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  • How to automate org-refile for multiple todo

    - by lawlist
    I'm looking to automate org-refile so that it will find all of the matches and re-file them to a specific location (but not archive). I found a fully automated method of archiving multiple todo, and I am hopeful to find or create (with some help) something similar to this awesome function (but for a different heading / location other than archiving): https://github.com/tonyday567/jwiegley-dot-emacs/blob/master/dot-org.el (defun org-archive-done-tasks () (interactive) (save-excursion (goto-char (point-min)) (while (re-search-forward "\* \\(None\\|Someday\\) " nil t) (if (save-restriction (save-excursion (org-narrow-to-subtree) (search-forward ":LOGBOOK:" nil t))) (forward-line) (org-archive-subtree) (goto-char (line-beginning-position)))))) I also found this (written by aculich), which is a step in the right direction, but still requires repeating the function manually: http://stackoverflow.com/questions/7509463/how-to-move-a-subtree-to-another-subtree-in-org-mode-emacs ;; I also wanted a way for org-refile to refile easily to a subtree, so I wrote some code and generalized it so that it will set an arbitrary immediate target anywhere (not just in the same file). ;; Basic usage is to move somewhere in Tree B and type C-c C-x C-m to mark the target for refiling, then move to the entry in Tree A that you want to refile and type C-c C-w which will immediately refile into the target location you set in Tree B without prompting you, unless you called org-refile-immediate-target with a prefix arg C-u C-c C-x C-m. ;; Note that if you press C-c C-w in rapid succession to refile multiple entries it will preserve the order of your entries even if org-reverse-note-order is set to t, but you can turn it off to respect the setting of org-reverse-note-order with a double prefix arg C-u C-u C-c C-x C-m. (defvar org-refile-immediate nil "Refile immediately using `org-refile-immediate-target' instead of prompting.") (make-local-variable 'org-refile-immediate) (defvar org-refile-immediate-preserve-order t "If last command was also `org-refile' then preserve ordering.") (make-local-variable 'org-refile-immediate-preserve-order) (defvar org-refile-immediate-target nil) "Value uses the same format as an item in `org-refile-targets'." (make-local-variable 'org-refile-immediate-target) (defadvice org-refile (around org-immediate activate) (if (not org-refile-immediate) ad-do-it ;; if last command was `org-refile' then preserve ordering (let ((org-reverse-note-order (if (and org-refile-immediate-preserve-order (eq last-command 'org-refile)) nil org-reverse-note-order))) (ad-set-arg 2 (assoc org-refile-immediate-target (org-refile-get-targets))) (prog1 ad-do-it (setq this-command 'org-refile))))) (defadvice org-refile-cache-clear (after org-refile-history-clear activate) (setq org-refile-targets (default-value 'org-refile-targets)) (setq org-refile-immediate nil) (setq org-refile-immediate-target nil) (setq org-refile-history nil)) ;;;###autoload (defun org-refile-immediate-target (&optional arg) "Set current entry as `org-refile' target. Non-nil turns off `org-refile-immediate', otherwise `org-refile' will immediately refile without prompting for target using most recent entry in `org-refile-targets' that matches `org-refile-immediate-target' as the default." (interactive "P") (if (equal arg '(16)) (progn (setq org-refile-immediate-preserve-order (not org-refile-immediate-preserve-order)) (message "Order preserving is turned: %s" (if org-refile-immediate-preserve-order "on" "off"))) (setq org-refile-immediate (unless arg t)) (make-local-variable 'org-refile-targets) (let* ((components (org-heading-components)) (level (first components)) (heading (nth 4 components)) (string (substring-no-properties heading))) (add-to-list 'org-refile-targets (append (list (buffer-file-name)) (cons :regexp (format "^%s %s$" (make-string level ?*) string)))) (setq org-refile-immediate-target heading)))) (define-key org-mode-map "\C-c\C-x\C-m" 'org-refile-immediate-target) It sure would be helpful if aculich, or some other maven, could please create a variable similar to (setq org-archive-location "~/0.todo.org::* Archived Tasks") so users can specify the file and heading, which is already a part of the org-archive-subtree functionality. I'm doing a search and mark because I don't have the wherewithal to create something like org-archive-location for this setup. EDIT: One step closer -- almost home free . . . (defun lawlist-auto-refile () (interactive) (beginning-of-buffer) (re-search-forward "\* UNDATED") (org-refile-immediate-target) ;; cursor must be on a heading to work. (save-excursion (re-search-backward "\* UNDATED") ;; must be written in such a way so that sub-entries of * UNDATED are not searched; or else infinity loop. (while (re-search-backward "\* \\(None\\|Someday\\) " nil t) (org-refile) ) ) )

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  • Hanging of host network connections when starting KVM guest on bridge

    - by Chris Phillips
    Hi, I've a KVM system upon which I'm running a network bridge directly between all VM's and a bond0 (eth0, eth1) on the host OS. As such, all machines are presented on the same subnet, available outside of the box. The bond is doing mode 1 active / passive, with an arp_ip_target set to the default gateway, which has caused some issues in itself, but I can't see the bond configs mattering here myself. I'm seeing odd things most times when I stop and start a guest on the platform, in that on the host I lose network connectivity (icmp, ssh) for about 30 seconds. I don't lose connectivity on the other already running VM's though... they can always ping the default GW, but the host can't. I say "about 30 seconds" but from some tests it actually seems to be 28 seconds usually (or at least, I lose 28 pings...) and I'm wondering if this somehow relates to the bridge config. I'm not running STP on the bridge at all, and the forwarding delay is set to 1 second, path cost on the bond0 lowered to 10 and port priority of bond0 also lowered to 1. As such I don't think that the bridge should ever be able to think that bond0 is not connected just fine (as continued guest connectivity implies) yet the IP of the host, which is on the bridge device (... could that matter?? ) becomes unreachable. I'm fairly sure it's about the bridged networking, but at the same time as this happens when a VM is started there are clearly loads of other things also happening so maybe I'm way off the mark. Lack of connectivity: # ping 10.20.11.254 PING 10.20.11.254 (10.20.11.254) 56(84) bytes of data. 64 bytes from 10.20.11.254: icmp_seq=1 ttl=255 time=0.921 ms 64 bytes from 10.20.11.254: icmp_seq=2 ttl=255 time=0.541 ms type=1700 audit(1293462808.589:325): dev=vnet6 prom=256 old_prom=0 auid=42949672 95 ses=4294967295 type=1700 audit(1293462808.604:326): dev=vnet7 prom=256 old_prom=0 auid=42949672 95 ses=4294967295 type=1700 audit(1293462808.618:327): dev=vnet8 prom=256 old_prom=0 auid=42949672 95 ses=4294967295 kvm: 14116: cpu0 unimplemented perfctr wrmsr: 0x186 data 0x130079 kvm: 14116: cpu0 unimplemented perfctr wrmsr: 0xc1 data 0xffdd694a kvm: 14116: cpu0 unimplemented perfctr wrmsr: 0x186 data 0x530079 64 bytes from 10.20.11.254: icmp_seq=30 ttl=255 time=0.514 ms 64 bytes from 10.20.11.254: icmp_seq=31 ttl=255 time=0.551 ms 64 bytes from 10.20.11.254: icmp_seq=32 ttl=255 time=0.437 ms 64 bytes from 10.20.11.254: icmp_seq=33 ttl=255 time=0.392 ms brctl output of relevant bridge: # brctl showstp brdev brdev bridge id 8000.b2e1378d1396 designated root 8000.b2e1378d1396 root port 0 path cost 0 max age 19.99 bridge max age 19.99 hello time 1.99 bridge hello time 1.99 forward delay 0.99 bridge forward delay 0.99 ageing time 299.95 hello timer 0.50 tcn timer 0.00 topology change timer 0.00 gc timer 0.04 flags vnet5 (3) port id 8003 state forwarding designated root 8000.b2e1378d1396 path cost 100 designated bridge 8000.b2e1378d1396 message age timer 0.00 designated port 8003 forward delay timer 0.00 designated cost 0 hold timer 0.00 flags vnet0 (2) port id 8002 state forwarding designated root 8000.b2e1378d1396 path cost 100 designated bridge 8000.b2e1378d1396 message age timer 0.00 designated port 8002 forward delay timer 0.00 designated cost 0 hold timer 0.00 flags bond0 (1) port id 0001 state forwarding designated root 8000.b2e1378d1396 path cost 10 designated bridge 8000.b2e1378d1396 message age timer 0.00 designated port 0001 forward delay timer 0.00 designated cost 0 hold timer 0.00 flags I do see the new port listed as learning, but in line with the forward delay, only for 1 or 2 seconds when polling the brctl output on a loop. All pointers, tips or stabs in the dark appreciated.

