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  • Q&amp;A: Where does high performance computing fit with Windows Azure?

    - by Eric Nelson
    Answer I have been asked a couple of times this year about taking compute intensive operations to Windows Azure and/or High Performance Computing on Windows Azure. It is an interesting (if slightly niche) area. The good news is we have a great paper from David Chappell on HPC Server and Windows Azure integration. As a taster: A SOA application running entirely on Windows Azure runs its WCF services in Azure Worker nodes. Download now Related Links: Other Q&A posts on my team blog Don’t forget to connect with the UK team if you stumbled across this post by accident/bing/google

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  • Are VM-based languages becoming viable for Graphics since the move to GPU computing?

    - by skiwi
    Perhaps the title is not the most clear, so let me elaborate it more: I am talking about VM-based languages, by that I mean languages that run on the JVM (java) and for example C#. Also I am talking about 3D graphics, just to be clear. Lately the trend has been that most computing is being done on the GPU and not on the CPU, and since times the issue with programming games on a VM-based language is that garbage collecting may happen randomly. So let's take a look which is responsible for what: Showing the graphics: GPU Uploading graphics to the GPU: CPU? Needs to be done every frame? Calculating physics constraints: GPU Doing the real game logic (Determining when to move objects (independent of physics calculations), processing AI): CPU Is my list actually correct? And if it is, is for example Java becoming more viable? Or is uploading the graphics (vertices) still the most expensive operation? Would like to get more insight into this.

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  • Raspberry Pi cluster, neuron networks and brain simulation

    - by jokoon
    Since the RBPI (Raspberry Pi) has very low power consumption and very low production price, it means one could build a very big cluster with those. I'm not sure, but a cluster of 100000 RBPI would take little power and little room. Now I think it might not be as powerful as existing supercomputers in terms of FLOPS or others sorts of computing measurements, but could it allow better neuronal network simulation ? I'm not sure if saying "1 CPU = 1 neuron" is a reasonable statement, but it seems valid enough. So does it mean such a cluster would more efficient for neuronal network simulation, since it's far more parallel than other classical clusters ?

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  • what is a data serialization system?

    - by Yang
    according to Apache AVRO project, "Avro is a serialization system". By saying data serialization system, does it mean that avro is a product or api? also, I am not quit sure about what a data serialization system is? for now, my understanding is that it is a protocol that defines how data object is passed over the network. Can anyone help explain it in an intuitive way that it is easier for people with limited distributed computing background to understand? Thanks in advance!

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  • Using Parallel Extensions In Web Applications

    - by Greg
    I'd like to hear some opinions as to what role, if any, parallel computing approaches, including the potential use of the parallel extensions (June CTP for example), have a in web applications. What scenarios does this approach fit and/or not fit for? My understanding of how exactly IIS and web browsers thread tasks is fairly limited. I would appreciate some insight on that if someone out there has a good understanding. I'm more curious to know if the way that IIS and web browsers work limits the ROI of creating threaded and/or asynchronous tasks in web applications in general. Thanks in advance.

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  • What considerations should be made for a web app to be released on a cloud hosted system?

    - by Rhubarb
    I have a web app that is primarily a WordPress app, but it pulls content from a Django app, simply by calling a service that uses Django models. My understanding of cloud computing is a bit vague. If the site needs to scale up with short notice, does the cloud provider (Amazon, Rackspace, whomever) simply spin up new instances (copies) of my initially configured server? How is state managed between all of them? Are there any good primers on this subject? It's hard to find much out there without getting caught up in the marketing.

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  • How can I call an executable to run on a separate machine within a program on my own machine (win xp

    - by Mr. H.
    My objective is to write a program which will call another executable on a separate computer(all with win xp) with parameters determined at run-time, then repeat for several more computers, and then collect the results. In short, I'm working on a grid-computing project. The algorithm itself being used is already coded in FORTRAN, but we are looking for an efficient way to run it on many computers at once. I suppose one way to accomplish this would be to upload a script to each computer and then run said script on each computer, all automatically and dependent on my own parameters. But how can I write a program which will write to, upload, and run a script on a separate computer? I had considered GridGain, but the algorithm is already coded and in a different language, so that is ruled out. My current guess at accomplishing this task is using Expect (wiki/Expect), but I have no knowledge of the tool. Any advice appreciated.

