Search Results

Search found 14861 results on 595 pages for 'high speed computing'.

Page 515/595 | < Previous Page | 511 512 513 514 515 516 517 518 519 520 521 522  | Next Page >

• Windows Phone 8 Announcement

  - by Tim Murphy

  As if the Surface announcement on Monday wasn’t exciting enough, today Microsoft announce that Windows Phone 8 will be coming this fall.  That itself is great news, but the features coming were like confetti flying in all different directions.  Given this speed I couldn’t capture every feature they covered.  A summary of what I did capture is listed below starting with their eight main features. Common Core The first thing that they covered is that Windows Phone 8 will share a core OS with Windows 8.  It will also run natively on multiple cores.  They mentioned that they have run it on up to 64 cores to this point.  The phones as you might expect will at least start as dual core.  If you remember there were metrics saying that Windows Phone 7 performed operations faster on a single core than other platforms did with dual cores.  The metrics they showed here indicate that Windows Phone 8 runs faster on comparable dual core hardware than other platforms. New Screen Resolutions Screen resolution has never been an issue for me, but it has been a criticism of Windows Phone 7 in the media.  Windows Phone 8 will supports three screen resolutions: WVGA 800 x 480, WXGA 1280 x 768, and 720 1280x720.  Hopefully this makes pixel counters a little happier. MicroSD Support This was one of my pet peeves when I got my Samsung Focus. With Windows Phone 8 the operating system will support adding MicroSD cards after initial setup.  Of course this is dependent on the hardware company on implementing it, but I think we have seen that even feature phone manufacturers have not had a problem supporting this in the past. NFC NFC has been an anticipated feature for some time.  What Microsoft showed today included the fact that they didn’t just want it to be for the phone.  There is cross platform NFC functionality between Windows Phone 8 and Windows 8.  The demos , while possibly a bit fanciful, showed would could be achieved even in a retail environment.  We are getting closer and closer to a Minority Report world with these technologies. Wallet Windows Phone 8 isn’t the first platform to have a wallet concept.  What they have done to differentiate themselves is to make it sot that it is not dependent on a SIM type chip like other platforms.  They have also expanded the concept beyond just banks to other types of credits such as airline miles. Nokia Mapping People have been envious of the Lumia phones having the Nokia mapping software.  Now all Windows Phone 8 devices will use NavTeq data and will have the capability to run in an offline fashion.  This is a major step forward from the Bing “touch for the next turn” maps. IT Administration The lack of features for enterprise administration and deployment was a complaint even before the Windows Phone 7 was released.  With the Windows Phone 8 release such features as Bitlocker and Secure boot will be baked into the OS. We will also have the ability to privately sign and distribute applications. Changing Start Screen Joe Belfiore made a big deal about this aspect of the new release.  Users will have more color themes available to them and the live tiles will be highly customizable. You will have the ability to resize and organize the tiles in a more dynamic way.  This allows for less important tiles or ones with less information to be made smaller.  And There Is More So what other tidbits came out of the presentation?  Later this summer the API for WP8 will be available.  There will be developer events coming to a city near you.  Another announcement of interest to developers is the ability to write applications at a native code level.  This is a boon for game developers and those who need highly efficient applications. As a topper on the cake there was mention of in app payment. On the consumer side we also found out that all updates will be available over the air.  Along with this came the fact that Microsoft will support all devices with updates for at least 18 month and you will be able to subscribe for early updates.  Update coming for Windows Phone 7.5 customers to WP7.8.  The main enhancement will be the new live tile features.  The big bonus is that the update will bypass the carriers.  I would assume though that you will be brought up to date with all previous patches that your carrier may not have released. There is so much more, but that is enough for one post.  Needless to say, EXCITING! del.icio.us Tags: Windows Phone 8,WP8,Windows Phone 7,WP7,Announcements,Microsoft

  Read the article

• Proxied calls not working as expected

  - by AndyH

  I have been modifying an application to have a cleaner client/server split to allow for load splitting and resource sharing etc. Everything is written to an interface so it was easy to add a remoting layer to the interface using a proxy. Everything worked fine. The next phase was to add a caching layer to the interface and again this worked fine and speed was improved but not as much as I would have expected. On inspection it became very clear what was going on. I feel sure that this behavior has been seen many times before and there is probably a design pattern to solve the problem but it eludes me and I'm not even sure how to describe it. It is easiest explained with an example. Let's imagine the interface is interface IMyCode { List<IThing> getLots( List<String> ); IThing getOne( String id ); } The getLots() method calls getOne() and fills up the list before returning. The interface is implemented at the client which is proxied to a remoting client which then calls the remoting server which in turn calls the implementation at the server. At the client and the server layers there is also a cache. So we have :- Client interface | Client cache | Remote client | Remote server | Server cache | Server interface If we call getOne("A") at the client interface, the call is passed to the client cache which faults. This then calls the remote client which passes the call to the remote server. This then calls the server cache which also faults and so the call is eventually passed to the server interface which actually gets the IThing. In turn the server cache is filled and finally the client cache also. If getOne("A") is again called at the client interface the client cache has the data and it gets returned immediately. If a second client called getOne("B") it would fill the server cache with "B" as well as it's own client cache. Then, when the first client calls getOne("B") the client cache faults but the server cache has the data. This is all as one would expect and works well. Now lets call getLots( [ "C", "D" ] ). This works as you would expect by calling getOne() twice but there is a subtlety here. The call to getLots() cannot directly make use of the cache. Therefore the sequence is to call the client interface which in turn calls the remote client, then the remote server and eventually the server interface. This then calls getOne() to fill the list before returning. The problem is that the getOne() calls are being satisfied at the server when ideally they should be satisfied at the client. If you imagine that the client/server link is really slow then it becomes clear why the client call is more efficient than the server call once the client cache has the data. This example is contrived to illustrate the point. The more general problem is that you cannot just keep adding proxied layers to an interface and expect it to work as you would imagine. As soon as the call goes 'through' the proxy any subsequent calls are on the proxied side rather than 'self' side. Have I failed to learn or not learned something correctly? All this is implemented in Java and I haven't used EJBs. It seems that the example may be confusing. The problem is nothing to do with cache efficiencies. It is more to do with an illusion created by the use of proxies or AOP techniques in general. When you have an object whose class implements an interface there is an assumption that a call on that object might make further calls on that same object. For example, public String getInternalString() { return InetAddress.getLocalHost().toString(); } public String getString() { return getInternalString(); } If you get an object and call getString() the result depends where the code is running. If you add a remoting proxy to the class then the result could be different for calls to getString() and getInternalString() on the same object. This is because the initial call gets 'deproxied' before the actual method is called. I find this not only confusing but I wonder how I can control this behavior especially as the use of the proxy may be by a third party. The concept is fine but the practice is certainly not what I expected. Have I missed the point somewhere?

