arbitrary precision - Page 73

MongoDB and datasets that don't fit in RAM no matter how hard you shove

- by sysadmin1138

This is very system dependent, but chances are near certain we'll scale past some arbitrary cliff and get into Real Trouble. I'm curious what kind of rules-of-thumb exist for a good RAM to Disk-space ratio. We're planning our next round of systems, and need to make some choices regarding RAM, SSDs, and how much of each the new nodes will get. But now for some performance details! During normal workflow of a single project-run, MongoDB is hit with a very high percentage of writes (70-80%). Once the second stage of the processing pipeline hits, it's extremely high read as it needs to deduplicate records identified in the first half of processing. This is the workflow for which "keep your working set in RAM" is made for, and we're designing around that assumption. The entire dataset is continually hit with random queries from end-user derived sources; though the frequency is irregular, the size is usually pretty small (groups of 10 documents). Since this is user-facing, the replies need to be under the "bored-now" threshold of 3 seconds. This access pattern is much less likely to be in cache, so will be very likely to incur disk hits. A secondary processing workflow is high read of previous processing runs that may be days, weeks, or even months old, and is run infrequently but still needs to be zippy. Up to 100% of the documents in the previous processing run will be accessed. No amount of cache-warming can help with this, I suspect. Finished document sizes vary widely, but the median size is about 8K. The high-read portion of the normal project processing strongly suggests the use of Replicas to help distribute the Read traffic. I have read elsewhere that a 1:10 RAM-GB to HD-GB is a good rule-of-thumb for slow disks, As we are seriously considering using much faster SSDs, I'd like to know if there is a similar rule of thumb for fast disks. I know we're using Mongo in a way where cache-everything really isn't going to fly, which is why I'm looking at ways to engineer a system that can survive such usage. The entire dataset will likely be most of a TB within half a year and keep growing.

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VPC SSH port forward into private subnet

- by CP510

Ok, so I've been racking my brain for DAYS on this dilema. I have a VPC setup with a public subnet, and a private subnet. The NAT is in place of course. I can connect from SSH into a instance in the public subnet, as well as the NAT. I can even ssh connect to the private instance from the public instance. I changed the SSHD configuration on the private instance to accept both port 22 and an arbitrary port number 1300. That works fine. But I need to set it up so that I can connect to the private instance directly using the 1300 port number, ie. ssh -i keyfile.pem [email protected] -p 1300 and 1.2.3.4 should route it to the internal server 10.10.10.10. Now I heard iptables is the job for this, so I went ahead and researched and played around with some routing with that. These are the rules I have setup on the public instance (not the NAT). I didn't want to use the NAT for this since AWS apperantly pre-configures the NAT instances when you set them up and I heard using iptables can mess that up. *filter :INPUT ACCEPT [129:12186] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [84:10472] -A INPUT -i lo -j ACCEPT -A INPUT -i eth0 -p tcp -m state --state NEW -m tcp --dport 1300 -j ACCEPT -A INPUT -d 10.10.10.10/32 -p tcp -m limit --limit 5/min -j LOG --log-prefix "SSH Dropped: " -A FORWARD -d 10.10.10.10/32 -p tcp -m tcp --dport 1300 -j ACCEPT -A OUTPUT -o lo -j ACCEPT COMMIT # Completed on Wed Apr 17 04:19:29 2013 # Generated by iptables-save v1.4.12 on Wed Apr 17 04:19:29 2013 *nat :PREROUTING ACCEPT [2:104] :INPUT ACCEPT [2:104] :OUTPUT ACCEPT [6:681] :POSTROUTING ACCEPT [7:745] -A PREROUTING -i eth0 -p tcp -m tcp --dport 1300 -j DNAT --to-destination 10.10.10.10:1300 -A POSTROUTING -p tcp -m tcp --dport 1300 -j MASQUERADE COMMIT So when I try this from home. It just times out. No connection refused messages or anything. And I can't seem to find any log messages about dropped packets. My security groups and ACL settings allow communications on these ports in both directions in both subnets and on the NAT. I'm at a loss. What am I doing wrong?

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Python cannot go over internet network

- by user1642826

I am currently trying to work with python networking and I have reached a bit of a road block. I am not able to network with any computer but localhost, which is kind-of useless with what networking is concerned. I have tried on my local network, from one computer to another, and I have tried over the internet, both fail. The only time I can make it work is if (when running on the server's computer) it's ip is set as 'localhost' or '192.168.2.129' (computers ip). I have spent hours going over opening ports with my isp and have gotten nowhere, so I decided to try this forum. I have my windows firewall down and I have included some pictures of important screen shots. I have no idea what the problem is and this has spanned almost a year of calls to my isp. The computer, modem, and router have all been replaced in that time. Screen shots: import socket import threading import socketserver class ThreadedTCPRequestHandler(socketserver.BaseRequestHandler): def handle(self): data = self.request.recv(1024) cur_thread = threading.current_thread() response = "{}: {}".format(cur_thread.name, data) self.request.sendall(b'worked') class ThreadedTCPServer(socketserver.ThreadingMixIn, socketserver.TCPServer): pass def client(ip, port, message): sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.connect((ip, port)) try: sock.sendall(message) response = sock.recv(1024) print("Received: {}".format(response)) finally: sock.close() if __name__ == "__main__": # Port 0 means to select an arbitrary unused port HOST, PORT = "192.168.2.129", 9000 server = ThreadedTCPServer((HOST, PORT), ThreadedTCPRequestHandler) ip, port = server.server_address # Start a thread with the server -- that thread will then start one # more thread for each request server_thread = threading.Thread(target=server.serve_forever) # Exit the server thread when the main thread terminates server_thread.daemon = True server_thread.start() print("Server loop running in thread:", server_thread.name) ip = '12.34.56.789' print(ip, port) client(ip, port, b'Hello World 1') client(ip, port, b'Hello World 2') client(ip, port, b'Hello World 3') server.shutdown() I do not know where the error is occurring. I get this error: Traceback (most recent call last): File "C:\Users\Dr.Frev\Desktop\serverTest.py", line 43, in <module> client(ip, port, b'Hello World 1') File "C:\Users\Dr.Frev\Desktop\serverTest.py", line 18, in client sock.connect((ip, port)) socket.error: [Errno 10061] No connection could be made because the target machine actively refused it Any help will be greatly appreciated. *if this isn't a proper forum for this, could someone direct me to a more appropriate one.

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Problem with waitable timers in Windows (timeSetEvent and CreateTimerQueueTimer)

- by MusiGenesis

I need high-resolution (more accurate than 1 millisecond) timing in my application. The waitable timers in Windows are (or can be made) accurate to the millisecond, but if I need a precise periodicity of, say, 35.7142857141 milliseconds, even a waitable timer with a 36 ms period will drift out of sync quickly. My "solution" to this problem (in ironic quotes because it's not working quite right) is to use a series of one-shot timers where I use the expiration of each timer to call the next timer. Normally a process like this would be subject to cumulative error over time, but in each timer callback I check the current time (with System.Diagnostics.Stopwatch) and use this to calculate what the period of the next timer needs to be (so if a timer happens to expire a little late, the next timer will automagically have a shorter period to compensate). This works as expected, except that after maybe 10-15 seconds the timer system seems to get bogged down, and a few timer callbacks here and there arrive anywhere from 25 to 100 milliseconds late. After a couple of seconds the problem goes away and everything runs smoothly again for 10-15 seconds, and then the stuttering again. Since I'm using Stopwatch to set each timer period, I'm also using it to monitor the arrival times of each timer callback. During the smooth-running periods, most (maybe 95%) of the intervals are either 35 or 36 milliseconds, and no intervals are ever more than 5 milliseconds away from the expected 35.7142857143. During the "glitchy" stretches, the distribution of intervals is very nearly identical, except that a very small number are unusually large (a couple more than 60 ms and one or two longer than 100 ms during maybe a 3-second stretch). This stuttering is very noticeable, and it's what I'm trying to fix, if possible. For the high-resolution timer, I was using the extremely antique timeSetEvent() multimedia timer from winmm.dll. In pursuit of this problem, I switched to using CreateTimerQueueTimer (along with timeBeginPeriod to set the high-resolution), but I'm seeing the same problem with both timer mechanisms. I've tried experimenting with the various flags for CreateTimerQueueTimer which determine which thread the timer runs on, but the stuttering appears no matter what. Is this just a fundamental problem with using timers in this way (i.e. using each one-shot timer to call the next)? If so, do I have any alternatives? One thing I was considering was to determine how many consecutive 1-millisecond-accuracy ticks would keep my within some arbitrary precision limit before I need to reset the timer. So, for example, if I wanted a 35.71428 period, I could let a 36 ms timer elapse 15 times before it was off by 5 milliseconds, then kill it and start a new one.

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How to override C# DateTime serialization with class auto-generated from wsdl?

- by Calvin Fisher

I have a WSDL that the consumer of my web service expects will be adhered to strictly. I converted it into an interface with wsdl.exe and had my web service implement it. Except for this problem, I have been generally pleased with the results. A simple GetCurrentTime method will have the following response class generated from the WSDL in the interface definition: [System.CodeDobmCompiler.GeneratedCodeAttribute("wsdl", "2.0.50727.3038")] [System.SerializableAttribute()] [System.Diagnostics.DebuggerStepThroughAttribute()] [System.ComponentModel.DesignerCategoryAttribute("code")] [System.Xml.Serialization.XmlTypeAttribute(Namespace="[Client Namespace]")] public partial class GetCurrentTimeResponse { private System.DateTime timeStampField; [System.Xml.Serialization.XmlElementAttribute(Form=System.Xml.Schema.XmlSchemaForm.Unqualified] public System.DateTime TimeStamp{ // [accesses timeStampField] } } When I put the response data into the automatically generated response class, it gets serialized into an appropriate XML response. (Most of the web methods have much more complicated return types with multiple levels of arrays.) The problem is that the default serialization of DateTime objects violates one of the requirements in the WSDL: ... <xsd:simpleType name="SearchTimeStamp"> <xsd:restriction base="xsd:dateTime"> <xsd:pattern value="[0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}(.[0-9]{1,7})?Z"> </xsd:restriction> </xsd:simpleType> ... Note the last part of the pattern where subseconds must be either 1 or 7 characters if they are included. The client seems to be rejecting the response because it does not match that requirement. The main issue is that when .NET serializes a DateTime object, it omits all trailing zeroes, meaning the resulting subsecond value varies in length. (e.g., "12:34:56.700" gets serialized as "<TimeStamp>12:34:56:7</TimeStamp>" by default). We use millisecond precision, so I need all timestamps to format with 7 subsecond digits in order to be compliant with the WSDL. It would be easy if I could specify a format string, but I'm not sure how to control the string that the DateTime object uses to serialize to XML, or to otherwise override the serialization behavior. How do I do this? Keeping in mind the following... I would like to modify the generated code as little as possible... preferably not at all if the change can be made through a partial class or inherited class. Using an inherited class for the return type of the web method will cause the web service to no longer implement the auto-generated interface. The TimeStamp type occurs in other, more complex response types. So, manually overriding the entire serialization process may be prohibitively time-consuming.

