Search Results

Search found 8266 results on 331 pages for 'distributed systems'.

Page 167/331 | < Previous Page | 163 164 165 166 167 168 169 170 171 172 173 174  | Next Page >

  • how random is Math.random() in java across different jvms or different machines

    - by user881480
    I have a large distributed program across many different physical servers, each program spawns many threads, each thread use Math.random() in its operations to draw a piece from many common resource pools. The goal is to utilize the pools evenly across all operations. Sometimes, it doesn't appear so random by looking at a snapshot on a resource pool to see which pieces it's getting at that instant (it might actually be, but it's hard to measure and find out for sure). Is there something that's better than Math.random() and performs just as good (not much worse at least)?

    Read the article

  • SQL Server, Remote Stored Procedure, and DTC Transactions

    - by marc
    Our organization has a lot of its essential data in a mainframe Adabas database. We have ODBC access to this data and from C# have queried/updated it successfully using ODBC/Natural "stored procedures". What we'd like to be able to do now is to query a mainframe table from within SQL Server 2005 stored procs, dump the results into a table variable, massage it, and join the result with native SQL data as a result set. The execution of the Natural proc from SQL works fine when we're just selecting it; however, when we insert the result into a table variable SQL seems to be starting a distributed transaction that in turn seems to be wreaking havoc with our connections. Given that we're not performing updates, is it possible to turn off this DTC-escalation behavior? Any tips on getting DTC set up properly to talk to DataDirect's (formerly Neon Systems) Shadow ODBC driver?

    Read the article

  • Enumerating and using wmp visualizers

    - by monoceres
    Hi! I want to use the systems available windows media player visualizers in my app. Apperently visualizers expose an IWMPEffects interface to the world. My question is how do I enumerate and create instances to the available visualizers on my system? Probably it's just a process of getting the cslid of the visualizers and then create the instance with CoCreateInstance. However I have no idea how to get these clsid's! Thanks!

    Read the article

  • Nhibernate 3.0 and FluentNHibernate

    - by Keith Nicholas
    is anyone building the truck NHibernate and FluentNhibernate together? How's it working? are you using it for production systems? How is the Linq support? Is it nearly ready for release? Is there a nice and concise way to keep up to date with what is going on in the world of NHibernate? (ie, without having to read lots of blogs, and mailing lists )

    Read the article

  • Recommended textbook for machine-level programming?

    - by Norman Ramsey
    I'm looking at textbooks for an undergraduate course in machine-level programming. If the perfect book existed, this is what it would look like: Uses examples written in C or assembly language, or both. Covers machine-level operations such as two's-complement integer arithmetic, bitwise operations, and floating-point arithmetic. Explains how caches work and how they affect performance. Explains machine instructions or assembly instructions. Bonus if the example assembly language includes x86; triple bonus if it includes x86-64 (aka AMD64). Explains how C values and data structures are represented using hardware registers and memory. Explains how C control structures are translated into assembly language using conditional and unconditional branch instructions. Explains something about procedure calling conventions and how procedure calls are implemented at the machine level. Books I might be interested in would probably have the words "machine organization" or "computer architecture" in the title. Here are some books I'm considering but am not quite happy with: Computer Systems: A Programmer's Perspective by Randy Bryant and Dave O'Hallaron. This is quite a nice book, but it's a book for a broad, shallow course in systems programming, and it contains a great deal of material my students don't need. Also, it is just out in a second edition, which will make it expensive. Computer Organization and Design: The Hardware/Software Interface by Dave Patterson and John Hennessy. This is also a very nice book, but it contains way more information about how the hardware works than my students need. Also, the exercises look boring. Finally, it has a show-stopping bug: it is based very heavily on MIPS hardware and the use of a MIPS simulator. My students need to learn how to use DDD, and I can't see getting this to work on a simulator. Not to mention that I can't see them cross-compiling their code for the simulator, and so on and so forth. Another flaw is that the book mentions the x86 architecture only to sneer at it. I am entirely sympathetic to this point of view, but news flash! You guys lost! Write Great Code Vol I: Understanding the Machine by Randall Hyde. I haven't evaluated this book as thoroughly as the other two. It has a lot of what I need, but the translation from high-level language to assembler is deferred to Volume Two, which has mixed reviews. My students will be annoyed if I make them buy a two-volume series, even if the price of those two volumes is smaller than the price of other books. I would really welcome other suggestions of books that would help students in a class where they are to learn how C-language data structures and code are translated to machine-level data structures and code and where they learn how to think about performance, with an emphasis on the cache.

    Read the article

  • iPhone - Developing on multiple Macs

    - by hecta
    I have a mac and a macbook, and one iPhone device and want to develop on both systems. My enrollment type is individual. How am I able to install the developer certificate and provisioning profiles on both machines? On the macbook it says 'a valid signing identity matching this profile could not be found in your keychain'. In my keychain I have a 'green status' for my developer certificate and in the xcode organizer for my device as well.

