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  • Neighbour table overflow on Linux hosts related to bridging and ipv6

    - by tim
    Note: I already have a workaround for this problem (as described below) so this is only a "want-to-know" question. I have a productive setup with around 50 hosts including blades running xen 4 and equallogics providing iscsi. All xen dom0s are almost plain Debian 5. The setup includes several bridges on every dom0 to support xen bridged networking. In total there are between 5 and 12 bridges on each dom0 servicing one vlan each. None of the hosts has routing enabled. At one point in time we moved one of the machines to a new hardware including a raid controller and so we installed an upstream 3.0.22/x86_64 kernel with xen patches. All other machines run debian xen-dom0-kernel. Since then we noticed on all hosts in the setup the following errors every ~2 minutes: [55888.881994] __ratelimit: 908 callbacks suppressed [55888.882221] Neighbour table overflow. [55888.882476] Neighbour table overflow. [55888.882732] Neighbour table overflow. [55888.883050] Neighbour table overflow. [55888.883307] Neighbour table overflow. [55888.883562] Neighbour table overflow. [55888.883859] Neighbour table overflow. [55888.884118] Neighbour table overflow. [55888.884373] Neighbour table overflow. [55888.884666] Neighbour table overflow. The arp table (arp -n) never showed more than around 20 entries on every machine. We tried the obvious tweaks and raised the /proc/sys/net/ipv4/neigh/default/gc_thresh* values. FInally to 16384 entries but no effect. Not even the interval of ~2 minutes changed which lead me to the conclusion that this is totally unrelated. tcpdump showed no uncommon ipv4 traffic on any interface. The only interesting finding from tcpdump were ipv6 packets bursting in like: 14:33:13.137668 IP6 fe80::216:3eff:fe1d:9d01 > ff02::1:ff1d:9d01: HBH ICMP6, multicast listener reportmax resp delay: 0 addr: ff02::1:ff1d:9d01, length 24 14:33:13.138061 IP6 fe80::216:3eff:fe1d:a8c1 > ff02::1:ff1d:a8c1: HBH ICMP6, multicast listener reportmax resp delay: 0 addr: ff02::1:ff1d:a8c1, length 24 14:33:13.138619 IP6 fe80::216:3eff:fe1d:bf81 > ff02::1:ff1d:bf81: HBH ICMP6, multicast listener reportmax resp delay: 0 addr: ff02::1:ff1d:bf81, length 24 14:33:13.138974 IP6 fe80::216:3eff:fe1d:eb41 > ff02::1:ff1d:eb41: HBH ICMP6, multicast listener reportmax resp delay: 0 addr: ff02::1:ff1d:eb41, length 24 which placed the idea in my mind that the problem maybe related to ipv6, since we have no ipv6 services in this setup. The only other hint was the coincidence of the host upgrade with the beginning of the problems. I powered down the host in question and the errors were gone. Then I subsequently took down the bridges on the host and when i took down (ifconfig down) one particularly bridge: br-vlan2159 Link encap:Ethernet HWaddr 00:26:b9:fb:16:2c inet6 addr: fe80::226:b9ff:fefb:162c/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:120 errors:0 dropped:0 overruns:0 frame:0 TX packets:9 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:5286 (5.1 KiB) TX bytes:726 (726.0 B) eth0.2159 Link encap:Ethernet HWaddr 00:26:b9:fb:16:2c inet6 addr: fe80::226:b9ff:fefb:162c/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1801 errors:0 dropped:0 overruns:0 frame:0 TX packets:20 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:126228 (123.2 KiB) TX bytes:1464 (1.4 KiB) bridge name bridge id STP enabled interfaces ... br-vlan2158 8000.0026b9fb162c no eth0.2158 br-vlan2159 8000.0026b9fb162c no eth0.2159 The errors went away again. As you can see the bridge holds no ipv4 address and it's only member is eth0.2159 so no traffic should cross it. Bridge and interface .2159 / .2157 / .2158 which are in all aspects identical apart from the vlan they are connected to had no effect when taken down. Now I disabled ipv6 on the entire host via sysctl net.ipv6.conf.all.disable_ipv6 and rebooted. After this even with bridge br-vlan2159 enabled no errors occur. Any ideas are welcome.

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  • php-fpm + persistent sockets = 502 bad gateway

    - by leeoniya
    Put on your reading glasses - this will be a long-ish one. First, what I'm doing. I'm building a web-app interface for some particularly slow tcp devices. Opening a socket to them takes 200ms and an fwrite/fread cycle takes another 300ms. To reduce the need for both of these actions on each request, I'm opening a persistent tcp socket which reduces the response time by the aforementioned 200ms. I was hoping PHP-FPM would share the persistent connections between requests from different clients (and indeed it does!), but there are some issues which I havent been able to resolve after 2 days of interneting, reading logs and modifying settings. I have somewhat narrowed it down though. Setup: Ubuntu 13.04 x64 Server (fully updated) on Linode PHP 5.5.0-6~raring+1 (fpm-fcgi) nginx/1.5.2 Relevent config: nginx worker_processes 4; php-fpm/pool.d pm = dynamic pm.max_children = 2 pm.start_servers = 2 pm.min_spare_servers = 2 Let's go from coarse to fine detail of what happens. After a fresh start I have 4x nginx processes and 2x php5-fpm processes waiting to handle requests. Then I send requests every couple seconds to the script. The first take a while to open the socket connection and returns with the data in about 500ms, the second returns data in 300ms (yay it's re-using the socket), the third also succeeds in about 300ms, the fourth request = 502 Bad Gateway, same with the 5th. Sixth request once again returns data, except now it took 500ms again. The process repeats for several cycles after which every 4 requests result in 2x 502 Bad Gateways and 2x 500ms Data responses. If I double all the fpm pool values and have 4x php-fpm processes running, the cycles settles in with 4x successful 500ms responses followed by 4x Bad Gateway errors. If I don't use persistent sockets, this issue goes away but then every request is 500ms. What I suspect is happening is the persistent socket keeps each php-fpm process from idling and ties it up, so the next one gets chosen until none are left and as they error out, maybe they are restarted and become available on the next round-robin loop ut the socket dies with the process. I haven't yet checked the 'slowlog', but the nginx error log shows lots of this: *188 recv() failed (104: Connection reset by peer) while reading response header from upstream, client:... All the suggestions on the internet regarding fixing nginx/php-fpm/502 bad gateway relate to high load or fcgi_pass misconfiguration. This is not the case here. Increasing buffers/sizes, changing timeouts, switching from unix socket to tcp socket for fcgi_pass, upping connection limits on the system....none of this stuff applies here. I've had some other success with setting pm = ondemand rather than dynamic, but as soon as the initial fpm-process gets killed off after idling, the persistent socket is gone for all subsequent php-fpm spawns. For the php script, I'm using stream_socket_client() with a STREAM_CLIENT_PERSISTENT flag. A while/stream_select() loop to detect socket data and fread($sock, 4096) to grab the data. I don't call fclose() obviously. If anyone has some additional questions or advice on how to get a persistent socket without tying up the php-fpm processes beyond the request completion, or maybe some other things to try, I'd appreciate it. some useful links: Nginx + php-fpm - recv() error Nginx + php-fpm "504 Gateway Time-out" error with almost zero load (on a test-server) Nginx + PHP-FPM "error 104 Connection reset by peer" causes occasional duplicate posts http://www.linuxquestions.org/questions/programming-9/php-pfsockopen-552084/ http://stackoverflow.com/questions/14268018/concurrent-use-of-a-persistent-php-socket http://devzone.zend.com/303/extension-writing-part-i-introduction-to-php-and-zend/#Heading3 http://stackoverflow.com/questions/242316/how-to-keep-a-php-stream-socket-alive http://php.net/manual/en/install.fpm.configuration.php https://www.google.com/search?q=recv%28%29+failed+%28104:+Connection+reset+by+peer%29+while+reading+response+header+from+upstream+%22502%22&ei=mC1XUrm7F4WQyAHbv4H4AQ&start=10&sa=N&biw=1920&bih=953&dpr=1

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  • Issues configuring Exchange 2010 as well as SSL problems.

    - by Eric Smith
    Possibly-Relevant Background Info: I've recently moved up from icky shared hosting to a glorious, Remote Desktop-administrated VPS server running Windows Server 2008 R2. Even though I'm only 21 now and a computer science major, I've tried to play with every Windows Server release since '03, just to learn new things. What usually happens is inevitably I'll do something wrong and pretty much ruin the install. You're dealing with an amateur here :) Through the past few months of working with my new server, I've mastered DNS, IIS, got Team Foundation Server running (yay!), and can install all of the other basics like SQL Server and Active Directory. The Problem: Now, these last few weeks I've been trying to install Exchange Server 2010 (SP1). To make a long story short, it took me several attempts, and I even had to get my server wiped just so I could start fresh since Exchange decided uninstalling properly was for sissies (cost me $20, bah). Today, at long last, I got Exchange mostly working. There were two main problems left, however, that left me unsatisfied: Exchange installed itself and all of its child sites into Default Web Site. I wanted to access Exchange via mail.domain.com, but instead everything was configured to domain.com. My limited server admin knowledge was not enough to configure IIS or Exchange to move itself over to the website I had set up for it, appropriately titled 'mail.domain.com', which I had bound to a dedicated IP address (I was told this was necessary, but he may have been wrong). I have two SSL certificates: one for my main domain and one for my mail subdomain. For whatever reason, I had issues geting Exchange to use my mail certificate, even though I had assigned the proper roles in the MMC. I did, at one point, get it to work (or mostly work, anyways. Frankly, my memory of today is clouded by intense frustration). Additionally, I was confused which type of SSL certificate I should be using for Exchange. My SSL provider, GoDaddy, allows me to request a new certificate whenever, so I can use either the certificate request provided by IIS or the more complicated and specific request you can create with Exchange. Which type should I be using, the IIS or Exchange certificate? If I must use the Exchange certificate, will that 1) cause issues when I bind that certificate to my mail.domain.com subdomain or 2) is that an unnecessary step? The SSL Certificate Strikes Back When I thought I had the proper SSL certificate assigned for those brief, sweet moments, Google Chrome reported the correct mail.domain.com certificate when browsing https://mail.domain.com. However, Outlook 2010 threw up an error when trying to configure my email account claiming that the certificate didn't match the domain of "mail.domain.com". Is this an issue that will be resolved by problem #2 or is it a separate one entirely? Apologies for the massive wall of text, but I wanted to provide as much info as I possibly could. Exchange is the last thing I'd like installed on my server, and naturally it's turning out to be the hardest. Thanks for any info at all. Even a point in a vague direction would be a huge help at this point. Thanks! -Eric P.S.: The reason I keep ruining my install is that when I attempt to uninstall Exchange, something invariably goes wrong. The last time the uninstaller complained that there was still a mailbox active and it couldn't proceed until I deleted it. ... The only mailbox left was the Administrator account, the built-in one I couldn't delete. So I attempted to manually uninstall it following several guides online only to now be stuck unable to launch the installer and have to get my system wiped AGAIN for the second time today ($40 down the drain, bah!). I do not understand at all why "uninstall" just can't mean "hey, you, delete everything and go away". There's not even a force uninstall option, only a "recover system" option that just fails to fix anything and makes it so I can't even use the GUI uninstaller. </rant>