  Read the article

• Java Port Socket Programming Error

  - by atrus-darkstone

  Hi- I have been working on a java client-server program using port sockets. The goal of this program is for the client to take a screenshot of the machine it is running on, break the RGB info of this image down into integers and arrays, then send this info over to the server, where it is reconstructed into a new image file. However, when I run the program I am experiencing the following two bugs: The first number recieved by the server, no matter what its value is according to the client, is always 49. The client only sends(or the server only receives?) the first value, then the program hangs forever. Any ideas as to why this is happening, and what I can do to fix it? The code for both client and server is below. Thanks! CLIENT: import java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.image.BufferedImage; import java.io.*; import java.net.Socket; import java.text.SimpleDateFormat; import java.util.*; import javax.swing.*; import javax.swing.Timer; public class ViewerClient implements ActionListener{ private Socket vSocket; private BufferedReader in; private PrintWriter out; private Robot robot; // static BufferedReader orders = null; public ViewerClient() throws Exception{ vSocket = null; in = null; out = null; robot = null; } public void setVSocket(Socket vs) { vSocket = vs; } public void setInput(BufferedReader i) { in = i; } public void setOutput(PrintWriter o) { out = o; } public void setRobot(Robot r) { robot = r; } /*************************************************/ public Socket getVSocket() { return vSocket; } public BufferedReader getInput() { return in; } public PrintWriter getOutput() { return out; } public Robot getRobot() { return robot; } public void run() throws Exception{ int speed = 2500; int pause = 5000; Timer timer = new Timer(speed, this); timer.setInitialDelay(pause); // System.out.println("CLIENT: Set up timer."); try { setVSocket(new Socket("Alex-PC", 4444)); setInput(new BufferedReader(new InputStreamReader(getVSocket().getInputStream()))); setOutput(new PrintWriter(getVSocket().getOutputStream(), true)); setRobot(new Robot()); // System.out.println("CLIENT: Established connection and IO ports."); // timer.start(); captureScreen(nameImage()); }catch(Exception e) { System.err.println(e); } } public void captureScreen(String fileName) throws Exception{ Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); Rectangle screenRectangle = new Rectangle(screenSize); BufferedImage image = getRobot().createScreenCapture(screenRectangle); int width = image.getWidth(); int height = image.getHeight(); int[] pixelData = new int[(width * height)]; image.getRGB(0,0, width, height, pixelData, width, height); byte[] imageData = new byte[(width * height)]; String fromServer = null; if((fromServer = getInput().readLine()).equals("READY")) { sendWidth(width); sendHeight(height); sendArrayLength((width * height)); sendImageInfo(fileName); sendImageData(imageData); } /* System.out.println(imageData.length); String fromServer = null; for(int i = 0; i < pixelData.length; i++) { imageData[i] = ((byte)pixelData[i]); } System.out.println("CLIENT: Pixel data successfully converted to byte data."); System.out.println("CLIENT: Waiting for ready message..."); if((fromServer = getInput().readLine()).equals("READY")) { System.out.println("CLIENT: Ready message recieved."); getOutput().println("SENDING ARRAY LENGTH..."); System.out.println("CLIENT: Sending array length..."); System.out.println("CLIENT: " + imageData.length); getOutput().println(imageData.length); System.out.println("CLIENT: Array length sent."); getOutput().println("SENDING IMAGE..."); System.out.println("CLIENT: Sending image data..."); for(int i = 0; i < imageData.length; i++) { getOutput().println(imageData[i]); } System.out.println("CLIENT: Image data sent."); getOutput().println("SENDING IMAGE WIDTH..."); System.out.println("CLIENT: Sending image width..."); getOutput().println(width); System.out.println("CLIENT: Image width sent."); getOutput().println("SENDING IMAGE HEIGHT..."); System.out.println("CLIENT: Sending image height..."); getOutput().println(height); System.out.println("CLIENT: Image height sent..."); getOutput().println("SENDING IMAGE INFO..."); System.out.println("CLIENT: Sending image info..."); getOutput().println(fileName); System.out.println("CLIENT: Image info sent."); getOutput().println("FINISHED."); System.out.println("Image data sent successfully."); } if((fromServer = getInput().readLine()).equals("CLOSE DOWN")) { getOutput().close(); getInput().close(); getVSocket().close(); } */ } public String nameImage() throws Exception { String dateFormat = "yyyy-MM-dd HH-mm-ss"; Calendar cal = Calendar.getInstance(); SimpleDateFormat sdf = new SimpleDateFormat(dateFormat); String fileName = sdf.format(cal.getTime()); return fileName; } public void sendArrayLength(int length) throws Exception { getOutput().println("SENDING ARRAY LENGTH..."); getOutput().println(length); } public void sendWidth(int width) throws Exception { getOutput().println("SENDING IMAGE WIDTH..."); getOutput().println(width); } public void sendHeight(int height) throws Exception { getOutput().println("SENDING IMAGE HEIGHT..."); getOutput().println(height); } public void sendImageData(byte[] imageData) throws Exception { getOutput().println("SENDING IMAGE..."); for(int i = 0; i < imageData.length; i++) { getOutput().println(imageData[i]); } } public void sendImageInfo(String info) throws Exception { getOutput().println("SENDING IMAGE INFO..."); getOutput().println(info); } public void actionPerformed(ActionEvent a){ String message = null; try { if((message = getInput().readLine()).equals("PROCESSING...")) { if((message = getInput().readLine()).equals("IMAGE RECIEVED SUCCESSFULLY.")) { captureScreen(nameImage()); } } }catch(Exception e) { JOptionPane.showMessageDialog(null, "Problem: " + e); } } } SERVER: import java.awt.image.BufferedImage; import java.io.*; import java.net.*; import javax.imageio.ImageIO; /*IMPORTANT TODO: * 1. CLOSE ALL STREAMS AND SOCKETS WITHIN CLIENT AND SERVER! * 2. PLACE MAIN EXEC CODE IN A TIMED WHILE LOOP TO SEND FILE EVERY X SECONDS * */ public class ViewerServer { private ServerSocket vServer; private Socket vClient; private PrintWriter out; private BufferedReader in; private byte[] imageData; private int width; private int height; private String imageInfo; private int[] rgbData; private boolean active; public ViewerServer() throws Exception{ vServer = null; vClient = null; out = null; in = null; imageData = null; width = 0; height = 0; imageInfo = null; rgbData = null; active = true; } public void setVServer(ServerSocket vs) { vServer = vs; } public void setVClient(Socket vc) { vClient = vc; } public void setOutput(PrintWriter o) { out = o; } public void setInput(BufferedReader i) { in = i; } public void setImageData(byte[] imDat) { imageData = imDat; } public void setWidth(int w) { width = w; } public void setHeight(int h) { height = h; } public void setImageInfo(String im) { imageInfo = im; } public void setRGBData(int[] rd) { rgbData = rd; } public void setActive(boolean a) { active = a; } /***********************************************/ public ServerSocket getVServer() { return vServer; } public Socket getVClient() { return vClient; } public PrintWriter getOutput() { return out; } public BufferedReader getInput() { return in; } public byte[] getImageData() { return imageData; } public int getWidth() { return width; } public int getHeight() { return height; } public String getImageInfo() { return imageInfo; } public int[] getRGBData() { return rgbData; } public boolean getActive() { return active; } public void run() throws Exception{ connect(); setActive(true); while(getActive()) { recieve(); } close(); } public void recieve() throws Exception{ String clientStatus = null; int clientData = 0; // System.out.println("SERVER: Sending ready message..."); getOutput().println("READY"); // System.out.println("SERVER: Ready message sent."); if((clientStatus = getInput().readLine()).equals("SENDING IMAGE WIDTH...")) { setWidth(getInput().read()); System.out.println("Width: " + getWidth()); } if((clientStatus = getInput().readLine()).equals("SENDING IMAGE HEIGHT...")) { setHeight(getInput().read()); System.out.println("Height: " + getHeight()); } if((clientStatus = getInput().readLine()).equals("SENDING ARRAY LENGTH...")) { clientData = getInput().read(); setImageData(new byte[clientData]); System.out.println("Array length: " + clientData); } if((clientStatus = getInput().readLine()).equals("SENDING IMAGE INFO...")) { setImageInfo(getInput().readLine()); System.out.println("Image Info: " + getImageInfo()); } if((clientStatus = getInput().readLine()).equals("SENDING IMAGE...")) { for(int i = 0; i < getImageData().length; i++) { getImageData()[i] = ((byte)getInput().read()); } } if((clientStatus = getInput().readLine()).equals("FINISHED.")) { getOutput().println("PROCESSING..."); setRGBData(new int[getImageData().length]); for(int i = 0; i < getRGBData().length; i++) { getRGBData()[i] = getImageData()[i]; } BufferedImage image = null; image.setRGB(0, 0, getWidth(), getHeight(), getRGBData(), getWidth(), getHeight()); ImageIO.write(image, "png", new File(imageInfo + ".png")); //create an image file out of the screenshot getOutput().println("IMAGE RECIEVED SUCCESSFULLY."); } } public void connect() throws Exception { setVServer(new ServerSocket(4444)); //establish server connection // System.out.println("SERVER: Connection established."); setVClient(getVServer().accept()); //accept client connection request // System.out.println("SERVER: Accepted connection request."); setOutput(new PrintWriter(vClient.getOutputStream(), true)); //set up an output channel setInput(new BufferedReader(new InputStreamReader(vClient.getInputStream()))); //set up an input channel // System.out.println("SERVER: Created IO ports."); } public void close() throws Exception { getOutput().close(); getInput().close(); getVClient().close(); getVServer().close(); } }