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  • Wear and tear on server hard drive from filesystem polling by PHP script

    - by jackie
    So I'm working on a discussion platform, and various clients will visit http://host/thread.php, which will render the discussion thread to date in addition to a form to submit a new post. When a new post is submitted, I would like all of the other clients with browser windows open to have it appear in near-real-time. One of the constraints of my script is that it may not use a DBMS and it must stay in the filesystem. Additionally, I can't use any PECL/PEAR extensions like inotify or anything like that for IPC. The flow will look like this: Client A requests thread.php and the thread is so far empty, but nonetheless it opens a Server-Side Event at eventPusher.php. Client B does the same. Client A fills out a post in the form and and submits (POSTs) it to subHandler.php. ??? (subHandler stores the new submission into the main thread storefile which gets read from when a fresh, new client requests thread.php, in addition to somehow signalling to the continually-running eventPusher event-source that a new comment was posted and that it should echo the event-json to the client. How, exactly, it will send this signal I'm yet unsure of, but there are a few options that I've thought of -- this is the crux of the question, so see below for more clarification) eventPusher.php happily pushes the new event to the client and it shows up soon after it was originally submitted on all clients who have the page open's screens. Now for the #4 missing-link mystery-step, I see a few problems. I mean, either way, eventPusher is gonna be doing a while loop of some sort -- it's gonna be polling something, I think that much is clear. (If that's a bad assumption please do let me know.) Now, the simplest way would be subHandler gets invoked on the form submission, writes it to the main store in addition to newComments.xml, then exits without doing anything else. Then eventPusher checks in newComments.xml every X seconds (by the way, what would be a reasonable time interval here?) and if it finds something then it emits an event to the client. Now, my fear with this is that the server's hard drive will have to constantly start spinning up. Maybe this isn't the case, perhaps it would just get cached in RAM and the linux kernel would take care of this transparently such that filesystem access doesn't actually engage the device because the kernel knows that that particular file hasn't changed since last read. * idea #2: I have no idea how to go about this, but perhaps there is a variable scope that gets stored in general RAM on the system which can be read by any process. Like if we mega-exported a bash variable so that $new_post is normally false but it gets toggled to true by subHandler, and then back to flase once it's pushed to the client. I doubt there's such a variable scope in PHP directly, but I struggle with the concept of variable scope, I just can't seem to understand it no matter what I read on it. * idea #3: eventPusher queries ps in its whileloop for another instance of itself. If there's not another eventPusher active then it's highly unlikely that new comments will be getting submitted. It's okay if this only works =90% of the time, it doesn't need to be completely foolproof. * idea #4: eventPusher queries DMESG to see if that file's been written to recently. So to sum everything up, I need to have inter-php-script-communication in near-real-time that will work on a standard mod_php shared hosting setup without any elevated privileges, PHP addon modules, or other system adjustments that can't be done from the PHP script itself at runtime. With*out* spinning up the drive more than a few times. No SQL servers either. Apologies if my english isn't the best, I'm still trying to improve on it.

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  • How to troubleshoot problem with OpenVPN Appliance Server not able to connect

    - by Peter
    1) I have a Windows Server 2008 Standard SP2 2) I am running Hyper-V and have the OpenVPN Appliance Server virtual running 3) I have configured it as it said, only issue was that the legacy network adapter does not have a setting the instructions mention "Enable spoofing of MAC Addresses". My understand is that before R2, this was on by default. 4) Server is running, web interfaces look good 5) I am trying to connect from a Vista 64 box and cannot 5a) If I set to UPD I am stuck at Authorizing and client log looks like: 10/11/09 15:00:42: INFO: OvpnConfig: connect... 10/11/09 15:00:42: INFO: Gui listen socket at 34567 10/11/09 15:00:42: INFO: sending start command to instantiator... 10/11/09 15:00:42: INFO: start 34567 ?C:\Users\Peter\AppData\Roaming\OpenVPNTech\config?02369512D0C82A04B88093022DA0226202218022A902264022AE022B? 10/11/09 15:00:42: INFO: Got line from MI->>INFO:OpenVPN Management Interface Version 1 -- type 'help' for more info 10/11/09 15:00:42: INFO: Got line from MI->>HOLD:Waiting for hold release 10/11/09 15:00:43: INFO: Got line from MI->SUCCESS: real-time state notification set to ON 10/11/09 15:00:43: INFO: Got line from MI->SUCCESS: bytecount interval changed 10/11/09 15:00:43: INFO: Got line from MI->SUCCESS: hold flag set to OFF 10/11/09 15:00:43: INFO: Got line from MI->SUCCESS: hold release succeeded 10/11/09 15:00:43: INFO: Got line from MI->>PASSWORD:Need 'Auth' username/password 10/11/09 15:00:43: INFO: Processing PASSWORD. 10/11/09 15:00:43: INFO: OvpnClient: setting need auth to true. 10/11/09 15:00:43: INFO: OvpnConfig: Setting need auth to true. 10/11/09 15:00:43: INFO: Got auth request from active_config from 0 10/11/09 15:00:47: INFO: Sending Credentials.... 10/11/09 15:00:47: INFO: Sending 25 bytes for username. 10/11/09 15:00:47: INFO: Sent 25 bytes for username. 10/11/09 15:00:47: INFO: Sending 30 bytes for password. 10/11/09 15:00:47: INFO: Sent 30 bytes for password. 10/11/09 15:00:48: INFO: Got line from MI->SUCCESS: 'Auth' username entered, but not yet verified 10/11/09 15:00:48: INFO: Got line from MI->SUCCESS: 'Auth' password entered, but not yet verified 10/11/09 15:00:48: INFO: Got line from MI->>STATE:1255287647,WAIT,,, 10/11/09 15:00:48: INFO: Got line from MI->>BYTECOUNT:0,42 10/11/09 15:00:48: INFO: Got line from MI->>BYTECOUNT:54,42 10/11/09 15:00:48: INFO: Got line from MI->>STATE:1255287648,AUTH,,, 10/11/09 15:00:50: INFO: Got line from MI->>BYTECOUNT:2560,2868 10/11/09 15:00:52: INFO: Got line from MI->>BYTECOUNT:2560,3378 5b) I setup server for tcp and try to connect, I get a loop of authorizing and reconnecting. Log looks like: 10/11/09 15:00:42: INFO: Got line from MI->>HOLD:Waiting for hold release 10/11/09 15:00:43: INFO: Got line from MI->SUCCESS: real-time state notification set to ON 10/11/09 15:00:43: INFO: Got line from MI->SUCCESS: bytecount interval changed 10/11/09 15:00:43: INFO: Got line from MI->SUCCESS: hold flag set to OFF 10/11/09 15:00:43: INFO: Got line from MI->SUCCESS: hold release succeeded 10/11/09 15:00:43: INFO: Got line from MI->>PASSWORD:Need 'Auth' username/password 10/11/09 15:00:43: INFO: Processing PASSWORD. 10/11/09 15:00:43: INFO: OvpnClient: setting need auth to true. 10/11/09 15:00:43: INFO: OvpnConfig: Setting need auth to true. 10/11/09 15:00:43: INFO: Got auth request from active_config from 0 10/11/09 15:00:47: INFO: Sending Credentials.... 10/11/09 15:00:47: INFO: Sending 25 bytes for username. 10/11/09 15:00:47: INFO: Sent 25 bytes for username. 10/11/09 15:00:47: INFO: Sending 30 bytes for password. 10/11/09 15:00:47: INFO: Sent 30 bytes for password. 10/11/09 15:00:48: INFO: Got line from MI->SUCCESS: 'Auth' username entered, but not yet verified 10/11/09 15:00:48: INFO: Got line from MI->SUCCESS: 'Auth' password entered, but not yet verified 10/11/09 15:00:48: INFO: Got line from MI->>STATE:1255287647,WAIT,,, 10/11/09 15:00:48: INFO: Got line from MI->>BYTECOUNT:0,42 10/11/09 15:00:48: INFO: Got line from MI->>BYTECOUNT:54,42 10/11/09 15:00:48: INFO: Got line from MI->>STATE:1255287648,AUTH,,, 10/11/09 15:00:50: INFO: Got line from MI->>BYTECOUNT:2560,2868 10/11/09 15:00:52: INFO: Got line from MI->>BYTECOUNT:2560,3378 10/11/09 15:00:54: INFO: Got line from MI->>BYTECOUNT:2560,3888 ... Is there anyway to turn on robust logging on the server to understand what is happening? Any ideas on how to hunt this down?

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  • Why does my computer run slowly and freeze sometimes?