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  • hostapd running on Ubuntu Server 13.04 only allows single station to connect when using wpa

    - by user450688
    Problem Only a single station can connect to hostapd at a time. Any single station can connect (W8, OSX, iOS, Nexus) but when two or more hosts are connected at the same time the first client loses its connectivity. However there are no connectivity issues when WPA is not used. Setup Linux (Ubuntu server 13.04) wireless router (with separate networks for wired WAN, wired LAN, and Wireless LAN. iptables-save output: *nat :PREROUTING ACCEPT [0:0] :INPUT ACCEPT [0:0] :OUTPUT ACCEPT [0:0] :POSTROUTING ACCEPT [0:0] -A POSTROUTING -s 10.0.0.0/24 -o p4p1 -j MASQUERADE -A POSTROUTING -s 10.0.1.0/24 -o p4p1 -j MASQUERADE COMMIT *mangle :PREROUTING ACCEPT [13:916] :INPUT ACCEPT [9:708] :FORWARD ACCEPT [4:208] :OUTPUT ACCEPT [9:3492] :POSTROUTING ACCEPT [13:3700] COMMIT *filter :INPUT DROP [0:0] :FORWARD DROP [0:0] :OUTPUT ACCEPT [9:3492] -A INPUT -i p4p1 -m state --state RELATED,ESTABLISHED -j ACCEPT -A INPUT -i p4p1 -p tcp -m tcp --dport 22 -m state --state NEW -j ACCEPT -A INPUT -i eth0 -j ACCEPT -A INPUT -i wlan0 -j ACCEPT -A INPUT -i lo -j ACCEPT -A FORWARD -i p4p1 -m state --state RELATED,ESTABLISHED -j ACCEPT -A FORWARD -i eth0 -j ACCEPT -A FORWARD -i wlan0 -j ACCEPT -A FORWARD -i lo -j ACCEPT COMMIT /etc/hostapd/hostapd.conf #Wireless Interface interface=wlan0 driver=nl80211 ssid=<removed> hw_mode=g channel=6 max_num_sta=15 auth_algs=3 ieee80211n=1 wmm_enabled=1 wme_enabled=1 #Configure Hardware Capabilities of Interface ht_capab=[HT40+][SMPS-STATIC][GF][SHORT-GI-20][SHORT-GI-40][RX-STBC12] #Accept all MAC address macaddr_acl=0 #Shared Key Authentication wpa=1 wpa_passphrase=<removed> wpa_key_mgmt=WPA-PSK wpa_pairwise=CCMP rsn_pairwise=CCMP ###IPad Connectivevity Repair ieee8021x=0 eap_server=0 Wireless Card #lshw output product: RT2790 Wireless 802.11n 1T/2R PCIe vendor: Ralink corp. physical id: 0 bus info: pci@0000:03:00.0 logical name: mon.wlan0 version: 00 serial: <removed> width: 32 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list logical wireless ethernet physical configuration: broadcast=yes driver=rt2800pci driverversion=3.8.0-25-generic firmware=0.34 ip=10.0.1.254 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn #iw list output Band 1: Capabilities: 0x272 HT20/HT40 Static SM Power Save RX Greenfield RX HT20 SGI RX HT40 SGI RX STBC 2-streams Max AMSDU length: 3839 bytes No DSSS/CCK HT40 Maximum RX AMPDU length 65535 bytes (exponent: 0x003) Minimum RX AMPDU time spacing: 2 usec (0x04) HT RX MCS rate indexes supported: 0-15, 32 TX unequal modulation not supported HT TX Max spatial streams: 1 HT TX MCS rate indexes supported may differ Frequencies: * 2412 MHz [1] (27.0 dBm) * 2417 MHz [2] (27.0 dBm) * 2422 MHz [3] (27.0 dBm) * 2427 MHz [4] (27.0 dBm) * 2432 MHz [5] (27.0 dBm) * 2437 MHz [6] (27.0 dBm) * 2442 MHz [7] (27.0 dBm) * 2447 MHz [8] (27.0 dBm) * 2452 MHz [9] (27.0 dBm) * 2457 MHz [10] (27.0 dBm) * 2462 MHz [11] (27.0 dBm) * 2467 MHz [12] (disabled) * 2472 MHz [13] (disabled) * 2484 MHz [14] (disabled) Bitrates (non-HT): * 1.0 Mbps * 2.0 Mbps (short preamble supported) * 5.5 Mbps (short preamble supported) * 11.0 Mbps (short preamble supported) * 6.0 Mbps * 9.0 Mbps * 12.0 Mbps * 18.0 Mbps * 24.0 Mbps * 36.0 Mbps * 48.0 Mbps * 54.0 Mbps max # scan SSIDs: 4 max scan IEs length: 2257 bytes Coverage class: 0 (up to 0m) Supported Ciphers: * WEP40 (00-0f-ac:1) * WEP104 (00-0f-ac:5) * TKIP (00-0f-ac:2) * CCMP (00-0f-ac:4) Available Antennas: TX 0 RX 0 Supported interface modes: * IBSS * managed * AP * AP/VLAN * WDS * monitor * mesh point software interface modes (can always be added): * AP/VLAN * monitor valid interface combinations: * #{ AP } <= 8, total <= 8, #channels <= 1 Supported commands: * new_interface * set_interface * new_key * new_beacon * new_station * new_mpath * set_mesh_params * set_bss * authenticate * associate * deauthenticate * disassociate * join_ibss * join_mesh * set_tx_bitrate_mask * set_tx_bitrate_mask * action * frame_wait_cancel * set_wiphy_netns * set_channel * set_wds_peer * Unknown command (84) * Unknown command (87) * Unknown command (85) * Unknown command (89) * Unknown command (92) * testmode * connect * disconnect Supported TX frame types: * IBSS: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0 * managed: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0 * AP: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0 * AP/VLAN: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0 * mesh point: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0 * P2P-client: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0 * P2P-GO: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0 * Unknown mode (10): 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0 Supported RX frame types: * IBSS: 0x40 0xb0 0xc0 0xd0 * managed: 0x40 0xd0 * AP: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0 * AP/VLAN: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0 * mesh point: 0xb0 0xc0 0xd0 * P2P-client: 0x40 0xd0 * P2P-GO: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0 * Unknown mode (10): 0x40 0xd0 Device supports RSN-IBSS. HT Capability overrides: * MCS: ff ff ff ff ff ff ff ff ff ff * maximum A-MSDU length * supported channel width * short GI for 40 MHz * max A-MPDU length exponent * min MPDU start spacing Device supports TX status socket option. Device supports HT-IBSS.

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  • Rosewill RSV-S5 and it's transferespeeds

    - by DoomStone
    I have just bought a Rosewill RSV-S5, I have installed 5x1,5Tb Western Digital Green disks in it. After that have I created a Raid5 on them all with the software that followed with the hardware. Not the raid it self works fine, but it is SLOW, I can only obtain a maximum of 25 MB/s, and if SABnzbd+ is downloading with 5 MB/s is it having a hard time streaming a normal DIVX (700 mb) movie. Is this normal or is there something wrong? Edit: should be able to handle 3 Gbps = 384 megabytes / second Edit 2: As you can see am I only downloading with 3,76 MB/s and I'm trying to watch V s02e08 (720p), but it is completely unwatchable, as I can see 30 sec, and the it buffers for 20 sec. Edit: Other information there might be required I'm running Windows Server 2008 R2, optimized for program performance. Windows is installed on a 60GB SSD. I have a 50 Mb/s internet connection and a 1 Gb/s LAN, all connected with Cat6 Ethernet cables. The MCE is using a Gigabyte EP35C-DS3R motherboard with 2 GB DDR2 ram. Edit 3: I have used chunk sizes for 128 KB Edit 4: I found this on newegg Pros: Enclosure for 5x2TB hard drive is fine. This is basically a rebranded San Digital TR5M-B product. For support Rosewill tells you to contact San Digital. No direct support from Silicon Image for the computer raid card. Cons: Includes computer Silicon Image 3132 raid card, extremely slow raid 5 write (our tests ~10MB/s). Compare to regular internal local drive write 30-60MB/s. We basically dumped the Sil3132 card and replaced with High Point RocketRaid 622 card for extra $69.99. Note for RR622, turn off ECRC (end to end CRC check) for card to work on IBM xserver. What took 12hrs to copy now took 2-3hrs. San Digital realized the problem and has the newer model TR5M-BP TowerRaid Plus that comes with High Point RocketRaid 622 card. Rosewill should discontinue this product and go with TR5M-BP. Could not get Silicon Image raid management software to work with complicated 2008R2 server with 10 NICs, application doesn't know how to talk to localhost port with all those NICs. No updates from Silicon Image and support from San Digital ignored. Gave up on Sil3132 card. Save yourself from a lot of headaches, get the RR622 card too if you are going to buy this product. Other Thoughts: The newer model is TR5M-BP TowerRaid Plus, comes with High Point RocketRaid 622 raid card for the PC instead of Silicon Image Sil3132. According to San Digital, raid 5 performance for Sil3132 read 80MB/s write 19MB/s, and RR622 read 154MB/s write 149MB/s. Our RR622 tests gave (8TB raid 5) write ~80-110MB/s copying 40GB file took 8mins. So I have now ordered a HighPoint RocketRAID 622 2P ext SATA III and hopes that it will solve my problems.