    Read the article

  • Procedural modeling of Robots?

    - by anon
    Procedural techniques is common for texture synthesis, modeling plants, and modeling terrains. However, I've seen very little work on algorithmic construction of robots, which is a bit surprising given how mechanical these systems are. Anyone have a good resource on the algorithmic construction of robots / robotic humanoids? Thanks!

    Read the article

  • What is the best way to password protect folder/page using php without a db or username

    - by Salt Packets
    What is the best way to password protect folder using php without a database or user name but using. Basically I have a page that will list contacts for organization and need to password protect that folder without having account for every user . Just one password that gets changes every so often and distributed to the group. I understand that it is not very secure but never the less I would like to know how to do this. In the best way. It would be nice if the password is remembered for a while once user entered it correctly.

    Read the article

  • Load balancer - how to write one for a custom application?

    - by Poni
    Hi! I've written a simple server application which will run distributed on several machines. My question is how does a network load balancer works, in general? I've heard of round-robin and other algorithms, but what I haven't got answer to is how does the process really goes? In socket terms. The client connects to one of the load balancer machines, asks for a "free-to-connect-to" server and simply connects to it? That's the simpliest way I can think of. .. or, does it use the load balancer as a proxy (that implies that all the NBs must be always connected to the application servers, and data is transferred through them)? It's more of a general question. How would you do this? Thank you all!

    Read the article

  • Maximum size of email X-Headers

    - by Spike Williams
    We are looking at sticking some metadata into the X-Headers of email messages. These emails are for consumption by internal systems, and will be hosted on an Exchange server. Is there a maximum size for the ammount of data that we can store in an X-Header? Are there any limitations, such as special characters, that I should know about?

    Read the article

  • Would Mercurial help me work from 2 PCs?

    - by rikh
    I currently use Perforce for source control, but want to start working on the code from 2 different PCs at the same time (desktop and laptop). The laptop would not be able to access the perforce server very often, which makes Perforce a poor choice in this setup. Distributed source control tools like Mercurial seem better suited to the task, but I am still not clear if this would work or not. Does anyone have any experience of using Mercurial to work on 2 machines at once (eg desktop in the week, laptop in evening and weekends). Does it help, or is it still a pain the butt keeping everything in sync and knowing what is going on.

    Read the article

  • SQL Server: How to call a UDF, if available?

    - by Ian Boyd
    Most systems will have a user-defined function (UDF) available. Some will not. i want to use the UDF if it's there: SELECT Users.*, dbo.UserGroupMembershipNames(Users.UserID) AS MemberOfGroupNames FROM Users Otherwise fallback to the acceptable alternative SELECT Users.*, (SELECT TOP 1 thing FROM Something WHERE Something.ID = Users.UserID) AS MemberGroupNames FROM Users How do? My first attempt, using the obvious solution, of course failed: SELECT Users.*, CASE WHEN (OBJECT_ID('dbo.UserGroupMembershipNames') IS NOT NULL) THEN dbo.UserGroupMembershipNames(Users.UserID) ELSE (SELECT TOP 1 thing FROM Something WHERE Something.ID = Users.UserID) END AS MemberOfGroupNames FROM Users for reasons beyond me

    Read the article

  • php cache zend framework

    - by msaif
    server side is PHP + zend framework. problem: i have huge of data appox 5000 records and no of columns are 5 in input.txt file. i like to read all data into memory only once and send some data to the every browser request. but if i update that input.txt file then updated data must be auto synchronized to that memory location. so i need to solve that problem by using memory caching technique.but caching technique has expire time.but if input.txt is updated before cache expire then i need to auto synchronize to that memory location. now i am using zend framework 1.10.is it possible in zend framework. can anybody give me some line of code of zendfrmawork i have no option to use memchached server(distributed). Only zend framwork.

    Read the article

  • Plugin architecture in .net: unloading

    - by henchman
    Hello everybody, I need to implement a plugin architecture within c#/.net in order to load custom user defined actions data type handling code for a custom data grid / conversion / ... from non-static linked assembly files. Because the application has to handle many custom user defined actions, Iam in need for unloading them once executed in order to reduce memory usage. I found several good articles about plugin architectures, eg: ExtensionManager PluginArchitecture ... but none of them gave me enough sausage for properly unloading an assembly. As the program is to be distributed and the user defined actions are (as the name states) user defined: how to i prevent the assembly from executing malicious code (eg. closing my progra, deleting files)? Are there any other pitfalls one of you has encountered?

    Read the article

  • List of private iPhone APIs?

