Search Results

Search found 18842 results on 754 pages for 'the machine'.

Page 701/754 | < Previous Page | 697 698 699 700 701 702 703 704 705 706 707 708  | Next Page >

• Access denied error while mounting a shared folder?

  - by SSH

  I am a linux newbie and I have a very basic question. I have three machines - machineA 10.108.24.132 machineB 10.108.24.133 machineC 10.108.24.134 and all those machines have Ubuntu 12.04 installed in it and I have root access to all those three machines. Now I am supposed to do below things in my above machines - Create mount point /opt/exhibitor/conf Mount the directory in all servers. sudo mount <NFS-SERVER>:/opt/exhibitor/conf /opt/exhibitor/conf/ I have already created /opt/exhibitor/conf directory in all those three machines as mentioned above. Now I am trying to create a Mount Point on all those three machines. So I followed the below process - Install NFS support files and NFS kernel server in all the above three machines $ sudo apt-get install nfs-common nfs-kernel-server Create the shared directory in all the above three machines $ mkdir /opt/exhibitor/conf/ Edited the /etc/exports and added the entry like this in all the above three machines - # /etc/exports: the access control list for filesystems which may be exported # to NFS clients. See exports(5). # # Example for NFSv2 and NFSv3: # /srv/homes hostname1(rw,sync,no_subtree_check) hostname2(ro,sync,no_subtree_check) # # Example for NFSv4: # /srv/nfs4 gss/krb5i(rw,sync,fsid=0,crossmnt,no_subtree_check) # /srv/nfs4/homes gss/krb5i(rw,sync,no_subtree_check) # /opt/exhibitor/conf/ 10.108.24.*(rw) Run exportfs in all the above three machines root@machineA:/# exportfs -rv exportfs: /etc/exports [1]: Neither 'subtree_check' or 'no_subtree_check' specified for export "10.108.24.*:/opt/exhibitor/conf/". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exporting 10.108.24.*:/opt/exhibitor/conf Now I did showmount on machineA root@machineA:/# showmount -e 10.108.24.132 Export list for 10.108.24.132: /opt/exhibitor/conf 10.108.24.* And also I have started the NFS server like this in all the above three machines - sudo /etc/init.d/nfs-kernel-server start And now when I did this, I am getting an error - root@machineA:/# sudo mount -t nfs 10.108.24.132:/opt/exhibitor/conf /opt/exhibitor/conf/ mount.nfs: access denied by server while mounting 10.108.24.132:/opt/exhibitor/conf I have also tried doing the same thing from machineB and machineC as well and still I get the same error- root@machineB:/# sudo mount -t nfs 10.108.24.132:/opt/exhibitor/conf /opt/exhibitor/conf/ root@machineC:/# sudo mount -t nfs 10.108.24.132:/opt/exhibitor/conf /opt/exhibitor/conf/ Did my /etc/exports file looks good? As I have the same content in all the three machines. And also are there any logs related to NFS which I can see to find any clues? Any idea what wrong I am doing here? UPDATE:- So my etc/exports files would be like this in all the three machines - # /etc/exports: the access control list for filesystems which may be exported # to NFS clients. See exports(5). # # Example for NFSv2 and NFSv3: # /srv/homes hostname1(rw,sync,no_subtree_check) hostname2(ro,sync,no_subtree_check) # # Example for NFSv4: # /srv/nfs4 gss/krb5i(rw,sync,fsid=0,crossmnt,no_subtree_check) # /srv/nfs4/homes gss/krb5i(rw,sync,no_subtree_check) # /opt/exhibitor/conf/ 10.108.24.132(rw) /opt/exhibitor/conf/ 10.108.24.133(rw) /opt/exhibitor/conf/ 10.108.24.134(rw) Just a quick check - The IP Address that I am taking for each machine as mentioned above is like this - root@machineB:/# ifconfig eth0 Link encap:Ethernet HWaddr 00:50:56:ad:5b:a7 inet addr:10.108.24.133 Bcast:10.108.27.255 Mask:255.255.252.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:5696812 errors:0 dropped:12462 overruns:0 frame:0 TX packets:5083427 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:7904369145 (7.9 GB) TX bytes:601844910 (601.8 MB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:187144 errors:0 dropped:0 overruns:0 frame:0 TX packets:187144 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:24012302 (24.0 MB) TX bytes:24012302 (24.0 MB) Here the IP Address that I am taking for machineB is 10.108.24.133.

  Read the article

• The battle between Java vs. C#

  The battle between Java vs. C# has been a big debate amongst the development community over the last few years. Both languages have specific pros and cons based on the needs of a particular project. In general both languages utilize a similar coding syntax that is based on C++, and offer developers similar functionality. This being said, the communities supporting each of these languages are very different. The divide amongst the communities is much like the political divide in America, where the Java community would represent the Democrats and the .Net community would represent the Republicans. The Democratic Party is a proponent of the working class and the general population. Currently, Java is deeply entrenched in the open source community that is distributed freely to anyone who has an interest in using it. Open source communities rely on developers to keep it alive by constantly contributing code to make applications better; essentially they develop code by the community. This is in stark contrast to the C# community that is typically a pay to play community meaning that you must pay for code that you want to use because it is developed as products to be marketed and sold for a profit. This ties back into my reference to the Republicans because they typically represent the needs of business and personal responsibility. This is emphasized by the belief that code is a commodity and that it can be sold for a profit which is in direct conflict to the laissez-faire beliefs of the open source community. Beyond the general differences between Java and C#, they also target two different environments. Java is developed to be environment independent and only requires that users have a Java virtual machine running in order for the java code to execute. C# on the other hand typically targets any system running a windows operating system and has the appropriate version of the .Net Framework installed. However, recently there has been push by a segment of the Open source community based around the Mono project that lets C# code run on other non-windows operating systems. In addition, another feature of C# is that it compiles into an intermediate language, and this is what is executed when the program runs. Because C# is reduced down to an intermediate language called Common Language Runtime (CLR) it can be combined with other languages that are also compiled in to the CLR like Visual Basic (VB) .Net, and F#. The allowance and interaction between multiple languages in the .Net Framework enables projects to utilize existing code bases regardless of the actual syntax because they can be compiled in to CLR and executed as one codebase. As a software engineer I personally feel that it is really important to learn as many languages as you can or at least be open to learn as many languages as you can because no one language will work in every situation.  In some cases Java may be a better choice for a project and others may be C#. It really depends on the requirements of a project and the time constraints. In addition, I feel that is really important to concentrate on understanding the logic of programming and be able to translate business requirements into technical requirements. If you can understand both programming logic and business requirements then deciding which language to use is just basically choosing what syntax to write for a given business problem or need. In regards to code refactoring and dynamic languages it really does not matter. Eventually all projects will be refactored or decommissioned to allow for progress. This is the way of life in the software development industry. The language of a project should not be chosen based on the fact that a project will eventually be refactored because they all will get refactored.

  Read the article

• Randomely loosing wireless connexion with Cubuntu 12.04

  - by statquant

  I am presently experiencing random disconnections from my wireless network. It looks like it is more and more frequent (however I have not seen any clear pattern). This is killing me... Here is some information that should help (from ubuntu forums). Thanks for reading Machine : Acer Aspire S3 statquant@euclide:~$ lsb_release -d Description: Ubuntu 12.04.1 LTS statquant@euclide:~$ uname -mr 3.2.0-33-generic x86_64 statquant@euclide:~$ sudo /etc/init.d/networking restart * Running /etc/init.d/networking restart is deprecated because it may not enable again some interfaces * Reconfiguring network interfaces... statquant@euclide:~$ lspci 02:00.0 Network controller: Atheros Communications Inc. AR9485 Wireless Network Adapter (rev 01) statquant@euclide:~$ lsusb Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 004: ID 064e:c321 Suyin Corp. Bus 002 Device 003: ID 0bda:0129 Realtek Semiconductor Corp. statquant@euclide:~$ ifconfig wlan0 Link encap:Ethernet HWaddr 74:de:2b:dd:c4:78 inet addr:192.168.1.3 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::76de:2bff:fedd:c478/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:913 errors:0 dropped:0 overruns:0 frame:0 TX packets:802 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:873218 (873.2 KB) TX bytes:125826 (125.8 KB) statquant@euclide:~$ iwconfig wlan0 IEEE 802.11bgn ESSID:"Bbox-D646D1" Mode:Managed Frequency:2.437 GHz Access Point: 00:19:70:80:01:6C Bit Rate=65 Mb/s Tx-Power=16 dBm Retry long limit:7 RTS thr:off Fragment thr:off Power Management:on Link Quality=56/70 Signal level=-54 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:71 Missed beacon:0 statquant@euclide:~$ dmesg | grep "wlan" [ 17.495866] ADDRCONF(NETDEV_UP): wlan0: link is not ready [ 17.498950] ADDRCONF(NETDEV_UP): wlan0: link is not ready [ 20.072015] wlan0: authenticate with 00:19:70:80:01:6c (try 1) [ 20.269853] wlan0: authenticate with 00:19:70:80:01:6c (try 2) [ 20.272386] wlan0: authenticated [ 20.298682] wlan0: associate with 00:19:70:80:01:6c (try 1) [ 20.302321] wlan0: RX AssocResp from 00:19:70:80:01:6c (capab=0x431 status=0 aid=1) [ 20.302325] wlan0: associated [ 20.307307] ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready [ 30.402292] wlan0: no IPv6 routers present statquant@euclide:~$ sudo lshw -C network [sudo] password for statquant: *-network description: Wireless interface product: AR9485 Wireless Network Adapter vendor: Atheros Communications Inc. physical id: 0 bus info: pci@0000:02:00.0 logical name: wlan0 version: 01 serial: 74:de:2b:dd:c4:78 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list rom ethernet physical wireless configuration: broadcast=yes driver=ath9k driverversion=3.2.0-33-generic firmware=N/A ip=192.168.1.3 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn resources: irq:17 memory:c0400000-c047ffff memory:afb00000-afb0ffff statquant@euclide:~$ iwlist scan wlan0 Scan completed : Cell 01 - Address: 00:19:70:80:01:6C Channel:6 Frequency:2.437 GHz (Channel 6) Quality=56/70 Signal level=-54 dBm Encryption key:on ESSID:"Bbox-D646D1" Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s 9 Mb/s; 12 Mb/s; 18 Mb/s Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s Mode:Master Extra:tsf=000000125fb152bb Extra: Last beacon: 40020ms ago IE: Unknown: 000B42626F782D443634364431 IE: Unknown: 010882848B960C121824 IE: Unknown: 030106 IE: IEEE 802.11i/WPA2 Version 1 Group Cipher : TKIP Pairwise Ciphers (2) : CCMP TKIP Authentication Suites (1) : PSK IE: WPA Version 1 Group Cipher : TKIP Pairwise Ciphers (2) : CCMP TKIP Authentication Suites (1) : PSK IE: Unknown: 2A0100 IE: Unknown: 32043048606C IE: Unknown: DD180050F2020101820003A4000027A4000042435E0062322F00 IE: Unknown: 2D1A4C101BFF00000000000000000000000000000000000000000000 IE: Unknown: 3D1606080800000000000000000000000000000000000000 IE: Unknown: DD0900037F01010000FF7F IE: Unknown: DD0A00037F04010000000000 And... finally, please note that I did the following (after looking for fixes of similar problems), but unfortunately it did not work sudo modprobe -r iwlwifi sudo modprobe iwlwifi 11n_disable=1