  Read the article

• Increasing efficiency of N-Body gravity simulation

  - by Postman

  I'm making a space exploration type game, it will have many planets and other objects that will all have realistic gravity. I currently have a system in place that works, but if the number of planets goes above 70, the FPS decreases an practically exponential rates. I'm making it in C# and XNA. My guess is that I should be able to do gravity calculations between 100 objects without this kind of strain, so clearly my method is not as efficient as it should be. I have two files, Gravity.cs and EntityEngine.cs. Gravity manages JUST the gravity calculations, EntityEngine creates an instance of Gravity and runs it, along with other entity related methods. EntityEngine.cs public void Update() { foreach (KeyValuePair<string, Entity> e in Entities) { e.Value.Update(); } gravity.Update(); } (Only relevant piece of code from EntityEngine, self explanatory. When an instance of Gravity is made in entityEngine, it passes itself (this) into it, so that gravity can have access to entityEngine.Entities (a dictionary of all planet objects)) Gravity.cs namespace ExplorationEngine { public class Gravity { private EntityEngine entityEngine; private Vector2 Force; private Vector2 VecForce; private float distance; private float mult; public Gravity(EntityEngine e) { entityEngine = e; } public void Update() { //First loop foreach (KeyValuePair<string, Entity> e in entityEngine.Entities) { //Reset the force vector Force = new Vector2(); //Second loop foreach (KeyValuePair<string, Entity> e2 in entityEngine.Entities) { //Make sure the second value is not the current value from the first loop if (e2.Value != e.Value ) { //Find the distance between the two objects. Because Fg = G * ((M1 * M2) / r^2), using Vector2.Distance() and then squaring it //is pointless and inefficient because distance uses a sqrt, squaring the result simple cancels that sqrt. distance = Vector2.DistanceSquared(e2.Value.Position, e.Value.Position); //This makes sure that two planets do not attract eachother if they are touching, completely unnecessary when I add collision, //For now it just makes it so that the planets are not glitchy, performance is not significantly improved by removing this IF if (Math.Sqrt(distance) > (e.Value.Texture.Width / 2 + e2.Value.Texture.Width / 2)) { //Calculate the magnitude of Fg (I'm using my own gravitational constant (G) for the sake of time (I know it's 1 at the moment, but I've been changing it) mult = 1.0f * ((e.Value.Mass * e2.Value.Mass) / distance); //Calculate the direction of the force, simply subtracting the positions and normalizing works, this fixes diagonal vectors //from having a larger value, and basically makes VecForce a direction. VecForce = e2.Value.Position - e.Value.Position; VecForce.Normalize(); //Add the vector for each planet in the second loop to a force var. Force = Vector2.Add(Force, VecForce * mult); //I have tried Force += VecForce * mult, and have not noticed much of an increase in speed. } } } //Add that force to the first loop's planet's position (later on I'll instead add to acceleration, to account for inertia) e.Value.Position += Force; } } } } I have used various tips (about gravity optimizing, not threading) from THIS question (that I made yesterday). I've made this gravity method (Gravity.Update) as efficient as I know how to make it. This O(N^2) algorithm still seems to be eating up all of my CPU power though. Here is a LINK (google drive, go to File download, keep .Exe with the content folder, you will need XNA Framework 4.0 Redist. if you don't already have it) to the current version of my game. Left click makes a planet, right click removes the last planet. Mouse moves the camera, scroll wheel zooms in and out. Watch the FPS and Planet Count to see what I mean about performance issues past 70 planets. (ALL 70 planets must be moving, I've had 100 stationary planets and only 5 or so moving ones while still having 300 fps, the issue arises when 70+ are moving around) After 70 planets are made, performance tanks exponentially. With < 70 planets, I get 330 fps (I have it capped at 300). At 90 planets, the FPS is about 2, more than that and it sticks around at 0 FPS. Strangely enough, when all planets are stationary, the FPS climbs back up to around 300, but as soon as something moves, it goes right back down to what it was, I have no systems in place to make this happen, it just does. I considered multithreading, but that previous question I asked taught me a thing or two, and I see now that that's not a viable option. I've also thought maybe I could do the calculations on my GPU instead, though I don't think it should be necessary. I also do not know how to do this, it is not a simple concept and I want to avoid it unless someone knows a really noob friendly simple way to do it that will work for an n-body gravity calculation. (I have an NVidia gtx 660) Lastly I've considered using a quadtree type system. (Barnes Hut simulation) I've been told (in the previous question) that this is a good method that is commonly used, and it seems logical and straightforward, however the implementation is way over my head and I haven't found a good tutorial for C# yet that explains it in a way I can understand, or uses code I can eventually figure out. So my question is this: How can I make my gravity method more efficient, allowing me to use more than 100 objects (I can render 1000 planets with constant 300+ FPS without gravity calculations), and if I can't do much to improve performance (including some kind of quadtree system), could I use my GPU to do the calculations?

  Read the article

• Data Source Connection Pool Sizing

  - by Steve Felts

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} One of the most time-consuming procedures of a database application is establishing a connection. The connection pooling of the data source can be used to minimize this overhead.  That argues for using the data source instead of accessing the database driver directly. Configuring the size of the pool in the data source is somewhere between an art and science – this article will try to move it closer to science.  From the beginning, WLS data source has had an initial capacity and a maximum capacity configuration values.  When the system starts up and when it shrinks, initial capacity is used.  The pool can grow to maximum capacity.  Customers found that they might want to set the initial capacity to 0 (more on that later) but didn’t want the pool to shrink to 0.  In WLS 10.3.6, we added minimum capacity to specify the lower limit to which a pool will shrink.  If minimum capacity is not set, it defaults to the initial capacity for upward compatibility.   We also did some work on the shrinking in release 10.3.4 to reduce thrashing; the algorithm that used to shrink to the maximum of the currently used connections or the initial capacity (basically the unused connections were all released) was changed to shrink by half of the unused connections. The simple approach to sizing the pool is to set the initial/minimum capacity to the maximum capacity.  Doing this creates all connections at startup, avoiding creating connections on demand and the pool is stable.  However, there are a number of reasons not to take this simple approach. When WLS is booted, the deployment of the data source includes synchronously creating the connections.  The more connections that are configured in initial capacity, the longer the boot time for WLS (there have been several projects for parallel boot in WLS but none that are available).  Related to creating a lot of connections at boot time is the problem of logon storms (the database gets too much work at one time).   WLS has a solution for that by setting the login delay seconds on the pool but that also increases the boot time. There are a number of cases where it is desirable to set the initial capacity to 0.  By doing that, the overhead of creating connections is deferred out of the boot and the database doesn’t need to be available.  An application may not want WLS to automatically connect to the database until it is actually needed, such as for some code/warm failover configurations. There are a number of cases where minimum capacity should be less than maximum capacity.  Connections are generally expensive to keep around.  They cause state to be kept on both the client and the server, and the state on the backend may be heavy (for example, a process).  Depending on the vendor, connection usage may cost money.  If work load is not constant, then database connections can be freed up by shrinking the pool when connections are not in use.  When using Active GridLink, connections can be created as needed according to runtime load balancing (RLB) percentages instead of by connection load balancing (CLB) during data source deployment. Shrinking is an effective technique for clearing the pool when connections are not in use.  In addition to the obvious reason that there times where the workload is lighter,  there are some configurations where the database and/or firewall conspire to make long-unused or too-old connections no longer viable.  There are also some data source features where the connection has state and cannot be used again unless the state matches the request.  Examples of this are identity based pooling where the connection has a particular owner and XA affinity where the connection is associated with a particular RAC node.  At this point, WLS does not re-purpose (discard/replace) connections and shrinking is a way to get rid of the unused existing connection and get a new one with the correct state when needed. So far, the discussion has focused on the relationship of initial, minimum, and maximum capacity.  Computing the maximum size requires some knowledge about the application and the current number of simultaneously active users, web sessions, batch programs, or whatever access patterns are common.  The applications should be written to only reserve and close connections as needed but multiple statements, if needed, should be done in one reservation (don’t get/close more often than necessary).  This means that the size of the pool is likely to be significantly smaller then the number of users.   If possible, you can pick a size and see how it performs under simulated or real load.  There is a high-water mark statistic (ActiveConnectionsHighCount) that tracks the maximum connections concurrently used.  In general, you want the size to be big enough so that you never run out of connections but no bigger.   It will need to deal with spikes in usage, which is where shrinking after the spike is important.  Of course, the database capacity also has a big influence on the decision since it’s important not to overload the database machine.  Planning also needs to happen if you are running in a Multi-Data Source or Active GridLink configuration and expect that the remaining nodes will take over the connections when one of the nodes in the cluster goes down.  For XA affinity, additional headroom is also recommended.  In summary, setting initial and maximum capacity to be the same may be simple but there are many other factors that may be important in making the decision about sizing.