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Panning weirdness on an UserControl

- by Matías

Hello, I'm trying to build my own "PictureBox like" control adding some functionalities. For example, I want to be able to pan over a big image by simply clicking and dragging with the mouse. The problem seems to be on my OnMouseMove method. If I use the following code I get the drag speed and precision I want, but of course, when I release the mouse button and try to drag again the image is restored to its original position. using System.Drawing; using System.Windows.Forms; namespace Testing { public partial class ScrollablePictureBox : UserControl { private Image image; private bool centerImage; public Image Image { get { return image; } set { image = value; Invalidate(); } } public bool CenterImage { get { return centerImage; } set { centerImage = value; Invalidate(); } } public ScrollablePictureBox() { InitializeComponent(); SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.OptimizedDoubleBuffer, true); Image = null; AutoScroll = true; AutoScrollMinSize = new Size(0, 0); } private Point clickPosition; private Point scrollPosition; protected override void OnMouseDown(MouseEventArgs e) { base.OnMouseDown(e); clickPosition.X = e.X; clickPosition.Y = e.Y; } protected override void OnMouseMove(MouseEventArgs e) { base.OnMouseMove(e); if (e.Button == MouseButtons.Left) { scrollPosition.X = clickPosition.X - e.X; scrollPosition.Y = clickPosition.Y - e.Y; AutoScrollPosition = scrollPosition; } } protected override void OnPaint(PaintEventArgs e) { base.OnPaint(e); e.Graphics.FillRectangle(new Pen(BackColor).Brush, 0, 0, e.ClipRectangle.Width, e.ClipRectangle.Height); if (Image == null) return; int centeredX = AutoScrollPosition.X; int centeredY = AutoScrollPosition.Y; if (CenterImage) { //Something not relevant } AutoScrollMinSize = new Size(Image.Width, Image.Height); e.Graphics.DrawImage(Image, new RectangleF(centeredX, centeredY, Image.Width, Image.Height)); } } } But if I modify my OnMouseMove method to look like this: protected override void OnMouseMove(MouseEventArgs e) { base.OnMouseMove(e); if (e.Button == MouseButtons.Left) { scrollPosition.X += clickPosition.X - e.X; scrollPosition.Y += clickPosition.Y - e.Y; AutoScrollPosition = scrollPosition; } } ... you will see that the dragging is not smooth as before, and sometimes behaves weird (like with lag or something). What am I doing wrong? I've also tried removing all "base" calls on a desperate movement to solve this issue, haha, but again, it didn't work. Thanks for your time.

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Wordpress Template HTML CSS Layout Confusion

- by Jess McKenzie

I am having huge confusion with a template that I have purchased and I am trying to modify to handle a widget contact form. I am getting close with this but I have now muddled up the CSS or I have a feeling every page has a different CSS structure. The General Layout: What I Manage To Get: HTML View Source: <div id="innerright"> <div id="home" class="page"> <div id="homeslides"> <div class="welcomeslide"> <h1 class="large">Welcome</h1> </div> </div> </div> <div id="portfolio" class="page"> <div class="verticalline"> <div class="scrollprevnext"></div> </div> <div class="pageheader"> <h3><span>P</span>ortfolio</h3> </div> <div id="portfolioscroller" class="scrollerenabledpage"> <div class="content"> <h5>Recent Work</h5> <ul class="thumb"> <li><a rel="precision_gallery" href="" title=""><img alt="" src="" /></a></li> </ul> </div> </div> </div> <div id="contact" class="page"> <div class="verticalline"> <div class="scrollprevnext"></div> </div> <div class="pageheader"> <h3><span>C</span>ontact</h3> </div> <div id="contactscroller"> <h5>Get In Touch</h5> <div id="contactform">content</div> </div> </div> </div> CSS: CSS index.php: <!DOCTYPE HTML> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title><?php bloginfo('name'); ?></title> <link rel="stylesheet" type="text/css" href="<?php echo get_template_directory_uri(); ?>/style.css" /> <link rel="stylesheet" type="text/css" href="<?php echo get_template_directory_uri(); ?>/fancybox/jquery.fancybox-1.3.4.css" media="screen" /> <?php // jquery will be included by wp_head function as well as scripts and styles by third party plugins wp_head(); ?> <script type="text/javascript" src="<?php echo get_template_directory_uri(); ?>/js/plugins.js"></script> <script type="text/javascript" src="<?php echo get_template_directory_uri(); ?>/js/script.js"></script> <script type="text/javascript" src="<?php echo get_template_directory_uri(); ?>/fancybox/jquery.fancybox-1.3.4.pack.js"></script> <?php // background image if one has been set via options if (function_exists('get_option_tree')) { $background_image = get_option_tree('precision_background_image'); //$background_image = ''; $background_color = get_option_tree('precision_background_color'); if ($background_color != '') { echo '<style>body { background-color:'.$background_color.'; }</style>'; } } ?> <script type="text/javascript"> jQuery(document).ready(function($) { $('.page').each(function(index, element) { $(this).css('left', index * 500); }); <?php // if background is set via the OptionTree then load it first if ($background_image != '') { ?> $.vegas({ src:'<?php echo $background_image; ?>', fade:1000, complete:function() { $("#wrapper").fadeIn(1000); $("#bgpanel").fadeIn(1000); $('#mainslide').crossSlide( { speed: 15, fade: 1 }, [ <?php echo $slides; ?> ] ) $('#homeslides').bxSlider({ mode: 'fade', auto: true, controls:false, speed:1000, pause:5000 }); } }); <?php } else { // if no background has been set then fade-in the page ?> $("#wrapper").fadeIn(1000); $("#bgpanel").fadeIn(1000); $('#mainslide').crossSlide( { speed: 15, fade: 1 }, [ //ENTER YOUR MAIN SLIDESHOW IMAGES HERE\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ <?php echo $slides; ?> ] ) $('#homeslides').bxSlider({ mode: 'fade', auto: true, controls:false, speed:1000, pause:5000 }); <?php } ?> //BX SLIDER INNER PAGE SCROLLERS//////////////////////// $('.scrollerenabledpage').each(function(index, element) { $('#' + $(this).attr('id')).bxSlider({ mode: 'vertical', easing: 'easeInOutQuint', auto: false, controls: true, prevImage:'<?php echo get_template_directory_uri(); ?>/images/up.png', nextImage:'<?php echo get_template_directory_uri(); ?>/images/down.png', infiniteLoop: false, hideControlOnEnd: true, pager: true, pagerType:'short', pagerShortSeparator:'of', speed:800, }); }); //END BX SLIDER INNER PAGE SCROLLERS///////////////// $('#submit').click(function(e) { e.preventDefault(); $('form').submit(); }); // contact form $('form').submit(function(e) { $('#main').append('<img src="<?php echo get_template_directory_uri(); ?>/images/loader.gif" class="loaderIcon" alt="Loading..." />'); $.post("<?php bloginfo('wpurl'); ?>/wp-admin/admin-ajax.php", {action:'precision_contact_form_handler', uname:$('input#uname').val(), uemail:$('input#uemail').val(), ucomments:$('textarea#ucomments').val()}, function(data) { $('#main img.loaderIcon').fadeOut(1000); if (data.status == "success") { $('#response').html("Forum has been successfully submitted."); } else { if (data.response != '') { $('#response').html(data.response); } else { $('#response').html("An error occurred while submitting the form. Please try again."); } } }, "json"); return false; }); }); //hides contact form labels when a field gets focus function initOverLabels () { if (!document.getElementById) return; var labels, id, field; labels = document.getElementsByTagName('label'); for (var i = 0; i < labels.length; i++) { if (labels[i].className == 'overlabel') { id = labels[i].htmlFor || labels[i].getAttribute('for'); if (!id || !(field = document.getElementById(id))) { continue; } labels[i].className = 'overlabel-apply'; if (field.value !== '') { hideLabel(field.getAttribute('id'), true); } field.onfocus = function () { hideLabel(this.getAttribute('id'), true); }; field.onblur = function () { if (this.value === '') { hideLabel(this.getAttribute('id'), false); } }; labels[i].onclick = function () { var id, field; id = this.getAttribute('for'); if (id && (field = document.getElementById(id))) { field.focus(); } }; } } }; function hideLabel(field_id, hide) { var field_for; var labels = document.getElementsByTagName('label'); for (var i = 0; i < labels.length; i++) { field_for = labels[i].htmlFor || labels[i].getAttribute('for'); if (field_for == field_id) { labels[i].style.textIndent = (hide) ? '-1000px' : '0px'; return true; } } } window.onload = function () { setTimeout(initOverLabels, 50); }; </script> <?php if (function_exists('get_option_tree')) { $precision_font_family_1 = get_option_tree('precision_font_family_1'); ?> <link href='http://fonts.googleapis.com/css?family=<?php echo $precision_font_family_1; ?>' rel='stylesheet' type='text/css'> <?php } ?> <style> h1, h2 { font-family:<?php echo $precision_font_family_1; ?>; } </style> </head> <body> <div id="wrapper"> <div id="innerleft"> <div id="header"> <?php if (function_exists('get_option_tree')) { $site_logo = get_option_tree('precision_site_logo'); ?> <a href="/" title="<?php bloginfo('name');?>"><img src="<?php echo $site_logo; ?>" alt="<?php bloginfo('name');?>" /></a> <?php } ?> </div> <?php if (function_exists('get_option_tree')) { $precision_slideshow_image = get_option_tree('precision_slideshow_image'); } ?> <ul id="nav"> <?php //instead of using wp_nav_menu, we use wp_get_nav_menu_items so that we can store the data in array and re-use it again //wp_nav_menu(array('theme_location' => 'precision-main-menu', 'container' => 'false')); $slt_menuItems = wp_get_nav_menu_items( "precision-main-menu" ); $menusItems = array(); foreach ($slt_menuItems as $slt_menuItem) { $page_title = $slt_menuItem->title; $menuItem = new stdClass; $menuItem->title = $page_title; $menuItem->page_id = $slt_menuItem->object_id; $menusItems[] = $menuItem; ?> <li id="<?php echo strtolower($page_title); ?>nav"><a href="#<?php echo strtolower($page_title); ?>"><?php echo $page_title; ?></a></li> <?php } ?> </ul> <div id="socialMedia"> <ul class="social"> <?php if (function_exists('get_option_tree')) { $twitter_link = get_option_tree('precision_twitter_link'); $facebook_link = get_option_tree('precision_facebook_link'); $gplus_link = get_option_tree('precision_gplus_link'); $delicious_link = get_option_tree('precision_delicious_link'); $flickr_link = get_option_tree('precision_flickr_link'); $vimeo_link = get_option_tree('precision_vimeo_link'); $youtube_link = get_option_tree('precision_youtube_link'); $linkedin_link = get_option_tree('precision_linkedin_link'); ?>  <?php if($linkedin_link != ''){ ?> <li><a href="<?php echo $linkedin_link;?>" title="Follow <?php bloginfo('name'); ?> on Linkedin"><img src="<?php echo get_template_directory_uri();?>/images/social-icons/linkedin.png" width="49" height="64" alt="<?php bloginfo('name'); ?> Linkedin"/></a><li> <?php } ?>   <?php if ($twitter_link != '') { ?> <li><a href="<?php echo $twitter_link; ?>" title="Follow <?php bloginfo('name'); ?> on Twitter"><img src="<?php echo get_template_directory_uri(); ?>/images/social-icons/twitter.png" width="49" height="64" alt="<?php bloginfo('name'); ?> Twitter" /></a></li> <?php } ?>   <?php if ($facebook_link != '') { ?> <li><a href="<?php echo $facebook_link; ?>" title="Follow <?php bloginfo('name'); ?> on Facebook"><img src="<?php echo get_template_directory_uri(); ?>/images/social-icons/facebook.png" width="49" height="64" alt="<?php bloginfo('name'); ?> Facebook" /></a></li> <?php } ?>   <?php if ($gplus_link != '') { ?> <li><a href="<?php echo $gplus_link; ?>"><img src="<?php echo get_template_directory_uri(); ?>/images/social-icons/google_plus.png" width="16" height="16" alt="google+" /></a></li> <?php } ?>   <?php if ($delicious_link != '') { ?> <li><a href="<?php echo $delicious_link; ?>"><img src="<?php echo get_template_directory_uri(); ?>/images/social-icons/delicious.png" width="16" height="16" alt="delicious" /></a></li> <?php } ?>   <?php if ($flickr_link != '') { ?> <li><a href="<?php echo $flickr_link; ?>"><img src="<?php echo get_template_directory_uri(); ?>/images/social-icons/flickr.png" width="16" height="16" alt="flickr" /></a></li> <?php } ?>   <?php if ($vimeo_link != '') { ?> <li><a href="<?php echo $vimeo_link; ?>"><img src="<?php echo get_template_directory_uri(); ?>/images/social-icons/vimeo.png" width="16" height="16" alt="vimeo" /></a></li> <?php } ?>   <?php if ($youtube_link != '') { ?> <li><a href="<?php echo $youtube_link; ?>"><img src="<?php echo get_template_directory_uri(); ?>/images/social-icons/youtube.png" width="16" height="16" alt="youtube" /></a></li> <?php } ?>  <?php } ?> </ul> </div> </div> <div id="innerright"> <?php if (function_exists('get_option_tree')) { $precision_home_page_option = get_option_tree('precision_home_page'); $precision_home_page = strtolower(get_the_title($precision_home_page_option)); if ($precision_home_page == '') { $precision_home_page = 'home'; } $precision_contact_page_option = get_option_tree('precision_contact_page'); $precision_contact_page = strtolower(get_the_title($precision_contact_page_option)); if ($precision_contact_page == '') { $precision_contact_page = 'contact'; } } foreach ($menusItems as $menuItem) { ?> <div id="<?php echo strtolower($menuItem->title); ?>" class="page"> <?php if (strtolower($menuItem->title) == $precision_home_page) { ?> <div id="homeslides"> <?php $page_data = get_page($menuItem->page_id); $content = apply_filters('the_content', $page_data->post_content); echo $content; ?> </div> <?php } else { ?> <div class="verticalline"> <div class="scrollprevnext"></div> </div> <div class="pageheader"> <h3><span><?php echo substr($menuItem->title, 0, 1); ?></span><?php echo substr($menuItem->title, 1); ?></h3> </div> <?php $classes = ''; if (strtolower($menuItem->title) == $precision_contact_page) { ?> <div id="<?php echo strtolower($menuItem->title); ?>scroller"> <?php $page_data = get_page($menuItem->page_id); $content = apply_filters('the_content', $page_data->post_content); echo $content; ?> </div> <?php } else { $classes = 'scrollerenabledpage'; ?> <div id="<?php echo strtolower($menuItem->title); ?>scroller" class="<?php echo $classes; ?>"> <?php $page_data = get_page($menuItem->page_id); $content = apply_filters('the_content', $page_data->post_content); echo $content; ?> </div> <?php } } ?> </div> <?php } ?> </div> <div id="footer"> <p>© <a href="/"><?php bloginfo('name');?></a> | <?php echo date('Y');?></p> </div> </div> </div>  </body> </html>