    - by Brae
    EDIT I disabled sound in the BIOS, rebooted and it hung. I removed the (previously) faulty HDD, rebooted and it hung. I have managed to get my Realtek audio manager open again after its mysterious disappearance. Subsequently my microphone is now working again, to fix it I had to uninstall audio drivers, disable audio in BIOS, install audio drivers, enable audio in BIOS. Access via network (with faulty HDD in) seems to not be triggering hangs at the moment. I think with the sound problem fixed it might play a little nicer, but I think its still going to hang. If it does, then I'm fairly sure its been narrowed down to the mobo. EDIT Pretty convinced my motherboard is the culprit, because nothing else seems to have any obvious problems (bar the hard drive, which the PC still hangs without it being plugged in) So thank you all for helping, once I get more rep ill up a few of the answers. My PC is doing some weird things... Sometimes when I open up a program, lets say Adobe Photoshop, it will load everything normally, nice and quick no problems and I can use it fine. Other times its a little odd, and it loads the program as if it's only using half of the CPU. It's pretty obvious when it does it, normally the loading screen skims past, but when it does this weird load you see it slowly tick though each thing, and the program itself becomes incredibly slow. Even Google Chrome does it sometimes. Yet when I exit and reopen the program without doing anything else, it typically opens fine without lagging. I think this problem is probably a symptom of something bigger, because of other problems I'm having. Random hangs; no matter what I have open or what I'm doing. My PC will sort of freeze up for a few seconds. If music is playing it will either loop the last second or two, or it will buzz. This only lasts for a few seconds then it returns to normal without having to restart. During this time all programs lock up and freeze, and the mouse and keyboard are useless. I am also having a weird issue with my audio jacks, without touching my PC at all, sometimes I will see a popup saying that I have unplugged something or plugged something in, neither of which has actually happened. Pretty sure this is cause by the motherboard. I recently had a 'Pink Screen of Death' (yes pink) which pointed to my audio drivers. The lockups seem to happen with some consistency when someone is accessing my shared files via my home LAN. Which leads me to believe either one of my hard drives is acting up or more likely the controller. One of my drives had a bit of a crash before, I used Spinrite and managed to recover my stuff and now the drive appears to be working okay. This is possibly adding to the problems. My best guess is something has gone wrong with my motherboard, possibly a power issue or a chip has died, I really don't know. So what I would like to know is: Have I have missed some obvious diagnostic to help figure out what it is, or should I just bite the bullet and assume its my motherboard acting up and buy a new system? dxdiag[64-bit] - http://pastebin.com/G30kb2TL PSOD (minidump) - http://pastebin.com/aZsv0H56 HWiNFO64 (system info / specs) - http://pastebin.com/X6h3K8g6

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  • Installing XP through USB-flash disc

    - by Crazy Buddy
    I don't know whether this could be asked here... So, Pardon me for this. Probably, this is based on My laptop and a contradiction to this question asked already here... I tried to format my "government-provided" laptop (No CD-drive). I thought those IT guys are proving that they're too smart..! I have the Windows XP CD right now. I didn't like to stick with some home-made OS from our Government. So, I used another laptop to format the govt. thing and tried to install XP (As I didn't have enough bills to invest on Windows 7 or 8). Case 1: First, I allowed WinSetupFromUSB 1.0 beta 8 to deal with the flash disk. I wondered for the first time that XP text-screen appeared. Using the first part, I formatted my laptop. It started to copy files, entered into the next part, and completed the installation. I started my PC for the first time. XP splash screen appeared. Suddenly, a blue screen flashed and disappeared (I can't even read what it says). Rebooted and arrived at the screen, "Start Windows Normally". It happens and happens still - like an infinite loop :-) Case 2: Next, I used Rufus 1.2.0 to transfer files to my Flash and it screwed everything out. Even if I used Flash to boot, it arrives to the same screen "Start Windows normally". It doesn't show any response of Flash being inserted. Then I recognized that, It's simply copies everything to the flash disk. Case 3: Then, I started with Novicorp WinToFlash (giving utmost priority to this site). I booted with the disk. I entered into the first part - "Text mode". Some lines started running like that "Press F6 if you..." like that. The last thing I saw was, "Setup is starting Windows..." Suddenly a blue screen appeared like this captured one. I've a suspicion that the same screen appears again & again in first case. Man, I'm dead. Case 4: For the sake of my last hope, I used WinSetupFromUSB 0.1.1. I was shocked on arriving at a screen which says something "GRUB4DOS" like that and some commands like {command line, reboot, halt, \find menu.lst} and when I go inside those "find" options, I see "Error:15 - File not found". Googling provided some commands to mount SETUPLDR.BIN file in the "grub" thing which also proved unsuccessful... Some sites say that Factory reset uses only some function keys. A guy said that it's F11 for lenovo. Screw him. It's all a waste-of-time. But, I think SE would help me out. Is our government IT guys doin' this to me? Are they Soooo smart to spark some blue screen in front of me to freak me out? Any suggestions or new (useful) USB transferring things would be appreciated. It's very urgent. So, It'd be better if you guys pay some attention in debugging and help me out..? Thanks for your time guys :-)

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  • Mod_Rewrite w Apache mod_jrun22.so & ColdFusion 9 on cPanel

    - by Eddie B
    How can I utilize mod_rewrite at either the httpd.conf level or per-directory level when mod_jrun22 seems to have short-stopped the rewrite process for ColdFusion pages? I have a ColdFusion 9 based site running on Centos 5.8 w cPanel. cPanel uses EasyApache 3 to manage virtual host containers and as such the conf for mod_jrun22.so, /usr/local/apache/conf/includes/pre_main_global.conf, is loaded prior to the main httpd.conf with the domain specific rules for the container. My assertion is that .cfm pages are failing to be rewritten due to the mod_jk22.so module having priority in the directive chain. To note, I also have a WordPress blog in the site where the rewrites appear to be working fine. For example the following code to remove the index file works fine for php and fails with cfm ... .htaccess under /blog/ : This works Options -Indexes -Multiviews <IfModule mod_rewrite.c> RewriteEngine On RewriteBase /blog/ RewriteRule ^index\.php$ - [L] RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule . /blog/index.php [L] </IfModule> .htaccess under / : This does not work as expected. Apache serves the page. ASSERT: This would redirect to domain.com/ without index.cfm Options -Indexes -Multiviews <IfModule mod_rewrite.c> RewriteEngine On RewriteBase / RewriteRule ^index\.cfm$ - [L] RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule . /index.cfm [L] </IfModule> .htaccess under / : This works I'm presuming this is working because the redirect is to another .cfm page and a 404 handler in Application.cfc ... Options -Indexes -Multiviews <IfModule mod_rewrite.c> RewriteEngine On RewriteBase / RewriteRule ^.*\.cfm$ - [L] RewriteCond %{REQUEST_FILENAME} !-d RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{ENV:REDIRECT_STATUS} =404 RewriteRule . /404.cfm$ [L] </IfModule> I've attempted numerous different methods to rewrite .cfm urls ... Adding [PT], [L], [R], [NS], Moving the script to Directory blocks under httpd.conf --- all with the same results ... either the rewrite doesn't work or Apache crashes in an endless loop ... Any help would be greatly appreciated. Below is a single-visit rewrite log snippet for a request to /index.cfm ... the pass-through is taking effect before the rewrite ... cat rewrite_dump_mod | grep index.cfm [perdir /home/foo/public_html/] strip per-dir prefix: /home/foo/public_html/index.cfm -> index.cfm [perdir /home/foo/public_html/] applying pattern '^.*\.cfm$' to uri 'index.cfm' [perdir /home/foo/public_html/] pass through /home/foo/public_html/index.cfm [perdir /home/foo/public_html/] strip per-dir prefix: /home/foo/public_html/index.cfm -> index.cfm [perdir /home/foo/public_html/] applying pattern '^.*\.cfm$' to uri 'index.cfm' [perdir /home/foo/public_html/] pass through /home/foo/public_html/index.cfm * UPDATE * I've managed to figure this out ... it took a while ... Options -Indexes -Multiviews +FollowSymLinks <IfModule mod_rewrite.c> RewriteEngine On RewriteBase / RewriteCond %{HTTP_HOST} !^www\. RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L] RewriteCond %{THE_REQUEST} ^.*/index\.cfm RewriteRule ^(.*)index.cfm http://%{HTTP_HOST}/$1 [R=301,L] </IfModule>

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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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  • ASP.NET MVC 3: Implicit and Explicit code nuggets with Razor