  Read the article

• Passing data between the VirtualBox Host and the Guest

  - by Fat Bloke

  Here's a good question: "How can you figure out the VM name from within the VM itself?" While this data is not automatically available, the general purpose, and very powerful VirtualBox "GuestProperty" APIs can be used from the host and guest to pass arbitrary data, in key/value pairs format, in and out of the guest. Note that this does require that the VirtualBox Guest Additions have been installed in the guest. To play with this, try using the "VBoxManage" command line on your VirtualBox host machine, and "VBoxControl" in the guest. Host syntax VBoxManage guestproperty get <vmname>|<uuid> <property> [--verbose] VBoxManage guestproperty set <vmname>|<uuid> <property> [<value> [--flags <flags>]] VBoxManage guestproperty enumerate <vmname>|<uuid> [--patterns <patterns>] VBoxManage guestproperty wait <vmname>|<uuid> <patterns> [--timeout <msec>] [--fail-on-timeout]   Guest syntax VBoxControl.exe guestproperty        get <property> [-verbose] VBoxControl.exe guestproperty        set <property> [<value> [-flags <flags>]] VBoxControl.exe guestproperty        enumerate [-patterns <patterns>] VBoxControl.exe guestproperty        wait <patterns>                                      [-timestamp <last timestamp>]                                      [-timeout <timeout in ms>  So to solve our problem above, we set the vm name in the Host system on an arbitrary key like this: $ VBoxManage guestproperty set "Windows 7 (x64)" /MyData/VMname "Windows 7 (x64)" And within the guest we can use: C:\Program Files\Oracle\VirtualBox Guest Additions>VBoxControl.exe guestproperty get /MyData/VMname Oracle VM VirtualBox Guest Additions Command Line Management Interface Version 4.1.14 (C) 2008-2012 Oracle Corporation All rights reserved. Value: Windows 7 (x64) The GuestProperty API is pretty powerful, so for the interested, get more info in the User Manual. - FB 

  Read the article

• Test your internet connection - Emtel Fixed Broadband

  Already at the begin of April, I had a phone conversation with my representative at Emtel Ltd. about some upcoming issues due to the ongoing construction work in my neighbourhood. Unfortunately, they finally raised the house two levels above ours, and of course this has to have a negative impact on the visibility between the WiMAX outdoor unit on the roof and the aimed access point at Medine. So, today I had a technical team here to do a site survey and to come up with potential solutions. Short version: It doesn't look good after all. The site survey Well, the two technicians did their work properly, even re-arranged the antenna to check the connection with another end point down at La Preneuse. But no improvements. Looks like we are out of luck since the construction next door hasn't finished yet and at the moment, it even looks like they are planning to put at least one more level on top. I really wonder about the sanity of the responsible bodies at the local district council. But that's another story. Anyway, the outdoor unit was once again pointed towards Medine and properly fixed with new cable guides (air from the sea and rust...). Both of them did a good job and fine-tuned the reception signal to a mere 3 over 9; compared to the original 7 over 9 I had before the daily terror started. The site survey has been done, and now it's up to Emtel to come up with (better) solutions. Well, I wouldn't mind to have an unlimited, symmetric 3G/UMTS or even LTE connection. Let's see what they can do... Testing the connection There are several online sites available which offer you to check certain aspects of your internet connection. Personally, I'm used to speedtest.net and it works very well. I think it is good and necessary to check your connection from time to time, and only a couple of days ago, I posted the following on Emtel's wall at Facebook (21.05.2013 - 14:06 hrs): Dear Emtel, could you eventually provide an answer on the miserable results of SpeedTest? I chose Rose Hill (Hosted by Emtel Ltd.) as testing endpoint... Sadly, no response to this. Seems that the marketing department is not willing to deal with customers on Facebook. Okay, over at speedtest.net you can use their Flash-based test suite to check your connection to quite a number of servers of different providers world-wide. It's actually very interesting to see the results for different end points and to compare them to each other. The results Following are the results of Rose Hill (hosted by Emtel) and respectively Frankfurt, Germany (hosted by Vodafone DE): Speedtest.net result of 30.05.2013 between Flic en Flac and Rose Hill, Mauritius (Emtel - Fixed Broadband) Speedtest.net result of 30.05.2013 between Flic en Flac and Frankfurt, Germany (Emtel - Fixed Broadband) Luckily, the results are quite similar in terms of connection speed; which is good. I'm currently on a WiMAX tariff called 'Classic Browsing 2', or Fixed Broadband as they call it now, which provides a symmetric line of 768 Kbps (or roughly 0.75 Mbps). In terms of downloads or uploads this means that I would be able to transfer files in either direction with approximately 96 KB/s. Frankly speaking, thanks to compression, my choice of browser and operating system I usually exceed this value and I have download rates up to 120 KB/s - not too bad after all. Only the ping times are a little bit of concern. Due to the difference in distance, or better said based on the number of hubs between the endpoints, they indicate the amount of time that it takes to send a package from your machine to the remote server and get a response back. A lower value is better, and usually the ping is less than 300 ms between Mauritius and Europe. The alternatives in Mauritius Not sure whether I should note this done because for my requirements there are no alternatives to Emtel WiMAX at the moment. It would be great to have your opinion on the situation of internet connectivity in Mauritius. Are there really alternatives? And if so, what are the conditions?

  Read the article

• eSTEP Newsletter November 2012

  - by mseika

  Dear Partners,We would like to inform you that the November '12 issue of our Newsletter is now available.The issue contains information to the following topics: News from CorpOracle Celebrates 25 Years of SPARC Innovation; IDC White Papers Finds Growing Customer Comfort with Oracle Solaris Operating System; Oracle Buys Instantis; Pillar Axiom OpenWorld Highlights; Announcement Oracle Solaris 11.1 Availability (data sheet, new features, FAQ's, corporate pages, internal blog, download links, Oracle shop); Announcing StorageTek VSM 6; Announcement Oracle Solaris Cluster 4.1 Availability (new features, FAQ's, cluster corp page, download site, shop for media); Announcement: Oracle Database Appliance 2.4 patch update becomes available Technical SectionOracle White papers on SPARC SuperCluster; Understanding Parallel Execution; With LTFS, Tape is Gaining Storage Ground with additional link to How to Create Oracle Solaris 11 Zones with Oracle Enterprise Manager Ops Center; Provisioning Capabilities of Oracle Enterprise Ops Center Manager 12c; Maximizing your SPARC T4 Oracle Solaris Application Performance with the following articles: SPARC T4 Servers Set World Record on Siebel CRM 8.1.1.4 Benchmark, SPARC T4-Based Highly Scalable Solutions Posts New World Record on SPECjEnterprise2010 Benchmark, SPARC T4 Server Delivers Outstanding Performance on Oracle Business Intelligence Enterprise Edition 11g; Oracle SUN ZFS Storage Appliance Reference Architecture for VMware vSphere4; Why 4K? - George Wilson's ZFS Day Talk; Pillar Axiom 600 with connected subjects: Oracle Introduces Pillar Axiom Release 5 Storage System Software, Driving down the high cost of Storage, This Provisioning with Pilar Axiom 600, Pillar Axiom 600- System overview and architecture; Migrate to Oracle;s SPARC Systems; Top 5 Reasons to Migrate to Oracle's SPARC Systems Learning & EventsRecently delivered Techcasts: Learning Paths; Oracle Database 11g: Database Administration (New) - Learning Path; Webcast: Drill Down on Disaster Recovery; What are Oracle Users Doing to Improve Availability and Disaster Recovery; SAP NetWeaver and Oracle Exadata Database Machine ReferencesARTstor Selects Oracle’s Sun ZFS Storage 7420 Appliances To Support Rapidly Growing Digital Image Library, Scottish Widows Cuts Sales Administration 20%, Reduces Time to Prepare Reports by 75%, and Achieves Return on Investment in First Year, Oracle's CRM Cloud Service Powers Innovation: Applications on Demand; Technology on Demand, How toHow to Migrate Your Data to Oracle Solaris 11 Using Shadow Migration; Using svcbundle to Create SMF Manifests and Profiles in Oracle Solaris 11; How to prepare a Sun ZFS Storage Appliance to Serve as a Storage Devise with Oracle Enterprise Manager Ops Center 12c; Command Summary: Basic Operations with the Image Packaging System In Oracle Solaris 11; How to Update to Oracle Solaris 11.1 Using the Image Packaging System, How to Migrate Oracle Database from Oracle Solaris 8 to Oracle Solaris 11; Setting Up, Configuring, and Using an Oracle WebLogic Server Cluster; Ease the Chaos with Automated Patching: Oracle Enterprise Manager Cloud Control 12c; Book excerpt: Oracle Exalogic Elastic Cloud HandbookYou find the Newsletter on our portal under eSTEP News ---> Latest Newsletter. You will need to provide your email address and the pin below to get access. Link to the portal is shown below.URL: http://launch.oracle.com/PIN: eSTEP_2011Previous published Newsletters can be found under the Archived Newsletters section and more useful information under the Events, Download and Links tab. Feel free to explore and any feedback is appreciated to help us improve the service and information we deliver.Thanks and best regards,Partner HW Enablement EMEA