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  • "cloud architecture" concepts in a system architecture diagrams

    - by markus
    If you design a distributed application for easy scale-out, or you just want to make use of any of the new “cloud computing” offerings by Amazon, Google or Microsoft, there are some typical concepts or components you usually end up using: distributed blob storage (aka S3) asynchronous, durable message queues (aka SQS) non-Relational-/non-transactional databases (like SimpleDB, Google BigTable, Azure SQL Services) distributed background worker pool load-balanced, edge-service processes handling user requests (often virtualized) distributed caches (like memcached) CDN (content delivery network like Akamai) Now when it comes to design and sketch an architecture that makes use of such patterns, are there any commonly used symbols I could use? Or even a download with some cool Visio stencils? :) It doesn’t have to be a formal system like UML but I think it would be great if there were symbols that everyone knows and understands, like we have commonly used shapes for databases or a documents, for example. I think it would be important to not mix it up with traditional concepts like a normal file system (local or network server/SAN), or a relational database. Simply speaking, I want to be able to draw some conclusions about an application’s scalability or data consistency issues by just looking at the system architecture overview diagram. Update: Thank you very much for your answers. I like the idea of putting a small "cloud symbol" on the traditional symbols. However I leave this thread open just in case someone will find specific symbols (maybe in a book or so) - or uploaded some pimped up Visio stencils ;)

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  • When should one use the following: Amazon EC2, Google App Engine, Microsoft Azure and Salesforce.com

    - by vicky21
    I am asking this in very general sense. Both from cloud provider and cloud consumer's perspective. Also the question is not for any specific kind of application (in fact the intention is to know which type of applications/domains can fit into which of the cloud slab -SaaS PaaS IaaS). My understanding so far is: IaaS: Raw Hardware (Processors, Networks, Storage). PaaS: OS, System Softwares, Development Framework, Virtual Machines. SaaS: Software Applications. It would be great if Stackoverflower's can share their understanding and experiences of cloud computing concept. EDIT: Ok, I will put it in more specific way - Amazon EC2: You don't have control over hardware layer. But you can take your choice of OS image, Dev Framework (.NET, J2EE, LAMP) and Application and put it on EC2 hardware. Can you deploy an applications built with Google App Engine or Azure on EC2? Google App Engine: You don't have control over hardware and OS and you get a specific Dev Framework to build your application. Can you take any existing Java or Python application and port it to GAE? Or vice versa, can applications that were built on GAE be taken out of GAE and ported to any Application Server like Websphere or Weblogic? Azure: You don't have control over hardware and OS and you get a specific Dev Framework to build your application. Can you take any existing .NET application and port it to Azure? Or vice versa, can applications that were built on Azure be taken out of Azure and ported to any Application Server like Biztalk?

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  • RMI no such object in table, Server communication error

    - by ben-casey
    My goal is to create a Distributed computing program that launches a server and client at the same time. I need it to be able to install on a couple of machines and have all the machines communicating with each other, i.e. Master node and 5 slave nodes all from one application. My problem is that I cannot properly use unicastRef, I'm thinking that it is a problem with launching everything on the same port, is there a better way I am overlooking? this is part of my code (the part that matters) try { RMIServer obj = new RMIServer(); obj.start(5225); } catch (Exception e) { e.printStackTrace(); } try { System.out.println("We are slave's "); Registry rr = LocateRegistry.getRegistry("127.0.0.1", Store.PORT, new RClient()); Call ss = (Call) rr.lookup("FILLER"); System.out.println(ss.getHello()); } catch (Exception e) { e.printStackTrace(); } } this is my main class (above) this is the server class (below) public RMIServer() { } public void start(int port) throws Exception { try { Registry registry = LocateRegistry.createRegistry(port, new RClient(), new RServer()); Call stuff = new Call(); registry.bind("FILLER", stuff); System.out.println("Server ready"); } catch (Exception e) { System.err.println("Server exception: " + e.toString()); e.printStackTrace(); } } I don't know what I am missing or what I am overlooking but the output looks like this. Listen on 5225 Listen on 8776 Server ready We are slave's Listen on 8776 java.rmi.NoSuchObjectException: no such object in table at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:255) at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:233) at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:359) at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source) at Main.main(Main.java:62) line 62 is this ::: Call ss = (Call) rr.lookup("FILLER");

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  • Moving a ASP.NET application to the cloud

    - by user102533
    I am new to cloud computing, so please bear with me here. I have an existing ASP.NET application with SQL Server 2008 hosted on a Virtual Private Server. Here's what it briefly does: The front end accepts user's requests and adds them to a DB table A Windows Service running in the background picks up the request, processes it and sets a flag. The Windows Services also creates a file for the user to download. User downloads file I'd like to move this web application with the service to the cloud. The architecture I envision is that I'll have 1 Web server in which I will install the front end and the windows service. I'll also have a cloud files server for file storage. The windows service should somehow create a file and transfer it to the cloud file server (I assume this is possible?) My questions: Does the architecture look like I am going in the right direction? I know Amazon has been providing cloud services for a long time. If I want to do minimal changes to my application, should I go with Amazon, Rackspace, Azure or some other provider? I understand that I would not only pay for file storage and web server but also for the bandwidth of users downloading the file and the windows servic uploading the file to the cloud server. Can I assume these costs are negligible? Should I go with VPS + Cloud Files combination to begin with? Any other thoughts/suggestions?