    - by ScottGu
    This is another in a series of posts I’m doing that cover some of the new ASP.NET MVC 3 features: New @model keyword in Razor (Oct 19th) Layouts with Razor (Oct 22nd) Server-Side Comments with Razor (Nov 12th) Razor’s @: and <text> syntax (Dec 15th) Implicit and Explicit code nuggets with Razor (today) In today’s post I’m going to discuss how Razor enables you to both implicitly and explicitly define code nuggets within your view templates, and walkthrough some code examples of each of them.  Fluid Coding with Razor ASP.NET MVC 3 ships with a new view-engine option called “Razor” (in addition to the existing .aspx view engine).  You can learn more about Razor, why we are introducing it, and the syntax it supports from my Introducing Razor blog post. Razor minimizes the number of characters and keystrokes required when writing a view template, and enables a fast, fluid coding workflow. Unlike most template syntaxes, you do not need to interrupt your coding to explicitly denote the start and end of server blocks within your HTML. The Razor parser is smart enough to infer this from your code. This enables a compact and expressive syntax which is clean, fast and fun to type. For example, the Razor snippet below can be used to iterate a collection of products and output a <ul> list of product names that link to their corresponding product pages: When run, the above code generates output like below: Notice above how we were able to embed two code nuggets within the content of the foreach loop.  One of them outputs the name of the Product, and the other embeds the ProductID within a hyperlink.  Notice that we didn’t have to explicitly wrap these code-nuggets - Razor was instead smart enough to implicitly identify where the code began and ended in both of these situations.  How Razor Enables Implicit Code Nuggets Razor does not define its own language.  Instead, the code you write within Razor code nuggets is standard C# or VB.  This allows you to re-use your existing language skills, and avoid having to learn a customized language grammar. The Razor parser has smarts built into it so that whenever possible you do not need to explicitly mark the end of C#/VB code nuggets you write.  This makes coding more fluid and productive, and enables a nice, clean, concise template syntax.  Below are a few scenarios that Razor supports where you can avoid having to explicitly mark the beginning/end of a code nugget, and instead have Razor implicitly identify the code nugget scope for you: Property Access Razor allows you to output a variable value, or a sub-property on a variable that is referenced via “dot” notation: You can also use “dot” notation to access sub-properties multiple levels deep: Array/Collection Indexing: Razor allows you to index into collections or arrays: Calling Methods: Razor also allows you to invoke methods: Notice how for all of the scenarios above how we did not have to explicitly end the code nugget.  Razor was able to implicitly identify the end of the code block for us. Razor’s Parsing Algorithm for Code Nuggets The below algorithm captures the core parsing logic we use to support “@” expressions within Razor, and to enable the implicit code nugget scenarios above: Parse an identifier - As soon as we see a character that isn't valid in a C# or VB identifier, we stop and move to step 2 Check for brackets - If we see "(" or "[", go to step 2.1., otherwise, go to step 3  Parse until the matching ")" or "]" (we track nested "()" and "[]" pairs and ignore "()[]" we see in strings or comments) Go back to step 2 Check for a "." - If we see one, go to step 3.1, otherwise, DO NOT ACCEPT THE "." as code, and go to step 4 If the character AFTER the "." is a valid identifier, accept the "." and go back to step 1, otherwise, go to step 4 Done! Differentiating between code and content Step 3.1 is a particularly interesting part of the above algorithm, and enables Razor to differentiate between scenarios where an identifier is being used as part of the code statement, and when it should instead be treated as static content: Notice how in the snippet above we have ? and ! characters at the end of our code nuggets.  These are both legal C# identifiers – but Razor is able to implicitly identify that they should be treated as static string content as opposed to being part of the code expression because there is whitespace after them.  This is pretty cool and saves us keystrokes. Explicit Code Nuggets in Razor Razor is smart enough to implicitly identify a lot of code nugget scenarios.  But there are still times when you want/need to be more explicit in how you scope the code nugget expression.  The @(expression) syntax allows you to do this: You can write any C#/VB code statement you want within the @() syntax.  Razor will treat the wrapping () characters as the explicit scope of the code nugget statement.  Below are a few scenarios where we could use the explicit code nugget feature: Perform Arithmetic Calculation/Modification: You can perform arithmetic calculations within an explicit code nugget: Appending Text to a Code Expression Result: You can use the explicit expression syntax to append static text at the end of a code nugget without having to worry about it being incorrectly parsed as code: Above we have embedded a code nugget within an <img> element’s src attribute.  It allows us to link to images with URLs like “/Images/Beverages.jpg”.  Without the explicit parenthesis, Razor would have looked for a “.jpg” property on the CategoryName (and raised an error).  By being explicit we can clearly denote where the code ends and the text begins. Using Generics and Lambdas Explicit expressions also allow us to use generic types and generic methods within code expressions – and enable us to avoid the <> characters in generics from being ambiguous with tag elements. One More Thing….Intellisense within Attributes We have used code nuggets within HTML attributes in several of the examples above.  One nice feature supported by the Razor code editor within Visual Studio is the ability to still get VB/C# intellisense when doing this. Below is an example of C# code intellisense when using an implicit code nugget within an <a> href=”” attribute: Below is an example of C# code intellisense when using an explicit code nugget embedded in the middle of a <img> src=”” attribute: Notice how we are getting full code intellisense for both scenarios – despite the fact that the code expression is embedded within an HTML attribute (something the existing .aspx code editor doesn’t support).  This makes writing code even easier, and ensures that you can take advantage of intellisense everywhere. Summary Razor enables a clean and concise templating syntax that enables a very fluid coding workflow.  Razor’s ability to implicitly scope code nuggets reduces the amount of typing you need to perform, and leaves you with really clean code. When necessary, you can also explicitly scope code expressions using a @(expression) syntax to provide greater clarity around your intent, as well as to disambiguate code statements from static markup. Hope this helps, Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

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  • TFS, G.I. Joe and Under-doing

    If I were to rank the most consistently irritating parts of my work day, using TFS would come in first by a wide margin. Even repeated network outages this week seem like a pleasant reprieve from this monolithic beast. This is not a reflexive anti-Microsoft feeling, that attitude just wouldnt work for a consultant who does .NET development. It is also not an utter dismissal of TFS as worthless; Ive seen people use it effectively on several projects. So why? Ill start with a laundry list of shortcomings. An out of the box UI for work items that is insultingly bad, a source control system that is confoundingly fragile when handling merges, folder renames and long file names, the arcane XML wizardry necessary to customize a template and a build system that adds an extra layer of oddness on top of msbuild. Im sure my legion of readers will soon point out to me how I can work around all these issues, how this is fixed in TFS 2010 or with this add-in, and how once you have everything set up, youre fine. And theyd be right, any one of these problems could be worked around. If not dirty laundry, what else? I thought about it for a while, and came to the conclusion that TFS is so irritating to me because it represents a vision of software development that I find unappealing. To expand upon this, lets start with some wisdom from those great PSAs at the end of the G.I. Joe cartoons of the 80s: Now you know, and knowing is half the battle. In software development, Id go further and say knowing is more than half the battle. Understanding the dimensions of the problem you are trying to solve, the needs of the users, the value that your software can provide are more than half the battle. Implementation of this understanding is not easy, but it is not even possible without this knowledge. Assuming we have a fixed amount of time and mental energy for any project, why does this spell trouble for TFS? If you think about what TFS is doing, its offering you a huge array of options to track the day to day implementation of your project. From tasks, to code churn, to test coverage. All valuable metrics, but only in exchange for valuable time to get it all working. In addition, when you have a shiny toy like TFS, the temptation is to feel obligated to use it. So the push from TFS is to encourage a project manager and team to focus on process and metrics around process. You can get great visibility, and graphs to show your project stakeholders, but none of that is important if you are not implementing the right product. Not just unimportant, these activities can be harmful as they drain your time and sap your creativity away from the rest of the project. To be more concrete, lets suppose your organization has invested the time to create a template for your projects and trained people in how to use it, so there is no longer a big investment of time for each project to get up and running. First, Id challenge if that template could be specific enough to be full featured and still applicable for any project. Second, the very existence of this template would be a indication to a project manager that the success of their project was somehow directly related to fitting management of that project into this format. Again, while the capabilities are wonderful, the mirage is there; just get everything into TFS and your project will run smoothly. Ill close the loop on this first topic by proposing a thought experiment. Think of the projects youve worked on. How many times have you been chagrined to discover youve implemented the wrong feature, misunderstood how a feature should work or just plain spent too much time on a screen that nobody uses? That sounds like a really worthwhile area to invest time in improving. How about going back to these projects and thinking about how many times you wished you had optimized the state change flow of your tasks or been embarrassed to not have a code churn report linked back to the latest changeset? With thanks to the Real American Heroes, Ill move on to a more current influence, that of the developers at 37signals, and their philosophy towards software development. This philosophy, fully detailed in the books Getting Real and Rework, is a vision of software that under does the competition. This is software that is deliberately limited in functionality in order to concentrate fully on making sure ever feature that is there is awesome and needed. Why is this relevant? Well, in one of those fun seeming paradoxes in life, constraints can be a spark for creativity. Think Twitter, the small screen of an iPhone, the limitations of HTML for applications, the low memory limits of older or embedded system. As long as there is some freedom within those constraints, amazing things emerge. For project management, some of the most respected people in the industry recommend using just index cards, pens and tape. They argue that with change the constant in software development, your process should be as limited (yet rigorous) as possible. Looking at TFS, this is not a system designed to under do anybody. It is a big jumble of components and options, with every feature you could think of. Predictably this means many basic functions are hard to use. For task management, many people just use an Excel spreadsheet linked up to TFS. Not a stirring endorsement of the tooling there. TFS as a whole would be far more appealing to me if there was less of it, but better. Id cut 50% of the features to make the other half really amaze and inspire me. And thats really the heart of the matter. TFS has great promise and I want to believe it can work better. But ultimately it focuses your attention on a lot of stuff that doesnt really matter and then clamps down your creativity in a mess of forms and dialogs obscuring what does.   --- Relevant Links --- All those great G.I. Joe PSAs are on YouTube, including lots of mashed up versions. A simple Google search will get you on the right track.Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • A Guided Tour of Complexity