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How to optimize my PostgreSQL DB for prefix search?

- by asmaier

I have a table called "nodes" with roughly 1.7 million rows in my PostgreSQL db =#\d nodes Table "public.nodes" Column | Type | Modifiers --------+------------------------+----------- id | integer | not null title | character varying(256) | score | double precision | Indexes: "nodes_pkey" PRIMARY KEY, btree (id) I want to use information from that table for autocompletion of a search field, showing the user a list of the ten titles having the highest score fitting to his input. So I used this query (here searching for all titles starting with "s") =# explain analyze select title,score from nodes where title ilike 's%' order by score desc; QUERY PLAN ----------------------------------------------------------------------------------------------------------------------- Sort (cost=64177.92..64581.38 rows=161385 width=25) (actual time=4930.334..5047.321 rows=161264 loops=1) Sort Key: score Sort Method: external merge Disk: 5712kB -> Seq Scan on nodes (cost=0.00..46630.50 rows=161385 width=25) (actual time=0.611..4464.413 rows=161264 loops=1) Filter: ((title)::text ~~* 's%'::text) Total runtime: 5260.791 ms (6 rows) This was much to slow for using it with autocomplete. With some information from Using PostgreSQL in Web 2.0 Applications I was able to improve that with a special index =# create index title_idx on nodes using btree(lower(title) text_pattern_ops); =# explain analyze select title,score from nodes where lower(title) like lower('s%') order by score desc limit 10; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------ Limit (cost=18122.41..18122.43 rows=10 width=25) (actual time=1324.703..1324.708 rows=10 loops=1) -> Sort (cost=18122.41..18144.60 rows=8876 width=25) (actual time=1324.700..1324.702 rows=10 loops=1) Sort Key: score Sort Method: top-N heapsort Memory: 17kB -> Bitmap Heap Scan on nodes (cost=243.53..17930.60 rows=8876 width=25) (actual time=96.124..1227.203 rows=161264 loops=1) Filter: (lower((title)::text) ~~ 's%'::text) -> Bitmap Index Scan on title_idx (cost=0.00..241.31 rows=8876 width=0) (actual time=90.059..90.059 rows=161264 loops=1) Index Cond: ((lower((title)::text) ~>=~ 's'::text) AND (lower((title)::text) ~<~ 't'::text)) Total runtime: 1325.085 ms (9 rows) So this gave me a speedup of factor 4. But can this be further improved? What if I want to use '%s%' instead of 's%'? Do I have any chance of getting a decent performance with PostgreSQL in that case, too? Or should I better try a different solution (Lucene?, Sphinx?) for implementing my autocomplete feature?

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drag to pan on an UserControl

- by Matías

Hello, I'm trying to build my own "PictureBox like" control adding some functionalities. For example, I want to be able to pan over a big image by simply clicking and dragging with the mouse. The problem seems to be on my OnMouseMove method. If I use the following code I get the drag speed and precision I want, but of course, when I release the mouse button and try to drag again the image is restored to its original position. using System.Drawing; using System.Windows.Forms; namespace Testing { public partial class ScrollablePictureBox : UserControl { private Image image; private bool centerImage; public Image Image { get { return image; } set { image = value; Invalidate(); } } public bool CenterImage { get { return centerImage; } set { centerImage = value; Invalidate(); } } public ScrollablePictureBox() { InitializeComponent(); SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.OptimizedDoubleBuffer, true); Image = null; AutoScroll = true; AutoScrollMinSize = new Size(0, 0); } private Point clickPosition; private Point scrollPosition; protected override void OnMouseDown(MouseEventArgs e) { base.OnMouseDown(e); clickPosition.X = e.X; clickPosition.Y = e.Y; } protected override void OnMouseMove(MouseEventArgs e) { base.OnMouseMove(e); if (e.Button == MouseButtons.Left) { scrollPosition.X = clickPosition.X - e.X; scrollPosition.Y = clickPosition.Y - e.Y; AutoScrollPosition = scrollPosition; } } protected override void OnPaint(PaintEventArgs e) { base.OnPaint(e); e.Graphics.FillRectangle(new Pen(BackColor).Brush, 0, 0, e.ClipRectangle.Width, e.ClipRectangle.Height); if (Image == null) return; int centeredX = AutoScrollPosition.X; int centeredY = AutoScrollPosition.Y; if (CenterImage) { //Something not relevant } AutoScrollMinSize = new Size(Image.Width, Image.Height); e.Graphics.DrawImage(Image, new RectangleF(centeredX, centeredY, Image.Width, Image.Height)); } } } But if I modify my OnMouseMove method to look like this: protected override void OnMouseMove(MouseEventArgs e) { base.OnMouseMove(e); if (e.Button == MouseButtons.Left) { scrollPosition.X += clickPosition.X - e.X; scrollPosition.Y += clickPosition.Y - e.Y; AutoScrollPosition = scrollPosition; } } ... you will see that the dragging is not smooth as before, and sometimes behaves weird (like with lag or something). What am I doing wrong? I've also tried removing all "base" calls on a desperate movement to solve this issue, haha, but again, it didn't work. Thanks for your time.