  Read the article

• The Growing Importance of Network Virtualization

  - by user12608550

  The Growing Importance of Network Virtualization We often focus on server virtualization when we discuss cloud computing, but just as often we neglect to consider some of the critical implications of that technology. The ability to create virtual environments (or VEs [1]) means that we can create, destroy, activate and deactivate, and more importantly, MOVE them around within the cloud infrastructure. This elasticity and mobility has profound implications for how network services are defined, managed, and used to provide cloud services. It's not just servers that benefit from virtualization, it's the network as well. Network virtualization is becoming a hot topic, and not just for discussion but for companies like Oracle and others who have recently acquired net virtualization companies [2,3]. But even before this topic became so prominent, Solaris engineers were working on technologies in Solaris 11 to virtualize network services, known as Project Crossbow [4]. And why is network virtualization so important? Because old assumptions about network devices, topology, and management must be re-examined in light of the self-service, elasticity, and resource sharing requirements of cloud computing infrastructures. Static, hierarchical network designs, and inter-system traffic flows, need to be reconsidered and quite likely re-architected to take advantage of new features like virtual NICs and switches, bandwidth control, load balancing, and traffic isolation. For example, traditional multi-tier Web services (Web server, App server, DB server) that share net traffic over Ethernet wires can now be virtualized and hosted on shared-resource systems that communicate within a larger server at system bus speeds, increasing performance and reducing wired network traffic. And virtualized traffic flows can be monitored and adjusted as needed to optimize network performance for dynamically changing cloud workloads. Additionally, as VEs come and go and move around in the cloud, static network configuration methods cannot easily accommodate the routing and addressing flexibility that VE mobility implies; virtualizing the network itself is a requirement. Oracle Solaris 11 [5] includes key network virtualization technologies needed to implement cloud computing infrastructures. It includes features for the creation and management of virtual NICs and switches, and for the allocation and control of the traffic flows among VEs [6]. Additionally it allows for both sharing and dedication of hardware components to network tasks, such as allocating specific CPUs and vNICs to VEs, and even protocol-specific management of traffic. So, have a look at your current network topology and management practices in view of evolving cloud computing technologies. And don't simply duplicate the physical architecture of servers and connections in a virtualized environment…rethink the traffic flows among VEs and how they can be optimized using Oracle Solaris 11 and other Oracle products and services. [1] I use the term "virtual environment" or VE here instead of the more commonly used "virtual machine" or VM, because not all virtualized operating system environments are full OS kernels under the control of a hypervisor…in other words, not all VEs are VMs. In particular, VEs include Oracle Solaris zones, as well as SPARC VMs (previously called LDoms), and x86-based Solaris and Linux VMs running under hypervisors such as OEL, Xen, KVM, or VMware. [2] Oracle follows VMware into network virtualization space with Xsigo purchase; http://www.mercurynews.com/business/ci_21191001/oracle-follows-vmware-into-network-virtualization-space-xsigo [3] Oracle Buys Xsigo; http://www.oracle.com/us/corporate/press/1721421 [4] Oracle Solaris 11 Networking Virtualization Technology, http://www.oracle.com/technetwork/server-storage/solaris11/technologies/networkvirtualization-312278.html [5] Oracle Solaris 11; http://www.oracle.com/us/products/servers-storage/solaris/solaris11/overview/index.html [6] For example, the Solaris 11 'dladm' command can be used to limit the bandwidth of a virtual NIC, as follows: dladm create-vnic -l net0 -p maxbw=100M vnic0

  Read the article

• MVC Communication Pattern

  - by Kedu

  This is kind of a follow up question to this http://stackoverflow.com/questions/23743285/model-view-controller-and-callbacks, but I wanted to post it separately, because its kind of a different topic. I'm working on a multiplayer cardgame for the Android platform. I split the project into MVC which fits the needs pretty good, but I'm currently stuck because I can't figure out a good way to communicate between the different parts. I have everything setup and working with the controller being a big state machine, which is called over and over from the gameloop, and calls getter methods from the GUI and the android/network part to get the input. The input itself in the GUI and network is set by inputlisteners that set a local variable which I read in the getter method. So far so good, this is working. But my problem is, the controller has to check every input separately,so if I want to add an input I have to check in which states its valid and call the getter method from all these states. This is not good, and lets the code look pretty ugly, makes additions uncomfortable and adds redundance. So what I've got from the question I mentioned above is that some kind of command or event pattern will fit my needs. What I want to do is to create a shared and threadsafe queue in the controller and instead of calling all these getter methods, I just check the queue for new input and proceed it. On the other side, the GUI and network don't have all these getters, but instead create an event or command and send it to the controller through, for example, observer/observable. Now my problem: I can't figure out a way, for these commands/events to fit a common interface (which the queue can store) and still transport different kind of data (button clicks, cards that are played, the player id the command comes from, synchronization data etc.). If I design the communication as command pattern, I have to stick all the information that is needed to execute the command into it when its created, that's impossible because the GUI or network has no knowledge of all the things the controller needs to execute stuff that needs to be done when for example a card is played. I thought about getting this stuff into the command when executing it. But over all the different commands I have, I would need all the information the controller has, and thus give the command a reference to the controller which would make everything in it public, which is real bad design I guess. So, I could try some kind of event pattern. I have to transport data in the event. So, like the command, I would have an interface, which all events have in common, and can be stored in the shared queue. I could create a big enum with all the different events that a are possible, save one of these enums in the actual event, and build a big switch case for the events, to proceed different stuff for different events. The problem here: I have different data for all the events. But I need a common interface, to store the events in a queue. How do I get the specific data, if I can only access the event through the interface? Even if that wouldn't be a problem, I'm creating another big switch case, which looks ugly, and when i want to add a new event, I have to create the event itself, the case, the enum, and the method that's called with the data. I could of course check the event with the enum and cast it to its type, so I can call event type specific methods that give me the data I need, but that looks like bad design too.

  Read the article

• Profiling Startup Of VS2012 &ndash; dotTrace Profiler

  - by Alois Kraus

  Jetbrains which is famous for the Resharper tool has also a profiler in its portfolio. I downloaded dotTrace 5.2 Professional (569€+VAT) to check how far I can profile the startup of VS2012. The most interesting startup option is “.NET Process”. With that you can profile the next started .NET process which is very useful if you want to profile an application which is not started by you.     I did select Tracing as and Wall time to get similar options across all profilers. For some reason the attach option did not work with .NET 4.5 on my home machine. But I am sure that it did work with .NET 4.0 some time ago. Since we are profiling devenv.exe we can also select “Standalone Application” and start it from the profiler. The startup time of VS does increase about a factor 3 but that is ok. You get mainly three windows to work with. The first one shows the threads where you can drill down thread wise where most time is spent. I The next window is the call tree which does merge all threads together in a similar view. The last and most useful view in my opinion is the Plain List window which is nearly the same as the Method Grid in Ants Profiler. But this time we do get when I enable the Show system functions checkbox not a 150 but 19407 methods to choose from! I really tried with Ants Profiler to find something about out how VS does work but look how much we were missing! When I double click on a method I do get in the lower pane the called methods and their respective timings. This is something really useful and I can nicely drill down to the most important stuff. The measured time seems to be Wall Clock time which is a good thing to see where my time is really spent. You can also use Sampling as profiling method but this does give you much less information. Except for getting a first idea where to look first this profiling mode is not very useful to understand how you system does interact.   The options have a good list of presets to hide by default many method and gray them out to concentrate on your code. It does not filter anything out if you enable Show system functions. By default methods from these assemblies are hidden or if the checkbox is checked grayed out. All in all JetBrains has made a nice profiler which does show great detail and it has nice drill down capabilities. The only thing is that I do not trust its measured timings. I did fall several times into the trap with this one to optimize at places which were already fast but the profiler did show high times in these methods. After measuring with Tracing I was certain that the measured times were greatly exaggerated. Especially when IO is involved it seems to have a hard time to subtract its own overhead. What I did miss most was the possibility to profile not only the next started process but to be able to select a process by name and perhaps a count to profile the next n processes of this name. Next: YourKit

