Search Results

Search found 22641 results on 906 pages for 'use case'.

Page 490/906 | < Previous Page | 486 487 488 489 490 491 492 493 494 495 496 497  | Next Page >

• How to prevent traffic to/from a slow Cassandra node using Python

  - by Sergio Ayestarán

  Intro: I have a Python application using a Cassandra 1.2.4 cluster with a replication factor of 3, all reads and writes are done with a consistency level of 2. To access the cluster I use the CQL library. The Cassandra cluster is running on rackspace's virtual servers. The problem: From time to time one of the nodes can become slower than usual, in this case I want to be able to detect this situation and prevent making requests to the slow node and if possible to stop using it at all (this should theoretically be possible since the RF is 3 and the CL is 2 for every single request). The questions: What's the best way of detecting the slow node from a Python application? Is there a way to stop using one of the Cassandra nodes from Python in this scenario without human intervention? Thanks in advance!

  Read the article

• Multiple merchant accounts with Activemerchant gem.

  - by sosborn

  I am developing a rails site that will allow a group of merchants (5 - 10) to accept credit card orders online. I plan on using the Activemerchant gem to handle the processing. In this case, each merchant will have their own merchant accounts to handle the payments. Storing banking information like that is not something I am a fan of. This could be solved by queing orders and allowing the merchant to log in to the site, input their credentials and process the order. However, if I go that route then it seems to me that I would have to store the customers' credit card information temporarily until the merchant has the opportunity to log in and process the order, which to me is the greater evil. Has anyone dealt with this situation? If so, what are the options available and what pitfalls should I look out for? In my mind, security customer credit card information is priority number one with the merchant account information a close second.

  Read the article

• mysql query clarification

  - by JPro

  I have a query which I am wondering if the result I am getting is the one that I am expecting. The table structure goes like this : Table : results ID TestCase Set Analyzed Verdict StartTime Platform 1 1010101 ros2 false fail 18/04/2010 20:23:44 P1 2 1010101 ros3 false fail 19/04/2010 22:22:33 P1 3 1232323 ros2 true pass 19/04/2010 22:22:33 P1 4 1232323 ros3 false fail 29/04/2010 22:22:33 P2 Table : testcases ID TestCase type 1 1010101 NOSNOS 2 1232323 N212NS is there any way to display only the latest fails on each platform? in the above case Result shoud be : ID TestCase Set Analyzed Verdict StartTime Platform type 2 1010101 ros3 false fail 19/04/2010 22:22:33 P1 NOSNOS 4 1232323 ros3 false fail 29/04/2010 22:22:33 P2 N212NS

  Read the article

• WPF Visual States and the transitions between them

  - by Mark

  I'm trying to define many different states in my app (around 7 in my case) and I have defined each one of them with a "Default Transition" of zero seconds, but the animation that accompanies each state goes for 1 second. When I fire up my app I have a button than goes through the states one by one, when I go "State1" - "State2" it looks perfect, but when I tell my app (which should be in State2 now) to go to "State3" it reverts all the objects in my scene back to their base state, and then animates to "State3", why doesnt it go from "State2" to "State3". I was hoping to only define each state's end position without defining a starting position as this would really take a long time to do. Can this be done? Any examples? Cheers, Mark

  Read the article

• MySql Friend of my friends and Friend of my of my Friends of my Friends

  - by user1907522

  i have a problem with mysql query, and can't get it done in any way. I already checked the other topics, but can't get any of the solutions to work in my case. I have 2 tables, one is users id, name, email.... and second for friends is named friends :) user1_id, user2_id now i need to get from the database all of the user info for friends of my friends, and next level friends, the Friend of my of my Friends of my Friends, those should be 2 separate queries. Of course the search should exclude me, and be distinct. Please help.

  Read the article

• What's the simplest way to ask for user input through Modal in Win Form

  - by Refracted Paladin

  What is the simplest way to implement a Modal(popup) MessageBox that allows a custom value to be entered and returned. In my case, a String. Maybe I am over thinking this but I figured I'd ask. I plan to just create a new Form. Add a label, a textbox, two buttons. Assign the textbox to a property and from my main form call a ShowDialog() on it. Will I be able to still access the property that way or should I somehow return the value? Is this a decent way of doing this?