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Runge-Kutta Method with adaptive step

- by infoholic_anonymous

I am implementing Runge-Kutta method with adaptive step in matlab. I get different results as compared to matlab's own ode45 and my own implementation of Runge-Kutta method with fixed step. What am I doing wrong in my code? Is it possible? function [ result ] = rk4_modh( f, int, init, h, h_min ) % % f - function handle % int - interval - pair (x_min, x_max) % init - initial conditions - pair (y1(0),y2(0)) % h_min - lower limit for h (step length) % h - initial step length % x - independent variable ( for example time ) % y - dependent variable - vertical vector - in our case ( y1, y2 ) function [ k1, k2, k3, k4, ka, y ] = iteration( f, h, x, y ) % core functionality performed within loop k1 = h * f(x,y); k2 = h * f(x+h/2, y+k1/2); k3 = h * f(x+h/2, y+k2/2); k4 = h * f(x+h, y+k3); ka = (k1 + 2*k2 + 2*k3 + k4)/6; y = y + ka; end % constants % relative error eW = 1e-10; % absolute error eB = 1e-10; s = 0.9; b = 5; % initialization i = 1; x = int(1); y = init; while true hy = y; hx = x; %algorithm [ k1, k2, k3, k4, ka, y ] = iteration( f, h, x, y ); % error estimation for j=1:2 [ hk1, hk2, hk3, hk4, hka, hy ] = iteration( f, h/2, hx, hy ); hx = hx + h/2; end err(:,i) = abs(hy - y); % step adjustment e = abs( hy ) * eW + eB; a = min( e ./ err(:,i) )^(0.2); mul = a * s; if mul >= 1 % step length admitted keepH(i) = h; k(:,:,i) = [ k1, k2, k3, k4, ka ]; previous(i,:) = [ x+h, y' ]; %' i = i + 1; if floor( x + h + eB ) == int(2) break; else h = min( [mul*h, b*h, int(2)-x] ); x = x + keepH(i-1); end else % step length requires further adjustments h = mul * h; if ( h < h_min ) error('Computation with given precision impossible'); end end end result = struct( 'val', previous, 'k', k, 'err', err, 'h', keepH ); end The function in question is: function [ res ] = fun( x, y ) % res(1) = y(2) + y(1) * ( 0.9 - y(1)^2 - y(2)^2 ); res(2) = -y(1) + y(2) * ( 0.9 - y(1)^2 - y(2)^2 ); res = res'; %' end The call is: res = rk4( @fun, [0,20], [0.001; 0.001], 0.008 ); The resulting plot for x1 : The result of ode45( @fun, [0, 20], [0.001, 0.001] ) is:

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Postgres Stored procedure using iBatis

- by Om Yadav

--- The error occurred while applying a parameter map. --- Check the newSubs-InlineParameterMap. --- Check the statement (query failed). --- Cause: org.postgresql.util.PSQLException: ERROR: wrong record type supplied in RETURN NEXT Where: PL/pgSQL function "getnewsubs" line 34 at return next the function detail is as below.... CREATE OR REPLACE FUNCTION getnewsubs(timestamp without time zone, timestamp without time zone, integer) RETURNS SETOF record AS $BODY$declare v_fromdt alias for $1; v_todt alias for $2; v_domno alias for $3; v_cursor refcursor; v_rec record; v_cpno bigint; v_actno int; v_actname varchar(50); v_actid varchar(100); v_cpntypeid varchar(100); v_mrp double precision; v_domname varchar(100); v_usedt timestamp without time zone; v_expirydt timestamp without time zone; v_createdt timestamp without time zone; v_ctno int; v_phone varchar; begin open v_cursor for select cpno,c.actno,usedt from cpnusage c inner join account s on s.actno=c.actno where usedt = $1 and usedt < $2 and validdomstat(s.domno,v_domno) order by c.usedt; fetch v_cursor into v_cpno,v_actno,v_usedt; while found loop if isactivation(v_cpno,v_actno,v_usedt) IS TRUE then select into v_actno,v_actname,v_actid,v_cpntypeid,v_mrp,v_domname,v_ctno,v_cpno,v_usedt,v_expirydt,v_createdt,v_phone a.actno,a.actname as name,a.actid as actid,c.descr as cpntypeid,l.mrp as mrp,s.domname as domname,c.ctno as ctno,b.cpno,b.usedt,b.expirydt,d.createdt,a.phone from account a inner join cpnusage b on a.actno=b.actno inner join cpn d on b.cpno=d.cpno inner join cpntype c on d.ctno=c.ctno inner join ssgdom s on a.domno=s.domno left join price_class l ON l.price_class_id=b.price_class_id where validdomstat(a.domno,v_domno) and b.cpno=v_cpno and b.actno=v_actno; select into v_rec v_actno,v_actname,v_actid,v_cpntypeid,v_mrp,v_domname,v_ctno,v_cpno,v_usedt,v_expirydt,v_createdt,v_phone; return next v_rec; end if; fetch v_cursor into v_cpno,v_actno,v_usedt; end loop; return ; end;$BODY$ LANGUAGE 'plpgsql' VOLATILE; ALTER FUNCTION getnewsubs(timestamp without time zone, timestamp without time zone, integer) OWNER TO radius If i am running the function from the console it is running fine and giving me the correct response. But when using through java causing the above error. Can ay body help in it..Its very urgent. Please response as soon as possible. Thanks in advance.

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Cepstral Analysis for pitch detection

- by Ohmu

Hi! I'm looking to extract pitches from a sound signal. Someone on IRC just explain to me how taking a double FFT achieves this. Specifically: take FFT take log of square of absolute value (can be done with lookup table) take another FFT take absolute value I am attempting this using vDSP I can't understand how I didn't come across this technique earlier. I did a lot of hunting and asking questions; several weeks worth. More to the point, I can't understand why I didn't think of it. I am attempting to achieve this with vDSP library. it looks as though it has functions to handle all of these tasks. However, I'm wondering about the accuracy of the final result. I have previously used a technique which scours the frequency bins of a single FFT for local maxima. when it encounters one, it uses a cunning technique (the change in phase since the last FFT) to more accurately place the actual peak within the bin. I am worried that this precision will be lost with this technique I'm presenting here. I guess the technique could be used after the second FFT to get the fundamental accurately. But it kind of looks like the information is lost in step 2. as this is a potentially tricky process, could someone with some experience just look over what I'm doing and check it for sanity? also, I've heard there is an alternative technique involving fitting a quadratic over neighbouring bins. Is this of comparable accuracy? if so, I would favour it, as it doesn't involve remembering bin phases. so questions: does this approach makes sense? Can it be improved? I'm a bit worried about And the log square component; there seems to be a vDSP function to do exactly that: vDSP_vdbcon however, there is no indication it precalculates a log-table -- I assume it doesn't, as the FFT function requires an explicit pre-calculation function to be called and passed into it. and this function doesn't. Is there some danger of harmonics being picked up? is there any cunning way of making vDSP pull out the maxima, biggest first? Can anyone point me towards some research or literature on this technique? the main question: is it accurate enough? Can the accuracy be improved? I have just been told by an expert that the accuracy IS INDEED not sufficient. Is this the end of the line? Pi PS I get SO annoyed (npi) when I want to create tags, but cannot. :| I have suggested to the maintainers that SO keep track of attempted tags, but I'm sure I was ignored. we need tags for vDSP, accelerate framework, cepstral analysis

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php download file slows

- by hobbywebsite

OK first off thanks for your time I wish I could give more than one point for this question. Problem: I have some music files on my site (.mp3) and I am using a php file to increment a database to count the number of downloads and to point to the file to download. For some reason this method starts at 350kb/s then slowly drops to 5kb/s which then the file says it will take 11hrs to complete. BUT if I go directly to the .mp3 file my browser brings up a player and then I can right click and "save as" which works fine complete download in 3mins. (Yes both during the same time for those that are thinking it's my connection or ISP and its not my server either.) So the only thing that I've been playing around with recently is the php.ini and the .htcaccess files. So without further ado, the php file, php.ini, and the .htcaccess: download.php <?php include("config.php"); include("opendb.php"); $filename = 'song_name'; $filedl = $filename . '.mp3'; $query = "UPDATE songs SET song_download=song_download+1 WHER song_linkname='$filename'"; mysql_query($query); header('Content-Disposition: attachment; filename='.basename($filedl)); header('Content-type: audio/mp3'); header('Content-Length: ' . filesize($filedl)); readfile('/music/' . $filename . '/' . $filedl); include("closedb.php"); ?> php.ini register_globals = off allow_url_fopen = off expose_php = Off max_input_time = 60 variables_order = "EGPCS" extension_dir = ./ upload_tmp_dir = /tmp precision = 12 SMTP = relay-hosting.secureserver.net url_rewriter.tags = "a=href,area=href,frame=src,input=src,form=,fieldset=" ; Defines the default timezone used by the date functions date.timezone = "America/Los_Angeles" .htaccess Options +FollowSymLinks RewriteEngine on RewriteCond %{HTTP_HOST} !^(www.MindCollar.com)?$ [NC] RewriteRule (.*) http://www.MindCollar.com/$1 [R=301,L] <IfModule mod_rewrite.c> RewriteEngine On ErrorDocument 404 /errors/404.php ErrorDocument 403 /errors/403.php ErrorDocument 500 /errors/500.php </IfModule> Options -Indexes Options +FollowSymlinks <Files .htaccess> deny from all </Files> thanks for you time

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How to manually (bitwise) perform (float)x? (homework)

- by Silver

Now, here is the function header of the function I'm supposed to implement: /* * float_from_int - Return bit-level equivalent of expression (float) x * Result is returned as unsigned int, but * it is to be interpreted as the bit-level representation of a * single-precision floating point values. * Legal ops: Any integer/unsigned operations incl. ||, &&. also if, while * Max ops: 30 * Rating: 4 */ unsigned float_from_int(int x) { ... } We aren't allowed to do float operations, or any kind of casting. Now I tried to implement the first algorithm given at this site: http://locklessinc.com/articles/i2f/ Here's my code: unsigned float_from_int(int x) { // grab sign bit int xIsNegative = 0; int absValOfX = x; if(x < 0){ xIsNegative = 1; absValOfX = -x; } // zero case if(x == 0){ return 0; } //int shiftsNeeded = 0; /*while(){ shiftsNeeded++; }*/ unsigned I2F_MAX_BITS = 15; unsigned I2F_MAX_INPUT = ((1 << I2F_MAX_BITS) - 1); unsigned I2F_SHIFT = (24 - I2F_MAX_BITS); unsigned result, i, exponent, fraction; if ((absValOfX & I2F_MAX_INPUT) == 0) result = 0; else { exponent = 126 + I2F_MAX_BITS; fraction = (absValOfX & I2F_MAX_INPUT) << I2F_SHIFT; i = 0; while(i < I2F_MAX_BITS) { if (fraction & 0x800000) break; else { fraction = fraction << 1; exponent = exponent - 1; } i++; } result = (xIsNegative << 31) | exponent << 23 | (fraction & 0x7fffff); } return result; } But it didn't work (see test error below): Test float_from_int(-2147483648[0x80000000]) failed... ...Gives 0[0x0]. Should be -822083584[0xcf000000] 4 4 0 float_times_four I don't know where to go from here. How should I go about parsing the float from this int?