  Read the article

• Different fan behaviour in my laptop after upgrade, what to do now?

  - by student

  After upgrading from lubuntu 13.10 to 14.04 the fan of my laptop seems to run much more often than in 13.10. When it runs, it doesn't run continously but starts and stops every second. fwts fan results in Results generated by fwts: Version V14.03.01 (2014-03-27 02:14:17). Some of this work - Copyright (c) 1999 - 2014, Intel Corp. All rights reserved. Some of this work - Copyright (c) 2010 - 2014, Canonical. This test run on 12/05/14 at 21:40:13 on host Linux einstein 3.13.0-24-generic #47-Ubuntu SMP Fri May 2 23:30:00 UTC 2014 x86_64. Command: "fwts fan". Running tests: fan. fan: Simple fan tests. -------------------------------------------------------------------------------- Test 1 of 2: Test fan status. Test how many fans there are in the system. Check for the current status of the fan(s). PASSED: Test 1, Fan cooling_device0 of type Processor has max cooling state 10 and current cooling state 0. PASSED: Test 1, Fan cooling_device1 of type Processor has max cooling state 10 and current cooling state 0. PASSED: Test 1, Fan cooling_device2 of type LCD has max cooling state 15 and current cooling state 10. Test 2 of 2: Load system, check CPU fan status. Test how many fans there are in the system. Check for the current status of the fan(s). Loading CPUs for 20 seconds to try and get fan speeds to change. Fan cooling_device0 current state did not change from value 0 while CPUs were busy. Fan cooling_device1 current state did not change from value 0 while CPUs were busy. ADVICE: Did not detect any change in the CPU related thermal cooling device states. It could be that the devices are returning static information back to the driver and/or the fan speed is automatically being controlled by firmware using System Management Mode in which case the kernel interfaces being examined may not work anyway. ================================================================================ 3 passed, 0 failed, 0 warning, 0 aborted, 0 skipped, 0 info only. ================================================================================ 3 passed, 0 failed, 0 warning, 0 aborted, 0 skipped, 0 info only. Test Failure Summary ================================================================================ Critical failures: NONE High failures: NONE Medium failures: NONE Low failures: NONE Other failures: NONE Test |Pass |Fail |Abort|Warn |Skip |Info | ---------------+-----+-----+-----+-----+-----+-----+ fan | 3| | | | | | ---------------+-----+-----+-----+-----+-----+-----+ Total: | 3| 0| 0| 0| 0| 0| ---------------+-----+-----+-----+-----+-----+-----+ Here is the output of lsmod lsmod Module Size Used by i8k 14421 0 zram 18478 2 dm_crypt 23177 0 gpio_ich 13476 0 dell_wmi 12761 0 sparse_keymap 13948 1 dell_wmi snd_hda_codec_hdmi 46207 1 snd_hda_codec_idt 54645 1 rfcomm 69160 0 arc4 12608 2 dell_laptop 18168 0 bnep 19624 2 dcdbas 14928 1 dell_laptop bluetooth 395423 10 bnep,rfcomm iwldvm 232285 0 mac80211 626511 1 iwldvm snd_hda_intel 52355 3 snd_hda_codec 192906 3 snd_hda_codec_hdmi,snd_hda_codec_idt,snd_hda_intel snd_hwdep 13602 1 snd_hda_codec snd_pcm 102099 3 snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel snd_page_alloc 18710 2 snd_pcm,snd_hda_intel snd_seq_midi 13324 0 snd_seq_midi_event 14899 1 snd_seq_midi snd_rawmidi 30144 1 snd_seq_midi coretemp 13435 0 kvm_intel 143060 0 kvm 451511 1 kvm_intel snd_seq 61560 2 snd_seq_midi_event,snd_seq_midi joydev 17381 0 serio_raw 13462 0 iwlwifi 169932 1 iwldvm pcmcia 62299 0 snd_seq_device 14497 3 snd_seq,snd_rawmidi,snd_seq_midi snd_timer 29482 2 snd_pcm,snd_seq lpc_ich 21080 0 cfg80211 484040 3 iwlwifi,mac80211,iwldvm yenta_socket 41027 0 pcmcia_rsrc 18407 1 yenta_socket pcmcia_core 23592 3 pcmcia,pcmcia_rsrc,yenta_socket binfmt_misc 17468 1 snd 69238 17 snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_hda_codec_idt,snd_pcm,snd_seq,snd_rawmidi,snd_hda_codec,snd_hda_intel,snd_seq_device,snd_seq_midi soundcore 12680 1 snd parport_pc 32701 0 mac_hid 13205 0 ppdev 17671 0 lp 17759 0 parport 42348 3 lp,ppdev,parport_pc firewire_ohci 40409 0 psmouse 102222 0 sdhci_pci 23172 0 sdhci 43015 1 sdhci_pci firewire_core 68769 1 firewire_ohci crc_itu_t 12707 1 firewire_core ahci 25819 2 libahci 32168 1 ahci i915 783485 2 wmi 19177 1 dell_wmi i2c_algo_bit 13413 1 i915 drm_kms_helper 52758 1 i915 e1000e 254433 0 drm 302817 3 i915,drm_kms_helper ptp 18933 1 e1000e pps_core 19382 1 ptp video 19476 1 i915 I tried one answer to the similar question: loud fan on Ubuntu 14.04 and created a /etc/i8kmon.conf like the following: # Run as daemon, override with --daemon option set config(daemon) 1 # Automatic fan control, override with --auto option set config(auto) 1 # Status check timeout (seconds), override with --timeout option set config(timeout) 2 # Report status on stdout, override with --verbose option set config(verbose) 1 # Temperature thresholds: {fan_speeds low_ac high_ac low_batt high_batt} set config(0) {{0 0} -1 55 -1 55} set config(1) {{0 1} 50 60 55 65} set config(2) {{1 1} 55 80 60 85} set config(3) {{2 2} 70 128 75 128} With this setup the fan goes on even if the temperature is below 50 degree celsius (I don't see a pattern). However I get the impression that the CPU got's hotter in average than without this file. What changes from 13.10 to 14.04 may be responsible for this? If this is a bug, for which package I should report the bug?