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  • Scientific calculator app/site that saves calculations for Win 7?

    - by verve
    Are there any scientific calculator apps that aren't browser specific that's easy to use which displays whatever is inputted clearly and one that can be used by a keyboard only but can be used by only a mouse too? Also, I want one that saves the history of calculations and lets us paste it into a document at another time. Also, please don't recommend ones from sketchy-looking sites. Freeware or paidware. I prefer paidware if it's the only way to guarantee accurate calculations. Win 7 Pro.

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  • Computing pixel's screen position in a vertex shader: right or wrong?

    - by cubrman
    I am building a deferred rendering engine and I have a question. The article I took the sample code from suggested computing screen position of the pixel as follows: VertexShaderFunction() { ... output.Position = mul(worldViewProj, input.Position); output.ScreenPosition = output.Position; } PixelShaderFunction() { input.ScreenPosition.xy /= input.ScreenPosition.w; float2 TexCoord = 0.5f * (float2(input.ScreenPosition.x,-input.ScreenPosition.y) + 1); ... } The question is what if I compute the position in the vertex shader (which should optimize the performance as VSF is launched significantly less number of times than PSF) would I get the per-vertex lighting insted. Here is how I want to do this: VertexShaderFunction() { ... output.Position = mul(worldViewProj, input.Position); output.ScreenPosition.xy = output.Position / output.Position.w; } PixelShaderFunction() { float2 TexCoord = 0.5f * (float2(input.ScreenPosition.x,-input.ScreenPosition.y) + 1); ... } What exactly happens with the data I pass from VS to PS? How exactly is it interpolated? Will it give me the right per-pixel result in this case? I tried launching the game both ways and saw no visual difference. Is my assumption right? Thanks. P.S. I am optimizing the point light shader, so I actually pass a sphere geometry into the VS.

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  • mrepo and grouplist/groupinstall?, mrepo not working as expected with group

    - by user52874
    All, I'm trying to set up mrepo so we can have internal repositories. After quite the slog, things seem to be working as expected EXCEPT for groups. From man createrepo: EXAMPLES Here is an example of a repository with a groups file. Note that the groups file should be in the same directory as the rpm packages (i.e. /path/to/rpms/comps.xml). createrepo -g comps.xml /path/to/rpms So here's what I'm doing: wget -c http://ftp.scientificlinux.org/linux/scientific/6/x86_64/os/repodata/comps-sl6-x86_64.xml cp comps-sl6-x86_64.xml /var/mrepo/SL6-x86_64/os/Packages/comps-sl6-x86_64.xml createrepo -g comps-sl6-x86_64.xml /var/mrepo/SL6-x86_64/os/Packages/ lots of output, no apparent errors or warnings BUT.. from a client: yum grouplist Loaded plugins: refresh-packagekit Setting up Group Process Error: No group data available for configured repositories Here's /etc/mrepo.conf: ### Configuration file for mrepo ### The [main] section allows to override mrepo's default settings ### The mrepo-example.conf gives an overview of all the possible settings [main] srcdir = /var/mrepo wwwdir = /var/www/mrepo confdir = /etc/mrepo.conf.d arch = x86_64 mailto = root@localhost smtp-server = localhost pxelinux = /usr/lib/syslinux/pxelinux.0 tftpdir = /tftpboot #rhnlogin = username:password ### Any other section is considered a definition for a distribution ### You can put distribution sections in /etc/mrepo.conf.d ### Examples can be found in the documentation. Here's /etc/mrepo.conf.d/sl6.mrepo: ### Scientific Linux 6 [SL6] name = Scientific Linux 6 release = 6 arch = x86_64 metadata = repomd repoview os = rsync://rsync.scientificlinux.org/scientific/$release/$arch/os/ updates = rsync://rsync.scientificlinux.org/scientific/$release/$arch/updates/ security = rsync://rsync.scientificlinux.org/scientific/$release/$arch/updates/security/ fastbugs = rsync://rsync.scientificlinux.org/scientific/$release/$arch/updates/fastbugs/