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Use ASP.NET 4 Browser Definitions with ASP.NET 3.5

- by Stephen Walther

We updated the browser definitions files included with ASP.NET 4 to include information on recent browsers and devices such as Google Chrome and the iPhone. You can use these browser definition files with earlier versions of ASP.NET such as ASP.NET 3.5. The updated browser definition files, and instructions for installing them, can be found here: http://aspnet.codeplex.com/releases/view/41420 The changes in the browser definition files can cause backwards compatibility issues when you upgrade an ASP.NET 3.5 web application to ASP.NET 4. If you encounter compatibility issues, you can install the old browser definition files in your ASP.NET 4 application. The old browser definition files are included in the download file referenced above. What’s New in the ASP.NET 4 Browser Definition Files The complete set of browsers supported by the new ASP.NET 4 browser definition files is represented by the following figure: If you look carefully at the figure, you’ll notice that we added browser definitions for several types of recent browsers such as Internet Explorer 8, Firefox 3.5, Google Chrome, Opera 10, and Safari 4. Furthermore, notice that we now include browser definitions for several of the most popular mobile devices: BlackBerry, IPhone, IPod, and Windows Mobile (IEMobile). The mobile devices appear in the figure with a purple background color. To improve performance, we removed a whole lot of outdated browser definitions for old cell phones and mobile devices. We also cleaned up the information contained in the browser files. Here are some of the browser features that you can detect: Are you a mobile device? <%=Request.Browser.IsMobileDevice %> Are you an IPhone? <%=Request.Browser.MobileDeviceModel == "IPhone" %> What version of JavaScript do you support? <%=Request.Browser["javascriptversion"] %> What layout engine do you use? <%=Request.Browser["layoutEngine"] %> Here’s what you would get if you displayed the value of these properties using Internet Explorer 8: Here’s what you get when you use Google Chrome: Testing Browser Settings When working with browser definition files, it is useful to have some way to test the capability information returned when you request a page with different browsers. You can use the following method to return the HttpBrowserCapabilities the corresponds to a particular user agent string and set of browser headers: public HttpBrowserCapabilities GetBrowserCapabilities(string userAgent, NameValueCollection headers) { HttpBrowserCapabilities browserCaps = new HttpBrowserCapabilities(); Hashtable hashtable = new Hashtable(180, StringComparer.OrdinalIgnoreCase); hashtable[string.Empty] = userAgent; // The actual method uses client target browserCaps.Capabilities = hashtable; var capsFactory = new System.Web.Configuration.BrowserCapabilitiesFactory(); capsFactory.ConfigureBrowserCapabilities(headers, browserCaps); capsFactory.ConfigureCustomCapabilities(headers, browserCaps); return browserCaps; } At the end of this blog entry, there is a link to download a simple Visual Studio 2008 project – named Browser Definition Test -- that uses this method to display capability information for arbitrary user agent strings. For example, if you enter the user agent string for an iPhone then you get the results in the following figure: The Browser Definition Test application enables you to submit a user-agent string and display a table of browser capabilities information. The browser definition files contain sample user-agent strings for each browser definition. I got the iPhone user-agent string from the comments in the iphone.browser file. Enumerating Browser Definitions Someone asked in the comments whether or not there is a way to enumerate all of the browser definitions. You can do this if you ware willing to use a little reflection and read a private property. The browser definition files in the config\browsers folder get parsed into a class named BrowserCapabilitesFactory. After you run the aspnet_regbrowsers tool, you can see the source for this class in the config\browser folder by opening a file named BrowserCapsFactory.cs. The BrowserCapabilitiesFactoryBase class has a protected property named BrowserElements that represents a Hashtable of all of the browser definitions. Here's how you can read this protected property and display the ID for all of the browser definitions: var propInfo = typeof(BrowserCapabilitiesFactory).GetProperty("BrowserElements", BindingFlags.NonPublic | BindingFlags.Instance); Hashtable browserDefinitions = (Hashtable)propInfo.GetValue(new BrowserCapabilitiesFactory(), null); foreach (var key in browserDefinitions.Keys) { Response.Write("" + key); } If you run this code using Visual Studio 2008 then you get the following results: You get a huge number of outdated browsers and devices. In all, 449 browser definitions are listed. If you run this code using Visual Studio 2010 then you get the following results: In the case of Visual Studio 2010, all the old browsers and devices have been removed and you get only 19 browser definitions. Conclusion The updated browser definition files included in ASP.NET 4 provide more accurate information for recent browsers and devices. If you would like to test the new browser definitions with different user-agent strings then I recommend that you download the Browser Definition Test project: Browser Definition Test Project

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Rendering ASP.NET MVC Razor Views outside of MVC revisited

- by Rick Strahl

Last year I posted a detailed article on how to render Razor Views to string both inside of ASP.NET MVC and outside of it. In that article I showed several different approaches to capture the rendering output. The first and easiest is to use an existing MVC Controller Context to render a view by simply passing the controller context which is fairly trivial and I demonstrated a simple ViewRenderer class that simplified the process down to a couple lines of code. However, if no Controller Context is available the process is not quite as straight forward and I referenced an old, much more complex example that uses my RazorHosting library, which is a custom self-contained implementation of the Razor templating engine that can be hosted completely outside of ASP.NET. While it works inside of ASP.NET, it’s an awkward solution when running inside of ASP.NET, because it requires a bit of setup to run efficiently.Well, it turns out that I missed something in the original article, namely that it is possible to create a ControllerContext, if you have a controller instance, even if MVC didn’t create that instance. Creating a Controller Instance outside of MVCThe trick to make this work is to create an MVC Controller instance – any Controller instance – and then configure a ControllerContext through that instance. As long as an HttpContext.Current is available it’s possible to create a fully functional controller context as Razor can get all the necessary context information from the HttpContextWrapper().The key to make this work is the following method:/// <summary> /// Creates an instance of an MVC controller from scratch /// when no existing ControllerContext is present /// </summary> /// <typeparam name="T">Type of the controller to create</typeparam> /// <returns>Controller Context for T</returns> /// <exception cref="InvalidOperationException">thrown if HttpContext not available</exception> public static T CreateController<T>(RouteData routeData = null) where T : Controller, new() { // create a disconnected controller instance T controller = new T(); // get context wrapper from HttpContext if available HttpContextBase wrapper = null; if (HttpContext.Current != null) wrapper = new HttpContextWrapper(System.Web.HttpContext.Current); else throw new InvalidOperationException( "Can't create Controller Context if no active HttpContext instance is available."); if (routeData == null) routeData = new RouteData(); // add the controller routing if not existing if (!routeData.Values.ContainsKey("controller") && !routeData.Values.ContainsKey("Controller")) routeData.Values.Add("controller", controller.GetType().Name .ToLower() .Replace("controller", "")); controller.ControllerContext = new ControllerContext(wrapper, routeData, controller); return controller; }This method creates an instance of a Controller class from an existing HttpContext which means this code should work from anywhere within ASP.NET to create a controller instance that’s ready to be rendered. This means you can use this from within an Application_Error handler as I needed to or even from within a WebAPI controller as long as it’s running inside of ASP.NET (ie. not self-hosted). Nice.So using the ViewRenderer class from the previous article I can now very easily render an MVC view outside of the context of MVC. Here’s what I ended up in my Application’s custom error HttpModule: protected override void OnDisplayError(WebErrorHandler errorHandler, ErrorViewModel model) { var Response = HttpContext.Current.Response; Response.ContentType = "text/html"; Response.StatusCode = errorHandler.OriginalHttpStatusCode; var context = ViewRenderer.CreateController<ErrorController>().ControllerContext; var renderer = new ViewRenderer(context); string html = renderer.RenderView("~/Views/Shared/GenericError.cshtml", model); Response.Write(html); }That’s pretty sweet, because it’s now possible to use ViewRenderer just about anywhere in any ASP.NET application, not only inside of controller code. This also allows the constructor for the ViewRenderer from the last article to work without a controller context parameter, using a generic view as a base for the controller context when not passed:public ViewRenderer(ControllerContext controllerContext = null) { // Create a known controller from HttpContext if no context is passed if (controllerContext == null) { if (HttpContext.Current != null) controllerContext = CreateController<ErrorController>().ControllerContext; else throw new InvalidOperationException( "ViewRenderer must run in the context of an ASP.NET " + "Application and requires HttpContext.Current to be present."); } Context = controllerContext; }In this case I use the ErrorController class which is a generic controller instance that exists in the same assembly as my ViewRenderer class and that works just fine since ‘generically’ rendered views tend to not rely on anything from the controller other than the model which is explicitly passed.While these days most of my apps use MVC I do still have a number of generic pieces in most of these applications where Razor comes in handy. This includes modules like the above, which when they error often need to display error output. In other cases I need to generate string template output for emailing or logging data to disk. Being able to render simply render an arbitrary View to and pass in a model makes this super nice and easy at least within the context of an ASP.NET application!You can check out the updated ViewRenderer class below to render your ‘generic views’ from anywhere within your ASP.NET applications. Hope some of you find this useful.ResourcesViewRenderer Class in Westwind.Web.Mvc Library (Github)Original ViewRenderer ArticleRazor Hosting Library (GitHub)Original Razor Hosting Article© Rick Strahl, West Wind Technologies, 2005-2013Posted in ASP.NET MVC Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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Formal Languages, Inductive Proofs & Regular Expressions

- by MarkPearl

So I am slogging away at my UNISA stuff. I have just finished doing the initial once non stop read through the first 11 chapters of my COS 201 Textbook - “Introduction to Computer Theory 2nd Edition” by Daniel Cohen. It has been an interesting couple of days, with familiar concepts coming up as well as some new territory. In this posting I am going to cover the first couple of chapters of the book. Let start with Formal Languages… What exactly is a formal language? Pretty much a no duh question for me but still a good one to ask – a formal language is a language that is defined in a precise mathematical way. Does that mean that the English language is a formal language? I would say no – and my main motivation for this is that one can have an English sentence that is correct grammatically that is also ambiguous. For example the ambiguous sentence: "I once shot an elephant in my pyjamas.” For this and possibly many other reasons that I am unaware of, English is termed a “Natural Language”. So why the importance of formal languages in computer science? Again a no duh question in my mind… If we want computers to be effective and useful tools then we need them to be able to evaluate a series of commands in some form of language that when interpreted by the device no confusion will exist as to what we were requesting. Imagine the mayhem that would exist if a computer misinterpreted a command to print a document and instead decided to delete it. So what is a Formal Language made up of… For my study purposes a language is made up of a finite alphabet. For a formal language to exist there needs to be a specification on the language that will describe whether a string of characters has membership in the language or not. There are two basic ways to do this: By a “machine” that will recognize strings of the language (e.g. Finite Automata). By a rule that describes how strings of a language can be formed (e.g. Regular Expressions). When we use the phrase “string of characters”, we can also be referring to a “word”. What is an Inductive Proof? So I am not to far into my textbook and of course it starts referring to proofs and different types. I have had to go through several different approaches of proofs in the past, but I can never remember their formal names , so when I saw “inductive proof” I thought to myself – what the heck is that? Google to the rescue… An inductive proof is like a normal proof but it employs a neat trick which allows you to prove a statement about an arbitrary number n by first proving it is true when n is 1 and then assuming it is true for n=k and showing it is true for n=k+1. The idea is that if you want to show that someone can climb to the nth floor of a fire escape, you need only show that you can climb the ladder up to the fire escape (n=1) and then show that you know how to climb the stairs from any level of the fire escape (n=k) to the next level (n=k+1). Does this sound like a form of recursion? No surprise then that in the same chapter they deal with recursive definitions. An example of a recursive definition for the language EVEN would the 3 rules below: 2 is in EVEN If x is in EVEN then so is x+2 The only elements in the set EVEN are those that be produced by the rules above. Nothing to exciting… So if a definition for a language is done recursively, then it makes sense that the language can be proved using induction. Regular Expressions So I am wondering to myself what use is this all – in fact – I find this the biggest challenge to any university material is that it is quite hard to find the immediate practical applications of some theory in real life stuff. How great was my joy when I suddenly saw the word regular expression being introduced. I had been introduced to regular expressions on Stack Overflow where I was trying to recognize if some text measurement put in by a user was in a valid form or not. For instance, the imperial system of measurement where you have feet and inches can be represented in so many different ways. I had eventually turned to regular expressions as an easy way to check if my parser could correctly parse the text or not and convert it to a normalize measurement. So some rules about languages and regular expressions… Any finite language can be represented by at least one if not more regular expressions A regular expressions is almost a rule syntax for expressing how regular languages can be formed regular expressions are cool For a regular expression to be valid for a language it must be able to generate all the words in the language and no other words. This is important. It doesn’t help me if my regular expression parses 100% of my measurement texts but also lets one or two invalid texts to pass as well. Okay, so this posting jumps around a bit – but introduces some very basic fundamentals for the subject which will be built on in later postings… Time to go and do some practical examples now…