  Read the article

• Test Drive for Partners on Oracle Endeca Information Discovery

  - by Mike.Hallett(at)Oracle-BI&EPM

  Normal 0 false false false EN-GB 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:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-fareast-language:EN-US;} Specifically for Oracle Partners, this half-day hands-on workshop allows you to experience Information Discovery from Oracle in order to: Understand Information Discovery and how it compliments classic BI solutions Use Search and Guided Navigation to see how structured and unstructured information can be rapidly brought together to unlock hidden value Explore all of your data in any format and from any source including social media, market surveys and reports Lay the foundation for helping business users who need fast answers to new questions Experience the amazing performance of Endeca on Oracle's in memory Exalytics machine Agenda After an introduction to Oracle Endeca Information Discovery, follow a self-paced, supervised, hands-on tutorial where you will see how easy it is to: Use Guided Navigation and Search to explore structured and unstructured data Rapidly integrate new and changing data sources such as Social Media Build new Discovery user interfaces Rapidly respond to changing business needs and data environments And ask questions of Oracle's Business Analytics experts throughout When 14th March 2013, Registration 9:00 a.m. - finish by 1:00 p.m.      Normal 0 false false false EN-GB 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:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-fareast-language:EN-US;} Register Now What: Oracle Endeca Information Discovery Test Drive Where: Oracle City Office, 1 South Place, London, EC2M 2RB

  Read the article

• Gnome-shell fails to load on 12.10

  - by Githlar

  I'm usually the one answering questions, but in this I'm throughly stumped! My Setup: Ubuntu 12.10 (Dist upgrade form 12.04) ATI M96 [Mobility Radeon HD 4650] Upon the first installation of 12.10 I had all kinds of issues getting the Legacy ATI drivers to install (I guess the source for the drivers isn't kosher with kernel 3.5). So, I added the repository ppa:makson96/fglrx - which has a version of the ATI source patched to work with kernel 3.5. After installation of fglrx-legacy from that PPA, gnome-shell and all my graphics work fine... until today. The Problem I unsuspended my computer today and the screen was black (not off, the black from the gnome lock screen). I'd move my mouse/hit a key and the background would flash and then it'd go back to black. Restarted via VT1 Logged into Gnome (gnome-shell) session, but no gnome-shell! Investigation: First, I went to VT1 and tried export DISPLAY=:0;gnome-shell --replace. It appeared to work fine, switch back to X and nothing. Went back to VT1 and saw this error message: JS ERROR: !!! Exception was: TypeError: Object 0x7fc748129c30 is not a subclass of (null), it's a xO JS ERROR: !!! message = '"Object 0x7fc748129c30 is not a subclass of (null), it's a xO"' JS ERROR: !!! fileName = '"/usr/share/gnome-shell/js/ui/tweener.js"' JS ERROR: !!! lineNumber = '218' JS ERROR: !!! stack = '"()@/usr/share/gnome-shell/js/ui/tweener.js:218 wrapper()@/usr/share/gjs-1.0/lang.js:204 ()@/usr/share/gjs-1.0/lang.js:145 ()@/usr/share/gjs-1.0/lang.js:239 init()@/usr/share/gnome-shell/js/ui/tweener.js:49 init()@/usr/share/gnome-shell/js/ui/environment.js:96 @<main>:1 "' Window manager warning: Log level 32: Execution of main.js threw exception: TypeError: Object 0x7fc748129c30 is not a subclass of (null), it's a xO Note: Everywhere it says "it's a xO", xO is actually garbled and changes every time (I'm thinking memory corruption?) This error is thrown by line 96 of /usr/share/gnome-shell/js/ui/environment.js: tweener.Init() Did a purge of fglrx-legacy, reboot, reinstall fglrx-legacy, reboot... same thing. Did a ppa-purge of ppa:gnome3-team/gnome3, and reinstalled gnome-shell and ubuntu-desktop from the standard repositores... same thing. I'm really at a loss here. I love gnome-shell and after using it for nearly a year now gnome classic just seems so archaic. Additional Information Apt log from the day I first suspended my machine (these are upgrades from the gnome3-team/gnome3 ppa and ubuntu-wine/ppa ppa): Start-Date: 2012-11-24 17:30:28 Commandline: aptdaemon role='role-commit-packages' sender=':1.618' Install: gkbd-capplet:amd64 (3.6.0-0ubuntu1), gnome-control-center-unity:amd64 (1.0-0ubuntu1~ubuntu12.10.1) Upgrade: nautilus:amd64 (3.6.2-0ubuntu0.1~quantal1, 3.6.3-0ubuntu2~ubuntu12.10.1), libgnome-control-center1:amd64 (3.4.2-0ubuntu19, 3.6.3-0ubuntu6~ubuntu12.10.1), wine1.5-i386:i386 (1.5.17-0ubuntu4, 1.5.18-0ubuntu1), wine1.5:amd64 (1.5.17-0ubuntu4, 1.5.18-0ubuntu1), gnome-settings-daemon:amd64 (3.4.2-0ubuntu14, 3.6.3-0ubuntu1~ubuntu12.10.1), gnome-control-center-data:amd64 (3.4.2-0ubuntu19, 3.6.3-0ubuntu6~ubuntu12.10.1), gnome-accessibility-themes:amd64 (3.6.0.2-0ubuntu1, 3.6.2-0ubuntu2~ubuntu12.10.1), gnome-themes-standard:amd64 (3.6.0.2-0ubuntu1, 3.6.2-0ubuntu2~ubuntu12.10.1), wine1.5-amd64:amd64 (1.5.17-0ubuntu4, 1.5.18-0ubuntu1), nautilus-data:amd64 (3.6.2-0ubuntu0.1~quantal1, 3.6.3-0ubuntu2~ubuntu12.10.1), gnome-control-center:amd64 (3.4.2-0ubuntu19, 3.6.3-0ubuntu6~ubuntu12.10.1), libnautilus-extension1a:amd64 (3.6.2-0ubuntu0.1~quantal1, 3.6.3-0ubuntu2~ubuntu12.10.1) End-Date: 2012-11-24 17:31:32 fglrxinfo (driver appears to be working): display: :0 screen: 0 OpenGL vendor string: Advanced Micro Devices, Inc. OpenGL renderer string: ATI Mobility Radeon HD 4650 OpenGL version string: 3.3.11653 Compatibility Profile Context Does anybody have any further ideas?

  Read the article

• Video works with 'Try me' but not after install. What is the difference? U12.04LTS,

  - by HarveyP

  My hard drive got corrupted so I did a reinstall. Tested Youtube in FF during 'try me' and it worked - jerky, but it worked. Instal without all the updates (576 outstanding now) in order to get ff installed as per the demo - to no avail. In 'try me' mode ff NEVER crashed! After install ff crashed whilst I was typing in 'youtube' in the address field. When I finally got to youtube - no video. What is the difference between ff in try me and ff after install? Off to try some selected updates now to see if I can see it for myself. In previous installation I had several profiles and aliased ff with -safe-mode switch to simplify startup of most stable ff. Also found that ff startup in graphic mode worked better (but still without video) with all of the extensions disabled and all of the plugins set to "ask" and always denied ... I have SiS graphic card in SiS Motherboard for XP and ancient Hyundai ImageQuest QV770 monitor. I have Ubuntu 12.04.01 LTS 1 day after install with only the immediate upgrades requested to language pack (English UK). Using FR Alternative keyboard. Connected with domestic wifi network from Orange (FT) I really want to use Skype, but won't bother installing it (again) without video as I can do my sms on FB - whilst ff is not crashed ... Update ... Is something overflowing? I have just had to reboot in order to get ff to restart in any way shape or form - restart on crash form generates new crash form, etc. It was however a good half hour before it crashed so some improvement over conditions before disk corruption. I have now installed all of the critical updates (332 recommended updates still outstanding) which included some relating to ff. Still no video. Still crashing - especially when on Grepolis website. Since the re-install I have had a lovely 1024x768 screen, but after last ff crash and reboot I got a message about 'low graphics mode' and 'setting things myself'. I was not sufficiently tuned in at the time to take proper note - I have no doubt I shall see it again and shall report accordingly. I still have only laptop options for my screen and do not know how to rectify this. Spent a few days with ubuntu on a different, newer machine which has now suffered a graphics breakdown. Returned to this old one again, but with new flat screen Monitor. Found SIS drivers for my graphics BUT it is intended for Red Hat 7.2. I chose this over the version for 7.0 because I thought what the hell, I might not be able to do anything with either of them but this is the later one ... The file will not open with software manager - found a similar problem on Overclock but it has not helped me to install this driver. File name is sis_drv.o-410 and it is currently idling away in my Downloads folder ... I have tried the solution offered on another sis problem, but this shows that my xserver-xorg-video-sis driver is up to date. I am now at a loss as to how to proceed if I can't install the latest sis driver from sis ... Does nobody know how FF changes from "try-me" to "installed"? Any time I MUST have video I reboot from the disk again, but this is tedious! Also one of the things I mock most about MS is the constant rebooting ... UPDATE 10/6/2014 I have installed chromium-browser - worse, crashes even more often than ff.I have installed epiphany - better; Video works but not the associated soundtrack.FireFox is version 14.01 in 'try me' and version 29.0 from my install. Would it be useful to try to downgrade FireFox in order to get video?