  Read the article

• Basic question about std::vector instantiation

  - by recipriversexclusion

  This looks simple but I am confused: The way I create a vector of hundred, say, ints is std::vector<int> *pVect = new std::vector<int>(100); However, looking at std::vector's documentation I see that its constructor is of the form explicit vector ( size_type n, const T& value= T(), const Allocator& = Allocator() ); So, how does the previous one work? Does new call the constructor with an initialization value obtained from the default constructor? If that is the case, would std::vector<int, my_allocator> *pVect = new std::vector<int>(100, my_allocator); where I pass my own allocator, also work?

  Read the article

• jQuery Validation Engine with Mime

  - by Diego Pucci

  I have this custom rule with tje jQuery validation Engine: "validateMIME": { "func": function(field, rules, i, options){ var fileInput = field[0].files[0]; var MimeFilter = new RegExp(rules[3],'i'); if (fileInput) { return MimeFilter.test(fileInput.type); } else { return true;} }, "alertText": "* Estensione non supportata" }, The problem is that this is working ONLY if the field is required. But in my case the field is not required, but if filled then the Mime type needs to be checked. How do I edit this function to work with non required fields? what's wrong with it? Thanks

  Read the article

• Zip Code Radius Search question...

  - by KnockKnockWhosThere

  I'm wondering if it's possible to find all points by longitude and latitude within X radius of one point? So, if I provide a latitude/longitude of -76.0000, 38.0000, is it possible to simply find all the possible coordinates within (for example) a 10 mile radius of that? I know that there's a way to calculate the distance between two points, which is why I'm not clear as to whether this is possible... Because, it seems like you need to know the center coordinates (-76 and 38 in this case) as well as the coordinates of every other point in order to determine whether it falls within the specified radius... Is that right?

  Read the article

• Flex: Prevent scrollbar from covering content when automatically displayed.

  - by Yaba

  I have a canvas in Flex that shall be able only to be scrolled in vertical direction, so I set the attributes of the canvas as follows: verticalScrollPolicy="auto" horizontalScrollPolicy="off" The problem here is that the vertical scrollbar covers the content when it appears - altough there is enough horizontal room left. I would have expected that the content size would have been automatically adjusted. When setting the vertical scroll policy to "on", no content is covered also. In case I set both scroll policies to 'auto' I also get a horizontal scroll bar just for scrolling to the area that is covered by the vertical scroll bar. Is there a workaround how I can relayout the content of the canvas when the vertical scroll bar is shown so that it does not cover any content?

  Read the article

• Using persistent and non-persistent connection together in a PHP MySQL app

  - by cappuccino

  There are parts of my app where a persistent connection is required, in particular the parts where every hour maybe 30,000 select requests are made by many different users, this is causing my mysql server to max out on the 100 connection limit, and i really don't want to increase it since 100 connections already seems like alot. So for the parts of the application where reading and selecting is the case I want to switch to persistent connections. The other parts where data is being modified is usually done through a transaction, and the general rule is never to use persistent connections for transactions according to the php documentation. So I would like to keep this on non-persistent connections. My question is, am i able to use persistent and non-persistent connections together in the same app, the same script etc? I am using PHP 5.2+, MySQL 5+ (InnoDB tables) and the Zend Framework 10.6+

  Read the article

• Amazon EC2 Load Balancer: Defending against DoS attack?

  - by netvope

  We usually blacklist IPs address with iptables. But in Amazon EC2, if a connection goes through the Elastic Load Balancer, the remote address will be replaced by the load balancer's address, rendering iptables useless. In the case for HTTP, apparently the only way to find out the real remote address is to look at the HTTP header HTTP_X_FORWARDED_FOR. To me, blocking IPs at the web application level is not an effective way. What is the best practice to defend against DoS attack in this scenario? In this article, someone suggested that we can replace Elastic Load Balancer with HAProxy. However, there are certain disadvantages in doing this, and I'm trying to see if there is any better alternatives.

  Read the article

• Invoke a subclass method of an anonymous class

  - by arjacsoh

  I am trying right now to dig into anonymous classes and one question was just arised I 'd prefer not to refer to much details and to pose my question straightforward: How can I invoke the method sizzle() in the following anonymous class: public class Popcorn { public void pop() { System.out.println("popcorn"); } } class Food { Popcorn p = new Popcorn() { public void sizzle() { System.out.println("anonymous sizzling popcorn"); } public void pop() { System.out.println("anonymous popcorn"); } }; public void popIt() { p.pop(); // OK, Popcorn has a pop() method p.sizzle(); // Not Legal! Popcorn does not have sizzle() } } It is known and definite in polymorphism rules that a refernce of a superclass cannot invoke methods of subclass without downcasting (even if it refers to an object of the given subclass). However in the above case what is the "key" to invoke the sizzle() method?