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  • IPv6: Should I have private addresses?

    - by AlReece45
    Right now, we have a rack of servers. Every server right now has at least 2 IP addresses, one for the public interface, another for the private. The servers that have SSL websites on them have more IP addresses. We also have virtual servers, that are configured similarly. Private Network The private range is currently just used for backups and monitoring. Its a gigabit port, the interface usage does not usually get very high. There are other technologies we're considering using that would use this port: iSCSI (implementations usually recommends dedicating an interface to it, which would be yet another IP network), VPN to get access to the private range (something I'd rather avoid) dedicated database servers LDAP centralized configuration (like puppet) centralized logging We don't have any private addresses in our DNS records (only public addresses). For our servers to utilize the correct IP address for the right interface (and not hard code the IP address) probably requires setting up a private DNS server (So now we add 2 different dns entries to 2 different systems). Public Network Our public range has a variety of services include web, email, and ftp. There is a hardware firewall between our network and the "public" network. We have (relatively secure) method to instruct the firewall to open and close administrative access (web interfaces, ssh, etc) for our current IP address. With either solution discussed, the host-based firewalls will be configured as well. The public network currently runs at a dedicated 20Mbps link. There are a couple of legacy servers with fast-ethernet ports, but they are scheduled for decommissioning. All of the other production boxes have at least 2 Gigabit Ethernet ports. The more traffic-heavy servers have 4-6 available (none is using more than the 2 Gigabit ports right now). IPv6 I want to get an IPv6 prefix from our ISP. So at least every "server" has at least one IPv6 interface. We'll still need to keep the IPv4 addressees up and available for legacy clients (web servers and email at the very least). We have two IP networks right now. Adding the public IPv6 address would make it three. Just use IPv6? I'm thinking about just dumping the private IPv4 range and using the IPv6 range as the primary means of all communications. If an interface starts reaching its capacity, utilize the newly free interfaces to create a trunk. It has the advantage that if either the public or private traffic needs to exceed 1Gbps. The traffic for each interface is already analyzed on a regular basis to predict future bandwidth use. In the rare instances where bandwidth unexpected peaks: utilize QoS to ensure traffic (like our limited SSH access) is prioritized correctly so the problem can be corrected (if possible, our WAN is the bottleneck right now). It also has the advantage of not needing to make an entry for every private address. We may have private DNS (or just LDAP), but it'll be much more limited in scope with less entries to duplicate. Summary I'm trying to make this network as "simple" as possible. At the same time, I want to make sure its reliable, upgradeable, scalable, and (eventually) redundant. Having one IPv6 network, and a legacy IPv4 network seems to be the best solution to me. Regarding using assigned IPv6 addresses for both networks, sharing the available bandwidth on one (more trunked if needed): Are there any technical disadvantages (limitations, buffers, scalability)? Are there any other security considerations (asides from firewalls mentioned above) to consider? Are there regulations or other security requirements (like PCI-DSS) that this doesn't meet? Is there typical software for setting up a Linux network that doesn't have IPv6 support yet? (logging, ldap, puppet) Some other thing I didn't consider?

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  • Installing EclipseFP on Mac OS X

    - by Dom Kennedy
    I am trying to install EclipseFP. I'm running OS X Mavericks. I've tried following both the official installation instructions and the advice in this answer on SU, but I'm still having the same problem. I can get the plugin itself installed painlessly using Help -> Install New Software..., Bbut when I restart and switch to the Haskell perspective, things start to go wrong. The installation instructions tells me that I should receive a prompt to install BuildWrapper and Scion Browser. I do not receive this prompt. Furthermore, if I create a new Haskell project, my code has no syntax highlighting, and the Hoogle search feature does not appear to do anything. It's clear that the plugin is not set up correctly yet. I've tried running cabal update in Terminal, but this does not change anything. After several attempts going round in circles with this on Eclipse Juno, I uninstalled Eclispe and the Haskell Platform and performed a clean install of Eclipse Luna and the latest Haskell Platform. However, the problems are persisting. I've tried going into Preferences to see if I could sort any of this out manually. I should initially point out that my GHC installation seems to be correctly references under Preferences -> Haskell Implementations Under Haskell -> Helper executables, there are areas for configuring the options of both BuildWrapper and Scion Browser. At present, both are blank. I tried clicking the Install from Hackage... button beside each of them with no success; I receive an error message saying Expected executable <workspace>/.metadata/.plugins/net.sf.eclipsefp.haskell.ui/sandbox/.cabal-sandbox/bin/buildwrapper not found!` (replace buildwrapper for scion-browser and the message is the same) The Eclipse console displays the following exception after doing the above with BuildWrapper: src/Language/Haskell/BuildWrapper/GHCStorage.hs:313:32: Not in scope: data constructor ‘MatchGroup’ cabal.real: Error: some packages failed to install: buildwrapper-0.7.4 failed during the building phase. The exception was: ExitFailure 1 and after doing it for Scion-Browser: zip-archive-0.2.3.4 (reinstall) changes: text-1.1.0.0 -> 0.11.3.1 pandoc-1.12.3.3 (latest: 1.13) -http-conduit (new version) Graphalyze-0.14.1.0 (reinstall) changes: pandoc-1.12.4.2 -> 1.12.3.3, text-1.1.0.0 -> 0.11.3.1 cabal.real: The following packages are likely to be broken by the reinstalls: pandoc-1.12.4.2 unordered-containers-0.2.4.0 aeson-0.7.0.4 scientific-0.2.0.2 case-insensitive-1.1.0.3 HTTP-4000.2.10 Use --force-reinstalls if you want to install anyway. After receiving similar results as the above on previous attempts, I've tried using force-reinstalls and ended up at more dead ends. I am at a loss as to what is wrong and how to solve this. I should point out that my GHC installation appears to be correctly configured under Preferences -> Haskell -> Haskell Implementations. Apologies if any of this information is irrelevant, I'm just not really sure what is important and what isn't at this point. Any help anyone could provide me with would be greatly appreciated.

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  • How to install Delorme StreetAtlas (any version) + GPS inside VirtualBox VM?

    - by hotei
    When I try to run the install program I get a popup message that says the installer program is not a valid executable. Background: I want a GPS with maps on my laptop running Ubuntu 10.4LTS. Unfortunately I can't find a decent native Linux GPS solution with 50 state US street level coverage. I have VirtualBox VMs available for WinXP and Win7 (among others). The VMs work fine with MicroSoft Streets and Trips (2010) and MapNGo 5 (a very! old Delorme product), but while both these products support GPS, they don't support the Earthmate LT-40 USB GPS I already have. I've got pretty much every Delorme Street Atlas they've released in the last decade and none of them will install in a VM. Any help would be much appreciated. Clarification: I've installed the Delorme products from these CDs before and the disks are fine - as long as installation is done on a "physical" machine. Added: I've tried install from an iso as well as the real CD. No difference in result (setup.exe is not a valid executable) The WinXP is SP-2 (held back on purpose at this point - I'll snapshot and fork a later SP to test). The Win2K is SP-6a. Win7(32) VM is whatever updates came out last week. The USB setup is working at least to the point where the GPS device is active in the device list (has an x in the box). At this point its not relevant because the program that needs to read it can't even be installed. Added 9-19: Added wine as harrymc suggested. Initial result was no change. Here's wines error message. The file '/media/Disk1/setup.exe' is not marked as executable. If this was downloaded or copied form an untrusted source, it may be dangerous to run. For more details, read about the executable bit. At first I thought the execute bit was the problem, but looking at several other windows CDs I see that the execute bit is not set on their exe files (which install to VM without error). Still it was worth a shot so I copied the StreetAtlas 9 DVD to my hard disk, changed the on-disk exe files to have the execute bit set and tried to install again. This time the install via wine got me through the installation process. When I start the program it bombs immediately, so we haven't made much real progress so far. I very much prefer the VM solution to wine, so I'm going back to that for now. To recap the VM situation, using an updated XP with SP3 and all recommended hotfixes: StreetAtlas 2009 USA fails with "not marked as executable". StreetAtlas 2007 USA fails with "not marked as executable". StreetAtlas 9 (copyright 2001) fails with "not marked as executable". SteeetAtlas (copyright 1991) fails with "not marked as executable" Delorme Topo 4 (copyright 2002) fails with "not marked as executable". Just about ready to give up. So I switched from XP VM to Win7 VM and tried StreetAtlas 2009 again. This time it installs. Earthmate USB GPS works. WTH? I feel like the monkey who just wrote a line of Shakespear. I'm smiling because it worked, but I have no clue why. I'm awarding the bounty to harrymc because wine did give some useful insight into the problem and a +1 to goyiux as thanks for helping.