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  • "Unable to associated Elastic IP with cluster" in Eclipse Plugin Tutorial

    - by Jeffrey Chee
    Hi all, I am currently trying to evaluate AWS for my company and was trying to follow the tutorials on the web. http://developer.amazonwebservices.com/connect/entry.jspa?externalID=2241 However I get the below error during startup of the server instance: Unable to associated Elastic IP with cluster: Unable to detect that the Elastic IP was orrectly associated. java.lang.Exception: Unable to detect that the Elastic IP was correctly associated at com.amazonaws.ec2.cluster.Cluster.associateElasticIp(Cluster.java:802) at com.amazonaws.ec2.cluster.Cluster.start(Cluster.java:311) at com.amazonaws.eclipse.wtp.ElasticClusterBehavior.launch(ElasticClusterBehavior.java:611) at com.amazonaws.eclipse.wtp.Ec2LaunchConfigurationDelegate.launch(Ec2LaunchConfigurationDelegate.java:47) at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:853) at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:703) at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:696) at org.eclipse.wst.server.core.internal.Server.startImpl2(Server.java:3051) at org.eclipse.wst.server.core.internal.Server.startImpl(Server.java:3001) at org.eclipse.wst.server.core.internal.Server$StartJob.run(Server.java:300) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55) Then after a while, another error occur: Unable to publish server configuration files: Unable to copy remote file after trying 4 timeslocal file: 'XXXXXXXX/XXX.zip' Results from first attempt: Unexpected exception: java.net.ConnectException: Connection timed out: connect root cause: java.net.ConnectException: Connection timed out: connect at com.amazonaws.eclipse.ec2.RemoteCommandUtils.copyRemoteFile(RemoteCommandUtils.java:128) at com.amazonaws.eclipse.wtp.tomcat.Ec2TomcatServer.publishServerConfiguration(Ec2TomcatServer.java:172) at com.amazonaws.ec2.cluster.Cluster.publishServerConfiguration(Cluster.java:369) at com.amazonaws.eclipse.wtp.ElasticClusterBehavior.publishServer(ElasticClusterBehavior.java:538) at org.eclipse.wst.server.core.model.ServerBehaviourDelegate.publish(ServerBehaviourDelegate.java:866) at org.eclipse.wst.server.core.model.ServerBehaviourDelegate.publish(ServerBehaviourDelegate.java:708) at org.eclipse.wst.server.core.internal.Server.publishImpl(Server.java:2731) at org.eclipse.wst.server.core.internal.Server$PublishJob.run(Server.java:278) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55) Can anyone point me to what I'm doing wrong? I followed the tutorials and the video tutorials on youtube exactly. Best Regards ~Jeffrey

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  • Hadoop safemode recovery - taking lot of time

    - by Algorist
    Hi, We are running our cluster on Amazon EC2. we are using cloudera scripts to setup hadoop. On the master node, we start below services. 609 $AS_HADOOP '"$HADOOP_HOME"/bin/hadoop-daemon.sh start namenode' 610 $AS_HADOOP '"$HADOOP_HOME"/bin/hadoop-daemon.sh start secondarynamenode' 611 $AS_HADOOP '"$HADOOP_HOME"/bin/hadoop-daemon.sh start jobtracker' 612 613 $AS_HADOOP '"$HADOOP_HOME"/bin/hadoop dfsadmin -safemode wait' On the slave machine, we run the below services. 625 $AS_HADOOP '"$HADOOP_HOME"/bin/hadoop-daemon.sh start datanode' 626 $AS_HADOOP '"$HADOOP_HOME"/bin/hadoop-daemon.sh start tasktracker' The main problem we are facing is, hdfs safemode recovery is taking more than an hour and this is causing delays in our job completion. Below are the main log messages. 1. domU-12-31-39-0A-34-61.compute-1.internal 10/05/05 20:44:19 INFO ipc.Client: Retrying connect to server: ec2-184-73-64-64.compute-1.amazonaws.com/10.192.11.240:8020. Already tried 21 time(s). 2. The reported blocks 283634 needs additional 322258 blocks to reach the threshold 0.9990 of total blocks 606499. Safe mode will be turned off automatically. The first message is thrown in task trackers log because, job tracker is not started. job tracker didn't start because of hdfs safemode recovery. The second message is thrown during the recovery process. Is there something I am doing wrong? How much time does normal hdfs safemode recovery takes? Will there be any speedup, by not starting task trackers till job tracker is started? Are there any known hadoop problems on amazon cluster? Thanks for your help. Regards Bala Mudiam

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  • Jini : single server with multiple clients