  Read the article

• Thread safe lockfree mutual ByteArray queue

  - by user313421

  A byte stream should be transferred and there is one producer thread and a consumer one. Speed of producer is higher than consumer most of the time, and I need enough buffered data for QoS of my application. I read about my problem and there are solutions like shared buffer, PipeStream .NET class ... This class is going to be instantiated many times on server so I need and optimized solution. Is it good idea to use a Queue of ByteArray ? If yes, I'll use an optimization algorithm to guess the Queue size and each ByteArray capacity and theoretically it fits my case. If no, I what's the best approach ? Please let me know if there's a good lock free thread safe implementation of ByteArray Queue in C# or VB. Thanks in advance

  Read the article

• Can someone explain me implicit parameters in Scala?

  - by Oscar Reyes

  And more specifically how does the BigInt works for convert int to BigInt? In the source code it reads: ... implicit def int2bigInt(i: Int): BigInt = apply(i) ... How is this code invoked? I can understand how this other sample: "Date literals" works. In. val christmas = 24 Dec 2010 Defined by: implicit def dateLiterals(date: Int) = new { import java.util.Date def Dec(year: Int) = new Date(year, 11, date) } When int get's passed the message Dec with an int as parameter, the system looks for another method that can handle the request, in this case Dec(year:Int) Q1. Am I right in my understanding of Date literals? Q2. How does it apply to BigInt? Thanks

  Read the article

• How to judge the relative efficiency of algorithms given runtimes as functions of 'n'?

  - by Lopa

  Consider two algorithms A and B which solve the same problem, and have time complexities (in terms of the number of elementary operations they perform) given respectively by a(n) = 9n+6 b(n) = 2(n^2)+1 (i) Which algorithm is the best asymptotically? (ii) Which is the best for small input sizes n, and for what values of n is this the case? (You may assume where necessary that n0.) i think its 9n+6. guys could you please help me with whether its right or wrong?? and whats the answer for part b. what exactly do they want?

  Read the article

• Smooth screen recording software

  - by user85658

  Hello everyone, I am preparing for my senior thesis presentation. I'd like to back myself up in case there is no internet connection available. Therefore I want to record a video showing the functionality of my software. I have tried Camtasia but all the smooth and slick animations I've created, do not look that appealing. Is there an alternative. Something that will capture my screen 1 to 1, or near that. Camtasia is great, but it does not serve the purpose. Any help would be greatly appreciated. Best Regards, Kiril

  Read the article

• UINavigationController Right button

  I am unable to set any property of parentController (which is always a UINavigationController in my case) from child views. e.g. I want to add a button on the navigation bar using following code: UINavigationController* parentController = (UINavigationController)self.parentViewController; UIBarButtonItem *addButton = [[[UIBarButtonItem alloc] initWithTitle:@"Something" style:UIBarButtonItemStyleBordered target:self action:@selector(doSomething)] autorelease]; [_parentController.navigationItem setRightBarButtonItem:addButton animated:YES]; This code runs perfectly without errors but I can't see any button added to the navigation bar. Thanks in advance.

  Read the article

• Compound dictionary keys

  - by John Keyes

  I have a particular case where using compound dictionary keys would make a task easier. I have a working solution, but feel it is inelegant. How would you do it? context = { 'database': { 'port': 9990, 'users': ['number2', 'dr_evil'] }, 'admins': ['[email protected]', '[email protected]'], 'domain.name': 'virtucon.com' } def getitem(key, context): if hasattr(key, 'upper') and key in context: return context[key] keys = key if hasattr(key, 'pop') else key.split('.') k = keys.pop(0) if keys: try: return getitem(keys, context[k]) except KeyError, e: raise KeyError(key) if hasattr(context, 'count'): k = int(k) return context[k] if __name__ == "__main__": print getitem('database', context) print getitem('database.port', context) print getitem('database.users.0', context) print getitem('admins', context) print getitem('domain.name', context) try: getitem('database.nosuchkey', context) except KeyError, e: print "Error:", e Thanks.