  Read the article

• JTF Tranlsation Festival 2011

  - by user13133135

  ?????????????????????? (MT) ??????????????????????? JTF ????????????????????????????????????????????????? ???5??!???21?JTF???????? ? ??:2011?11?29?(?)9:30~20:30(??9:00) ? ??:??????????(????)?(??) ? ??:(?)?????? ??:JTF?????????? ? http://www.jtf.jp/jp/festival/festival_top.html ????????????????????????????????MT ????????????????????????????????????????????????? 90 ???!??(!?)?????????????????????????????????????????????????????????????????????????????? ????????????????? http://www.jtf.jp/jp/festival/festival_program.html#koen_04 ?????????????????????????????? English:  It's been a while since the last post... I have been working on machine translation (MT) and post editing (PE) for Japanese.  Last year was my first step in MT+PE area, and I would take this year as an advanced step.  I plan to talk over Post editing 2011 (Advanced Step) on November 27 at JTF Translation Festival.  ?5 days before application due? 21st JTF Translation Festival ? Date:Nov 29, 2011 Tuesday 9:30~20:30(Gate open: 9:00) ? Place:Arcadia Ichigaya Tokyo ? http://www.jtf.jp/jp/festival/festival_top.html In this session, I would like to expand the thought on "how to best utilize MT and PE" either from the view of Client and Translator.  I will show some examples of post editing as a guideline to know what is the best way and most effective way to do post-edit for Japanese.  Also, I will discuss what is the best practice for MT users (Client). The session lasts 90 minutes... sound a little long for me, but I want to spend more time for discussion than last year.  It would be great to exchange thought or experiences about MT and PE.  What is your concerns or problems in the daily work with MT ?  If you have some, please bring them to my session at JTF Translation Festival.  Here is my session details (Japanese): http://www.jtf.jp/jp/festival/festival_program.html#koen_04 Here is the outline of my session: What is the advantage of MT ? Does it solve all the problems about cost, resource, and quality ?  Well, it is not a magic.  So, you cannot expect all at once.  When you have a problem, there are 3 options... 1. Be patient and wait until everything is ready, 2. Run a workaround using anything available now, 3. Find out something completely new and spend time and money. This time, I will focus Option 2 - do something with what we already have.  That is, I will discuss how we can best utilize MT in our daily business.  My view is two ways: From Client point of view, and From Translator point of view Looking forward to meeting many people and exchanging thoughts and information!

  Read the article

• Shrinking a Linux OEL 6 virtual Box image (vdi) hosted on Windows 7

  - by AndyBaker

  v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Recently for a customer demonstration there was a requirement to build a virtual box image with Oracle Enterprise Manager Cloud Control 12c. This meant installing OEL Linux 6 as well as creating an 11gr2 database and Oracle Enterprise Manager Cloud Control 12c on a single virtual box. Storage was sized at 300Gb using dynamically allocated storage for the virtual box and about 10Gb was used for Linux and the initial build. After copying over all the binaries and performing all the installations the virtual box became in the region of 80Gb used size on the host operating system, however internally it only really needed around 20Gb. This meant 60Gb had been used when copying over all the binaries and although now free was not returned to the host operating system due to the growth of the virtual box storage '.vdi' file.  Once the ‘vdi’ storage had grown it is not shrunk automatically afterwards. Space is always tight on the laptop so it was desirable to shrink the virtual box back to a minimal size and here is the process that was followed. Install 'zerofree' Linux package into the OEL6 virtual box The RPM was downloaded and installed from a site similar to below; http://rpm.pbone.net/index.php3/stat/4/idpl/12548724/com/zerofree-1.0.1-5.el5.i386.rpm.html A simple internet search for ’zerofree Linux rpm’ was easy to perform and find the required rpm. Execute 'zerofree' package on the desired Linux file system To execute this package the desired file system needs to be mounted read only. The following steps outline this process. As root: # umount /u01 As root:# mount –o ro –t ext4 /u01 NOTE: The –o is options and the –t is the file system type found in the /etc/fstab. Next run zerofree against the required storage, this is located by a simple ‘df –h’ command to see the device associated with the mount. As root:# zerofree –v /dev/sda11   NOTE: This takes a while to run but the ‘-v’ option gives feedback on the process. What does Zerofree do? Zerofree’s purpose is to go through the file system and zero out any unused sectors on the volume so that the later stages can shrink the virtual box storage obtaining the free space back. When zerofree has completed the virtual box can be shutdown as the last stage is performed on the physical host where the virtual box vdi files are located. Compact the virtual box ‘.vdi’ files The final stage is to get virtual box to shrink back the storage that has been correctly flagged as free space after executing zerofree. On the physical host in this case a windows 7 laptop a DOS window was opened. At the prompt the first step is to put the virtual box binaries onto the PATH. C:\ >echo %PATH%   The above shows the current value of the PATH environment variable. C:\ >set PATH=%PATH%;c:\program files\Oracle\Virtual Box;   The above adds onto the existing path the virtual box binary location. C:\>cd c:\Users\xxxx\OEL6.1   The above changes directory to where the VDI files are located for the required virtual box machine. C:\Users\xxxxx\OEL6.1>VBoxManage.exe modifyhd zzzzzz.vdi compact  NOTE: The zzzzzz.vdi is the name of the required vdi file to shrink. Finally the above command is executed to perform the compact operation on the ‘.vdi’ file(s). This also takes a long time to complete but shrinks the VDI file back to a minimum size. In the case of the demonstration virtual box OEM12c this reduced the virtual box to 20Gb from 80Gb which was a great outcome to achieve.

  Read the article

• Ubuntu 12.04 Hp G72 Problem Installing proprietary wireless driver

  - by user69402

  I have a fresh Ubuntu 12.04 installed on HP G72 machine. In order for my wireless to work I need the proprietary driver installed - Broadcom STA wireless driver. Trying to install it from the System Settings gives me the error: "Sorry, installation of this driver failed. Please have a look at the log file for details: /var/log/jockey.log". So far I suspect the error to be caused by the bad "bcmwl-kernel-source" installation. What i tried: 1. remove "bcmwl-kernel-source" 2. install "bcmwl-kernel-source" installation through the terminal ends with "error code (1)". I would greatly appreciate any help Here is everything that the terminal returns: Reading package lists... Done Building dependency tree Reading state information... Done The following NEW packages will be installed: bcmwl-kernel-source 0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded. Need to get 0 B/1,151 kB of archives. After this operation, 3,514 kB of additional disk space will be used. Selecting previously unselected package bcmwl-kernel-source. (Reading database ... 170331 files and directories currently installed.) Unpacking bcmwl-kernel-source (from .../bcmwl-kernel-source_5.100.82.38+bdcom-0ubuntu6.1_amd64.deb) ... Setting up bcmwl-kernel-source (5.100.82.38+bdcom-0ubuntu6.1) ... Loading new bcmwl-5.100.82.38+bdcom DKMS files... /usr/sbin/dkms: line 467: unset: POST_REMOVE$PRE_BUMLD': not a valid identifier /usr/sbin/dkms: line 467: unset:BUILD_E\CLUWIVE_ARCH': not a valid identifier /usr/sbin/dkms: line 467: unset: $': not a valid identifier /usr/sbin/dkms: line 467: unset:$': not a valid identifier /usr/sbin/dkms: line 467: unset: modules_conf_arra}': not a valid identifier /usr/sbin/dkms: line 467: unset:$': not a valid identifier /usr/sbin/dkms: line 467: unset: $': not a valid identifier /usr/sbin/dkms: line 467: unset:$': not a valid identifier /usr/sbin/dkms: line 467: unset: $': not a valid identifier /usr/sbin/dkms: line 467: unset:$': not a valid identifier /usr/sbin/dkms: line 467: unset: `$': not a valid identifier /usr/sbin/dkms: line 419: ${!POST_REMOVE$PRE_BUMLD[@]}: bad substitution /usr/sbin/dkms: line 419: ${!BUILD_E\CLUWIVE_ARCH[@]}: bad substitution /usr/sbin/dkms: line 419: ${!$[@]}: bad substitution /usr/sbin/dkms: line 419: ${!$[@]}: bad substitution /usr/sbin/dkms: line 419: ${!$[@]}: bad substitution /usr/sbin/dkms: line 419: ${!$[@]}: bad substitution /usr/sbin/dkms: line 419: ${!$[@]}: bad substitution /usr/sbin/dkms: line 419: ${!$[@]}: bad substitution /usr/sbin/dkms: line 419: ${!$[@]}: bad substitution /usr/sbin/dkms: line 419: ${!$[@]}: bad substitution malloc: ../bash/subst.c:3671: assertion botched free: start and end chunk sizes differ Aborting.../tmp/tmp.pEXTnftUfI: line 4: modules_conf_arra}[[@]}]=[[@]}]}: command not found dkms.conf: Error! No 'DEST_MODULE_LOCATION' directive specified for record #0. dkms.conf: Error! Directive 'DEST_MODULE_LOCATION' does not begin with '/kernel', '/updates', or '/extra' in record #0. dkms.conf: Error! No 'PACKAGE_VERSION' directive specified. Error! Bad conf file. File: /usr/src/bcmwl-5.100.82.38+bdcom/dkms.conf does not represent a valid dkms.conf file. dpkg: error processing bcmwl-kernel-source (--configure): subprocess installed post-installation script returned error exit status 8 Errors were encountered while processing: bcmwl-kernel-source E: Sub-process /usr/bin/dpkg returned an error code (1)