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PHP OCI8 and Oracle 11g DRCP Connection Pooling in Pictures

- by christopher.jones

Here is a screen shot from a PHP OCI8 connection pooling demo that I like to run. It graphically shows how little database host memory is needed when using DRCP connection pooling with Oracle Database 11g. Migrating to DRCP can be as simple as starting the pool and changing the connection string in your PHP application. The script that generated the data for this graph was a simple "Parts" query application being run under various simulated user loads. I was running the database on a small Oracle Linux server with just 2G of memory. I used PHP OCI8 1.4. Apache is in pre-fork mode, as needed for PHP. Each graph has time on the horizontal access in arbitrary 'tick' time units. Click the image to see it full sized. Pooled connections Beginning with the top left graph, At tick time 65 I used Apache's 'ab' tool to start 100 concurrent 'users' running the application. These users connected to the database using DRCP: $c = oci_pconnect('phpdemo', 'welcome', 'myhost/orcl:pooled'); A second hundred DRCP users were added to the system at tick 80 and a final hundred users added at tick 100. At about tick 110 I stopped the test and restarted Apache. This closed all the connections. The bottom left graph shows the number of statements being executed by the database per second, with some spikes for background database activity and some variability for this small test. Each extra batch of users adds another 'step' of load to the system. Looking at the top right Server Process graph shows the database server processes doing the query work for each web user. As user load is added, the DRCP server pool increases (in green). The pool is initially at its default size 4 and quickly ramps up to about (I'm guessing) 35. At tick time 100 the pool increases to my configured maximum of 40 processes. Those 40 processes are doing the query work for all 300 web users. When I stopped the test at tick 110, the pooled processes remained open waiting for more users to connect. If I had left the test quiet for the DRCP 'inactivity_timeout' period (300 seconds by default), the pool would have shrunk back to 4 processes. Looking at the bottom right, you can see the amount of memory being consumed by the database. During the initial quiet period about 500M of memory was in use. The absolute number is just an indication of my particular DB configuration. As the number of pooled processes increases, each process needs more memory. You can see the shape of the memory graph echoes the Server Process graph above it. Each of the 300 web users will also need a few kilobytes but this is almost too small to see on the graph. Non-pooled connections Compare the DRCP case with using 'dedicated server' processes. At tick 140 I started 100 web users who did not use pooled connections: $c = oci_pconnect('phpdemo', 'welcome', 'myhost/orcl'); This connection string change is the only difference between the two tests. At ticks 155 and 165 I started two more batches of 100 simulated users each. At about tick 195 I stopped the user load but left Apache running. Apache then gradually returned to its quiescent state, killing idle httpd processes and producing the downward slope at the right of the graphs as the persistent database connection in each Apache process was closed. The Executions per Second graph on the bottom left shows the same step increases as for the earlier DRCP case. The database is handling this load. But look at the number of Server processes on the top right graph. There is now a one-to-one correspondence between Apache/PHP processes and DB server processes. Each PHP processes has one DB server processes dedicated to it. Hence the term 'dedicated server'. The memory required on the database is proportional to all those database server processes started. Almost all my system's memory was consumed. I doubt it would have coped with any more user load. Summary Oracle Database 11g DRCP connection pooling significantly reduces database host memory requirements allow more system memory to be allocated for the SGA and allowing the system to scale to handled thousands of concurrent PHP users. Even for small systems, using DRCP allows more web users to be active. More information about PHP and DRCP can be found in the PHP Scalability and High Availability chapter of The Underground PHP and Oracle Manual.

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Partition Wise Joins

- by jean-pierre.dijcks

Some say they are the holy grail of parallel computing and PWJ is the basis for a shared nothing system and the only join method that is available on a shared nothing system (yes this is oversimplified!). The magic in Oracle is of course that is one of many ways to join data. And yes, this is the old flexibility vs. simplicity discussion all over, so I won't go there... the point is that what you must do in a shared nothing system, you can do in Oracle with the same speed and methods. The Theory A partition wise join is a join between (for simplicity) two tables that are partitioned on the same column with the same partitioning scheme. In shared nothing this is effectively hard partitioning locating data on a specific node / storage combo. In Oracle is is logical partitioning. If you now join the two tables on that partitioned column you can break up the join in smaller joins exactly along the partitions in the data. Since they are partitioned (grouped) into the same buckets, all values required to do the join live in the equivalent bucket on either sides. No need to talk to anyone else, no need to redistribute data to anyone else... in short, the optimal join method for parallel processing of two large data sets. PWJ's in Oracle Since we do not hard partition the data across nodes in Oracle we use the Partitioning option to the database to create the buckets, then set the Degree of Parallelism (or run Auto DOP - see here) and get our PWJs. The main questions always asked are: How many partitions should I create? What should my DOP be? In a shared nothing system the answer is of course, as many partitions as there are nodes which will be your DOP. In Oracle we do want you to look at the workload and concurrency, and once you know that to understand the following rules of thumb. Within Oracle we have more ways of joining of data, so it is important to understand some of the PWJ ideas and what it means if you have an uneven distribution across processes. Assume we have a simple scenario where we partition the data on a hash key resulting in 4 hash partitions (H1 -H4). We have 2 parallel processes that have been tasked with reading these partitions (P1 - P2). The work is evenly divided assuming the partitions are the same size and we can scan this in time t1 as shown below. Now assume that we have changed the system and have a 5th partition but still have our 2 workers P1 and P2. The time it takes is actually 50% more assuming the 5th partition has the same size as the original H1 - H4 partitions. In other words to scan these 5 partitions, the time t2 it takes is not 1/5th more expensive, it is a lot more expensive and some other join plans may now start to look exciting to the optimizer. Just to post the disclaimer, it is not as simple as I state it here, but you get the idea on how much more expensive this plan may now look... Based on this little example there are a few rules of thumb to follow to get the partition wise joins. First, choose a DOP that is a factor of two (2). So always choose something like 2, 4, 8, 16, 32 and so on... Second, choose a number of partitions that is larger or equal to 2* DOP. Third, make sure the number of partitions is divisible through 2 without orphans. This is also known as an even number... Fourth, choose a stable partition count strategy, which is typically hash, which can be a sub partitioning strategy rather than the main strategy (range - hash is a popular one). Fifth, make sure you do this on the join key between the two large tables you want to join (and this should be the obvious one...). Translating this into an example: DOP = 8 (determined based on concurrency or by using Auto DOP with a cap due to concurrency) says that the number of partitions >= 16. Number of hash (sub) partitions = 32, which gives each process four partitions to work on. This number is somewhat arbitrary and depends on your data and system. In this case my main reasoning is that if you get more room on the box you can easily move the DOP for the query to 16 without repartitioning... and of course it makes for no leftovers on the table... And yes, we recommend up-to-date statistics. And before you start complaining, do read this post on a cool way to do stats in 11.

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Review of ComponentOne Silverlight Controls (Free License Giveaway).

- by mbcrump

ComponentOne has several great products that target Silverlight Developers. One of them is their Silverlight Controls and the other is the XAP Optimizer. I decided that I would check out the controls and Xap Optimizer and feature them on my blog. After talking with ComponentOne, they agreed to take part in my Monthly Silverlight giveaway. The details are listed below: ----------------------------------------------------------------------------------------------------------------------------------------------------------- Win a FREE developer’s license of ComponentOne Silverlight Controls + XAP Optimizer! (the winner also gets a license to Silverlight Spy) Random winner will be announced on March 1st, 2011! To be entered into the contest do the following things: Subscribe to my feed. Leave a comment below with a valid email account (I WILL NOT share this info with anyone.) Retweet the following : I just entered to win free #Silverlight controls from @mbcrump and @ComponentOne http://mcrump.me/fTSmB8 ! Don’t change the URL because this will allow me to track the users that Tweet this page. Don’t forget to visit ComponentOne because they made this possible. MichaelCrump.Net provides Silverlight Giveaways every month. You can also see the latest giveaway by bookmarking http://giveaways.michaelcrump.net . ---------------------------------------------------------------------------------------------------------------------------------------------------------- Before we get started with the Silverlight Controls, here is a couple of links to bookmark: The Live Demos of the Silverlight Controls is located here. The XAP Optimizer page is here. One thing that I liked about the help documentation is that you can grab a PDF that only contains documentation for that control. This allows you to get the information you need without going through several hundred pages. You can also download the full documentation from their site. ComponentOne Silverlight Controls I recently built a hobby project and decided to use ComponentOne Silverlight Controls. The main reason for this is that the controls are heavily documented, they look great and getting help was just a tweet or forum click away. So, the first question that you may ask is, “What is included?” Here is the official list below. I wanted to show several of the controls that I think developers will use the most. 1) ComponentOne’s Image Control – Display animated GIF images on your Silverlight pages as you would in traditional Web apps. Add attractive visuals with minimal effort. 2) HTML Host - Render HTML and arbitrary URI content from within Silverlight. 3) Chart3D - Create 3D surface charts with options for contour levels, zones, a chart legend and more. 4) PDFViewer - View PDF files in Silverlight! That is just a fraction of the controls available. If you want to check out several of them in a “real” application then check out my Silverlight page at http://michaelcrump.info. This brings me to the second part of the giveaway. XAP Optimizer – Is designed to reduce the size of your XAP File. It also includes built-in obfuscation and signing. With my personal project, I decided to use the XAP Optimizer by ComponentOne. It was so easy to use. You basically give it your .XAP file and it provides an output file. If you prefer to prune unused references manually then you can prune your XAP file manually by selecting the option below. I went ahead and added Obfuscation just to try it out and it worked great. You may notice from the screenshot below that I only obfuscated assemblies that I built. The other dlls anyone can grab off the net so we have no reason to obfuscate them. You also have the option to automatically sign your .xap with the SN.exe tool. So how did it turn out? Well, I reduced my XAP size from 2.4 to 1.8 with simply a click of a button. I added obfuscation with a click of a button: Screenshot of no obfuscation on my XAP File Screenshot of obfuscation on my XAP File with XAP Optimizer. So, with 2 button clicks, I reduce my XAP file and obfuscated my assembly. What else can you want? Well, they provide a nice HTML report that gives you an optimization summary. So what if you don’t want to launch this tool every time you deploy a Silverlight application? Well the official documentation provided a way to do it in your built event in Visual Studio. Click the Build Events tab on the left side of the Properties window. Enter the following command in the Post-build event command line: $Program Files\ComponentOne\XapOptimizer\XapOptimizer.exe /cmd /p:$(ProjectDir)$(ProjectName).xoproj In the end, this is a great product. I love code that I don’t have to write and utilities that just work. ComponentOne delivers with both the Silverlight Controls and the XAP Optimizer. Don’t forget to leave a comment below in order to win a set of the controls! Subscribe to my feed

