Word.cpp:10:21: error: ‘memset’ was not declared in this scope Word.cpp: In constructor ‘Word::Word(char*)’: Word.cpp:16:21: error: ‘memset’ was not declared in this scope Word.cpp:19:34: error: ‘strlen’ was not declared in this scope Word.cpp:19:35: error: ‘strncpy’ was not declared in this scope Word.cpp: In member function ‘void Word::operator=(const Word&)’: Word.cpp:37:42: error: ‘strlen’ was not declared in this scope Word.cpp:37:43: error: ‘strncpy’ was not declared in this scope Word.cpp: In copy constructor ‘Word::Word(const Word&)’: Word.cpp:44:21: error: ‘memset’ was not declared in this scope Word.cpp:45:52: error: ‘strlen’ was not declared in this scope Word.cpp:45:53: error: ‘strncpy’ was not declared in this scope So basically g++ 4.6.3 on Ubuntu 12.04 is not able to recognize the standard c++ headers. And I am not finding a way out of this situation. Second problem: In order to make progress, I included < string.h instead of < string. But now I am facing linking errors with my message queue and pthread library functions. Here's the error that I am getting: mriganka@ubuntu:~/WordCount$ make g++ -c -g -ansi Word.cpp -o Word.o g++ -lrt -I/usr/lib/i386-linux-gnu Word.o HashMap.o main.o -o word_count main.o: In function `main': /home/mriganka/WordCount/main.cpp:75: undefined reference to `pthread_create' /home/mriganka/WordCount/main.cpp:90: undefined reference to `mq_open' /home/mriganka/WordCount/main.cpp:93: undefined reference to `mq_getattr' /home/mriganka/WordCount/main.cpp:113: undefined reference to `mq_send' /home/mriganka/WordCount/main.cpp:123: undefined reference to `pthread_join' /home/mriganka/WordCount/main.cpp:129: undefined reference to `mq_close' /home/mriganka/WordCount/main.cpp:130: undefined reference to `mq_unlink' main.o: In function `count_words(void*)': /home/mriganka/WordCount/main.cpp:151: undefined reference to `mq_open' /home/mriganka/WordCount/main.cpp:154: undefined reference to `mq_getattr' /home/mriganka/WordCount/main.cpp:162: undefined reference to `mq_timedreceive' collect2: ld returned 1 exit status Here's my makefile: CC=g++ CFLAGS=-c -g -ansi LDFLAGS=-lrt INC=-I/usr/lib/i386-linux-gnu SOURCES=Word.cpp HashMap.cpp main.cpp OBJECTS=$(SOURCES:.cpp=.o) EXECUTABLE=word_count all: $(SOURCES) $(EXECUTABLE) $(EXECUTABLE): $(OBJECTS) $(CC) $(LDFLAGS) $(INC) -pthread $(OBJECTS) -o $@ .cpp.o: $(CC) $(CFLAGS) $< -o $@ clean: rm -f *.o word_count Please help me to resolve both the issues. I searched online relentlessly for any solution of these problems, but no one seems to have encountered these issues.

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• RPi and Java Embedded GPIO: Writing Java code to blink LED

  - by hinkmond

  So, you've followed the previous steps to install Java Embedded on your Raspberry Pi ?, you went to Fry's and picked up some jumper wires, LEDs, and resistors ?, you hooked up the wires, LED, and resistor the the correct pins ?, and now you want to start programming in Java on your RPi? Yes? ???????! OK, then... Here we go. You can use the following source code to blink your first LED on your RPi using Java. In the code you can see that I'm not using any complicated gpio libraries like wiringpi or pi4j, and I'm not doing any low-level pin manipulation like you can in C. And, I'm not using python (hell no!). This is Java programming, so we keep it simple (and more readable) than those other programming languages. See: Write Java code to do this In the Java code, I'm opening up the RPi Debian Wheezy well-defined file handles to control the GPIO ports. First I'm resetting everything using the unexport/export file handles. (On the RPi, if you open the well-defined file handles and write certain ASCII text to them, you can drive your GPIO to perform certain operations. See this GPIO reference). Next, I write a "1" then "0" to the value file handle of the GPIO0 port (see the previous pinout diagram). That makes the LED blink. Then, I loop to infinity. Easy, huh? import java.io.* /* * Java Embedded Raspberry Pi GPIO app */ package jerpigpio; import java.io.FileWriter; /** * * @author hinkmond */ public class JerpiGPIO { static final String GPIO_OUT = "out"; static final String GPIO_ON = "1"; static final String GPIO_OFF = "0"; static final String GPIO_CH00="0"; /** * @param args the command line arguments */ public static void main(String[] args) { FileWriter commandFile; try { /*** Init GPIO port for output ***/ // Open file handles to GPIO port unexport and export controls FileWriter unexportFile = new FileWriter("/sys/class/gpio/unexport"); FileWriter exportFile = new FileWriter("/sys/class/gpio/export"); // Reset the port unexportFile.write(GPIO_CH00); unexportFile.flush(); // Set the port for use exportFile.write(GPIO_CH00); exportFile.flush(); // Open file handle to port input/output control FileWriter directionFile = new FileWriter("/sys/class/gpio/gpio"+GPIO_CH00+"/direction"); // Set port for output directionFile.write(GPIO_OUT); directionFile.flush(); /*--- Send commands to GPIO port ---*/ // Opne file handle to issue commands to GPIO port commandFile = new FileWriter("/sys/class/gpio/gpio"+GPIO_CH00+"/value"); // Loop forever while (true) { // Set GPIO port ON commandFile.write(GPIO_ON); commandFile.flush(); // Wait for a while java.lang.Thread.sleep(200); // Set GPIO port OFF commandFile.write(GPIO_OFF); commandFile.flush(); // Wait for a while java.lang.Thread.sleep(200); } } catch (Exception exception) { exception.printStackTrace(); } } } Hinkmond

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