  Read the article

• Application Logging needs work

  Application Logging Application logging is the act of logging events that occur within an application much like how a court report documents what happens in court case. Application logs can be useful for several reasons, but the most common use for logs is to recreate steps to find the root cause of applications errors. Other uses can include the detection of Fraud, verification of user activity, or provide audits on user/data interactions. “Logs can contain different kinds of data. The selection of the data used is normally affected by the motivation leading to the logging. “ (OWASP, 2009) OWASP also stats that logging include applicable debugging information like the event date time, responsible process, and a description of the event. “There are many reasons why a logging system is a necessary part of delivering a distributed application. One of the most important is the ability to track exactly how many users are using the application during different time periods.” (Hatton, 2000) Hatton also states that application logging helps system designers determine whether parts of an application aren't being used as designed. He implies that low usage can be used to identify if users like or do not like aspects of a system based on user usage of the application. This enables application designers to extract why users don't like aspects of an application so that changes can be made to increase its usefulness and effectiveness. “Logging memory usage can also assist you in tuning up the internals of your application. If you're experiencing a randomly occurring problem, being able to match activities performed with the memory status at the time may enable you to discover the cause of the problem. It also gives you a good indication of the health of the distributed server machine at the time any activity is performed. “ (Hatton, 2000) Commonly Logged Application Events (Defined by OWASP) Access of Data Creation of Data Modification of Data in any form Administrative Functions  Configuration Changes Debugging Information(Application Events)  Authorization Attempts  Data Deletion Network Communication  Authentication Events  Errors/Exceptions Application Error Logging The functionality associated with application error logging is actually the combination of proper error handling and applications logging.  If we look back at Figure 4 and Figure 5, these code examples allow developers to handle various types of errors that occur within the life cycle of an application’s execution. Application logging can be applied within the Catch section of the TryCatch statement allowing for the errors to be logged when they occur. By placing the logging within the Catch section specific error details can be accessed that help identify the source of the error, the path to the error, what caused the error and definition of the error that occurred. This can then be logged and reviewed at a later date in order recreate the error that was received based data found in the application log. By allowing applications to log errors developers IT staff can use them to recreate errors that are encountered by end-users or other dependent systems.

  Read the article

• Failed to unmount partitions

  - by msknapp

  I'm trying to install ubuntu from a pen drive. I have windows 7 installed already and want to keep that installation. I have a 3TB drive that has one 2TB partition on it, so the last 1TB is completely unused, which is where I want to install ubuntu. I started ubuntu in "try ubuntu" mode and then opened gparted, and then deleted the unused partition for the last third of my drive, then tried to install ubuntu. During the install, it asked me if I wanted to unmount the drives I already have The installer has detected that the following disks have mounted partitions: /dev/sda, /dev/sdb Do you want the installer to try to unmount the partitions on these disks before continuing? If you leave them mounted, you will not be able to create, delete, or resize partitions on these disks, but you may be able to install to existing partitions there. No, Yes I said no because I don't want to lose my windows 7 installation, nor any of that data. I wonder, if I had said yes above, would I have lost all the data on those drives? Anyways, I hit no and continued. I chose to install ubuntu alongside windows 7, and hit continue. A few minutes passed when this popup appeared: Failed to unmount partitions The installer needs to commit changes to partition tables, but cannot do so because the partitions on the following mount points could not be unmounted: /media/ubuntu/Three\ Terabyte Drive Terabyte\ DriveDrive Please close any applications using these mount points. Would you like the installer to try to unmount these partitions again? Go Back, Continue Why is this not working? What am I supposed to do? ========== Update: I went ahead and said yes, it can unmount those partitions. It finished installing Ubuntu, but now when i start my machine it just takes me to the grub rescue prompt. Seems like it broke something. What can I do now? =============== Results of fdisk -l: Disk /dev/sda: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00027e14 Device Boot Start End Blocks Id System /dev/sda1 * 2048 206847 102400 7 HPFS/NTFS/exFAT /dev/sda2 206848 976771071 488282112 7 HPFS/NTFS/exFAT WARNING: GPT (GUID Partition Table) detected on '/dev/sdb'! The util fdisk doesn't support GPT. Use GNU Parted. Disk /dev/sdb: 3000.6 GB, 3000592982016 bytes 255 heads, 63 sectors/track, 364801 cylinders, total 5860533168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disk identifier: 0x00000000 Device Boot Start End Blocks Id System /dev/sdb1 1 4294967295 2147483647+ ee GPT Partition 1 does not start on physical sector boundary. Disk /dev/sdc: 16.0 GB, 16008609792 bytes 255 heads, 63 sectors/track, 1946 cylinders, total 31266816 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 Device Boot Start End Blocks Id System /dev/sdc1 * 32 31266815 15633392 c W95 FAT32 (LBA) Disk /dev/sdd: 999.5 GB, 999501594624 bytes 255 heads, 63 sectors/track, 121515 cylinders, total 1952151552 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0002ae3f Device Boot Start End Blocks Id System /dev/sdd1 2048 1952151551 976074752 7 HPFS/NTFS/exFAT

  Read the article

• Oracle Excellence Award

  - by Hartmut Wiese

  CALL FOR NOMINATIONS 2014 Oracle Excellence Award: Sustainability Innovation Is your organization using an Oracle product to help with a sustainability initiative while reducing costs? Saving energy? Saving gas? Saving paper? For example, you may use Oracle’s Agile Product Lifecycle Management to design more eco-friendly products, Oracle Transportation Management to reduce fleet emissions, Oracle Exadata Database Machine to decrease power and cooling needs while increasing database performance, Oracle Business Intelligence to measure environmental impacts, or one of many other Oracle products. Your organization may be eligible for the 2014 Oracle Excellence Award: Sustainability Innovation. Submit a nomination form located here by Friday June 20 if your company is using any Oracle product to take an environmental lead as well as to reduce costs and improve business efficiencies by using green business practices. These awards will be presented during Oracle OpenWorld 2014 (September 28-October 2) in San Francisco.  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 About the Award • Winners will be selected from the customer and/or partner nominations. Either a customer, their partner, or Oracle representative can submit the nomination form on behalf of the customer.• There is a nomination form here to discuss your use of Oracle products and how they have helped your sustainability efforts and reduced costs. • Winners will be selected based on the extent of the environmental impact they have had as well as the business efficiencies they have achieved through their combined use of Oracle products. Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Nomination Eligibility • Your company uses at least one component of Oracle products, whether it's the Oracle database, business applications, Fusion Middleware, or Sun servers/storage. • This solution should be in production or in active development. • Nomination deadline: Friday June 20, 2014. Benefits to Award Winners • Award presented to winners during Oracle OpenWorld by Jeff Henley, Oracle Chairman of the Board • Free Oracle OpenWorld registration pass for each winning customer • 2014 Oracle Excellence Award: Sustainability Innovation award logo for inclusion on your own website &/or press release • Possible placement in Oracle Profit Magazine &/or Oracle Magazine • ‘Enable the Eco-Enterprise’ podcast opportunity See last year's winners here Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 ______________________________________________________________________________________ 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:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Questions? Send an email to: [email protected] Follow Oracle’s Sustainability Solutions on Twitter, LinkedIn, YouTube, and the Sustainability Matters blog Web page with award details:  http://www.oracle.com/us/products/applications/green/call-for-nominations-185050.html  

  Read the article

• Software Center seems to freeze system when installing, syslog has "blocked for more than 120 seconds" errors

  - by nbm

  12.04 (precise) 64-bit Kernel Linux 3.2.0-39 3.6GB memory Intel Core 2 Duo CPU @ 2.40GHz x2 WUBI-installed Ubuntu running on a MacBook Pro 7.1 with OSX running Vista via Boot Camp (hey, I like lots of OS's m'kay?) When installing from Ubuntu software center my system very frequently freezes. This has happened 4 of the last 5 installs. Most recently I was installing the Google Earth .deb from Google's website: clicking the .deb file automatically opens Software Center (otherwise I would have used Synaptic, as I've grown to expect Software Center to freeze my system and I'm rather tired of it.) By "freeze" I mean nothing works: no dash, no launcher, no mouse movement, no alt-tab, can't open terminal (keyboard does not work). Software center does show the "installing" icon but after that it greys out and I can't click anything. REISUB has no effect but a cold power-down and restart is possible. Occasionally, after 5-10 minutes, I'll be able to move the mouse / use the keyboard and run a launcher command or two, although other open apps (Chrome and Software Center) will still be greyed-out/frozen. (I've never waited longer than that - if still unresponsive after 15 minutes I just power down and restart.) Most recently, which is why I am finally posting a question, I waited about 15 minutes and was finally able to open System Monitor while this was going on. Processes tells me that System Monitor is using about 20% of CPU, and nothing else is using much (zeros mostly). In fact I didn't even see Software Center listed? However at this point the system finally partially unfroze, the installation completed, and while I wasn't about to close Software Center I was able to do a system shutdown and fresh restart and I went and took a look at the syslog. In /var/log/syslog I see a lot of ":blocked for more than 120 seconds" messages. Similar to ubuntu hang out with this message :blocked for more than 120 seconds Which has not been answered, and I'm not running a virtual machine. My full syslog with stack traces looks very, very similar to this: Why do tasks on Amazon Xen instance block for over 120 seconds causing server to hang? Note that that question was solved, but that's because the problem was being caused by Amazon and Amazon fixed the bug. I'm not running anything Amazon-related. My syslog does look very similar, however. My question is also similar to this: Troubleshooting server hang But the referenced "duplicate" in that question is about how to kill processes/restart when the system freezes. I know how to kill processes and restart. I want to figure out what is causing the problem so I can try to fix it. I realize that I could just use Synaptic instead of Ubuntu Software Center, but I'd like to try to solve the problem if possible. I'm thinking I should perhaps submit a bug report, but I wanted to first see if anyone else was having any similar problems, and if so what you all did to fix it. I see a number of questions about Software Center freezing and others, including those I linked, about the "blocked for more than 120 seconds" log error, but I didn't see any question that links the two. I did save a copy of the syslog report if anyone wants to see it, but as mentioned it's quite similar to the one posted in the Amazon-related question...and I didn't want to take up even more space unnecessarily as, my apologies - this question has already become extremely verbose!