  Read the article

• Tweaking Hudson memory usage

  - by rovarghe

  Hudson 3.1 has some performance optimizations that greatly reduces its memory footprint. Prior to this Hudson used to always hold the entire data model (all jobs and all builds) in memory which affected scalability. Some installations configured heap sizes in excess of 1GB to counteract this. Hudson 3.1.x maintains an MRU cache and only loads jobs and builds as they are required. Because of the inability to change existing APIs and be backward compatible with plugins, there were limits to how far we could go with this approach. Memory optimizations almost always come with a related cost, in this case its additional I/O that has to be performed to load data on request. On a small site that has frequent traffic, this is usually not noticeable since the MRU cache will usually hold on to all the data. A large site with infrequent traffic might experience some delays when the first request hits the server after a long gap. If you have a large heap and are able to allocate more memory, the cache settings can be adjusted to take advantage of this and even go back to pre-3.1 behavior. All the cache settings can be passed as options to the JVM container (Tomcat or the default Jetty container) using the -D option. There are two caches, independant of each other, one for Jobs and the other for Builds. For the jobs cache: hudson.jobs.cache.evict_in_seconds ( default=60 ) Seconds from last access (could be because of a servlet request or a background cron thread) a job should be purged from the cache. Set this to 0 to never purge based on time. hudson.jobs.cache.initial_capacity ( default=1024 ) Initial number of jobs the cache can accomodate. Setting this to the number of jobs you typically display on your Hudson landing page or home page will speed up consecutive access to that page. If the default is too large you may consider downsizing and using that memory for the Builds cache instead. hudson.jobs.cache.max_entries ( default=1024) Maximum number of jobs in the cache. The default is large enough for most installations, but if you find I/O activity when always accessing the hudson home page you might consider increasing this, but first verify if the I/O is caused by frequent eviction (see above), rather than by the cache not being large enough. For the builds cache: The builds cache is used to store Build objects as they are read from storage. Typically this happens when a user drills down into the details of a particular Job from the hudson hom epage. The cache is shared among builds for different jobs since in most installations all jobs are not accessed with the same frequency, so a per-job builds cache would be a waste of memory. hudson.job.builds.cache.evict_in_seconds ( default=60 ) Same as the equivalent Job cache, applied to Build. hudson.job.builds.cache.initial_capacity" ( default=512 ) Same as equivalent Job cache setting. Note the smaller initial size. If your site stores a large number of builds and has frequent access to more builds you might consider bumping this up. hudson.job.builds.cache.max_entries ( default=10240 ) The default max is large enough for most installations, the builds cache has bigger sized objects, so be careful about increasing the upper limit on this. See section on monitoring below. Sample usage: java -jar hudson-war-3.1.2-SNAPSHOT.war -Dhudson.jobs.cache.evict_in_seconds=300 \ -Dhudson.job.builds.cache.evict_in_seconds=300 Monitoring cache usage The 'jmap' tool that comes with the JDK can be used to monitor cache performance in an indirect way by looking at the number of Job and Build objects in each cache. Find the PID of the hudson instance and run $ jmap -histo:live <pid | grep 'hudson.model.*Lazy.*Key$' Here's a sample output: num #instances #bytes class name 523: 28 896 hudson.model.RunMap$LazyRunValue$Key 1200: 3 96 hudson.model.LazyTopLevelItem$Key These are the keys to the Jobs (LazyTopLevelItem$Key) and Builds (RunMap$LazyRunValue$Key) in the caches, so counting the number of keys is a good indicator of the number of items in the cache at any given moment. The size in bytes can be ignored, they are just the size of the keys, not the actual sizes of the objects they hold. Those sizes can only be obtained with a profiler. With the output above we can conclude that there are 3 jobs and 28 builds in memory. The 28 builds can all be from 1 job or all 3 jobs. Over time on an idle system, these should get evicted and memory cache should be empty. In practice, because of background cron threads and triggers, jobs rarely fall down to zero. Access of a job or a build by a cron thread resets the eviction timer.

  Read the article

• Reactive Extensions vs FileSystemWatcher

  - by Joel Mueller

  One of the things that has long bugged me about the FileSystemWatcher is the way it fires multiple events for a single logical change to a file. I know why it happens, but I don't want to have to care - I just want to reparse the file once, not 4-6 times in a row. Ideally, there would be an event that only fires when a given file is done changing, rather than every step along the way. Over the years I've come up with various solutions to this problem, of varying degrees of ugliness. I thought Reactive Extensions would be the ultimate solution, but there's something I'm not doing right, and I'm hoping someone can point out my mistake. I have an extension method: public static IObservable<IEvent<FileSystemEventArgs>> GetChanged(this FileSystemWatcher that) { return Observable.FromEvent<FileSystemEventArgs>(that, "Changed"); } Ultimately, I would like to get one event per filename, within a given time period - so that four events in a row with a single filename are reduced to one event, but I don't lose anything if multiple files are modified at the same time. BufferWithTime sounds like the ideal solution. var bufferedChange = watcher.GetChanged() .Select(e => e.EventArgs.FullPath) .BufferWithTime(TimeSpan.FromSeconds(1)) .Where(e => e.Count > 0) .Select(e => e.Distinct()); When I subscribe to this observable, a single change to a monitored file triggers my subscription method four times in a row, which rather defeats the purpose. If I remove the Distinct() call, I see that each of the four calls contains two identical events - so there is some buffering going on. Increasing the TimeSpan passed to BufferWithTime seems to have no effect - I went as high as 20 seconds without any change in behavior. This is my first foray into Rx, so I'm probably missing something obvious. Am I doing it wrong? Is there a better approach? Thanks for any suggestions...

  Read the article

• Android: Autoscrolling HorizontalScrollView

  - by DroidIn.net

  I'm using the following code to simulate tabs and since there are more tabs that width can accommodate user can scroll left or right to make a tab button visible. It all works, however I also provide user with ability to fling between tabs by swiping finger left or right on the tab contents. Again - it works. But when I fling to the rightmost tab its corresponding button is barely visible. I want to autoscroll table inside the HorizontalScrollView so the selected tab button will be visible but when I execute HorizontalScrollView.smoothScrollTo(300, 0) nothing happens. It doen't matter how high I set first x parameter nothing will ever move (yes I do have an algorithm to calculate exact position). Here's XML code for scrolling tab buttons <HorizontalScrollView android:layout_width="fill_parent" android:background="@color/tabs_header" android:layout_height="55dip" android:scrollbars="none" android:id="@+id/tabsButtonView"> <TableLayout android:id="@+id/TableLayout01" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TableRow android:id="@+id/TableRow01" android:layout_width="fill_parent" android:layout_weight="1" android:layout_height="0dip" android:paddingTop="5dip" android:paddingLeft="3dip"> <ImageButton android:src="@drawable/linkup_logo_small" android:id="@+id/tabBtt0" android:layout_width="wrap_content" android:layout_marginLeft="2dip" android:layout_marginRight="2dip" android:layout_height="fill_parent" android:padding="5dip" android:background="@drawable/tab_selected"></ImageButton> <ImageButton android:src="@drawable/simplyhired_small" android:id="@+id/tabBtt1" android:layout_height="fill_parent" android:layout_width="fill_parent" android:layout_marginLeft="2dip" android:layout_marginRight="2dip" android:padding="5dip" android:background="@drawable/tab_normal"></ImageButton> <ImageButton android:src="@drawable/indeedcom_small" android:id="@+id/tabBtt2" android:layout_width="fill_parent" android:layout_height="fill_parent" android:padding="5dip" android:layout_marginLeft="2dip" android:layout_marginRight="2dip" android:background="@drawable/tab_normal"></ImageButton> <ImageButton android:src="@drawable/careerbuilder_logo_small" android:id="@+id/tabBtt3" android:layout_width="fill_parent" android:layout_height="fill_parent" android:padding="5dip" android:layout_marginLeft="2dip" android:layout_marginRight="2dip" android:background="@drawable/tab_normal"></ImageButton> </TableRow> </TableLayout> </HorizontalScrollView>

  Read the article

• Do SEO-friendly URLs really affect a page's ranking?