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  • Apache Getting Bogged Down By Certain Script (Wp-Cron.php) - How To Kill Process Automatically

    - by user50037
    I have a server that is running a number of wordpress blogs, and a number of them have several hundred/thousand posts. Every couple of days, the server slows to a crawl due to a file being run on Wordpress called WP-cron.php. My entire apache process log turns into this : http:// imgur.com/A7K9k.png Times that by quite a bit. And server no go. Each process takes up about 1.1% of ram. And when we have 50 of them on the go. It gets insane. Not all of them are coming from the same blog, they are pretty widespread. In the Apache process page of WHM, they are usually ALL set to the status of "C", which means closing. But they can sit there until they crash the server, and they still hold the memory. Just google "wp-cron.php load" and you will find plenty of people with similar issues. In anycase, we have think it is down to users adding a tonne of dead "pinglists" to their wordpress installation. Which in turn wordpress loops through them endlessly. Problem number 1. Does anyone have any other suggestions about what would cause the Wordpress file wp-cron.php to loop endlessly. I still think it is down to pings, because all of the people we have contacted about their account load going sky high, have had massive ping lists. Problem number 2. Even if it is down to excessive pinglists in wordpress. We cannot be babying every single account on the server waiting for it to start spawning the wp-cron processes. It often happens overnight, and I start getting SMS alerts at 2am about the load. I have CSF installed, which apparently would have ended the processes if they ran over XXX time. But I have been told that it won't catch the processes because they end up in this state of "closing" (They show up as "C" on the Apache page of WHM). Apparently CSF will only kill processes that are "running" which C does not count. I have seen various other scripts such as : http://dltj.org/article/die-apache-die/ . I took a look at the stat of /proc. But I was boggled at which delimited part was the time running. And if there was any way I could connect it back to an actual Apache process, so that I could see what file was running (So only close connections connected to wp-cron.php, with a state of "C"). Overall I know Problem 2 glosses over the real reason. But I do put the whole thing to excessive pinglists in Wordpress. But I just cannot sit there and babysit every single installation 24/7. So I need a way to save the server when I am not available. Any help would be much appreciated.

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  • SQLAuthority News – SQL Server Technology Evangelists and Evangelism

    - by pinaldave
    This is the exact conversation that I had with three people during the recent SQL Server Public Training. Person 1: “Are you an SQL Server Evangelist?” Pinal : “No, but Vinod Kumar is.” Person 1: “Who are you?” Person 2: “He is Pinal, haha!” Person 1: “I know that, but don’t you evangelize SQL Server Technology?” Pinal : “Hmm… I do that…” Person 1: “In that case, why don’t you call yourself an Evangelist?” Pinal : “…! …” Person 2: “Good Question! Who are you Pinal?” Pinal : “I think you are asking my title, is that correct?” Person 1: “Maybe.” Pinal : “I am a Mentor, and I work for Solid Quality Mentors.” Person 2: “I have seen you listing yourself as the Founder of SQLAuthority.com… so…” Pinal : “Yeah that’s true.” Person 3: “Let me summarize what these people are asking. What they are asking is that you can have multiple titles, so is being an evangelist one of your titles or not?” Pinal : “Well, I am an SQL Server MVP and lots of people say that we are also evangelists of technology. In fact,  we are all evangelists of technology, aren’t we?” Person 1: “So let me come back to my original topic: If you are an SQL Server Evangelist, then what is this evangelism?” Person 2: “And who is Vinod Kumar – I have heard about him a lot.” Pinal : “Oh okay. Now I got it. Let me explain …” The answer was quite long but since this conversation, I have been thinking about the words “evangelist” and “evangelism.” I think being an evangelist is one of the most respected jobs in the world and to do this job one must bear lots of responsibilities. There were two questions asked to me, so let me answer both one by one. Who is Vinod Kumar? Vinod Kumar is a Technology Evangelist for Microsoft and one of the most respected persons in the SQL Server Community in India. Let me copy-paste my note from the previous TechEd India 2010 article. “I attended 2 sessions of Vinod Kumar. Vinod is a natural storyteller so there was no doubt that his sessions would be jam-packed. People attended his sessions simply because Vinod was the best speaker in the event. He did not have a single time that disappointed audience; he is truly a good speaker. He knows his stuff very well. I personally do not think that in India he can be compared to anyone for SQL.” Pinal Dave and Vinod Kumar What is Technology Evangelism? Here I am listing three posts written by Vinod Kumar, wherein he talks about Technology Evangelism and Technology Evangelist in an in-depth manner. They are highly-regarded articles in the Community. Evangelism beyond boundaries with an Evangelists !!! Technology Evangelism Demystified New face of Online Technology Evangelism I strongly recommend reading them all. These are wonderful blog posts. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: About Me, MVP, Pinal Dave, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority News, T SQL, Technology

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  • Updated Security Baseline (7u45) impacts Java 7u40 and before with High Security settings

    - by costlow
    The Java Security Baseline has been increased from 7u25 to 7u45.  For versions of Java below 7u45, this means unsigned Java applets or Java applets that depend on Javascript LiveConnect calls will be blocked when using the High Security setting in the Java Control Panel. This issue only affects Applets and Web Start applications. It does not affect other types of Java applications. The Short Answer Users upgrading to Java 7 update 45 will automatically fix this and is strongly recommended. The More Detailed Answer There are two items involved as described on the deployment flowchart: The Security Baseline – a dynamically updated attribute that checks to see which Java version contains the most recent security patches. The Security Slider – the user-controlled setting of when to prompt/run/block applets. The Security Baseline Java clients periodically check in to understand what version contains the most recent security patches. Versions are released in-between that contain bug fixes. For example: 7u25 (July 2013) was the previous secure baseline. 7u40 contained bug fixes. Because this did not contain security patches, users were not required to upgrade and were welcome to remain on 7u25. When 7u45 was released (October, 2013), this critical patch update contained security patches and raised the secure baseline. Users are required to upgrade from earlier versions. For users that are not regularly connected to the internet, there is a built in Expiration Date. Because of the pre-established quarterly critical patch updates, we are able to determine an approximate date of the next version. A critical patch released in July will have its successor released, at latest, in July + 3 months: October. The Security Slider The security slider is located within the Java control panel and determines which Applets & Web Start applications will prompt, which will run, and which will be blocked. One of the questions used to determine prompt/run/block is, “At or Above the Security Baseline.” The Combination JavaScript calls made from LiveConnect do not reside within signed JAR files, so they are considered to be unsigned code. This is correct within networked systems even if the domain uses HTTPS because signed JAR files represent signed "data at rest" whereas TLS (often called SSL) literally stands for "Transport Level Security" and secures the communication channel, not the contents/code within the channel. The resulting flow of users who click "update later" is: Is the browser plug-in registered and allowed to run? Yes. Does a rule exist for this RIA? No rules apply. Does the RIA have a valid signature? Yes and not revoked. Which security prompt is needed? JRE is below the baseline. This is because 7u45 is the baseline and the user, clicked "upgrade later." Under the default High setting, Unsigned code is set to "Don’t Run" so users see: Additional Notes End Users can control their own security slider within the control panel. System Administrators can customize the security slider during automated installations. As a reminder, in the future, Java 7u51 (January 2014) will block unsigned and self-signed Applets & Web Start applications by default.

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  • What I don&rsquo;t like about WIF&rsquo;s Claims-based Authorization

    - by Your DisplayName here!
    In my last post I wrote about what I like about WIF’s proposed approach to authorization – I also said that I definitely would build upon that infrastructure for my own systems. But implementing such a system is a little harder as it could be. Here’s why (and that’s purely my perspective): First of all WIF’s authorization comes in two “modes” Per-request authorization. When an ASP.NET/WCF request comes in, the registered authorization manager gets called. For SOAP the SOAP action gets passed in. For HTTP requests (ASP.NET, WCF REST) the URL and verb. Imperative authorization This happens when you explicitly call the claims authorization API from within your code. There you have full control over the values for action and resource. In ASP.NET per-request authorization is optional (depends on if you have added the ClaimsAuthorizationHttpModule). In WCF you always get the per-request checks as soon as you register the authorization manager in configuration. I personally prefer the imperative authorization because first of all I don’t believe in URL based authorization. Especially in the times of MVC and routing tables, URLs can be easily changed – but then you also have to adjust your authorization logic every time. Also – you typically need more knowledge than a simple “if user x is allowed to invoke operation x”. One problem I have is, both the per-request calls as well as the standard WIF imperative authorization APIs wrap actions and resources in the same claim type. This makes it hard to distinguish between the two authorization modes in your authorization manager. But you typically need that feature to structure your authorization policy evaluation in a clean way. The second problem (which is somehow related to the first one) is the standard API for interacting with the claims authorization manager. The API comes as an attribute (ClaimsPrincipalPermissionAttribute) as well as a class to use programmatically (ClaimsPrincipalPermission). Both only allow to pass in simple strings (which results in the wrapping with standard claim types mentioned earlier). Both throw a SecurityException when the check fails. The attribute is a code access permission attribute (like PrincipalPermission). That means it will always be invoked regardless how you call the code. This may be exactly what you want, or not. In a unit testing situation (like an MVC controller) you typically want to test the logic in the function – not the security check. The good news is, the WIF API is flexible enough that you can build your own infrastructure around their core. For my own projects I implemented the following extensions: A way to invoke the registered claims authorization manager with more overloads, e.g. with different claim types or a complete AuthorizationContext. A new CAS attribute (with the same calling semantics as the built-in one) with custom claim types. A MVC authorization attribute with custom claim types. A way to use branching – as opposed to catching a SecurityException. I will post the code for these various extensions here – so stay tuned.