    - by JoshReuben
    I just re-read Complexity – A Guided Tour by Melanie Mitchell , protégé of Douglas Hofstadter ( author of “Gödel, Escher, Bach”) http://www.amazon.com/Complexity-Guided-Tour-Melanie-Mitchell/dp/0199798109/ref=sr_1_1?ie=UTF8&qid=1339744329&sr=8-1 here are some notes and links:   Evolved from Cybernetics, General Systems Theory, Synergetics some interesting transdisciplinary fields to investigate: Chaos Theory - http://en.wikipedia.org/wiki/Chaos_theory – small differences in initial conditions (such as those due to rounding errors in numerical computation) yield widely diverging outcomes for chaotic systems, rendering long-term prediction impossible. System Dynamics / Cybernetics - http://en.wikipedia.org/wiki/System_Dynamics – study of how feedback changes system behavior Network Theory - http://en.wikipedia.org/wiki/Network_theory – leverage Graph Theory to analyze symmetric  / asymmetric relations between discrete objects Algebraic Topology - http://en.wikipedia.org/wiki/Algebraic_topology – leverage abstract algebra to analyze topological spaces There are limits to deterministic systems & to computation. Chaos Theory definitely applies to training an ANN (artificial neural network) – different weights will emerge depending upon the random selection of the training set. In recursive Non-Linear systems http://en.wikipedia.org/wiki/Nonlinear_system – output is not directly inferable from input. E.g. a Logistic map: Xt+1 = R Xt(1-Xt) Different types of bifurcations, attractor states and oscillations may occur – e.g. a Lorenz Attractor http://en.wikipedia.org/wiki/Lorenz_system Feigenbaum Constants http://en.wikipedia.org/wiki/Feigenbaum_constants express ratios in a bifurcation diagram for a non-linear map – the convergent limit of R (the rate of period-doubling bifurcations) is 4.6692016 Maxwell’s Demon - http://en.wikipedia.org/wiki/Maxwell%27s_demon - the Second Law of Thermodynamics has only a statistical certainty – the universe (and thus information) tends towards entropy. While any computation can theoretically be done without expending energy, with finite memory, the act of erasing memory is permanent and increases entropy. Life & thought is a counter-example to the universe’s tendency towards entropy. Leo Szilard and later Claude Shannon came up with the Information Theory of Entropy - http://en.wikipedia.org/wiki/Entropy_(information_theory) whereby Shannon entropy quantifies the expected value of a message’s information in bits in order to determine channel capacity and leverage Coding Theory (compression analysis). Ludwig Boltzmann came up with Statistical Mechanics - http://en.wikipedia.org/wiki/Statistical_mechanics – whereby our Newtonian perception of continuous reality is a probabilistic and statistical aggregate of many discrete quantum microstates. This is relevant for Quantum Information Theory http://en.wikipedia.org/wiki/Quantum_information and the Physics of Information - http://en.wikipedia.org/wiki/Physical_information. Hilbert’s Problems http://en.wikipedia.org/wiki/Hilbert's_problems pondered whether mathematics is complete, consistent, and decidable (the Decision Problem – http://en.wikipedia.org/wiki/Entscheidungsproblem – is there always an algorithm that can determine whether a statement is true).  Godel’s Incompleteness Theorems http://en.wikipedia.org/wiki/G%C3%B6del's_incompleteness_theorems  proved that mathematics cannot be both complete and consistent (e.g. “This statement is not provable”). Turing through the use of Turing Machines (http://en.wikipedia.org/wiki/Turing_machine symbol processors that can prove mathematical statements) and Universal Turing Machines (http://en.wikipedia.org/wiki/Universal_Turing_machine Turing Machines that can emulate other any Turing Machine via accepting programs as well as data as input symbols) that computation is limited by demonstrating the Halting Problem http://en.wikipedia.org/wiki/Halting_problem (is is not possible to know when a program will complete – you cannot build an infinite loop detector). You may be used to thinking of 1 / 2 / 3 dimensional systems, but Fractal http://en.wikipedia.org/wiki/Fractal systems are defined by self-similarity & have non-integer Hausdorff Dimensions !!!  http://en.wikipedia.org/wiki/List_of_fractals_by_Hausdorff_dimension – the fractal dimension quantifies the number of copies of a self similar object at each level of detail – eg Koch Snowflake - http://en.wikipedia.org/wiki/Koch_snowflake Definitions of complexity: size, Shannon entropy, Algorithmic Information Content (http://en.wikipedia.org/wiki/Algorithmic_information_theory - size of shortest program that can generate a description of an object) Logical depth (amount of info processed), thermodynamic depth (resources required). Complexity is statistical and fractal. John Von Neumann’s other machine was the Self-Reproducing Automaton http://en.wikipedia.org/wiki/Self-replicating_machine  . Cellular Automata http://en.wikipedia.org/wiki/Cellular_automaton are alternative form of Universal Turing machine to traditional Von Neumann machines where grid cells are locally synchronized with their neighbors according to a rule. Conway’s Game of Life http://en.wikipedia.org/wiki/Conway's_Game_of_Life demonstrates various emergent constructs such as “Glider Guns” and “Spaceships”. Cellular Automatons are not practical because logical ops require a large number of cells – wasteful & inefficient. There are no compilers or general program languages available for Cellular Automatons (as far as I am aware). Random Boolean Networks http://en.wikipedia.org/wiki/Boolean_network are extensions of cellular automata where nodes are connected at random (not to spatial neighbors) and each node has its own rule –> they demonstrate the emergence of complex  & self organized behavior. Stephen Wolfram’s (creator of Mathematica, so give him the benefit of the doubt) New Kind of Science http://en.wikipedia.org/wiki/A_New_Kind_of_Science proposes the universe may be a discrete Finite State Automata http://en.wikipedia.org/wiki/Finite-state_machine whereby reality emerges from simple rules. I am 2/3 through this book. It is feasible that the universe is quantum discrete at the plank scale and that it computes itself – Digital Physics: http://en.wikipedia.org/wiki/Digital_physics – a simulated reality? Anyway, all behavior is supposedly derived from simple algorithmic rules & falls into 4 patterns: uniform , nested / cyclical, random (Rule 30 http://en.wikipedia.org/wiki/Rule_30) & mixed (Rule 110 - http://en.wikipedia.org/wiki/Rule_110 localized structures – it is this that is interesting). interaction between colliding propagating signal inputs is then information processing. Wolfram proposes the Principle of Computational Equivalence - http://mathworld.wolfram.com/PrincipleofComputationalEquivalence.html - all processes that are not obviously simple can be viewed as computations of equivalent sophistication. Meaning in information may emerge from analogy & conceptual slippages – see the CopyCat program: http://cognitrn.psych.indiana.edu/rgoldsto/courses/concepts/copycat.pdf Scale Free Networks http://en.wikipedia.org/wiki/Scale-free_network have a distribution governed by a Power Law (http://en.wikipedia.org/wiki/Power_law - much more common than Normal Distribution). They are characterized by hubs (resilience to random deletion of nodes), heterogeneity of degree values, self similarity, & small world structure. They grow via preferential attachment http://en.wikipedia.org/wiki/Preferential_attachment – tipping points triggered by positive feedback loops. 2 theories of cascading system failures in complex systems are Self-Organized Criticality http://en.wikipedia.org/wiki/Self-organized_criticality and Highly Optimized Tolerance http://en.wikipedia.org/wiki/Highly_optimized_tolerance. Computational Mechanics http://en.wikipedia.org/wiki/Computational_mechanics – use of computational methods to study phenomena governed by the principles of mechanics. This book is a great intuition pump, but does not cover the more mathematical subject of Computational Complexity Theory – http://en.wikipedia.org/wiki/Computational_complexity_theory I am currently reading this book on this subject: http://www.amazon.com/Computational-Complexity-Christos-H-Papadimitriou/dp/0201530821/ref=pd_sim_b_1   stay tuned for that review!