  Read the article

• What is the proper way to resolve Eclipse warning "isn't parameterized"?

  - by Morinar

  I'm trying to clean up some warnings in some old Java code (in Eclipse), and I'm unsure what the proper thing to do is in this case. The block looks more or less like this: Transferable content = getToolkit().getSystemClipboard().getContents( null ); java.util.List clipboardFileList = null; if( content.isDataFlavorSupported( DataFlavor.javaFileListFlavor ) ) { try { clipboardFileList = (java.util.List)content.getTransferData( DataFlavor.javaFileListFlavor); } /* Do other crap, etc. */ } The List generates a warning as it isn't parameterized, however, if I parameterize it with <File>, which I'm pretty sure is what it requires, it complains that it can't convert from Object to List<File>. I could merely suppress the unchecked warning for the function, but would prefer to avoid that if there is a "good" solution. Thoughts?

  Read the article

• How should I rewrite my code to make it amenable to unittesting?

  - by justin

  I've been trying to get started with unit-testing while working on a little cli program. My program basically parses the command line arguments and options, and decides which function to call. Each of the functions performs some operation on a database. So, for instance, I might have a create function: def create(self, opts, args): #I've left out the error handling. strtime = datetime.datetime.now().strftime("%D %H:%M") vals = (strtime, opts.message, opts.keywords, False) self.execute("insert into mytable values (?, ?, ?, ?)", vals) self.commit() Should my test case call this function, then execute the select sql to check that the row was entered? That sounds reasonable, but also makes the tests more difficult to maintain. Would you rewrite the function to return something and check for the return value? Thanks

  Read the article

• System.WIndows.Application static members are thread safe?

  - by Lirik

  The Application static members are supposed to be thread safe: The public static (Shared in Visual Basic) members of this type are thread safe. In addition, the FindResource and TryFindResource methods and the Properties and Resources properties are thread safe.1 How much can we trust that statement in a multithreaded environment when calling static member methods of System.Windows.Application? Update: It's all in reference to this question: http://stackoverflow.com/questions/2463822/threading-errors-with-application-loadcomponent-key-already-exists/2463866#2463866 I never thought I'd see a real bug in the library, but this must be the day for me... that question seems to show a genuine bug. Usually it's "user error," but this doesn't seem to be the case.

  Read the article

• How to handle request-wise DB transactions in ASP.NET MVC?

  - by Dario Solera

  I'm using SubSonic 3.0 (SimpleRepository) to handle database access in my ASP.NET MVC 1.0 application. It would be nice to handle a transaction for every web request, committing if everything went smooth and rolling back in case of exception. Is this possible? If so, how? I know this topic has been discussed many times, but I just couldn't find a satisfactory answer. I have built my own solution (create a TransactionScope in the controller, then commit/rollback in OnActionExecuted), but it turns out to be very unreliable.

  Read the article

• Using boost.python to import a method with opencv calls but failing due to symbols not being found a

  - by nmz787

  So I don't have the code right now, as I am not home... but i used the boost library for python in C++ to allow python to access a function called something like loadImageIntoMainWindow(string filepath) in the C++ source code the method calls opencv methods that are imported at the top of the file, I included opencv in my Jamroot file, and also found a way to compile and link manually on the command line... in either case when I run my python file it complains that the symbols aren't found for the first function call to an opencv method... I will update as soon as I get home with the C++, the command line compilation lines, the Jamroot, and the python files

  Read the article

• Sqlite: CURRENT_TIMESTAMP is in GMT, not the timezone of the machine

  - by BrianH

  I have a sqlite (v3) table with this column definition: "timestamp" DATETIME DEFAULT CURRENT_TIMESTAMP The server that this database lives on is in the CST time zone. When I insert into my table without including the timestamp column, sqlite automatically populates that field with the current timestamp in GMT, not CST. Is there a way to modify my insert statement to force the stored timestamp to be in CST? On the other hand, it is probably better to store it in GMT (in case the database gets moved to a different timezone, for example), so is there a way I can modify my select SQL to convert the stored timestamp to CST when I extract it from the table? Thanks in advance!

  Read the article

< Previous Page | 486 487 488 489 490 491 492 493 494 495 496 497  | Next Page >