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  • Collaborate10 &ndash; THEconference

    - by jean-pierre.dijcks
    After spending a few days in Mandalay Bay's THEHotel, I guess I now call everything THE... Seriously, they even tag their toilet paper with THEtp... I guess the brand builders in Vegas thought that once you are on to something you keep on doing it, and granted it is a nice hotel with nice rooms. THEanalytics Most of my collab10 experience was in a room called Reef C, where the BIWA bootcamp was held. Two solid days of BI, Warehousing and Analytics organized by the BIWA SIG at IOUG. Didn't get to see all sessions, but what struck me was the high interest in Analytics. Marty Gubar's OLAP session was full and he did some very nice things with the OLAP option. The cool bit was that he actually gets all the advanced calculations in OLAP to show up in OBI EE without any effort. It was nice to see that the idea from OWB where you generate an RPD is now also in AWM. I think it makes life so much simpler to generate these RPD's from your data model. Even if the end RPD needs some tweaking, it is all a lot less effort to get something going. You can see this stuff for yourself in this demo (click here). OBI EE uses just SQL to get to the calculations, and so, if you prefer APEX, you can build you application there and get the same nice calculations in an APEX application. Marty also showed the Simba MDX driver used with Excel. I guess we should call that THEcoolone... and it is very slick and wonderfully useful for all of you who actually know Excel. The nice thing is that you leverage pure Excel for all operations (no plug-ins). That means no new tools to learn, no new controls, all just pure Excel. THEdatabasemachine Got some very good questions in my "what makes Exadata fast" session and overall, the interest in Exadata is overwhelming. One of the things that I did try to do in my session is to get people to think in new patterns rather than in patterns based on Oracle 9i running on some random hardware configuration. We talked a little bit about the often over-indexing and how everyone has to unlearn all of that on Exadata. The main thing however is that everyone needs to get used to the shear size of some of the components in a Database machine V2. 5TB of flash cache is a lot of very fast data storage, half a TB of memory gets quite interesting as well. So what I did there was really focus on some of the content in these earlier posts on Upward ILM and In-Memory processing. In short, I do believe the these newer media point out a trend. In-memory and other fast media will get cheaper and will see more use. Some of that we do automatically by adding new functionality, but in some cases I think the end user of the system needs to start thinking about how to leverage all this new hardware. I think most people got very excited about these new capabilities and opportunities. THEcoolkids One of the cool things about the BIWA track was the hand-on track. Very cool to see big crowds for both OLAP and OWB hands-on. Also quite nice to see that the folks at RittmanMead spent so much time on preparing for that session. While all of them put down cool stuff, none was more cool that seeing Data Mining on an Apple iPAD... it all just looks great on an iPAD! Very disappointing to see that Mark Rittman still wasn't showing OWB on his iPAD ;-) THEend All in all this was a great set of sessions in the BIWA track. Lots of value to our guests (we hope) and we hope they all come again next year!

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  • Where’s my MD.050?

    - by Dave Burke
    A question that I’m sometimes asked is “where’s my MD.050 in OUM?” For those not familiar with an MD.050, it serves the purpose of being a Functional Design Document (FDD) in one of Oracle’s legacy Methods. Functional Design Documents have existed for many years with their primary purpose being to describe the functional aspects of one or more components of an IT system, typically, a Custom Extension of some sort. So why don’t we have a direct replacement for the MD.050/FDD in OUM? In simple terms, the disadvantage of the MD.050/FDD approach is that it tends to lead practitioners into “Design mode” too early in the process. Whereas OUM encourages more emphasis on gathering, and describing the functional requirements of a system ahead of the formal Analysis and Design process. So that just means more work up front for the Business Analyst or Functional Consultants right? Well no…..the design of a solution, particularly when it involves a complex custom extension, does not necessarily take longer just because you put more thought into the functional requirements. In fact, one could argue the complete opposite, in that by putting more emphasis on clearly understanding the nuances of functionality requirements early in the process, then the overall time and cost incurred during the Analysis to Design process should be less. In short, as your understanding of requirements matures over time, it is far easier (and more cost effective) to update a document or a diagram, than to change lines of code. So how does that translate into Tasks and Work Products in OUM? Let us assume you have reached a point on a project where a Custom Extension is needed. One of the first things you should consider doing is creating a Use Case, and remember, a Use Case could be as simple as a few lines of text reflecting a “User Story”, or it could be what Cockburn1 describes a “fully dressed Use Case”. It is worth mentioned at this point the highly scalable nature of OUM in the sense that “documents” should not be produced just because that is the way we have always done things. Some projects may well be predicated upon a base of electronic documents, whilst other projects may take a much more Agile approach to describing functional requirements; through “User Stories” perhaps. In any event, it is quite common for a Custom Extension to involve the creation of several “components”, i.e. some new screens, an interface, a report etc. Therefore several Use Cases might be required, which in turn can then be assembled into a Use Case Package. Once you have the Use Cases attributed to an appropriate (fit-for-purpose) level of detail, and assembled into a Package, you can now create an Analysis Model for the Package. An Analysis Model is conceptual in nature, and depending on the solution being developing, would involve the creation of one or more diagrams (i.e. Sequence Diagrams, Collaboration Diagrams etc.) which collectively describe the Data, Behavior and Use Interface requirements of the solution. If required, the various elements of the Analysis Model may be indexed via an Analysis Specification. For Custom Extension projects that follow a pure Object Orientated approach, then the Analysis Model will naturally support the development of the Design Model without any further artifacts. However, for projects that are transitioning to this approach, then the various elements of the Analysis Model may be represented within the Analysis Specification. If we now return to the original question of “Where’s my MD.050”. The full answer would be: Capture the functional requirements within a Use Case Group related Use Cases into a Package Create an Analysis Model for each Package Consider creating an Analysis Specification (AN.100) as a index to each Analysis Model artifact An alternative answer for a relatively simple Custom Extension would be: Capture the functional requirements within a Use Case Optionally, group related Use Cases into a Package Create an Analysis Specification (AN.100) for each package 1 Cockburn, A, 2000, Writing Effective Use Case, Addison-Wesley Professional; Edition 1

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  • Using NServiceBus behind a custom web service

    - by Michael Stephenson
    In this post I'd like to talk about an architecture scenario we had recently and how we were able to utilise NServiceBus to help us address this problem. Scenario Cognos is a reporting system used by one of my clients. A while back we developed a web service façade to allow line of business applications to be able to access reports from Cognos to support their various functions. The service was intended to provide access to reports which were quick running reports or pre-generated reports which could be accessed real-time on demand. One of the key aims of the web service was to provide a simple generic interface to allow applications to get any report without needing to worry about the complex .net SDK for Cognos. The web service also supported multi-hop kerberos delegation so that report data could be accesses under the context of the end user. This service was working well for a period of time. The Problem The problem we encountered was that reports were now also required to be available to batch processes. The original design was optimised for low latency so users would enjoy a positive experience, however when the batch processes started to request 250+ concurrent reports over an extended period of time you can begin to imagine the sorts of problems that come into play. The key problems this new scenario caused are: Users may be affected and the latency of on demand reports was significantly slower The Cognos infrastructure was not scaled sufficiently to be able to cope with these long peaks of load From a cost perspective it just isn't feasible to scale the Cognos infrastructure to be able to handle the load when it is only for a couple of hour window each night. We really needed to introduce a second pattern for accessing this service which would support high through-put scenarios. We also had little control over the batch process in terms of being able to throttle its load. We could however make some changes to the way it accessed the reports. The Approach My idea was to introduce a throttling mechanism between the Web Service Façade and Cognos. This would allow the batch processes to push reports requests hard at the web service which we were confident the web service can handle. The web service would then queue these requests and process them behind the scenes and make a call back to the batch application to provide the report once it had been accessed. In terms of technology we had some limitations because we were not able to use WCF or IIS7 where the MSMQ-Activated WCF services could have helped, but we did have MSMQ as an option and I thought NServiceBus could do just the job to help us here. The flow of how this would work was as follows: The batch applications would send a request for a report to the web service The web service uses NServiceBus to send the message to a Queue The NServiceBus Generic Host is running as a windows service with a message handler which subscribes to these messages The message handler gets the message, accesses the report from Cognos The message handler calls back to the original batch application, this is decoupled because the calling application provides a call back url The report gets into the batch application and is processed as normal This approach looks something like the below diagram: The key points are an application wanting to take advantage of the batch driven reports needs to do the following: Implement our call back contract Make a call to the service providing a call back url Provide a correlation ID so it knows how to tie each response back to its request What does NServiceBus offer in this solution So this scenario is not the typical messaging service bus type of solution people implement with NServiceBus, but it did offer the following: Simplified interaction with MSMQ Offered the ability to configure the number of processes working through the queue so we could find a balance between load on Cognos versus the applications end to end processing time NServiceBus offers retries and a way to manage failed messages NServiceBus offers a high availability setup The simple thing is that NServiceBus gave us the platform to build the solution on. We just implemented a message handler which functionally processed a message and we could rely on NServiceBus to do all of the hard work around managing the queues and all of the lower level things that would have took ages to write to any kind of robust level. Conclusion With this approach we were able to deal with a fairly significant performance issue with out too much rework. Hopefully this write up gives people some insight into ideas on how to leverage the excellent NServiceBus framework to help solve integration and high through-put scenarios.