  - by Lee Harold

  SEO-friendly URLs are all the rage these days. But do they actually have a meaningful impact on a page's ranking in Google and other search engines? If so, why? If not, why not? (Note that I would absolutely agree that SEO-friendly URLs are nicer to use for human beings. My question is whether they actually make a difference to the ranking algorithms.) Update: As it turns out, the Google post that endorphine points to here has caused tremendous confusion in the SEO community. For a sampling of the discussion, see here, here, and here. Part of the problem is that the Google post is addressing the worst case where URL rewriting is done poorly and so you'd be better off sticking with a dynamic URL rather than a mangled static "SEO-friendly" URL. There's no question dynamic URLs can be crawled by Google and can achieve high rankings. Maybe it would be easier to reframe the question more concretely: given 2 otherwise equivalent pages, which will rank higher for the search "do seo friendly urls really affect page ranking"? A) http://stackoverflow.com/questions/505793/do-seo-friendly-urls-really-affect-a-pages-ranking or B) http://stackoverflow.com?question=505793 (a fake URL for comparison only)

  Read the article

• MemoryStream and BitmapSource

  - by Vinjamuri

  I have a MemoryStream of 10K which was created from a bitmap of 2MB and compressed using JPEG. Since MemoryStream can’t directly be placed in System.Windows.Controls.Image for the GUI, I am using the following intermediate code to convert this back to BitmapImage and eventually System.Windows.Controls.Image. System.Windows.Controls.Image image = new System.Windows.Controls.Image(); BitmapImage imageSource = new BitmapImage(); s.SlideInformation.Thumbnail.Seek(0, SeekOrigin.Begin); imageSource.BeginInit(); imageSource.CacheOption = BitmapCacheOption.OnDemand; imageSource.CreateOptions = BitmapCreateOptions.DelayCreation; imageSource.StreamSource = s.SlideInformation.Thumbnail; imageSource.EndInit(); imageSource.Freeze(); image.Source = imageSource; ret = image.Source; My question is, when I store this in BitmapImage, the memory allocation is taking around 2MB. Is this expected? Is there any way to reduce the memory? I have around 300 thumbnails and this converstion takes around 600MB, which is very high. Appreciate your help!

  Read the article

• WCF listenBacklog and maxConnections can't be set higher than 10. Why not?

  - by NeedWCFPro

  My service works great under low load. But under high load I start to get connection errors. I know about other settings but I am trying to change the listenBacklog parameter in particular for my TCP Buffered binding. If I set listenBacklog="10" I am able to telnet into the port where my WCF service is running. If I change listenBacklog to anything higher than 10 it will not let me telnet into my service when it is running. No errors seem to be thrown. What can I do? I get the same problem when I change my maxConnections away from 10. All other properties of the binding I can set higher without a problem. Here is what my binding looks like: <bindings> <netTcpBinding> <binding name="NetTcpBinding_IMyService" closeTimeout="00:01:00" openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00" transactionFlow="false" transferMode="Buffered" transactionProtocol="OleTransactions" hostNameComparisonMode="StrongWildcard" listenBacklog="10" maxBufferPoolSize="524288" maxBufferSize="1048576" maxConnections="10" maxReceivedMessageSize="1048576"> <readerQuotas maxDepth="2147483647" maxStringContentLength="2147483647" maxArrayLength="2147483647" maxBytesPerRead="2147483647" maxNameTableCharCount="2147483647" /> <reliableSession ordered="true" inactivityTimeout="00:10:00" enabled="false" /> <security mode="Transport"> <transport clientCredentialType="Windows" protectionLevel="EncryptAndSign"> </transport> <message clientCredentialType="Windows" /> </security> </binding> ... I really need to increase the values of maxConnections and listenBacklog

  Read the article

• Code Golf: Code 39 Bar Code

  - by gwell

  The challenge The shortest code by character count to draw an ASCII representation of a Code 39 bar code. Wikipedia article about Code 39: http://en.wikipedia.org/wiki/Code_39 Input The input will be a string of legal characters for Code 39 bar codes. This means 43 characters are valid: 0-9 A-Z (space) and -.$/+%. The * character will not appear in the input as it is used as the start and stop characters. Output Each character encoded in Code 39 bar codes have nine elements, five bars and four spaces. Bars will be represented with # characters, and spaces will be represented with the space character. Three of the nine elements will be wide. The narrow elements will be one character wide, and the wide elements will be three characters wide. A inter-character space of a single space should be added between each character pattern. The pattern should be repeated so that the height of the bar code is eight characters high. The start/stop character * (bWbwBwBwb) would be represented like this: # # ### ### # # # ### ### # # # ### ### # # # ### ### # # # ### ### # # # ### ### # # # ### ### # # # ### ### # ^ ^ ^^ ^ ^ ^ ^^^ | | || | | | ||| narrow bar -+ | || | | | ||| wide space ---+ || | | | ||| narrow bar -----+| | | | ||| narrow space ------+ | | | ||| wide bar --------+ | | ||| narrow space ----------+ | ||| wide bar ------------+ ||| narrow space --------------+|| narrow bar ---------------+| inter-character space ----------------+ The start and stop character * will need to be output at the start and end of the bar code. No quiet space will need to be included before or after the bar code. No check digit will need to be calculated. Full ASCII Code39 encoding is not required, just the standard 43 characters. No text needs to be printed below the ASCII bar code representation to identify the output contents. The character # can be replaced with another character of higher density if wanted. Using the full block character U+2588, would allow the bar code to actually scan when printed. Test cases Input: ABC Output: # # ### ### # ### # # # ### # ### # # ### ### ### # # # # # ### ### # # # ### ### # ### # # # ### # ### # # ### ### ### # # # # # ### ### # # # ### ### # ### # # # ### # ### # # ### ### ### # # # # # ### ### # # # ### ### # ### # # # ### # ### # # ### ### ### # # # # # ### ### # # # ### ### # ### # # # ### # ### # # ### ### ### # # # # # ### ### # # # ### ### # ### # # # ### # ### # # ### ### ### # # # # # ### ### # # # ### ### # ### # # # ### # ### # # ### ### ### # # # # # ### ### # # # ### ### # ### # # # ### # ### # # ### ### ### # # # # # ### ### # Input: 1/3 Output: # # ### ### # ### # # # ### # # # # # ### ### # # # # # ### ### # # # ### ### # ### # # # ### # # # # # ### ### # # # # # ### ### # # # ### ### # ### # # # ### # # # # # ### ### # # # # # ### ### # # # ### ### # ### # # # ### # # # # # ### ### # # # # # ### ### # # # ### ### # ### # # # ### # # # # # ### ### # # # # # ### ### # # # ### ### # ### # # # ### # # # # # ### ### # # # # # ### ### # # # ### ### # ### # # # ### # # # # # ### ### # # # # # ### ### # # # ### ### # ### # # # ### # # # # # ### ### # # # # # ### ### # Input: - $ (minus space dollar) Output: # # ### ### # # # # ### ### # ### # ### # # # # # # # # ### ### # # # ### ### # # # # ### ### # ### # ### # # # # # # # # ### ### # # # ### ### # # # # ### ### # ### # ### # # # # # # # # ### ### # # # ### ### # # # # ### ### # ### # ### # # # # # # # # ### ### # # # ### ### # # # # ### ### # ### # ### # # # # # # # # ### ### # # # ### ### # # # # ### ### # ### # ### # # # # # # # # ### ### # # # ### ### # # # # ### ### # ### # ### # # # # # # # # ### ### # # # ### ### # # # # ### ### # ### # ### # # # # # # # # ### ### # Code count includes input/output (full program).

  Read the article

• What is the difference between System.Speech.Recognition and Microsoft.Speech.Recognition?

  - by Michael

  There are two similar namespaces and assemblies for speech recognition in .NET. I’m trying to understand the differences and when it is appropriate to use one or the other. There is System.Speech.Recognition from the assembly System.Speech (in System.Speech.dll). System.Speech.dll is a core DLL in the .NET Framework class library 3.0 and later There is also Microsoft.Speech.Recognition from the assembly Microsoft.Speech (in microsoft.speech.dll). Microsoft.Speech.dll is part of the UCMA 2.0 SDK I find the docs confusing and I have the following questions: System.Speech.Recognition says it is for "The Windows Desktop Speech Technology", does this mean it cannot be used on a server OS or cannot be used for high scale applications? The UCMA 2.0 Speech SDK ( http://msdn.microsoft.com/en-us/library/dd266409%28v=office.13%29.aspx ) says that it requires Microsoft Office Communications Server 2007 R2 as a prerequisite. However, I’ve been told at conferences and meetings that if I do not require OCS features like presence and workflow I can use the UCMA 2.0 Speech API without OCS. Is this true? If I’m building a simple recognition app for a server application (say I wanted to automatically transcribe voice mails) and I don’t need features of OCS, what are the differences between the two APIs?