    - by diego nunes
    . . Hi there, everybody. . . I need to do an app to be distributed ad hoc (it doesn't need to go to the store) but I need to get the information about the "data usage" (gprs/3g traffic). It is available on the system, but there is no official API call to get that info. One app made it through Apple testing (it's called "Download Meter"), though, and I emailed the guys to see if they would share the call, but they were not in that mood. . . Is there any list of private APIs or anything like that? Does anyone have any ideas of how could I get that info? Again: the app doesn't need to go to the store, but I need to install it on stock iPhone (ad hoc will do). . Thanks.

    Read the article

  • git: having 2 push/pull repos in sync (or 1 push/pull and 1 pull in sync)

    - by xavjuan
    Hello, We work on multiple geographically seperate sites. Today I have our git clones all live on one site A. Then users from site B have to ssh over to do a git clone or to push in changes. These are bare repos where the update is through pushes. Ideally, for git clone/push performance, I'd like to limit having to go over ssh. I'd like to have a copy of git repo X live on site A and site B... and have some syncing mechanism between them. OR to have X live on both sites, but only allow pushing to A (and have that setup correctly at clone time on B) I'm worried about the case where someone on site A pushes changes to the repo at site A at the same time that someone on site B pushes a truely conflicting change to the repo at site B. Is there some 'sync'ing solution built into git for distributed open repos like this? Or a way to have a clone from X set the origin/parent to the X from the other site? thanks, -John

    Read the article

  • Anyone have a database of file extensions & icons to go with the extensions?

    - by neddy
    Ok, im developing some software which requires file icons to display lists of files on a computer... i don't want to use the system ExtractAssociatedIcon api's i'd rather load the icons for the file extensions out of a database... (as some systems may not have certain files associated etc)... Does anyone have a database of file extensions & icons to go with the extensions that i can use? Cheers in advance,

    Read the article

  • Building Cocoa UIs for OS X with C# and Mono

    - by Antony Perkov
    Has anyone spent any time comparing the various Objective C bridges and associated Cocoa wrappers for Mono? I want to port an existing C# application to run on OS X. Ideally I'd run the application on Mono, and build a native Cocoa UI for it. I'm wondering which bridge would be the best choice. In case it's useful to anyone, here are some links to bridges I've found so far: CocoSharp - distributed with Mono on OS X - www.cocoa-sharp.com Monobjc - better documentation than the others (in my opinion) - www.mono-project.com/CocoaSharp and www.monobjc.net NObjective - (apparently) faster than the others - code.google.com/p/nobjective MObjc / MCocoa - code.google.com/p/mobjc and code.google.com/p/mcocoa ObjC# - www.mono-project.com/ObjCSharp

    Read the article

  • Is it possible to partition more than one way at a time in SQL Server?

    - by meeting_overload
    I'm considering various ways to partition my data in SQL Server. One approach I'm looking at is to partition a particular huge table into 8 partitions, then within each of these partitions to partition on a different partition column. Is this even possible in SQL Server, or am I limited to definining one parition column+function+scheme per table? I'm interested in the more general answer, but this strategy is one I'm considering for Distributed Partitioned View, where I'd partition the data under the first scheme using DPV to distribute the huge amount of data over 8 machines, and then on each machine partition that portion of the full table on another parition key in order to be able to drop (for example) sub-paritions as required.