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  • SQL Server – SafePeak “Logon Trigger” Feature for Managing Data Access

    - by pinaldave
    Lately I received an interesting question about the abilities of SafePeak for SQL Server acceleration software: Q: “I would like to use SafePeak to make my CRM application faster. It is an application we bought from some vendor, after a while it became slow and we can’t reprogram it. SafePeak automated caching sounds like an easy and good solution for us. But, in my application there are many servers and different other applications services that address its main database, and some even change data, and I feel that there is a chance that some servers that during the connection process we may miss some. Is there a way to ensure that SafePeak will be aware of all connections to the SQL Server, so its cache will remain intact?” Interesting question, as I remember that SafePeak (http://www.safepeak.com/Product/SafePeak-Overview) likes that all traffic to the database will go thru it. I decided to check out the features of SafePeak latest version (2.1) and seek for an answer there. A: Indeed I found SafePeak has a feature they call “Logon Trigger” and is designed for that purpose. It is located in the user interface, under: Settings -> SQL instances management  ->  [your instance]  ->  [Logon Trigger] tab. From here you activate / deactivate it and control a white-list of enabled server IPs and Login names that SafePeak will ignore them. Click to Enlarge After activation of the “logon trigger” Safepeak server is notified by the SQL Server itself on each new opened connection. Safepeak monitors those connections and decides if there is something to do with them or not. On a typical installation SafePeak likes all application and users connections to go via SafePeak – this way it knows about data and schema updates immediately (real time). With activation of the safepeak “logon trigger”  a special CLR trigger is deployed on the SQL server and notifies Safepeak on any connection that has not arrived via SafePeak. In such cases Safepeak can act to clear and lock the cache or to ignore it. This feature enables to make sure SafePeak will be aware of all connections so SafePeak cache will maintain exactly correct all times. So even if a user, like a DBA will connect to the SQL Server not via SafePeak, SafePeak will know about it and take actions. The notification does not impact the work of that connection, the user or application still continue to do whatever they planned to do. Note: I found that activation of logon trigger in SafePeak requires that SafePeak SQL login will have the next permissions: 1) CONTROL SERVER; 2) VIEW SERVER STATE; 3) And the SQL Server instance is CLR enabled; Seeing SafePeak in action, I can say SafePeak brings fantastic resource for those who seek to get performance for SQL Server critical apps. SafePeak promises to accelerate SQL Server applications in just several hours of installation, automatic learning and some optimization configuration (no code changes!!!). If better application and database performance means better business to you – I suggest you to download and try SafePeak. The solution of SafePeak is indeed unique, and the questions I receive are very interesting. Have any more questions on SafePeak? Please leave your question as a comment and I will try to get an answer for you. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Should I upgrade to "Ubuntu 14.04 'Trusty Tahr'" from "Ubuntu 12.04 LTS" and what care do I need to take if I upgrade?

    - by PHPLover
    I'm basically a Web Developer(PHP Developer) by profession. I mainly work on PHP, jQuery, AJAX, Smarty, HTML and CSS, Bootstrap front-end web development framework. I've also installed and using IDEs/editors like Sublime Text, NetBeans. I'm also using Git repository for my website development as a versioning tool. I'm using "Ubuntu 12.04 LTS" on my machine almost since last two years. My machine configuraion is as follows: Memory : 3.7 GiB Processor : Intel® Core™ i3 CPU M 370 @ 2.40GHz × 4 Graphics : Unknown OS type : 64-bit Disk : 64-bit The important softwares present on my machine and which I'm using daily for my work are as follows: PHP : PHP 5.3.10-1ubuntu3.13 with Suhosin-Patch (cli) (built: Jul 7 2014 18:54:55) Copyright (c) 1997-2012 The PHP Group Zend Engine v2.3.0, Copyright (c) 1998-2012 Zend Technologies Apache web server : /usr/sbin/apachectl: 87: ulimit: error setting limit (Operation not permitted) Server version: Apache/2.2.22 (Ubuntu) Server built: Jul 22 2014 14:35:25 Server's Module Magic Number: 20051115:30 Server loaded: APR 1.4.6, APR-Util 1.3.12 Compiled using: APR 1.4.6, APR-Util 1.3.12 Architecture: 64-bit Server MPM: Prefork threaded: no forked: yes (variable process count) Server compiled with.... -D APACHE_MPM_DIR="server/mpm/prefork" -D APR_HAS_SENDFILE -D APR_HAS_MMAP -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled) -D APR_USE_SYSVSEM_SERIALIZE -D APR_USE_PTHREAD_SERIALIZE -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT -D APR_HAS_OTHER_CHILD -D AP_HAVE_RELIABLE_PIPED_LOGS -D DYNAMIC_MODULE_LIMIT=128 -D HTTPD_ROOT="/etc/apache2" -D SUEXEC_BIN="/usr/lib/apache2/suexec" -D DEFAULT_PIDLOG="/var/run/apache2.pid" -D DEFAULT_SCOREBOARD="logs/apache_runtime_status" -D DEFAULT_LOCKFILE="/var/run/apache2/accept.lock" -D DEFAULT_ERRORLOG="logs/error_log" -D AP_TYPES_CONFIG_FILE="mime.types" -D SERVER_CONFIG_FILE="apache2.conf" MySQL : 5.5.38-0ubuntu0.12.04.1 Smarty : 2.6.18 **NetBeans :** NetBeans IDE 8.0 (Build 201403101706) Sublime Text 2 : Version 2.0.2, Build 2221 Yesterday suddenly a pop-up message appeared on my screen asking me to upgrade to "Ubuntu 14.04 'Trusty Tahr'". I'd also be very happy to upgrade my system to "Ubuntu 14.04 'Trusty Tahr'". Following are the issues about which I'm little bit scared about and I need you all talented people's expert advice/help/suggestions on it: Will upgrading to "Ubuntu 14.04 'Trusty Tahr'" affect the softwares I mentioned above? I mean will I need to re-install/un-install and install these softwares too? Do I really need to and is it really a worth to upgrade to "Ubuntu 14.04 'Trusty Tahr'" from "Ubuntu 12.04 LTS" now? If I upgrade to "Ubuntu 14.04 'Trusty Tahr'" what advantage I'll get from web developer's point of view? Will the upgrade be hassle free and will I be ablr to continue my on-going work without any difficulties? Is "Ubuntu 14.04 'Trusty Tahr'" a LTS version and if yes till when it's going to provide support? These are the five crucial queries I have. If you want any further explanation from me please feel free to ask me. Thanks for spending some of your vaulable time in reading and understanding my issue. Any kind of help/comment/suggestion/answer would be highly appreciated. Though if someone gives canonical, precise and up to the mark answer, it will be of great help to me as well as other web developers using Ubuntu around the world. Once again thank you so much you great people around the globe. Waiting for your precious replies.

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  • SQL SERVER – Puzzle – Statistics are not Updated but are Created Once

    - by pinaldave
    After having excellent response to my quiz – Why SELECT * throws an error but SELECT COUNT(*) does not?I have decided to ask another puzzling question to all of you. I am running this test on SQL Server 2008 R2. Here is the quick scenario about my setup. Create Table Insert 1000 Records Check the Statistics Now insert 10 times more 10,000 indexes Check the Statistics – it will be NOT updated Note: Auto Update Statistics and Auto Create Statistics for database is TRUE Expected Result – Statistics should be updated – SQL SERVER – When are Statistics Updated – What triggers Statistics to Update Now the question is why the statistics are not updated? The common answer is – we can update the statistics ourselves using UPDATE STATISTICS TableName WITH FULLSCAN, ALL However, the solution I am looking is where statistics should be updated automatically based on algorithm mentioned here. Now the solution is to ____________________. Vinod Kumar is not allowed to take participate over here as he is the one who has helped me to build this puzzle. I will publish the solution on next week. Please leave a comment and if your comment consist valid answer, I will publish with due credit. Here is the script to reproduce the scenario which I mentioned. -- Execution Plans Difference -- Create Sample Database CREATE DATABASE SampleDB GO USE SampleDB GO -- Create Table CREATE TABLE ExecTable (ID INT, FirstName VARCHAR(100), LastName VARCHAR(100), City VARCHAR(100)) GO -- Insert One Thousand Records -- INSERT 1 INSERT INTO ExecTable (ID,FirstName,LastName,City) SELECT TOP 1000 ROW_NUMBER() OVER (ORDER BY a.name) RowID, 'Bob', CASE WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%2 = 1 THEN 'Smith' ELSE 'Brown' END, CASE WHEN ROW_NUMBER() OVER (ORDER BY a.name)%20 = 1 THEN 'New York' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 5 THEN 'San Marino' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 3 THEN 'Los Angeles' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 7 THEN 'La Cinega' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 13 THEN 'San Diego' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 17 THEN 'Las Vegas' ELSE 'Houston' END FROM sys.all_objects a CROSS JOIN sys.all_objects b GO -- Display statistics of the table - none listed sp_helpstats N'ExecTable', 'ALL' GO -- Select Statement SELECT FirstName, LastName, City FROM ExecTable WHERE City  = 'New York' GO -- Display statistics of the table sp_helpstats N'ExecTable', 'ALL' GO -- Replace your Statistics over here -- NOTE: Replace your _WA_Sys with stats from above query DBCC SHOW_STATISTICS('ExecTable', _WA_Sys_00000004_7D78A4E7); GO -------------------------------------------------------------- -- Round 2 -- Insert Ten Thousand Records -- INSERT 2 INSERT INTO ExecTable (ID,FirstName,LastName,City) SELECT TOP 10000 ROW_NUMBER() OVER (ORDER BY a.name) RowID, 'Bob', CASE WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%2 = 1 THEN 'Smith' ELSE 'Brown' END, CASE WHEN ROW_NUMBER() OVER (ORDER BY a.name)%20 = 1 THEN 'New York' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 5 THEN 'San Marino' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 3 THEN 'Los Angeles' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 7 THEN 'La Cinega' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 13 THEN 'San Diego' WHEN  ROW_NUMBER() OVER (ORDER BY a.name)%20 = 17 THEN 'Las Vegas' ELSE 'Houston' END FROM sys.all_objects a CROSS JOIN sys.all_objects b GO -- Select Statement SELECT FirstName, LastName, City FROM ExecTable WHERE City  = 'New York' GO -- Display statistics of the table sp_helpstats N'ExecTable', 'ALL' GO -- Replace your Statistics over here -- NOTE: Replace your _WA_Sys with stats from above query DBCC SHOW_STATISTICS('ExecTable', _WA_Sys_00000004_7D78A4E7); GO -- You will notice that Statistics are still updated with 1000 rows -- Clean up Database DROP TABLE ExecTable GO USE MASTER GO ALTER DATABASE SampleDB SET SINGLE_USER WITH ROLLBACK IMMEDIATE; GO DROP DATABASE SampleDB GO Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Index, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: SQL Statistics, Statistics

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  • Guest (and occasional co-host) on Jesse Liberty's Yet Another Podcast