  Read the article

• Come up with a real-world problem in which only the best solution will do (a problem from Introduction to algorithms) [closed]

  - by Mike

  EDITED (I realized that the question certainly needs a context) The problem 1.1-5 in the book of Thomas Cormen et al Introduction to algorithms is: "Come up with a real-world problem in which only the best solution will do. Then come up with one in which a solution that is “approximately” the best is good enough." I'm interested in its first statement. And (from my understanding) it is asked to name a real-world problem where only the exact solution will work as opposed to a real-world problem where good-enough solution will be ok. So what is the difference between the exact and good enough solution. Consider some physics problem for example the simulation of the fulid flow in the permeable medium. To make this simulation happen some simplyfing assumptions have to be made when deriving a mathematical model. Otherwise the model becomes at least complex and unsolvable. Virtually any particle in the universe has its influence on the fluid flow. But not all particles are equal. Those that form the permeable medium are much more influental than the ones located light years away. Then when the mathematical model needs to be solved an exact solution can rarely be found unless the mathematical model is simple enough (wich probably means the model isn't close to reality). We take an approximate numerical method and after hours of coding and days of verification come up with the program or algorithm which is a solution. And if the model and an algorithm give results close to a real problem by some degree that is good enough soultion. Its worth noting the difference between exact solution algorithm and exact computation result. When considering real-world problems and real-world computation machines I believe all physical problems solutions where any calculations are taken can not be exact because universal physical constants are represented approximately in the computer. Any numbers are represented with the limited precision, at least limited by amount of memory available to computing machine. I can imagine plenty of problems where good-enough, good to some degree solution will work, like train scheduling, automated trading, satellite orbit calculation, health care expert systems. In that cases exact solutions can't be derived due to constraints on computation time, limitations in computer memory or due to the nature of problems. I googled this question and like what this guy suggests: there're kinds of mathematical problems that need exact solutions (little note here: because the question is taken from the book "Introduction to algorithms" the term "solution" means an algorithm or a program, which in this case gives exact answer on each input). But that's probably more of theoretical interest. So I would like to narrow down the question to: What are the real-world practical problems where only the best (exact) solution algorithm or program will do (but not the good-enough solution)? There are problems like breaking of cryptographic ciphers where only exact solution matters in practice and again in practice the process of deciphering without knowing a secret should take reasonable amount of time. Returning to the original question this is the problem where good-enough (fast-enough) solution will do there's no practical need in instant crack though it's desired. So the quality of "best" can be understood in any sense: exact, fastest, requiring least memory, having minimal possible network traffic etc. And still I want this question to be theoretical if possible. In a sense that there may be example of computer X that has limited resource R of amount Y where the best solution to problem P is the one that takes not more than available Y for inputs of size N*Y. But that's the problem of finding solution for P on computer X which is... well, good enough. My final thought that we live in a world where it is required from programming solutions to practical purposes to be good enough. In rare cases really very very good but still not the best ones. Isn't it? :) If it's not can you provide an example? Or can you name any such unsolved problem of practical interest?

  Read the article

• Why is the framerate (fps) capped at 60?

  - by dennmat

  ISSUE I recently moved a project from my laptop to my desktop(machine info below). On my laptop the exact same code displays the fps(and ms/f) correctly. On my desktop it does not. What I mean by this is on the laptop it will display 300 fps(for example) where on my desktop it will show only up to 60. If I add 100 objects to the game on the laptop I'll see my frame rate drop accordingly; the same test on the desktop results in no change and the frames stay at 60. It takes a lot(~300) entities before I'll see a frame drop on the desktop, then it will descend. It seems as though its "theoretical" frames would be 400 or 500 but will never actually get to that and only do 60 until there's too much to handle at 60. This 60 frame cap is coming from no where. I'm not doing any frame limiting myself. It seems like something external is limiting my loop iterations on the desktop, but for the last couple days I've been scratching my head trying to figure out how to debug this. SETUPS Desktop: Visual Studio Express 2012 Windows 7 Ultimate 64-bit Laptop: Visual Studio Express 2010 Windows 7 Ultimate 64-bit The libraries(allegro, box2d) are the same versions on both setups. CODE Main Loop: while(!abort) { frameTime = al_get_time(); if (frameTime - lastTime >= 1.0) { lastFps = fps/(frameTime - lastTime); lastTime = frameTime; avgMspf = cumMspf/fps; cumMspf = 0.0; fps = 0; } /** DRAWING/UPDATE CODE **/ fps++; cumMspf += al_get_time() - frameTime; } Note: There is no blocking code in the loop at any point. Where I'm at My understanding of al_get_time() is that it can return different resolutions depending on the system. However the resolution is never worse than seconds, and the double is represented as [seconds].[finer-resolution] and seeing as I'm only checking for a whole second al_get_time() shouldn't be responsible. My project settings and compiler options are the same. And I promise its the same code on both machines. My googling really didn't help me much, and although technically it's not that big of a deal. I'd really like to figure this out or perhaps have it explained, whichever comes first. Even just an idea of how to go about figuring out possible causes, because I'm out of ideas. Any help at all is greatly appreciated. EDIT: Thanks All. For any others that find this to disable vSync(windows only) in opengl: First get "wglext.h". It's all over the web. Then you can use a tool like GLee or just write your own quick extensions manager like: bool WGLExtensionSupported(const char *extension_name) { PFNWGLGETEXTENSIONSSTRINGEXTPROC _wglGetExtensionsStringEXT = NULL; _wglGetExtensionsStringEXT = (PFNWGLGETEXTENSIONSSTRINGEXTPROC) wglGetProcAddress("wglGetExtensionsStringEXT"); if (strstr(_wglGetExtensionsStringEXT(), extension_name) == NULL) { return false; } return true; } and then create and setup your function pointers: PFNWGLSWAPINTERVALEXTPROC wglSwapIntervalEXT = NULL; PFNWGLGETSWAPINTERVALEXTPROC wglGetSwapIntervalEXT = NULL; if (WGLExtensionSupported("WGL_EXT_swap_control")) { // Extension is supported, init pointers. wglSwapIntervalEXT = (PFNWGLSWAPINTERVALEXTPROC) wglGetProcAddress("wglSwapIntervalEXT"); // this is another function from WGL_EXT_swap_control extension wglGetSwapIntervalEXT = (PFNWGLGETSWAPINTERVALEXTPROC) wglGetProcAddress("wglGetSwapIntervalEXT"); } Then just call wglSwapIntervalEXT(0) to disable vSync and 1 to enable vSync. I found the reason this is windows only is that openGl actually doesn't deal with anything other than rendering it leaves the rest up to the OS and Hardware. Thanks everyone saved me a lot of time!

  Read the article

• Identity in .NET 4.5&ndash;Part 3: (Breaking) changes

  - by Your DisplayName here!

  I recently started porting a private build of Thinktecture.IdentityModel to .NET 4.5 and noticed a number of changes. The good news is that I can delete large parts of my library because many features are now in the box. Along the way I found some other nice additions. ClaimsIdentity now has methods to query the claims collection, e.g. HasClaim(), FindFirst(), FindAll(). ClaimsPrincipal has those methods as well. But they work across all contained identities. Nice! ClaimsPrincipal.Current retrieves the ClaimsPrincipal from Thread.CurrentPrincipal. Combined with the above changes, no casting necessary anymore. SecurityTokenHandler now has read and write methods that work directly with strings. This makes it much easier to deal with non-XML tokens like SWT or JWT. A new session security token handler that uses the ASP.NET machine key to protect the cookie. This makes it easier to get started in web farm scenarios. No need for a custom service host factory or the federation behavior anymore. WCF can be switched into “WIF mode” with the useIdentityConfiguration switch (odd name though). Tooling has become better and the new test STS makes it very easy to get started. On the other hand – and that was kind of expected – to bring claims into the core framework, there are also some breaking changes for WIF code. If you want to migrate (and I would recommend that), most changes to your code are mechanical. The following is a brain dump of the changes I encountered. Assembly Microsoft.IdentityModel is gone. The new functionality is now in mscorlib, System.IdentityModel(.Services) and System.ServiceModel. All the namespaces have changed as well. No IClaimsPrincipal and IClaimsIdentity anymore. Configuration section has been split into <system.identityModel /> and <system.identityModel.services />. WCF configuration story has changed as well. Claim.ClaimType is now Claim.Type. ClaimCollection is now IEnumerable<Claim>. IsSessionMode is now IsReferenceMode. Bootstrap token handling is different now. ClaimsPrincipalHttpModule is gone. This is not really needed anymore, apart from maybe claims transformation (see here). Various factory methods on ClaimsPrincipal are gone (e.g. ClaimsPrincipal.CreateFromIdentity()). SecurityTokenHandler.ValidateToken now returns a ReadOnlyCollection<ClaimsIdentity>. Some lower level helper classes are gone or internal now (e.g. KeyGenerator). The WCF WS-Trust bindings are gone. I think this is a pity. They were *really* useful when doing work with WSTrustChannelFactory. Since WIF is part of the Windows operating system and also supported in future versions of .NET, there is no urgent need to migrate to the 4.5 claims model. But obviously, going forward, at some point you want to make the move.