    Read the article

  • XML over HTTP with JMS and Spring

    - by Will Sumekar
    I have a legacy HTTP server where I need to send an XML file over HTTP request (POST) using Java (not browser) and the server will respond with another XML in its HTTP response. It is similar to Web Service but there's no WSDL and I have to follow the existing XML structure to construct my XML to be sent. I have done a research and found an example that matches my requirement here. The example uses HttpClient from Apache Commons. (There are also other examples I found but they use java.net networking package (like URLConnection) which is tedious so I don't want to use them). But it's also my requirement to use Spring and JMS. I know from Spring's reference that it's possible to combine HttpClient, JMS and Spring. My question is, how? Note that it's NOT in my requirement to use HttpClient. If you have a better suggestion, I'm welcome. Appreciate it. For your reference, here's the XML-over-HTTP example I've been talking about: /* * $Header: * $Revision$ * $Date$ * ==================================================================== * * Copyright 2002-2004 The Apache Software Foundation * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * * [Additional notices, if required by prior licensing conditions] * */ import java.io.File; import java.io.FileInputStream; import org.apache.commons.httpclient.HttpClient; import org.apache.commons.httpclient.methods.InputStreamRequestEntity; import org.apache.commons.httpclient.methods.PostMethod; /** * * This is a sample application that demonstrates * how to use the Jakarta HttpClient API. * * This application sends an XML document * to a remote web server using HTTP POST * * @author Sean C. Sullivan * @author Ortwin Glück * @author Oleg Kalnichevski */ public class PostXML { /** * * Usage: * java PostXML http://mywebserver:80/ c:\foo.xml * * @param args command line arguments * Argument 0 is a URL to a web server * Argument 1 is a local filename * */ public static void main(String[] args) throws Exception { if (args.length != 2) { System.out.println( "Usage: java -classpath <classpath> [-Dorg.apache.commons."+ "logging.simplelog.defaultlog=<loglevel>]" + " PostXML <url> <filename>]"); System.out.println("<classpath> - must contain the "+ "commons-httpclient.jar and commons-logging.jar"); System.out.println("<loglevel> - one of error, "+ "warn, info, debug, trace"); System.out.println("<url> - the URL to post the file to"); System.out.println("<filename> - file to post to the URL"); System.out.println(); System.exit(1); } // Get target URL String strURL = args[0]; // Get file to be posted String strXMLFilename = args[1]; File input = new File(strXMLFilename); // Prepare HTTP post PostMethod post = new PostMethod(strURL); // Request content will be retrieved directly // from the input stream // Per default, the request content needs to be buffered // in order to determine its length. // Request body buffering can be avoided when // content length is explicitly specified post.setRequestEntity(new InputStreamRequestEntity( new FileInputStream(input), input.length())); // Specify content type and encoding // If content encoding is not explicitly specified // ISO-8859-1 is assumed post.setRequestHeader( "Content-type", "text/xml; charset=ISO-8859-1"); // Get HTTP client HttpClient httpclient = new HttpClient(); // Execute request try { int result = httpclient.executeMethod(post); // Display status code System.out.println("Response status code: " + result); // Display response System.out.println("Response body: "); System.out.println(post.getResponseBodyAsString()); } finally { // Release current connection to the connection pool // once you are done post.releaseConnection(); } } }

    Read the article

  • FileInputStream for a generic file System

    - by Akhil
    I have a file that contains java serialized objects like "Vector". I have stored this file over Hadoop Distributed File System(HDFS). Now I intend to read this file (using method readObject) in one of the map task. I suppose FileInputStream in = new FileInputStream("hdfs/path/to/file"); wont' work as the file is stored over HDFS. So I thought of using org.apache.hadoop.fs.FileSystem class. But Unfortunately it does not have any method that returns FileInputStream. All it has is a method that returns FSDataInputStream but I want a inputstream that can read serialized java objects like vector from a file rather than just primitive data types that FSDataInputStream would do. Please help!

    Read the article

  • Which programming language to choose? (for a specific problem/domain, details inside)

    - by Bijan
    I am building a trading portfolio management system that is responsible for production, optimization, and simulation of non-high frequency trading portfolios (dealing with 1min or 3min bars of data, not tick data). I plan on employing Amazon web services to take on the entire load of the application. I have four choices that I am considering as language. a) Java b) C++ c) C# d) Python Here is the scope of the extremes of the project scope. This isn't how it will be, maybe ever, but it's within the scope of the requirements: Weekly simulation of 10,000,000 trading systems. (Each trading system is expected to have its own data mining methods, including feature selection algorithms which are extremely computationally-expensive. Imagine 500-5000 features using wrappers. These are not run often by any means, but it's still a consideration) Real-time production of portfolio w/ 100,000 trading strategies Taking in 1 min or 3 min data from every stock/futures market around the globe (approx 100,000) Portfolio optimization of portfolios with up to 100,000 strategies. (rather intensive algorithm) Speed is a concern, but I believe that Java can handle the load. I just want to make sure that Java CAN handle the above requirements comfortably. I don't want to do the project in C++, but I will if it's required. The reason C# is on there is because I thought it was a good alternative to Java, even though I don't like Windows at all and would prefer Java if all things are the same. Python - I've read somethings on PyPy and pyscho that claim python can be optimized with JIT compiling to run at near C-like speeds.... That's pretty much the only reason it is on this list, besides that fact that Python is a great language and would probably be the most enjoyable language to code in, which is not a factor at all for this project, but a perk. To sum up: - real time production - weekly simulations of a large number of systems - weekly/monthly optimizations of portfolios - large numbers of connections to collect data from There is no dealing with millisecond or even second based trades. The only consideration is if Java can possibly deal with this kind of load when spread out of a necessary amount of EC2 servers. Thank you guys so much for your wisdom.

    Read the article

  • amazon design doubt

    - by praveen
    I was looking at the amazon website and was wondering how one of the feature would have been implemented. The feature : what customers buy after viewing a particular item. If i were to develop such a feature i would probably generate a session id for each user session and store the session id-page id combination in a log file. and if a book is bought set a separate flag for the session id-page id. A separate program can then be run on the log file periodically, to identify the groups that were bought together/viewed together and that information can be stored in a persistent file. This is ofcourse a simple solution without taking into consideration the distributed nature of the servers - but would this suffice or can you help me identify a better design.

    Read the article

< Previous Page | 163 164 165 166 167 168 169 170 171 172 173 174  | Next Page >