    - by Jon Galloway
    I was a recent guest on Jesse Liberty's Yet Another Podcast talking about the latest Visual Studio, ASP.NET and Azure releases. Download / Listen: Yet Another Podcast #75–Jon Galloway on ASP.NET/ MVC/ Azure Co-hosted shows: Jesse's been inviting me to co-host shows and I told him I'd show up when I was available. It's a nice change to be a drive-by co-host on a show (compared with the work that goes into organizing / editing / typing show notes for Herding Code shows). My main focus is on Herding Code, but it's nice to pop in and talk to Jesse's excellent guests when it works out. Some shows I've co-hosted over the past year: Yet Another Podcast #76–Glenn Block on Node.js & Technology in China Yet Another Podcast  #73 - Adam Kinney on developing for Windows 8 with HTML5 Yet Another Podcast #64 - John Papa & Javascript Yet Another Podcast #60 - Steve Sanderson and John Papa on Knockout.js Yet Another Podcast #54–Damian Edwards on ASP.NET Yet Another Podcast #53–Scott Hanselman on Blogging Yet Another Podcast #52–Peter Torr on Windows Phone Multitasking Yet Another Podcast #51–Shawn Wildermuth: //build, Xaml Programming & Beyond And some more on the way that haven't been released yet. Some of these I'm pretty quiet, on others I get wacky and hassle the guests because, hey, not my podcast so not my problem. Show notes from the ASP.NET / MVC / Azure show: What was just released Visual Studio 2012 Web Developer features ASP.NET 4.5 Web Forms Strongly Typed data controls Data access via command methods Similar Binding syntax to ASP.NET MVC Some context: Damian Edwards and WebFormsMVP Two questions from Jesse: Q: Are you making this harder or more complicated for Web Forms developers? Short answer: Nothing's removed, it's just a new option History of SqlDataSource, ObjectDataSource Q: If I'm using some MVC patterns, why not just move to MVC? Short answer: This works really well in hybrid applications, doesn't require a rewrite Allows sharing models, validation, other code between Web Forms and MVC ASP.NET MVC Adaptive Rendering (oh, also, this is in Web Forms 4.5 as well) Display Modes Mobile project template using jQuery Mobile OAuth login to allow Twitter, Google, Facebook, etc. login Jon (and friends') MVC 4 book on the way: Professional ASP.NET MVC 4 Windows 8 development Jesse and Jon announce they're working on a new book: Pro Windows 8 Development with XAML and C# Jon and Jesse agree that it's nice to be able to write Windows 8 applications using the same skills they picked up for Silverlight, WPF, and Windows Phone development. Compare / contrast ASP.NET MVC and Windows 8 development Q: Does ASP.NET and HTML5 development overlap? Jon thinks they overlap in the MVC world because you're writing HTML views without controls Jon describes how his web development career moved from a preoccupation with server code to a focus on user interaction, which occurs in the browser Jon mentions his NDC Oslo presentation on Learning To Love HTML as Beautiful Code Q: How do you apply C# / XAML or HTML5 skills to Windows 8 development? Q: If I'm a XAML programmer, what's the learning curve on getting up to speed on ASP.NET MVC? Jon describes the difference in application lifecycle and state management Jon says it's nice that web development is really interactive compared to application development Q: Can you learn MVC by reading a book? Or is it a lot bigger than that? What is Azure, and why would I use it? Jon describes the traditional Azure platform mode and how Azure Web Sites fits in Q: Why wouldn't Jesse host his blog on Azure Web Sites? Domain names on Azure Web Sites File hosting options Q: Is Azure just another host? How is it different from any of the other shared hosting options? A: Azure gives you the ability to scale up or down whenever you want A: Other services are available if or when you want them

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  • A debugging experience with "highly compatible" ASP.NET 4.5

    - by Jeff
    I have to admit that I will pretty much upgrade software for no reason other than being on the latest version. I won't do it if it's super expensive (Adobe gets money from me about once every three or four years at best), but particularly with frameworks and stuff generally available as part of my MSDN subscription, I'll be bleeding edge. CoasterBuzz was running on the MVC 4 framework pretty much as soon as they did a "go live" license for it. I didn't really jump in head-first with Windows 8 and Visual Studio 2012, in part because I just wasn't interested in doing the reinstalls for each new version. Turns out there weren't that many revisions anyway. But when the final versions were released a week and a half ago, I jumped in. I saw on one of the Microsoft sites that .Net 4.5 was a "highly compatible in-place update" to the framework. Good enough for me. I was obviously running it by default in Windows 8, and installed it on my production server. I suppose it's "highly compatible," except when it isn't. Three of my sites are running with various flavors of the MVC version of POP Forums. All of them stopped working under ASP.NET 4.5. It was not immediately obvious what the problem might be beyond an exception indicating that there were no repository classes registered with Ninject, which I use for dependency injection in the forums. This was made all the more weird by the fact that it ran fine locally in the dev Web host. My first instinct was to spin up a Windows Server VM on my local box and put the remote debugger on it. (Side note: running multiple VM's on a Retina MacBook Pro with 16 gigs of RAM is pretty much the most awesome thing ever. I can't believe this computer is for real, and not a 50-pound tower under my desk.) What might have been going on in IIS that doesn't happen in Visual Studio? In the debugging process, I realized that I might be looking in the wrong place. POP Forums creates a Ninject container using a method called from a PreApplicationStartMethod attribute, and at that time registers a module (what Ninject uses to map interfaces to implementations) that maps all of the core dependencies. It also creates an instance of an HttpModule that originally hosted the "services" (search indexing, mailer, etc.), but now just records errors. That's all well and good, but the actual repository mapping, where data is actually read or persisted, happens in Application_Start() in global.asax. The idea there is that you can swap out the SqlSingleWebServer repos for something tuned for multiple servers, Oracle or something else. Of course, if I used something like StructureMap, which does convention-based mapping for dependency injection (a class implementing ISettingsRepository called SettingsRepository is automagically mapped), I wouldn't have to worry about it. In any case, the HttpModule, being instantiated before Application_Start() gets to run, would throw because there was no repo mapped where it could get settings from the database. This makes total sense. The fix is sort of a hack, where I don't setup the innards of the HttpModule until a call to its BeginRequest is made. I say it's a hack, because its primary function, logging exceptions, won't work until the app has warmed up. Still, this brings up an interesting question about the race condition, and what changed in 4.5 when it's running in IIS. In ASP.NET 4, it would appear that the code called via the PreApplicationStartMethod was either failing silently, and running again later, or it was getting to that code after Application_Start was called. In any case, weird thing. The real pain point I'm experiencing now is a bug in MVC 4 that is extremely serious because it renders the mobile/alternate view functionality very much broken.

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  • How Exactly Is One Linux OS “Based On” Another Linux OS?

    - by Jason Fitzpatrick
    When reviewing different flavors of Linux, you’ll frequently come across phrases like “Ubuntu is based on Debian” but what exactly does that mean? Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites. The Question SuperUser reader PLPiper is trying to get a handle on how Linux variants work: I’ve been looking through quite a number of Linux distros recently to get an idea of what’s around, and one phrase that keeps coming up is that “[this OS] is based on [another OS]“. For example: Fedora is based on Red Hat Ubuntu is based on Debian Linux Mint is based on Ubuntu For someone coming from a Mac environment I understand how “OS X is based on Darwin”, however when I look at Linux Distros, I find myself asking “Aren’t they all based on Linux..?” In this context, what exactly does it mean for one Linux OS to be based on another Linux OS? So, what exactly does it mean when we talk about one version of Linux being based off another version? The Answer SuperUser contributor kostix offers a solid overview of the whole system: Linux is a kernel — a (complex) piece of software which works with the hardware and exports a certain Application Programming Interface (API), and binary conventions on how to precisely use it (Application Binary Interface, ABI) available to the “user-space” applications. Debian, RedHat and others are operating systems — complete software environments which consist of the kernel and a set of user-space programs which make the computer useful as they perform sensible tasks (sending/receiving mail, allowing you to browse the Internet, driving a robot etc). Now each such OS, while providing mostly the same software (there are not so many free mail server programs or Internet browsers or desktop environments, for example) differ in approaches to do this and also in their stated goals and release cycles. Quite typically these OSes are called “distributions”. This is, IMO, a somewhat wrong term stemming from the fact you’re technically able to build all the required software by hand and install it on a target machine, so these OSes distribute the packaged software so you either don’t need to build it (Debian, RedHat) or they facilitate such building (Gentoo). They also usually provide an installer which helps to install the OS onto a target machine. Making and supporting an OS is a very complicated task requiring a complex and intricate infrastructure (upload queues, build servers, a bug tracker, and archive servers, mailing list software etc etc etc) and staff. This obviously raises a high barrier for creating a new, from-scratch OS. For instance, Debian provides ca. 37k packages for some five hardware architectures — go figure how much work is put into supporting this stuff. Still, if someone thinks they need to create a new OS for whatever reason, it may be a good idea to use an existing foundation to build on. And this is exactly where OSes based on other OSes come into existence. For instance, Ubuntu builds upon Debian by just importing most packages from it and repackaging only a small subset of them, plus packaging their own, providing their own artwork, default settings, documentation etc. Note that there are variations to this “based on” thing. For instance, Debian fosters the creation of “pure blends” of itself: distributions which use Debian rather directly, and just add a bunch of packages and other stuff only useful for rather small groups of users such as those working in education or medicine or music industry etc. Another twist is that not all these OSes are based on Linux. For instance, Debian also provide FreeBSD and Hurd kernels. They have quite tiny user groups but anyway. Have something to add to the explanation? Sound off in the the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.     