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A C# implementation of the CallStream pattern

- by Bertrand Le Roy

Dusan published this interesting post a couple of weeks ago about a novel JavaScript chaining pattern: http://dbj.org/dbj/?p=514 It’s similar to many existing patterns, but the syntax is extraordinarily terse and it provides a new form of friction-free, plugin-less extensibility mechanism. Here’s a JavaScript example from Dusan’s post: CallStream("#container") (find, "div") (attr, "A", 1) (css, "color", "#fff") (logger); The interesting thing here is that the functions that are being passed as the first argument are arbitrary, they don’t need to be declared as plug-ins. Compare that with a rough jQuery equivalent that could look something like this: $.fn.logger = function () { /* ... */ } $("selector") .find("div") .attr("A", 1) .css("color", "#fff") .logger(); There is also the “each” method in jQuery that achieves something similar, but its syntax is a little more verbose. Of course, that this pattern can be expressed so easily in JavaScript owes everything to the extraordinary way functions are treated in that language, something Douglas Crockford called “the very best part of JavaScript”. One of the first things I thought while reading Dusan’s post was how I could adapt that to C#. After all, with Lambdas and delegates, C# also has its first-class functions. And sure enough, it works really really well. After about ten minutes, I was able to write this: CallStreamFactory.CallStream (p => Console.WriteLine("Yay!")) (Dump, DateTime.Now) (DumpFooAndBar, new { Foo = 42, Bar = "the answer" }) (p => Console.ReadKey()); Where the Dump function is: public static void Dump(object options) { Console.WriteLine(options.ToString()); } And DumpFooAndBar is: public static void DumpFooAndBar(dynamic options) { Console.WriteLine("Foo is {0} and bar is {1}.", options.Foo, options.Bar); } So how does this work? Well, it really is very simple. And not. Let’s say it’s not a lot of code, but if you’re like me you might need an Advil after that. First, I defined the signature of the CallStream method as follows: public delegate CallStream CallStream (Action<object> action, object options = null); The delegate define a call stream as something that takes an action (a function of the options) and an optional options object and that returns a delegate of its own type. Tricky, but that actually works, a delegate can return its own type. Then I wrote an implementation of that delegate that calls the action and returns itself: public static CallStream CallStream (Action<object> action, object options = null) { action(options); return CallStream; } Pretty nice, eh? Well, yes and no. What we are doing here is to execute a sequence of actions using an interesting novel syntax. But for this to be actually useful, you’d need to build a more specialized call stream factory that comes with some sort of context (like Dusan did in JavaScript). For example, you could write the following alternate delegate signature that takes a string and returns itself: public delegate StringCallStream StringCallStream(string message); And then write the following call stream (notice the currying): public static StringCallStream CreateDumpCallStream(string dumpPath) { StringCallStream str = null; var dump = File.AppendText(dumpPath); dump.AutoFlush = true; str = s => { dump.WriteLine(s); return str; }; return str; } (I know, I’m not closing that stream; sure; bad, bad Bertrand) Finally, here’s how you use it: CallStreamFactory.CreateDumpCallStream(@".\dump.txt") ("Wow, this really works.") (DateTime.Now.ToLongTimeString()) ("And that is all."); Next step would be to combine this contextual implementation with the one that takes an action parameter and do some really fun stuff. I’m only scratching the surface here. This pattern could reveal itself to be nothing more than a gratuitous mind-bender or there could be applications that we hardly suspect at this point. In any case, it’s a fun new construct. Or is this nothing new? You tell me… Comments are open :)

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Cant get lm-sensors to load ATI Radeon temp or fan

- by woody

New to Linux and having minor issues :/ . I followed this guide initially but did not recieve the proper output and did not show my ATI Radeon HD 5000 temp or fan speed. Then used this guide, same problems exhibited. No issues installing and no errors. I think its not reading i2c for some reason. The proprietary driver is installed and functioning correctly according fglrxinfo. I can use aticonfig commands and view both temp and fan. Any ideas on how to get it working under 'sensors'? When i run 'sudo sensors-detect' this is my ouput # sensors-detect revision 5984 (2011-07-10 21:22:53 +0200) # System: LENOVO IdeaPad Y560 (laptop) # Board: Lenovo KL3 This program will help you determine which kernel modules you need to load to use lm_sensors most effectively. It is generally safe and recommended to accept the default answers to all questions, unless you know what you're doing. Some south bridges, CPUs or memory controllers contain embedded sensors. Do you want to scan for them? This is totally safe. (YES/no): y Silicon Integrated Systems SIS5595... No VIA VT82C686 Integrated Sensors... No VIA VT8231 Integrated Sensors... No AMD K8 thermal sensors... No AMD Family 10h thermal sensors... No AMD Family 11h thermal sensors... No AMD Family 12h and 14h thermal sensors... No AMD Family 15h thermal sensors... No AMD Family 15h power sensors... No Intel digital thermal sensor... Success! (driver `coretemp') Intel AMB FB-DIMM thermal sensor... No VIA C7 thermal sensor... No VIA Nano thermal sensor... No Some Super I/O chips contain embedded sensors. We have to write to standard I/O ports to probe them. This is usually safe. Do you want to scan for Super I/O sensors? (YES/no): y Probing for Super-I/O at 0x2e/0x2f Trying family `National Semiconductor/ITE'... Yes Found unknown chip with ID 0x8502 Probing for Super-I/O at 0x4e/0x4f Trying family `National Semiconductor/ITE'... No Trying family `SMSC'... No Trying family `VIA/Winbond/Nuvoton/Fintek'... No Trying family `ITE'... No Some hardware monitoring chips are accessible through the ISA I/O ports. We have to write to arbitrary I/O ports to probe them. This is usually safe though. Yes, you do have ISA I/O ports even if you do not have any ISA slots! Do you want to scan the ISA I/O ports? (YES/no): y Probing for `National Semiconductor LM78' at 0x290... No Probing for `National Semiconductor LM79' at 0x290... No Probing for `Winbond W83781D' at 0x290... No Probing for `Winbond W83782D' at 0x290... No Lastly, we can probe the I2C/SMBus adapters for connected hardware monitoring devices. This is the most risky part, and while it works reasonably well on most systems, it has been reported to cause trouble on some systems. Do you want to probe the I2C/SMBus adapters now? (YES/no): y Using driver `i2c-i801' for device 0000:00:1f.3: Intel 3400/5 Series (PCH) Now follows a summary of the probes I have just done. Just press ENTER to continue: Driver `coretemp': * Chip `Intel digital thermal sensor' (confidence: 9) To load everything that is needed, add this to /etc/modules: #----cut here---- # Chip drivers coretemp #----cut here---- If you have some drivers built into your kernel, the list above will contain too many modules. Skip the appropriate ones! Do you want to add these lines automatically to /etc/modules? (yes/NO) My output for 'sensors' is: acpitz-virtual-0 Adapter: Virtual device temp1: +58.0°C (crit = +100.0°C) coretemp-isa-0000 Adapter: ISA adapter Core 0: +56.0°C (high = +84.0°C, crit = +100.0°C) Core 1: +57.0°C (high = +84.0°C, crit = +100.0°C) Core 2: +58.0°C (high = +84.0°C, crit = +100.0°C) Core 3: +57.0°C (high = +84.0°C, crit = +100.0°C) and my '/etc/modules' is: # /etc/modules: kernel modules to load at boot time. # # This file contains the names of kernel modules that should be loaded # at boot time, one per line. Lines beginning with "#" are ignored. lp rtc # Generated by sensors-detect on Fri Nov 30 23:24:31 2012 # Chip drivers coretemp

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IBM "per core" comparisons for SPECjEnterprise2010