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  • Listing common SQL Code Smells.

    - by Phil Factor
    Once you’ve done a number of SQL Code-reviews, you’ll know those signs in the code that all might not be well. These ’Code Smells’ are coding styles that don’t directly cause a bug, but are indicators that all is not well with the code. . Kent Beck and Massimo Arnoldi seem to have coined the phrase in the "OnceAndOnlyOnce" page of www.C2.com, where Kent also said that code "wants to be simple". Bad Smells in Code was an essay by Kent Beck and Martin Fowler, published as Chapter 3 of the book ‘Refactoring: Improving the Design of Existing Code’ (ISBN 978-0201485677) Although there are generic code-smells, SQL has its own particular coding habits that will alert the programmer to the need to re-factor what has been written. See Exploring Smelly Code   and Code Deodorants for Code Smells by Nick Harrison for a grounding in Code Smells in C# I’ve always been tempted by the idea of automating a preliminary code-review for SQL. It would be so useful to trawl through code and pick up the various problems, much like the classic ‘Lint’ did for C, and how the Code Metrics plug-in for .NET Reflector by Jonathan 'Peli' de Halleux is used for finding Code Smells in .NET code. The problem is that few of the standard procedural code smells are relevant to SQL, and we need an agreed list of code smells. Merrilll Aldrich made a grand start last year in his blog Top 10 T-SQL Code Smells.However, I'd like to make a start by discovering if there is a general opinion amongst Database developers what the most important SQL Smells are. One can be a bit defensive about code smells. I will cheerfully write very long stored procedures, even though they are frowned on. I’ll use dynamic SQL occasionally. You can only use them as an aid for your own judgment and it is fine to ‘sign them off’ as being appropriate in particular circumstances. Also, whole classes of ‘code smells’ may be irrelevant for a particular database. The use of proprietary SQL, for example, is only a ‘code smell’ if there is a chance that the database will have to be ported to another RDBMS. The use of dynamic SQL is a risk only with certain security models. As the saying goes,  a CodeSmell is a hint of possible bad practice to a pragmatist, but a sure sign of bad practice to a purist. Plamen Ratchev’s wonderful article Ten Common SQL Programming Mistakes lists some of these ‘code smells’ along with out-and-out mistakes, but there are more. The use of nested transactions, for example, isn’t entirely incorrect, even though the database engine ignores all but the outermost: but it does flag up the possibility that the programmer thinks that nested transactions are supported. If anything requires some sort of general agreement, the definition of code smells is one. I’m therefore going to make this Blog ‘dynamic, in that, if anyone twitters a suggestion with a #SQLCodeSmells tag (or sends me a twitter) I’ll update the list here. If you add a comment to the blog with a suggestion of what should be added or removed, I’ll do my best to oblige. In other words, I’ll try to keep this blog up to date. The name against each 'smell' is the name of the person who Twittered me, commented about or who has written about the 'smell'. it does not imply that they were the first ever to think of the smell! Use of deprecated syntax such as *= (Dave Howard) Denormalisation that requires the shredding of the contents of columns. (Merrill Aldrich) Contrived interfaces Use of deprecated datatypes such as TEXT/NTEXT (Dave Howard) Datatype mis-matches in predicates that rely on implicit conversion.(Plamen Ratchev) Using Correlated subqueries instead of a join   (Dave_Levy/ Plamen Ratchev) The use of Hints in queries, especially NOLOCK (Dave Howard /Mike Reigler) Few or No comments. Use of functions in a WHERE clause. (Anil Das) Overuse of scalar UDFs (Dave Howard, Plamen Ratchev) Excessive ‘overloading’ of routines. The use of Exec xp_cmdShell (Merrill Aldrich) Excessive use of brackets. (Dave Levy) Lack of the use of a semicolon to terminate statements Use of non-SARGable functions on indexed columns in predicates (Plamen Ratchev) Duplicated code, or strikingly similar code. Misuse of SELECT * (Plamen Ratchev) Overuse of Cursors (Everyone. Special mention to Dave Levy & Adrian Hills) Overuse of CLR routines when not necessary (Sam Stange) Same column name in different tables with different datatypes. (Ian Stirk) Use of ‘broken’ functions such as ‘ISNUMERIC’ without additional checks. Excessive use of the WHILE loop (Merrill Aldrich) INSERT ... EXEC (Merrill Aldrich) The use of stored procedures where a view is sufficient (Merrill Aldrich) Not using two-part object names (Merrill Aldrich) Using INSERT INTO without specifying the columns and their order (Merrill Aldrich) Full outer joins even when they are not needed. (Plamen Ratchev) Huge stored procedures (hundreds/thousands of lines). Stored procedures that can produce different columns, or order of columns in their results, depending on the inputs. Code that is never used. Complex and nested conditionals WHILE (not done) loops without an error exit. Variable name same as the Datatype Vague identifiers. Storing complex data  or list in a character map, bitmap or XML field User procedures with sp_ prefix (Aaron Bertrand)Views that reference views that reference views that reference views (Aaron Bertrand) Inappropriate use of sql_variant (Neil Hambly) Errors with identity scope using SCOPE_IDENTITY @@IDENTITY or IDENT_CURRENT (Neil Hambly, Aaron Bertrand) Schemas that involve multiple dated copies of the same table instead of partitions (Matt Whitfield-Atlantis UK) Scalar UDFs that do data lookups (poor man's join) (Matt Whitfield-Atlantis UK) Code that allows SQL Injection (Mladen Prajdic) Tables without clustered indexes (Matt Whitfield-Atlantis UK) Use of "SELECT DISTINCT" to mask a join problem (Nick Harrison) Multiple stored procedures with nearly identical implementation. (Nick Harrison) Excessive column aliasing may point to a problem or it could be a mapping implementation. (Nick Harrison) Joining "too many" tables in a query. (Nick Harrison) Stored procedure returning more than one record set. (Nick Harrison) A NOT LIKE condition (Nick Harrison) excessive "OR" conditions. (Nick Harrison) User procedures with sp_ prefix (Aaron Bertrand) Views that reference views that reference views that reference views (Aaron Bertrand) sp_OACreate or anything related to it (Bill Fellows) Prefixing names with tbl_, vw_, fn_, and usp_ ('tibbling') (Jeremiah Peschka) Aliases that go a,b,c,d,e... (Dave Levy/Diane McNurlan) Overweight Queries (e.g. 4 inner joins, 8 left joins, 4 derived tables, 10 subqueries, 8 clustered GUIDs, 2 UDFs, 6 case statements = 1 query) (Robert L Davis) Order by 3,2 (Dave Levy) MultiStatement Table functions which are then filtered 'Sel * from Udf() where Udf.Col = Something' (Dave Ballantyne) running a SQL 2008 system in SQL 2000 compatibility mode(John Stafford)

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  • How to Upload a file from client to server using OFBIZ?