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  • 24 hours to pass until 24 Hours of PASS

    - by Rob Farley
    There’s a bunch of stuff going on at the moment in the SQL world, so if you’ve missed this particular piece of news, let me tell you a bit about it. Twice a year, the SQL community puts on its biggest virtual event – 24 Hours of PASS. And the next one is tomorrow – March 21st, 2012. Twenty-four sessions, back-to-back, featuring a selection of some of the best presenters in the SQL world, speakers from all over the world, coming together in an online collaboration that so far has well over thirty thousand registrations across the presentations. Some people are signed up for all 24 sessions, some only one. Traditionally, LiveMeeting has been used as the platform for this event, but this year we’re going with a new platform – IBTalk. It promises big, and we’re hoping it won’t let us down. LiveMeeting has been great, and we thank Microsoft for providing it as a platform for the past few years. However, as the event has grown, we’ve found that a new idea is necessary. Last year a search was done for a new platform, and IBTalk ticked the right boxes. The feedback from the presenters and moderators so far has been overwhelmingly positive, and we’re hoping that this is going to really enhance the user experience. One of my favourite features of the platform is the language side. It provides a pretty good translation service. Users who join a session will see a flag on the left of the screen. If they click it, they can change the language to one of 15 on offer. Picking this changes all the labels on everything. It even translates the text in the Q&A window. What this means is that someone from Brazil can ask their question in Portuguese, and the presenter will see it in English. Then if the answer is typed in English, the questioner will be able to see the answer, also in Portuguese. Or they can switch to English to see it as the answerer typed it. I know there’s always the risk of bad translations going on, but I’ve heard good things about this translation service. But there’s more – IBTalk are providing staff to type up closed captioning live during the event. So if English isn’t your first language, don’t worry! Picking your language will also let you see subtitles in your chosen language. I’m hoping that this event is the start of PASS being able to reach people from all corners of the world. Wouldn’t it be great to find that this event is successful, and that the next 24HOP (later in the year, our Summit Preview event) has just as many non-English speakers tuning in as English speakers? If you haven’t been planning which sessions you’re going to attend, you really should get over to sqlpass.org/24hours and have a look through what’s on offer. There’s some amazing material from some of the industry’s brightest, covering a wide range of topics, from classic SQL areas to the brand new SQL 2012 features. There really should be something for every SQL professional. Check the time zones though – if you’re in the US you might be on Summer time, and an hour closer to GMT than normal. Massive thanks must go to Microsoft, SQL Sentry and Idera for sponsoring this event. Without sponsors we wouldn’t be able to put any of this on. These companies are helping 24HOP continue to grow into an event for the whole world. See you tomorrow! @rob_farley | #24hop | #sqlpass

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  • 24 hours to pass until 24 Hours of PASS

    - by Rob Farley
    There’s a bunch of stuff going on at the moment in the SQL world, so if you’ve missed this particular piece of news, let me tell you a bit about it. Twice a year, the SQL community puts on its biggest virtual event – 24 Hours of PASS. And the next one is tomorrow – March 21st, 2012. Twenty-four sessions, back-to-back, featuring a selection of some of the best presenters in the SQL world, speakers from all over the world, coming together in an online collaboration that so far has well over thirty thousand registrations across the presentations. Some people are signed up for all 24 sessions, some only one. Traditionally, LiveMeeting has been used as the platform for this event, but this year we’re going with a new platform – IBTalk. It promises big, and we’re hoping it won’t let us down. LiveMeeting has been great, and we thank Microsoft for providing it as a platform for the past few years. However, as the event has grown, we’ve found that a new idea is necessary. Last year a search was done for a new platform, and IBTalk ticked the right boxes. The feedback from the presenters and moderators so far has been overwhelmingly positive, and we’re hoping that this is going to really enhance the user experience. One of my favourite features of the platform is the language side. It provides a pretty good translation service. Users who join a session will see a flag on the left of the screen. If they click it, they can change the language to one of 15 on offer. Picking this changes all the labels on everything. It even translates the text in the Q&A window. What this means is that someone from Brazil can ask their question in Portuguese, and the presenter will see it in English. Then if the answer is typed in English, the questioner will be able to see the answer, also in Portuguese. Or they can switch to English to see it as the answerer typed it. I know there’s always the risk of bad translations going on, but I’ve heard good things about this translation service. But there’s more – IBTalk are providing staff to type up closed captioning live during the event. So if English isn’t your first language, don’t worry! Picking your language will also let you see subtitles in your chosen language. I’m hoping that this event is the start of PASS being able to reach people from all corners of the world. Wouldn’t it be great to find that this event is successful, and that the next 24HOP (later in the year, our Summit Preview event) has just as many non-English speakers tuning in as English speakers? If you haven’t been planning which sessions you’re going to attend, you really should get over to sqlpass.org/24hours and have a look through what’s on offer. There’s some amazing material from some of the industry’s brightest, covering a wide range of topics, from classic SQL areas to the brand new SQL 2012 features. There really should be something for every SQL professional. Check the time zones though – if you’re in the US you might be on Summer time, and an hour closer to GMT than normal. Massive thanks must go to Microsoft, SQL Sentry and Idera for sponsoring this event. Without sponsors we wouldn’t be able to put any of this on. These companies are helping 24HOP continue to grow into an event for the whole world. See you tomorrow! @rob_farley | #24hop | #sqlpass

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  • Code is not the best way to draw

    - by Bertrand Le Roy
    It should be quite obvious: drawing requires constant visual feedback. Why is it then that we still draw with code in so many situations? Of course it’s because the low-level APIs always come first, and design tools are built after and on top of those. Existing design tools also don’t typically include complex UI elements such as buttons. When we launched our Touch Display module for Netduino Go!, we naturally built APIs that made it easy to draw on the screen from code, but very soon, we felt the limitations and tedium of drawing in code. In particular, any modification requires a modification of the code, followed by compilation and deployment. When trying to set-up buttons at pixel precision, the process is not optimal. On the other hand, code is irreplaceable as a way to automate repetitive tasks. While tools like Illustrator have ways to repeat graphical elements, they do so in a way that is a little alien and counter-intuitive to my developer mind. From these reflections, I knew that I wanted a design tool that would be structurally code-centric but that would still enable immediate feedback and mouse adjustments. While thinking about the best way to achieve this goal, I saw this fantastic video by Bret Victor: The key to the magic in all these demos is permanent execution of the code being edited. Whenever a parameter is being modified, everything is re-executed immediately so that the impact of the modification is instantaneously visible. If you do this all the time, the code and the result of its execution fuse in the mind of the user into dual representations of a single object. All mental barriers disappear. It’s like magic. The tool I built, Nutshell, is just another implementation of this principle. It manipulates a list of graphical operations on the screen. Each operation has a nice editor, and translates into a bit of code. Any modification to the parameters of the operation will modify the bit of generated code and trigger a re-execution of the whole program. This happens so fast that it feels like the drawing reacts instantaneously to all changes. The order of the operations is also the order in which the code gets executed. So if you want to bring objects to the front, move them down in the list, and up if you want to move them to the back: But where it gets really fun is when you start applying code constructs such as loops to the design tool. The elements that you put inside of a loop can use the loop counter in expressions, enabling crazy scenarios while retaining the real-time edition features. When you’re done building, you can just deploy the code to the device and see it run in its native environment: This works thanks to two code generators. The first code generator is building JavaScript that is executed in the browser to build the canvas view in the web page hosting the tool. The second code generator is building the C# code that will run on the Netduino Go! microcontroller and that will drive the display module. The possibilities are fascinating, even if you don’t care about driving small touch screens from microcontrollers: it is now possible, within a reasonable budget, to build specialized design tools for very vertical applications. Direct feedback is a powerful ally in many domains. Code generation driven by visual designers has become more approachable than ever thanks to extraordinary JavaScript libraries and to the powerful development platform that modern browsers provide. I encourage you to tinker with Nutshell and let it open your eyes to new possibilities that you may not have considered before. It’s open source. And of course, my company, Nwazet, can help you develop your own custom browser-based direct feedback design tools. This is real visual programming…

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  • Apache returns 304, I want it to ignore anything from client and send the page

    - by Ayman
    I am using Apache HTTPD 2.2 on Windows. mod_expires is commented out. Most other stuff are not changed from the defaults. gzip is on. I made some changes to my .js files. My client gets one 304 response for one of the .js files and never gets the rest. How can I force Apache to sort of flush everything and send all new files to the client? The main html file includes these scripts in the head section of the main page: <script src="js/jquery-1.7.1.min.js" type="text/javascript"> </script> <script src="js/jquery-ui-1.8.17.custom.min.js" type="text/javascript"></script> <script src="js/trex.utils.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.core.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.codes.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.emv.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.b24xtokens.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.iso.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.span2.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.amex.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.abi.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.barclays.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.bnet.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.visa.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.atm.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.apacs.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.pstm.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.stm.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.thales.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.fps-saf.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.fps-iso.js" type="text/javascript" charset="utf-8"></script> <script src="js/trex.app.js" type="text/javascript" charset="utf-8"></script> Apache access log has the following: [07/Jul/2013:16:50:40 +0300] "GET /trex/index.html HTTP/1.1" 200 2033 "-" [07/Jul/2013:16:50:40 +0300] "GET /trex/js/trex.fps-iso.js HTTP/1.1" 304 [08/Jul/2013:07:54:35 +0300] "GET /trex/index.html HTTP/1.1" 304 - "-" [08/Jul/2013:07:54:35 +0300] "GET /trex/js/trex.iso.js HTTP/1.1" 200 12417 [08/Jul/2013:07:54:35 +0300] "GET /trex/js/trex.amex.js HTTP/1.1" 200 6683 [08/Jul/2013:07:54:35 +0300] "GET /trex/js/trex.fps-saf.js HTTP/1.1" 200 2925 [08/Jul/2013:07:54:35 +0300] "GET /trex/js/trex.fps-iso.js HTTP/1.1" 304 Chrome request headers are as below: THis file is ok, latest: Request URL:http://localhost/trex/js/trex.iso.js Request Method:GET Status Code:200 OK (from cache) THis file is ok, latest: Request URL:http://localhost/trex/js/trex.amex.js Request Method:GET Status Code:200 OK (from cache) This one is also ok: Request URL:http://localhost/trex/js/trex.fps-iso.js Request Method:GET Status Code:200 OK (from cache) The rest of the scrips all have 200 OK (from cache).

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