    - by user200340
    Hi all, I have a question about how to make multiple clients can access a single file located on server side and keep the file consistent. I have a simple PhoneBook server-client Jini program running at the moment, and server only provides some getter functions to clients, such as getName(String number), getNumber(String name) from a PhoneBook class(serializable), phonebook data are stored in a text file (phonebook.txt) at the moment. I have tried to implement some functions allowing to write a new records into the phonebook.txt file. If the writing record (name) is existing, an integer number will be added into the writing record. for example the existing phonebook.txt is .... John 01-01010101 .... if the writing record is "John 01-12345678",then "John_1 01-12345678" will be writen into phonebook.txt However, if i start with two clients A and B (on the same machine using localhost), and A tries to write "John 01-11111111", B tries to write "John 01-22222222". The early record will be overwritten later record. So, there must be something i did complete wrong. My client and server code are just like Jini HelloWorld example. My server side code is . 1. LookupDiscovery with parameter new String[]{""}; 2. DiscoveryListener for LookupDiscovery 3. registrations are saved into a HashTable 4. for every discovered lookup service, i use registrar to register the ServiceItem, ServiceItem contains a null attributeSets, a null serviceId, and a service. The client code has: 1. LookupDiscovery with parameter new String[]{""}; 2. DiscoveryListener for LookupDiscovery 3. a ServiceTemplate with null attributeSets, a null serviceId and a type, the type is the interface class. 4. for each found ServiceRegistrar, if it can find the looking for ServiceTemplate, the returned Object is cast into the type of the interface class. I have tried to google more details, and i found JavaSpace could be the one i missed. But i am still not sure about it (i only start Jini for a very short time). So any help would be greatly appreciated.

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  • Best cubicle toys for programming

    - by dlamblin
    I need some employee/co-worker Christmas gift ideas. Do you have any good cubicle toys that help you to do any of: think about programming problems solve programming problems by representing common abstractions can be directly programmed can interface with a PC based IDE to be programmed. it may present problems that can be solved, to kick start problem solving. Disallowed items are: reference material in book, pamphlet, poster or cheat-sheet form, even if it has kick ass pop-cultural references. edibles. [discuss separately] things that need their own lab-space and/or extensive tools to be worked with. So yes, Lego Mindstorms come to mind, but they aren't cubicle toys because they cost more than cubicle toys would, and they have too many losable parts. comments on the answers so far: The 20 Questions game sounds quite neat as it could get you thinking; The bean balls could be used as tokens in a problem, so I can see that working. The magnetic toys like ball of whacks or the ball-and-stick ones present hands on fun of a structural nature... now can there be a similar hands on fun toy that aids in representing a solution to a problem? The Gui Mags clearly could, but they're quite utility oriented. The AVR Butterfly is less of a toy but definitely priced attractively, cheaper and more responsive than a basic stamp. I'm not going to pick an answer; there's several great suggestions here. Thank you.

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  • Software tools for allowing end users to reprogram interfaces

    - by iceman
    What would be the examples of commercial software products (specially web-services) which allow the end user to reprogram their user-interface? I mean end users who do not know programming and they are allowed to add more functionality. One way of doing it is allowing XML gadgets like iGoogle does. What are the other approaches and also the technologies enabling them? This would be a futuristic application like collaborative software development for users.

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  • Hadooop map reduce

    - by Aina Ari
    Im very much new to map reduce and i completed hadoop wordcount example. In that example it produces unsorted file (with key value) of word counts. So is it possible to make it sorted according to the most number of word occurrences by combining another map reduce task to the earlier one. Thanks in Advance

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  • Draw on screen border in Commodore 64

    - by Stefano Borini
    Ok. I hope it does not get closed because I have this curiosity since 25 years and I would love to understand the trick. In the commodore 64 the border was not addressable by the 6569 VIC. All you could do was to draw pixels in the central area, the one where the cursor moved. The border was always uniform, although you could change its color with poke 53280,color if i remember correctly. Nevertheless I clearly remember games intros where the border was featured with graphics, like it was fully addressable. I tried to understand how it worked but never got to the point. legends say it was a clever use of sprites, which could, under some circumstances, be drawn on the border, but I don't know if it's an urban legend. edit: just read this from one of the provided links Sprites were multiplexed across vertical raster lines (over 8 sprites, sometimes up to 120 sprites). Until the Group Crest released Krestage 3 in May 2007 there was the common perception that no more than 8 sprites could appear at one raster line, but assigning new Y coordinates made it reappear further down the screen. This is evil.... you beat the raster and reposition the sprite before it gets there...

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