    - by SIVAKUMAR.J
    I'm new to ofbiz so try to keep your answer as simple as possibly. If you can give examples that would be kind. My problem is I created a project inside the ofbiz/hot-deploy folder namely productionmgntSystem. Inside the folder ofbiz\hot-deploy\productionmgntSystem\webapp\productionmgntSystem I created a file app_details_1.ftl. The following are the code of this file <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Insert title here</title> <script TYPE="TEXT/JAVASCRIPT" language=""JAVASCRIPT"> function uploadFile() { //alert("Before calling upload.jsp"); window.location='<@ofbizUrl>testing_service1</@ofbizUrl>' } </script> </head> <!-- <form action="<@ofbizUrl>testing_service1</@ofbizUrl>" enctype="multipart/form-data" name="app_details_frm"> --> <form action="<@ofbizUrl>logout1</@ofbizUrl>" enctype="multipart/form-data" name="app_details_frm"> <center style="height: 299px; "> <table border="0" style="height: 177px; width: 788px"> <tr style="height: 115px; "> <td style="width: 103px; "> <td style="width: 413px; "><h1>APPLICATION DETAILS</h1> <td style="width: 55px; "> </tr> <tr> <td style="width: 125px; ">Application name : </td> <td> <input name="app_name_txt" id="txt_1" value=" " /> </td> </tr> <tr> <td style="width: 125px; ">Excell sheet &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;: </td> <td> <input type="file" name="filename"/> </td> </tr> <tr> <td> <!-- <input type="button" name="logout1_cmd" value="Logout" onclick="logout1()"/> --> <input type="submit" name="logout_cmd" value="logout"/> </td> <td> <!-- <input type="submit" name="upload_cmd" value="Submit" /> --> <input type="button" name="upload1_cmd" value="Upload" onclick="uploadFile()"/> </td> </tr> </table> </center> </form> </html> the following coding is present in the file ofbiz\hot-deploy\productionmgntSystem\webapp\productionmgntSystem\WEB-INF\controller.xml ...... ....... ........ <request-map uri="testing_service1"> <security https="true" auth="true"/> <event type="java" path="org.ofbiz.productionmgntSystem.web_app_req.WebServices1" invoke="testingService"/> <response name="ok" type="view" value="ok_view"/> <response name="exception" type="view" value="exception_view"/> </request-map> .......... ............ .......... <view-map name="ok_view" type="ftl" page="ok_view.ftl"/> <view-map name="exception_view" type="ftl" page="exception_view.ftl"/> ................ ............. ............. The following are the coding present in the file ofbiz\hot-deploy\productionmgntSystem\src\org\ofbiz\productionmgntSystem\web_app_req\WebServices1.java package org.ofbiz.productionmgntSystem.web_app_req; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.DataInputStream; import java.io.FileOutputStream; import java.io.IOException; public class WebServices1 { public static String testingService(HttpServletRequest request, HttpServletResponse response) { //int i=0; String result="ok"; System.out.println("\n\n\t*************************************\n\tInside WebServices1.testingService(HttpServletRequest request, HttpServletResponse response)- Start"); String contentType=request.getContentType(); System.out.println("\n\n\t*************************************\n\tInside WebServices1.testingService(HttpServletRequest request, HttpServletResponse response)- contentType : "+contentType); String str=new String(); // response.setContentType("text/html"); //PrintWriter writer; if ((contentType != null) && (contentType.indexOf("multipart/form-data") >= 0)) { System.out.println("\n\n\t**********************************\n\tInside WebServices1.testingService(HttpServletRequest request, HttpServletResponse response) after if (contentType != null)"); try { // writer=response.getWriter(); System.out.println("\n\n\t**********************************\n\tInside WebServices1.testingService(HttpServletRequest request, HttpServletResponse response) - try Start"); DataInputStream in = new DataInputStream(request.getInputStream()); int formDataLength = request.getContentLength(); byte dataBytes[] = new byte[formDataLength]; int byteRead = 0; int totalBytesRead = 0; //this loop converting the uploaded file into byte code while (totalBytesRead < formDataLength) { byteRead = in.read(dataBytes, totalBytesRead,formDataLength); totalBytesRead += byteRead; } String file = new String(dataBytes); //for saving the file name String saveFile = file.substring(file.indexOf("filename=\"") + 10); saveFile = saveFile.substring(0, saveFile.indexOf("\n")); saveFile = saveFile.substring(saveFile.lastIndexOf("\\")+ 1,saveFile.indexOf("\"")); int lastIndex = contentType.lastIndexOf("="); String boundary = contentType.substring(lastIndex + 1,contentType.length()); int pos; //extracting the index of file pos = file.indexOf("filename=\""); pos = file.indexOf("\n", pos) + 1; pos = file.indexOf("\n", pos) + 1; pos = file.indexOf("\n", pos) + 1; int boundaryLocation = file.indexOf(boundary, pos) - 4; int startPos = ((file.substring(0, pos)).getBytes()).length; int endPos = ((file.substring(0, boundaryLocation)).getBytes()).length; //creating a new file with the same name and writing the content in new file FileOutputStream fileOut = new FileOutputStream("/"+saveFile); fileOut.write(dataBytes, startPos, (endPos - startPos)); fileOut.flush(); fileOut.close(); System.out.println("\n\n\t**********************************\n\tInside WebServices1.testingService(HttpServletRequest request, HttpServletResponse response) - try End"); } catch(IOException ioe) { System.out.println("\n\n\t*********************************\n\tInside WebServices1.testingService(HttpServletRequest request, HttpServletResponse response) - Catch IOException"); //ioe.printStackTrace(); return("exception"); } catch(Exception ex) { System.out.println("\n\n\t*********************************\n\tInside WebServices1.testingService(HttpServletRequest request, HttpServletResponse response) - Catch Exception"); return("exception"); } } else { System.out.println("\n\n\t********************************\n\tInside WebServices1.testingService(HttpServletRequest request, HttpServletResponse response) else part"); result="exception"; } System.out.println("\n\n\t*************************************\n\tInside WebServices1.testingService(HttpServletRequest request, HttpServletResponse response)- End"); return(result); } } I want to upload a file to the server. The file is get from user " tag in the "app_details_1.ftl" file & it is updated into the server by using the method "testingService(HttpServletRequest request, HttpServletResponse response)" in the class "WebServices1". But the file is not uploaded. Give me a good solution for uploading a file to the server.

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  • SQL SERVER – Extending SQL Azure with Azure worker role – Guest Post by Paras Doshi

    - by pinaldave
    This is guest post by Paras Doshi. Paras Doshi is a research Intern at SolidQ.com and a Microsoft student partner. He is currently working in the domain of SQL Azure. SQL Azure is nothing but a SQL server in the cloud. SQL Azure provides benefits such as on demand rapid provisioning, cost-effective scalability, high availability and reduced management overhead. To see an introduction on SQL Azure, check out the post by Pinal here In this article, we are going to discuss how to extend SQL Azure with the Azure worker role. In other words, we will attempt to write a custom code and host it in the Azure worker role; the aim is to add some features that are not available with SQL Azure currently or features that need to be customized for flexibility. This way we extend the SQL Azure capability by building some solutions that run on Azure as worker roles. To understand Azure worker role, think of it as a windows service in cloud. Azure worker role can perform background processes, and to handle processes such as synchronization and backup, it becomes our ideal tool. First, we will focus on writing a worker role code that synchronizes SQL Azure databases. Before we do so, let’s see some scenarios in which synchronization between SQL Azure databases is beneficial: scaling out access over multiple databases enables us to handle workload efficiently As of now, SQL Azure database can be hosted in one of any six datacenters. By synchronizing databases located in different data centers, one can extend the data by enabling access to geographically distributed data Let us see some scenarios in which SQL server to SQL Azure database synchronization is beneficial To backup SQL Azure database on local infrastructure Rather than investing in local infrastructure for increased workloads, such workloads could be handled by cloud Ability to extend data to different datacenters located across the world to enable efficient data access from remote locations Now, let us develop cloud-based app that synchronizes SQL Azure databases. For an Introduction to developing cloud based apps, click here Now, in this article, I aim to provide a bird’s eye view of how a code that synchronizes SQL Azure databases look like and then list resources that can help you develop the solution from scratch. Now, if you newly add a worker role to the cloud-based project, this is how the code will look like. (Note: I have added comments to the skeleton code to point out the modifications that will be required in the code to carry out the SQL Azure synchronization. Note the placement of Setup() and Sync() function.) Click here (http://parasdoshi1989.files.wordpress.com/2011/06/code-snippet-1-for-extending-sql-azure-with-azure-worker-role1.pdf ) Enabling SQL Azure databases synchronization through sync framework is a two-step process. In the first step, the database is provisioned and sync framework creates tracking tables, stored procedures, triggers, and tables to store metadata to enable synchronization. This is one time step. The code for the same is put in the setup() function which is called once when the worker role starts. Now, the second step is continuous (or on demand) synchronization of SQL Azure databases by propagating changes between databases. This is done on a continuous basis by calling the sync() function in the while loop. The code logic to synchronize changes between SQL Azure databases should be put in the sync() function. Discussing the coding part step by step is out of the scope of this article. Therefore, let me suggest you a resource, which is given here. Also, note that before you start developing the code, you will need to install SYNC framework 2.1 SDK (download here). Further, you will reference some libraries before you start coding. Details regarding the same are available in the article that I just pointed to. You will be charged for data transfers if the databases are not in the same datacenter. For pricing information, go here Currently, a tool named DATA SYNC, which is built on top of sync framework, is available in CTP that allows SQL Azure <-> SQL server and SQL Azure <-> SQL Azure synchronization (without writing single line of code); however, in some cases, the custom code shown in this blogpost provides flexibility that is not available with Data SYNC. For instance, filtering is not supported in the SQL Azure DATA SYNC CTP2; if you wish to have such a functionality now, then you have the option of developing a custom code using SYNC Framework. Now, this code can be easily extended to synchronize at some schedule. Let us say we want the databases to get synchronized every day at 10:00 pm. This is what the code will look like now: (http://parasdoshi1989.files.wordpress.com/2011/06/code-snippet-2-for-extending-sql-azure-with-azure-worker-role.pdf) Don’t you think that by writing such a code, we are imitating the functionality provided by the SQL server agent for a SQL server? Think about it. We are scheduling our administrative task by writing custom code – in other words, we have developed a “Light weight SQL server agent for SQL Azure!” Since the SQL server agent is not currently available in cloud, we have developed a solution that enables us to schedule tasks, and thus we have extended SQL Azure with the Azure worker role! Now if you wish to track jobs, you can do so by storing this data in SQL Azure (or Azure tables). The reason is that Windows Azure is a stateless platform, and we will need to store the state of the job ourselves and the choice that you have is SQL Azure or Azure tables. Note that this solution requires custom code and also it is not UI driven; however, for now, it can act as a temporary solution until SQL server agent is made available in the cloud. Moreover, this solution does not encompass functionalities that a SQL server agent provides, but it does open up an interesting avenue to schedule some of the tasks such as backup and synchronization of SQL Azure databases by writing some custom code in the Azure worker role. Now, let us see one more possibility – i.e., running BCP through a worker role in Azure-hosted services and then uploading the backup files either locally or on blobs. If you upload it locally, then consider the data transfer cost. If you upload it to blobs residing in the same datacenter, then no transfer cost applies but the cost on blob size applies. So, before choosing the option, you need to evaluate your preferences keeping the cost associated with each option in mind. In this article, I have shown that Azure worker role solution could be developed to synchronize SQL Azure databases. Moreover, a light-weight SQL server agent for SQL Azure can be developed. Also we discussed the possibility of running BCP through a worker role in Azure-hosted services for backing up our precious SQL Azure data. Thus, we can extend SQL Azure with the Azure worker role. But remember: you will be charged for running Azure worker roles. So at the end of the day, you need to ask – am I willing to build a custom code and pay money to achieve this functionality? I hope you found this blog post interesting. If you have any questions/feedback, you can comment below or you can mail me at Paras[at]student-partners[dot]com Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Azure, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • JMaghreb 2012 Trip Report