  Read the article

• Google Map API v3 — set bounds and center

  - by Michael Bradley

  Hi, I've recently switched to Google Maps API V3. I'm working of a simple example which plots markers from an array, however I do not know how to center and zoom automatically with respect to the markers. I've searched the net high and low, including Google's own documentation, but have not found a clear answer. I know I could simply take an average of the co-ordinates, but how would I set the zoom accordingly? Could somebody please point me in the right direction? Perhaps you know of a good tutorial. Many thanks in advance, Michael function initialize() { var myOptions = { zoom: 10, center: new google.maps.LatLng(-33.9, 151.2), mapTypeId: google.maps.MapTypeId.ROADMAP } var map = new google.maps.Map(document.getElementById("map_canvas"),myOptions); setMarkers(map, beaches); } var beaches = [ ['Bondi Beach', -33.890542, 151.274856, 4], ['Coogee Beach', -33.423036, 151.259052, 5], ['Cronulla Beach', -34.028249, 121.157507, 3], ['Manly Beach', -33.80010128657071, 151.28747820854187, 2], ['Maroubra Beach', -33.450198, 151.259302, 1] ]; function setMarkers(map, locations) { var image = new google.maps.MarkerImage('images/beachflag.png', new google.maps.Size(20, 32), new google.maps.Point(0,0), new google.maps.Point(0, 32)); var shadow = new google.maps.MarkerImage('images/beachflag_shadow.png', new google.maps.Size(37, 32), new google.maps.Point(0,0), new google.maps.Point(0, 32)); var lat = map.getCenter().lat(); var lng = map.getCenter().lng(); var shape = { coord: [1, 1, 1, 20, 18, 20, 18 , 1], type: 'poly' }; for (var i = 0; i < locations.length; i++) { var beach = locations[i]; var myLatLng = new google.maps.LatLng(beach[1], beach[2]); var marker = new google.maps.Marker({ position: myLatLng, map: map, shadow: shadow, icon: image, shape: shape, title: beach[0], zIndex: beach[3] }); } }

  Read the article

• Merge method in MergeSort Algorithm .

  - by Tony

  I've seen many mergeSort implementations .Here is the version in Data Structures and Algorithms in Java (2nd Edition) by Robert Lafore : private void recMergeSort(long[] workSpace, int lowerBound,int upperBound) { if(lowerBound == upperBound) // if range is 1, return; // no use sorting else { // find midpoint int mid = (lowerBound+upperBound) / 2; // sort low half recMergeSort(workSpace, lowerBound, mid); // sort high half recMergeSort(workSpace, mid+1, upperBound); // merge them merge(workSpace, lowerBound, mid+1, upperBound); } // end else } // end recMergeSort() private void merge(long[] workSpace, int lowPtr, int highPtr, int upperBound) { int j = 0; // workspace index int lowerBound = lowPtr; int mid = highPtr-1; int n = upperBound-lowerBound+1; // # of items while(lowPtr <= mid && highPtr <= upperBound) if( theArray[lowPtr] < theArray[highPtr] ) workSpace[j++] = theArray[lowPtr++]; else workSpace[j++] = theArray[highPtr++]; while(lowPtr <= mid) workSpace[j++] = theArray[lowPtr++]; while(highPtr <= upperBound) workSpace[j++] = theArray[highPtr++]; for(j=0; j<n; j++) theArray[lowerBound+j] = workSpace[j]; } // end merge() One interesting thing about merge method is that , almost all the implementations didn't pass the lowerBound parameter to merge method . lowerBound is calculated in the merge . This is strange , since lowerPtr = mid + 1 ; lowerBound = lowerPtr -1 ; that means lowerBound = mid ; Why the author didn't pass mid to merge like merge(workSpace, lowerBound,mid, mid+1, upperBound); ? I think there must be a reason , otherwise I can't understand why an algorithm older than half a center ,and have all coincident in the such little detail.

  Read the article

• How to analyze 'dbcc memorystatus' result in SQL Server 2008

  - by envykok

  Currently i am facing a sql memory pressure issue. i have run 'dbcc memorystatus', here is part of my result: Memory Manager KB VM Reserved 23617160 VM Committed 14818444 Locked Pages Allocated 0 Reserved Memory 1024 Reserved Memory In Use 0 Memory node Id = 0 KB VM Reserved 23613512 VM Committed 14814908 Locked Pages Allocated 0 MultiPage Allocator 387400 SinglePage Allocator 3265000 MEMORYCLERK_SQLBUFFERPOOL (node 0) KB VM Reserved 16809984 VM Committed 14184208 Locked Pages Allocated 0 SM Reserved 0 SM Committed 0 SinglePage Allocator 0 MultiPage Allocator 408 MEMORYCLERK_SQLCLR (node 0) KB VM Reserved 6311612 VM Committed 141616 Locked Pages Allocated 0 SM Reserved 0 SM Committed 0 SinglePage Allocator 1456 MultiPage Allocator 20144 CACHESTORE_SQLCP (node 0) KB VM Reserved 0 VM Committed 0 Locked Pages Allocated 0 SM Reserved 0 SM Committed 0 SinglePage Allocator 3101784 MultiPage Allocator 300328 Buffer Pool Value Committed 1742946 Target 1742946 Database 1333883 Dirty 940 In IO 1 Latched 18 Free 89 Stolen 408974 Reserved 2080 Visible 1742946 Stolen Potential 1579938 Limiting Factor 13 Last OOM Factor 0 Page Life Expectancy 5463 Process/System Counts Value Available Physical Memory 258572288 Available Virtual Memory 8771398631424 Available Paging File 16030617600 Working Set 15225597952 Percent of Committed Memory in WS 100 Page Faults 305556823 System physical memory high 1 System physical memory low 0 Process physical memory low 0 Process virtual memory low 0 Procedure Cache Value TotalProcs 11382 TotalPages 430160 InUsePages 28 Can you lead me to analyze this result ? Is it a lot execute plan have been cached causing the memory issue or other reasons?

  Read the article

• Using LINQ to SQL in ASP.NET MVC2 project

  - by mazhar

  Well I am new to this ORM stuff. We have to create a large project. I read about LINQ to SQL. will it be appropriate to use it in the project of high risk. i found no problem with it personally but the thing is that there will be no going back once started.So i need some feedback from the ORM gurus here at the MSDN. Will entity framework will be better? (I am in doubt about LINK to SQL because I have read and heard negative feedback here and there) I will be using MVC2 as the framework. So please give the feedback about LINQ to SQL in this regard. Q2) Also I am a fan of stored procedure as they are precomputed and fasten up the thing and I have never worked without them.I know that LINQ to SQL support stored procedures but will it be feasible to give up stored procedure seeing the beautiful data access layer generated with little effort as we are also in a need of rapid development. Q3) If some changes to some fields required in the database in LINK to SQL how will the changes be accommodated in the data access layer.

  Read the article

• DDD/NHibernate Use of Aggregate root and impact on web design - ex. Editing children of aggregate ro

  - by pbrophy

  Hopefully, this fictitious example will illustrate my problem: Suppose you are writing a system which tracks complaints for a software product, as well as many other attributes about the product. In this case the SoftwareProduct is our aggregate root and Complaints are entities that only can exist as a child of the product. In other words, if the software product is removed from the system, so shall the complaints. In the system, there is a dashboard like web page which displays many different aspects of a single SoftwareProduct. One section in the dashboard, displays a list of Complaints in a grid like fashion, showing only some very high level information for each complaint. When an admin type user chooses one of these complaints, they are directed to an edit screen which allows them to edit the detail of a single Complaint. The question is: what is the best way for the edit screen to retrieve the single Complaint, so that it can be displayed for editing purposes? Keep in mind we have already established the SoftwareProduct as an aggregate root, therefore direct access to a Complaint should not be allowed. Also, the system is using NHibernate, so eager loading is an option, but my understanding is that even if a single Complaint is eager loaded via the SoftwareProduct, as soon as the Complaints collection is accessed the rest of the collection is loaded. So, how do you get the single Complaint through the SoftwareProduct without incurring the overhead of loading the entire Complaints collection?