- by jhenning

I recently stumbled upon a blog entry from Roman Kharkovski (an IBM employee) comparing some SPECjEnterprise2010 results for IBM vs. Oracle. Mr. Kharkovski's blog claims that SPARC delivers half the transactions per core vs. POWER7. Prior to any argument, I should say that my predisposition is to like Mr. Kharkovski, because he says that his blog is intended to be factual; that the intent is to try to avoid marketing hype and FUD tactic; and mostly because he features a picture of himself wearing a bike helmet (me too). Therefore, in a spirit of technical argument, rather than FUD fight, there are a few areas in his comparison that should be discussed. Scaling is not free For any benchmark, if a small system scores 13k using quantity R1 of some resource, and a big system scores 57k using quantity R2 of that resource, then, sure, it's tempting to divide: is 13k/R1 > 57k/R2 ? It is tempting, but not necessarily educational. The problem is that scaling is not free. Building big systems is harder than building small systems. Scoring 13k/R1 on a little system provides no guarantee whatsoever that one can sustain that ratio when attempting to handle more than 4 times as many users. Choosing the denominator radically changes the picture When ratios are used, one can vastly manipulate appearances by the choice of denominator. In this case, lots of choices are available for the resource to be compared (R1 and R2 above). IBM chooses to put cores in the denominator. Mr. Kharkovski provides some reasons for that choice in his blog entry. And yet, it should be noted that the very concept of a core is: arbitrary: not necessarily comparable across vendors; fluid: modern chips shift chip resources in response to load; and invisible: unless you have a microscope, you can't see it. By contrast, one can actually see processor chips with the naked eye, and they are a bit easier to count. If we put chips in the denominator instead of cores, we get: 13161.07 EjOPS / 4 chips = 3290 EjOPS per chip for IBM vs 57422.17 EjOPS / 16 chips = 3588 EjOPS per chip for Oracle The choice of denominator makes all the difference in the appearance. Speaking for myself, dividing by chips just seems to make more sense, because: I can see chips and count them; and I can accurately compare the number of chips in my system to the count in some other vendor's system; and Tthe probability of being able to continue to accurately count them over the next 10 years of microprocessor development seems higher than the probability of being able to accurately and comparably count "cores". SPEC Fair use requirements Speaking as an individual, not speaking for SPEC and not speaking for my employer, I wonder whether Mr. Kharkovski's blog article, taken as a whole, meets the requirements of the SPEC Fair Use rule www.spec.org/fairuse.html section I.D.2. For example, Mr. Kharkovski's footnote (1) begins Results from http://www.spec.org as of 04/04/2013 Oracle SUN SPARC T5-8 449 EjOPS/core SPECjEnterprise2010 (Oracle's WLS best SPECjEnterprise2010 EjOPS/core result on SPARC). IBM Power730 823 EjOPS/core (World Record SPECjEnterprise2010 EJOPS/core result) The questionable tactic, from a Fair Use point of view, is that there is no such metric at the designated location. At www.spec.org, You can find the SPEC metric 57422.17 SPECjEnterprise2010 EjOPS for Oracle and You can also find the SPEC metric 13161.07 SPECjEnterprise2010 EjOPS for IBM. Despite the implication of the footnote, you will not find any mention of 449 nor anything that says 823. SPEC says that you can, under its fair use rule, derive your own values; but it emphasizes: "The context must not give the appearance that SPEC has created or endorsed the derived value." Substantiation and transparency Although SPEC disclaims responsibility for non-SPEC information (section I.E), it says that non-SPEC data and methods should be accurate, should be explained, should be substantiated. Unfortunately, it is difficult or impossible for the reader to independently verify the pricing: Were like units compared to like (e.g. list price to list price)? Were all components (hw, sw, support) included? Were all fees included? Note that when tpc.org shows IBM pricing, there are often items such as "PROCESSOR ACTIVATION" and "MEMORY ACTIVATION". Without the transparency of a detailed breakdown, the pricing claims are questionable. T5 claim for "Fastest Processor" Mr. Kharkovski several times questions Oracle's claim for fastest processor, writing You see, when you publish industry benchmarks, people may actually compare your results to other vendor's results. Well, as we performance people always say, "it depends". If you believe in performance-per-core as the primary way of looking at the world, then yes, the POWER7+ is impressive, spending its chip resources to support up to 32 threads (8 cores x 4 threads). Or, it just might be useful to consider performance-per-chip. Each SPARC T5 chip allows 128 hardware threads to be simultaneously executing (16 cores x 8 threads). The Industry Standard Benchmark that focuses specifically on processor chip performance is SPEC CPU2006. For this very well known and popular benchmark, SPARC T5: provides better performance than both POWER7 and POWER7+, for 1 chip vs. 1 chip, for 8 chip vs. 8 chip, for integer (SPECint_rate2006) and floating point (SPECfp_rate2006), for Peak tuning and for Base tuning. For example, at the 8-chip level, integer throughput (SPECint_rate2006) is: 3750 for SPARC 2170 for POWER7+. You can find the details at the March 2013 BestPerf CPU2006 page SPEC is a trademark of the Standard Performance Evaluation Corporation, www.spec.org. The two specific results quoted for SPECjEnterprise2010 are posted at the URLs linked from the discussion. Results for SPEC CPU2006 were verified at spec.org 1 July 2013, and can be rechecked here.

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Cant get lm-sensors to load ATI Radeon temp and fan or output all settings

- by woody

New to Linux and having minor issues :/ . I followed this guide initially but did not recieve the proper output and did not show my ATI Radeon HD 5000 temp or fan speed. Then used this guide, same problems exhibited. No issues installing and no errors. I think its not reading i2c for some reason. The proprietary driver is installed and functioning correctly according fglrxinfo. I can use aticonfig commands and view both temp and fan. Any ideas on how to get the ATI Radeon sensors working under 'sensors'? When i run 'sudo sensors-detect' this is my ouput # sensors-detect revision 5984 (2011-07-10 21:22:53 +0200) # System: LENOVO IdeaPad Y560 (laptop) # Board: Lenovo KL3 This program will help you determine which kernel modules you need to load to use lm_sensors most effectively. It is generally safe and recommended to accept the default answers to all questions, unless you know what you're doing. Some south bridges, CPUs or memory controllers contain embedded sensors. Do you want to scan for them? This is totally safe. (YES/no): y Silicon Integrated Systems SIS5595... No VIA VT82C686 Integrated Sensors... No VIA VT8231 Integrated Sensors... No AMD K8 thermal sensors... No AMD Family 10h thermal sensors... No AMD Family 11h thermal sensors... No AMD Family 12h and 14h thermal sensors... No AMD Family 15h thermal sensors... No AMD Family 15h power sensors... No Intel digital thermal sensor... Success! (driver `coretemp') Intel AMB FB-DIMM thermal sensor... No VIA C7 thermal sensor... No VIA Nano thermal sensor... No Some Super I/O chips contain embedded sensors. We have to write to standard I/O ports to probe them. This is usually safe. Do you want to scan for Super I/O sensors? (YES/no): y Probing for Super-I/O at 0x2e/0x2f Trying family `National Semiconductor/ITE'... Yes Found unknown chip with ID 0x8502 Probing for Super-I/O at 0x4e/0x4f Trying family `National Semiconductor/ITE'... No Trying family `SMSC'... No Trying family `VIA/Winbond/Nuvoton/Fintek'... No Trying family `ITE'... No Some hardware monitoring chips are accessible through the ISA I/O ports. We have to write to arbitrary I/O ports to probe them. This is usually safe though. Yes, you do have ISA I/O ports even if you do not have any ISA slots! Do you want to scan the ISA I/O ports? (YES/no): y Probing for `National Semiconductor LM78' at 0x290... No Probing for `National Semiconductor LM79' at 0x290... No Probing for `Winbond W83781D' at 0x290... No Probing for `Winbond W83782D' at 0x290... No Lastly, we can probe the I2C/SMBus adapters for connected hardware monitoring devices. This is the most risky part, and while it works reasonably well on most systems, it has been reported to cause trouble on some systems. Do you want to probe the I2C/SMBus adapters now? (YES/no): y Using driver `i2c-i801' for device 0000:00:1f.3: Intel 3400/5 Series (PCH) Now follows a summary of the probes I have just done. Just press ENTER to continue: Driver `coretemp': * Chip `Intel digital thermal sensor' (confidence: 9) To load everything that is needed, add this to /etc/modules: #----cut here---- # Chip drivers coretemp #----cut here---- If you have some drivers built into your kernel, the list above will contain too many modules. Skip the appropriate ones! Do you want to add these lines automatically to /etc/modules? (yes/NO) My output for 'sensors' is: acpitz-virtual-0 Adapter: Virtual device temp1: +58.0°C (crit = +100.0°C) coretemp-isa-0000 Adapter: ISA adapter Core 0: +56.0°C (high = +84.0°C, crit = +100.0°C) Core 1: +57.0°C (high = +84.0°C, crit = +100.0°C) Core 2: +58.0°C (high = +84.0°C, crit = +100.0°C) Core 3: +57.0°C (high = +84.0°C, crit = +100.0°C) and my '/etc/modules' is: # /etc/modules: kernel modules to load at boot time. # # This file contains the names of kernel modules that should be loaded # at boot time, one per line. Lines beginning with "#" are ignored. lp rtc # Generated by sensors-detect on Fri Nov 30 23:24:31 2012 # Chip drivers coretemp

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Writing an ASP.Net Web based TFS Client

- by Glav

So one of the things I needed to do was write an ASP.Net MVC based application for our senior execs to manage a set of arbitrary attributes against stories, bugs etc to be able to attribute whether the item was related to Research and Development, and if so, what kind. We are using TFS Azure and don’t have the option of custom templates. I have decided on using a string based field within the template that is not very visible and which we don’t use to write a small set of custom which will determine the research and development association. However, this string munging on the field is not very user friendly so we need a simple tool that can display attributes against items in a simple dropdown list or something similar. Enter a custom web app that accesses our TFS items in Azure (Note: We are also using Visual Studio 2012) Now TFS Azure uses your Live ID and it is not really possible to easily do this in a server based app where no interaction is available. Even if you capture the Live ID credentials yourself and try to submit them to TFS Azure, it wont work. Bottom line is that it is not straightforward nor obvious what you have to do. In fact, it is a real pain to find and there are some answers out there which don’t appear to be answers at all given they didn’t work in my scenario. So for anyone else who wants to do this, here is a simple breakdown on what you have to do: Go here and get the “TFS Service Credential Viewer”. Install it, run it and connect to your TFS instance in azure and create a service account. Note the username and password exactly as it presents it to you. This is the magic identity that will allow unattended, programmatic access. Without this step, don’t bother trying to do anything else. In your MVC app, reference the following assemblies from “C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE\ReferenceAssemblies\v2.0”: Microsoft.TeamFoundation.Client.dll Microsoft.TeamFoundation.Common.dll Microsoft.TeamFoundation.VersionControl.Client.dll Microsoft.TeamFoundation.VersionControl.Common.dll Microsoft.TeamFoundation.WorkItemTracking.Client.DataStoreLoader.dll Microsoft.TeamFoundation.WorkItemTracking.Client.dll Microsoft.TeamFoundation.WorkItemTracking.Common.dll If hosting this in Internet Information Server, for the application pool this app runs under, you will need to enable 32 Bit support. You also have to allow the TFS client assemblies to store a cache of files on your system. If you don’t do this, you will authenticate fine, but then get an exception saying that it is unable to access the cache at some directory path when you query work items. You can set this up by adding the following to your web.config, in the <appSettings> element as shown below: <appSettings>  <add key="WorkItemTrackingCacheRoot" value="C:\windows\temp" /> </appSettings> With all that in place, you can write the following code: var token = new Microsoft.TeamFoundation.Client.SimpleWebTokenCredential("{you-service-account-name", "{your-service-acct-password}"); var clientCreds = new Microsoft.TeamFoundation.Client.TfsClientCredentials(token); var currentCollection = new TfsTeamProjectCollection(new Uri(“https://{yourdomain}.visualstudio.com/defaultcollection”), clientCreds); TfsConfigurationServercurrentCollection.EnsureAuthenticated(); In the above code, not the URL contains the “defaultcollection” at the end of the URL. Obviously replace {yourdomain} with whatever is defined for your TFS in Azure instance. In addition, make sure the service user account and password that was generated in the first step is substituted in here. Note: If something is not right, the “EnsureAuthenticated()” call will throw an exception with the message being you are not authorised. If you forget the “defaultcollection” on the URL, it will still fail but with a message saying you are not authorised. That is, a similar but different exception message. And that is it. You can then query the collection using something like: var service = currentCollection.GetService<WorkItemStore>(); var proj = service.Projects[0]; var allQueries = proj.StoredQueries; for (int qcnt = 0; qcnt < allQueries.Count; qcnt++) { var query = allQueries[qcnt]; var queryDesc = string.format(“Query found named: {0}”,query.Name); } You get the idea. If you search around, you will find references to the ServiceIdentityCredentialProvider which is referenced in this article. I had no luck with this method and it all looked too hard since it required an extra KB article and other magic sauce. So I hope that helps. This article certainly would have helped me save a boat load of time and frustration.

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