  Read the article

• How to restore/change Alt+Tab behaviour/ram usage and a few other things after Ubuntu upgrade from 11.04 to 11.10?

  - by fiktor

  I use Ubuntu for programming. I recently updated it from 11.04 to 11.10. There are some things I don't like in the new version of Unity desktop interface. I don't actually know if it is hard to restore previous behavior or not, and if it is not, where should I look to do that. I know a bit of programming, but I really don't know much about Linux settings. I used to have 3-6 terminal windows and switch between them with Alt+Tab and Shift+Alt+Tab. I liked half-transparent terminal windows, since with them I could open web-page with some instruction in Firefox, press Alt+Tab and type commands in a console window, being able to recognize text on a web-page under it. Now I have problems with my usual work-style because of the following. List of "negative" changes Alt+Tab shows just one icon for all console windows. When I wait some time, it, however, shows all windows, but I don't like to wait. I prefer to remember order of windows and press Alt+Tab as many times as I need to switch to the right window. Alt+Shift+Tab to switch in reverse order doesn't work now. Console windows are not transparent any more. When I don't wait, and switch to this icon, it shows all console windows altogether. So even if they were transparent, I wouldn't be able to see anything below them (I can read something only from the window, which is directly under current one, not a few levels under). When I run a few console windows in Unity I had 740Mb used on Ubuntu 11.04, but I have 1050Mb now. The question is how to make it back to 750-. I really need my memory, since I use my computer to work with 1512Mb of data and I try to save every 10Mb possible (if it doesn't take too much of machine and, more importantly, my time). When I press "The Super key" I have a field to type the name of the program I want to run. But now it sometimes shows this field, but when I'm trying to type nothing happens. Probably, focus is not on the right field. I don't really mean to restore exactly the same behavior, but I want to make my work in Ubuntu 11.10 efficient (at least as efficient as in Ubuntu 11.04). I would be happy if there are some ways to accomplish that. What have I tried I have installed CompizConfig Settings Manager. I have read this question. However enabling "Static Application Switcher" makes Alt+Tab crazy: after enabling it It says about key-binding conflicts with "Ubuntu Unity Plugin"; "Alt+Tab" switching doesn't change, but "Shift+Alt+Tab" now works and shows all windows; Memory usage increases. I have tried turning off Ubuntu Unity Plugin, but this doesn't seem right thing to do, since it seems to turn off all menus, a lot of keystrokes and app-launcher, which usually activates with "The Super key". I have found, that window transparency can be enabled by "Opacity, Brightness and Saturation" plugin from Accessibility. However I don't know if enabling it is the right thing to do (at least it increases memory usage). Update: everything solved but #3: see my own answer below. I have made a separate question about issue #3 (transparency).

  Read the article

• Software and/(x)or Hardware Projects for Pre-School Kids

  - by haylem

  I offered to participate at my kid's pre-school for various activities (yes, I'm crazy like that), and one of them is to help them discover extra-curricular (big word for a pre-school, but by lack of a better one... :)) hobbies, which may or may not relate to a professional activity. At first I thought that it wouldn't be really easy to have pre-schoolers relate to programming or the internal workings of a computer system in general (and I'm more used to teaching middle-school to university-level students), but then I thought there must be a way. So I'm trying to figure out ways to introduce very young kids (3yo) to computer systems in a fun and preferably educational way. Of course, I don't expect them to start smashing the stack for fun and profit right away (or at least not voluntarily, though I could use the occasion for some toddler tests...), but I'm confident there must be ways to get them interested in both: using the systems, becoming curious about understanding what they do, interacting with the systems to modify them. I guess this setting is not really relevant after all, it's pretty much the same as if you were aiming to achieve the same for your own kids at home. Ideas Considering we're talking 3yo pre-schoolers here, and that at this age some kids are already quite confident using a mouse (some even a keyboard, if not for typing, at least to press some buttons they've come to associate with actions) while others have not yet had any interaction with computers of any kind, it needs to be: rather basic, demonstrated and played with in less then 5 or 10 minutes, doable in in groups or alone, scalable and extendable in complexity to accommodate their varying abilities. The obvious options are: basic smallish games to play with, interactive systems like LOGO, Kojo, Squeak and clones (possibly even simpler than that), or thngs like Lego Systems. I guess it can be a thing to reflect on both at the software and the hardware levels: it could be done with a desktop or laptop machine, a tablet, a smartphone (or a crap-phone, for that matter, as long as you can modify it), or even get down to building something from scratch (Raspberry Pi and Arduino being popular options at the moment). I can probably be in the form of games, funny visualizations (which are pretty much games) w/ Prototype, virtual worlds to explore. I also thought on the moment (and I hope this won't offend anyone) that some approaches to teaching pets could work (reward systems, haptic feedback and such things could quickly point a kid in the right direction to understanding how things work, in a similar fashion - I'm not suggesting to shock the kids!). Hmm, Is There an Actual Question in There? What type of systems do you think might be a good fit, both in terms of hardware and software? Do you have seen such systems, or have anything in mind to work on? Are you aware of some research in this domain, with tangible results? Any input is welcome. It's not that I don't see options: there are tons, but I have a harder time pinpointing a more concrete and definite type of project/activity, so I figure some have valuable ideas or existing ones. Note: I am not advocating that every kid should learn to program, be interested in computer systems, or that all of them in a class would even care enough to follow such an introduction with more than a blank stare. I don't buy into the "everybody would benefit from learning to program" thing. Wouldn't hurt, but not necessary in any way. But if I can walk out of there with a few of them having smiled using the thing (or heck, cried because others took them away from them), that'd be good enough. Related Questions I've seen and that seem to complement what I'm looking for, but not exactly for the same age groups or with the same goals: Teaching Programming to Kids Recommendations for teaching kids math concepts & skills for programming?

  Read the article

• Using WKA in Large Coherence Clusters (Disabling Multicast)

  - by jpurdy

  Disabling hardware multicast (by configuring well-known addresses aka WKA) will place significant stress on the network. For messages that must be sent to multiple servers, rather than having a server send a single packet to the switch and having the switch broadcast that packet to the rest of the cluster, the server must send a packet to each of the other servers. While hardware varies significantly, consider that a server with a single gigabit connection can send at most ~70,000 packets per second. To continue with some concrete numbers, in a cluster with 500 members, that means that each server can send at most 140 cluster-wide messages per second. And if there are 10 cluster members on each physical machine, that number shrinks to 14 cluster-wide messages per second (or with only mild hyperbole, roughly zero). It is also important to keep in mind that network I/O is not only expensive in terms of the network itself, but also the consumption of CPU required to send (or receive) a message (due to things like copying the packet bytes, processing a interrupt, etc). Fortunately, Coherence is designed to rely primarily on point-to-point messages, but there are some features that are inherently one-to-many: Announcing the arrival or departure of a member Updating partition assignment maps across the cluster Creating or destroying a NamedCache Invalidating a cache entry from a large number of client-side near caches Distributing a filter-based request across the full set of cache servers (e.g. queries, aggregators and entry processors) Invoking clear() on a NamedCache The first few of these are operations that are primarily routed through a single senior member, and also occur infrequently, so they usually are not a primary consideration. There are cases, however, where the load from introducing new members can be substantial (to the point of destabilizing the cluster). Consider the case where cluster in the first paragraph grows from 500 members to 1000 members (holding the number of physical machines constant). During this period, there will be 500 new member introductions, each of which may consist of several cluster-wide operations (for the cluster membership itself as well as the partitioned cache services, replicated cache services, invocation services, management services, etc). Note that all of these introductions will route through that one senior member, which is sharing its network bandwidth with several other members (which will be communicating to a lesser degree with other members throughout this process). While each service may have a distinct senior member, there's a good chance during initial startup that a single member will be the senior for all services (if those services start on the senior before the second member joins the cluster). It's obvious that this could cause CPU and/or network starvation. In the current release of Coherence (3.7.1.3 as of this writing), the pure unicast code path also has less sophisticated flow-control for cluster-wide messages (compared to the multicast-enabled code path), which may also result in significant heap consumption on the senior member's JVM (from the message backlog). This is almost never a problem in practice, but with sufficient CPU or network starvation, it could become critical. For the non-operational concerns (near caches, queries, etc), the application itself will determine how much load is placed on the cluster. Applications intended for deployment in a pure unicast environment should be careful to avoid excessive dependence on these features. Even in an environment with multicast support, these operations may scale poorly since even with a constant request rate, the underlying workload will increase at roughly the same rate as the underlying resources are added. Unless there is an infrastructural requirement to the contrary, multicast should be enabled. If it can't be enabled, care should be taken to ensure the added overhead doesn't lead to performance or stability issues. This is particularly crucial in large clusters.

  Read the article

< Previous Page | 697 698 699 700 701 702 703 704 705 706 707 708  | Next Page >