  Read the article

• Schliemann's method of programming language learning

  - by DVK

  Background: 19th-century German archeologist Heinrich Schliemann was of course famous for his successful quest to find and excavate the city of Troy (an actual archeological site for the Troy of Homer's Iliad). However, he is just as famous for being an astonishing learner of languages - within the space of two years, he taught himself fluent Dutch, English, French, Spanish, Italian and Portuguese, and later went on to learn seven more, including both modern and ancient Greek. One of the methods he famously used was comparison of a known text, e.g. take a book in a language one is fluent in, take a good translation of a book in a language you wish to learn, and go over them in parallel. (various sources cited the book used by Schliemann to be the Bible, or, as the link above states, a novel). Now, for the actual question. Has anyone used (or heard of) an equivalent of Schliemann's method for learning a new programming language? E.g. instead of basing the leaning on references and tutorials, take a somewhat comprehensive set of programs known to have high-quality code in both languages implementing similar/identical algorithms and learn by comparing them? I'm curious about either personal experiences of applying such an approach, or references to something published, or existance of codebases which could be used for such an approach? What got me thinking about the idea was Project Euler and some code snippets I saw on SO, in C++, Perl and Lisp.

  Read the article

• Webforms MVP Passive View - event handling

  - by ss2k

  Should the view have nothing event specific in its interface and call the presenter plain methods to handle events and not have any official EventHandlers? For instance // ASPX protected void OnSaveButtonClicked(object sender, EventArgs e) { _Presenter.OnSave(); } Or should the view have event EventHandlers defined in its interface and link those up explicitly to control events on the page // View public interface IView { ... event EventHandler Saved; ... } // ASPX Page implementing the view protected override void OnInit(EventArgs e) { base.OnInit(e); SaveButton.Click += delegate { Saved(this, e); }; } // Presenter internal Presenter(IView view,IRepository repository) { _view = view; _repository = repository; view.Saved += Save; } The second seems like a whole lot of plumbing code to add all over. My intention is to understand the benefits of each style and not just a blanket answer of which to use. My main goals is clarity and high value testability. Testability overall is important, but I wouldn't sacrifice design simplicity and clarity to be able to add another type of test that doesn't lead to too much gain over the test cases already possible with a simpler design. If a design choice does off more testability please include an example (pseudo code is fine) of the type of test it can now offer so I can make my decision if I value that type of extra test enough. Thanks!

  Read the article

• T4 vs CodeDom vs Oslo

  - by Ryan Riley

  In an application scaffolding project on which I'm working, I'm trying to decide whether to use Oslo, T4 or CodeDom for generating code. Our goals are to keep dependencies to a minimum and drive code generation for a domain driven design from user stories. The first step will be to create the tests from the user stories, but we want the domain experts to be able to write their stories in a variety of different media (e.g. custom app, Word, etc.) and still generate the tests from the stories. What I know so far: CodeDom requires .NET but can only output .NET class files (e.g. .cs, .vb). Level of difficulty is fairly high. T4 requires CodeDom and VS Standard+. Level of difficulty is fairly reasonable, especially with the T4 Toolbox. Oslo is very new. I have no idea of the dependencies, but I imagine you must be on at least .NET 3.5. I'm also not certain as to the code generation abilities or the complexity for adding new grammars. However, domain experts could probably write user stories in Intellipad quite easily. Also not sure about ease of converting stories in Word to an MGrammar. What are your thoughts, experiences, etc. with any of the above tools. We want to stick with Microsoft or open source tools.

  Read the article

• C# Design How to Elegantly wrap a DAL class

  - by guazz

  I have an application which uses MyGeneration's dOODads ORM to generate it's Data Access Layer. dOODad works by generating a persistance class for each table in the database. It works like so: // Load and Save Employees emps = new Employees(); if(emps.LoadByPrimaryKey(42)) { emps.LastName = "Just Got Married"; emps.Save(); } // Add a new record Employees emps = new Employees(); emps.AddNew(); emps.FirstName = "Mr."; emps.LastName = "dOOdad"; emps.Save(); // After save the identity column is already here for me. int i = emps.EmployeeID; // Dynamic Query - All Employees with 'A' in thier last name Employees emps = new Employees(); emps.Where.LastName.Value = "%A%"; emps.Where.LastName.Operator = WhereParameter.Operand.Like; emps.Query.Load(); For the above example(i.e. Employees DAL object) I would like to know what is the best method/technique to abstract some of the implementation details on my classes. I don't believe that an Employee class should have Employees(the DAL) specifics in its methods - or perhaps this is acceptable? Is it possible to implement some form of repository pattern? Bear in mind that this is a high volume, perfomacne critical application. Thanks, j

  Read the article

• ssh tunneling with visualsvn

  - by DeveloperChris

  I have been asked to setup visualsvn for visual studio 2008 Due to firewall restrictions and server configuration. I need to use ssh tunneling. My problem is this. The local machine needs to connect to a gateway machine via ssh then connect to the subversion server so Local machine ---{ssh}--- gateway ---{ssh}-- subversion server I am not exactly sure of the correct process to do this. It appears that I must start a ssh process using plink to open a local port and forward that to the remote subversion server. eg: plink user@gateway -L 22:192.168.1.1:22 Then when visualsvn starts it uses tortoiseplink to make the actual connection through to the subversion server using svn+ssh://username@localhost:22/myrepo This seems very very clunky. firstly it needs several steps to setup the connection secondly I need plink running which leaves a command prompt on the desktop (clutter = yuck) lastly I need to use two different programs that do the same thing. (plink + tortoiseplink) The problem is that tortoiseplink doesn't run in the background. As soon as I connect to the ssh gateway and enter the password it closes again. So I can't use it to create the initial connection. If I use plink instead of tortoiseplink in visualsvn then I never get prompted for the password. so it just hangs with an open command prompt and no password request. Is there a way to setup visualsvn so that everything happens in one command line? I have searched high and low for a suitable and clean method to tunnel from visualsvn to the remote server and have found very little. it all either assumes one hop (not two like mine) or it glosses over all the hard bits. DC

  Read the article

• How to handle ViewModel and Database in C#/WPF/MVVM App

  - by Mike B

  I have a task management program with a "Urgency" field. Valid values are Int16 currently mapped to 1 (High), 2 (Medium), 3 (Low), 4 (None) and 99 (Closed). The urgency field is used to rank tasks as well as alter the look of the items in the list and detail view. When a user is editing or adding a new task they select or view the urgency in a ComboBox. A Converter passes Strings to replace the Ints. The urgency collection is so simple I did not make it a table in the database, instead it is a, ObservableCollection(Int16) that is populated by a method. Since the same screen may be used to view a closed task the "Closed" urgency must be in the ItemsSource but I do not want the user to be able to select it. In order to prevent the user from being able to select that item in the ComboBox but still be able to see it if the item in the database has that value should I... Manually disable the item in the ComboBox in code or Xaml (I doubt it) Change the Urgency collection from an Int16 to an Object with a Selectable Property that the isEnabled property of the ComboBoxItem Binds to. Do as in 2 but also separate the urgency information into its own table in the database with a foreign key in the Tasks table None of the above (I suspect this is the correct answer) I ask this because this is a learning project (My first real WPF and first ever MVVM project). I know there is rarely one Right way to do something but I want to make sure I am learning in a reasonable manner since it if far harder to Unlearn bad habits Thanks Mike

  Read the article

< Previous Page | 511 512 513 514 515 516 517 518 519 520 521 522  | Next Page >