    - by arungupta
    JMaghreb is the inaugural Java conference organized by Morocco JUG. It is the biggest Java conference in Maghreb (5 countries in North West Africa). Oracle was the exclusive platinum sponsor with several others. The registrations had to be closed at 1412 for the free conference and several folks were already on the waiting list. Rabat with 531 registrations and Casablanca with 426 were the top cities. Some statistics ... 850+ attendees over 2 days, 500+ every day 30 sessions were delivered by 18 speakers from 10 different countries 10 sessions in French and 20 in English 6 of the speakers spoke at JavaOne 2012 8 will be at Devoxx Attendees from 5 different countries and 57 cities in Morocco 40.9% qualified them as professional and rest as students Topics ranged from HTML5, Java EE 7, ADF, JavaFX, MySQL, JCP, Vaadin, Android, Community, JCP Java EE 6 hands-on lab was sold out within 7 minutes and JavaFX in 12 minutes I gave the keynote along with Simon Ritter which was basically a recap of the Strategy and Technical keynotes presented at JavaOne 2012. An informal survey during the keynote showed the following numbers: 25% using NetBeans, 90% on Eclipse, 3 on JDeveloper, 1 on IntelliJ About 10 subscribers to free online Java magazine. This digital magazine is a comprehensive source of information for everything Java - subscribe for free!! About 10-15% using Java SE 7. Download JDK 7 and get started today! Even JDK 8 builds have been available for a while now. My second talk explained the core concepts of WebSocket and how JSR 356 is providing a standard API to build WebSocket-driven applications in Java EE 7. TOTD #183 explains how you can easily get started with WebSocket in GlassFish 4. The complete slide deck is available: Next day started with a community keynote by Sonya Barry. Some of us live the life of JCP, JSR, EG, EC, RI, etc every day, but not every body is. To address that, Sonya prepared an excellent introductory presentation providing an explanation of these terms and how java.net infrastructure supports Java development. The registration for the lab showed there is a definite demand for these technologies in this part of the world. I delivered the Java EE 6 hands-on lab to a packed room of about 120 attendees. Most of the attendees were able to progress and follow the lab instructions. Some of the attendees did not have a laptop but were taking extensive notes on paper notepads. Several attendees were already using Java EE 6 in their projects and typically they are the ones asking deep dive questions. Also gave out three copies of my recently released Java EE 6 Pocket Guide and new GlassFish t-shirts. Definitely feels happy to coach ~120 more Java developers learn standards-based enterprise Java programming. I also participated in a JCP BoF along with Werner, Sonya, and Badr. Adotp-a-JSR, java.net infrastructure, how to file a JSR, what is an RI, and other similar topics were discussed in a candid manner. You can follow @JMaghrebConf or check out their facebook page. java.net published a timely conversation with Badr El Houari - the fearless leader of the Morocco JUG team. Did you know that Morocco JUG stood for JCP EC elections (ADD LINK) ? Even though they did not get elected but did fairly well. Now some sample tweets from #JMaghreb ... #JMaghreb is over. Impressive for a first edition! Thanks @badrelhouari and all the @MoroccoJUG team ! Since you @speakjava : System.out.println("Thank you so much dear Tech Evangelist ! The JavaFX was pretty amazing !!! "); #JMaghreb @YounesVendetta @arungupta @JMaghrebConf Right ! hope he will be back to morocco again and again .. :) @Alji_ @arungupta @JMaghrebConf That dude is a genius ;) Put it on your wall :p @arungupta rocking Java EE 6 at @JMaghrebConf #Java #JavaEE #JMaghreb http://t.co/isl0Iq5p @sonyabarry you are an awesome speaker ;-) #JMaghreb rich more than 550 attendees in day one. Expecting more tomorrow! ongratulations @badrelhouari the organisation was great! The talks were pretty interesting, and the turnout was surprising at #JMaghreb! #JMaghreb is truly awesome... The speakers are unbelievable ! #JavaFX... Just amazing #JMaghreb Charmed by the talk about #javaFX ( nodes architecture, MVC, Lazy loading, binding... ) gotta start using it intead of SWT. #JMaghreb JavaFX is killing JFreeChart. It supports Charts a lot of kind of them ... #JMaghreb The british man is back #JMaghreb I do like him!! #JMaghreb @arungupta rocking @JMaghrebConf. pic.twitter.com/CNohA3PE @arungupta Great talk about the future of Java EE (JEE 7 & JEE 8) Thank you. #JMaghreb JEE7 more mooore power , leeess less code !! #JMaghreb They are simplifying the existing API for Java Message Service 2.0 #JMaghreb good to know , the more the code is simplified the better ! The Glassdoor guy #arungupta is doing it RIGHT ! #JMaghreb Great presentation of The Future of the Java Platform: Java EE 7, Java SE 8 & Beyond #jMaghreb @arungupta is a great Guy apparently #JMaghreb On a personal front, the hotel (Soiftel Jardin des Roses) was pretty nice and the location was perfect. There was a 1.8 mile loop dirt trail right next to it so I managed to squeeze some runs before my upcoming marathon. Also enjoyed some great Moroccan cuisine - Couscous, Tajine, mint tea, and moroccan salad. Visit to Kasbah of the Udayas, Hassan II (one of the tallest mosque in the world), and eating in a restaurant in a kasbah are some of the exciting local experiences. Now some pictures from the event (and around the city) ... And the complete album: Many thanks to Badr, Faisal, and rest of the team for organizing a great conference. They are already thinking about how to improve the content, logisitics, and flow for the next year. I'm certainly looking forward to JMaghreb 2.0 :-)

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  • Replication Services as ETL extraction tool

    - by jorg
    In my last blog post I explained the principles of Replication Services and the possibilities it offers in a BI environment. One of the possibilities I described was the use of snapshot replication as an ETL extraction tool: “Snapshot Replication can also be useful in BI environments, if you don’t need a near real-time copy of the database, you can choose to use this form of replication. Next to an alternative for Transactional Replication it can be used to stage data so it can be transformed and moved into the data warehousing environment afterwards. In many solutions I have seen developers create multiple SSIS packages that simply copies data from one or more source systems to a staging database that figures as source for the ETL process. The creation of these packages takes a lot of (boring) time, while Replication Services can do the same in minutes. It is possible to filter out columns and/or records and it can even apply schema changes automatically so I think it offers enough features here. I don’t know how the performance will be and if it really works as good for this purpose as I expect, but I want to try this out soon!” Well I have tried it out and I must say it worked well. I was able to let replication services do work in a fraction of the time it would cost me to do the same in SSIS. What I did was the following: Configure snapshot replication for some Adventure Works tables, this was quite simple and straightforward. Create an SSIS package that executes the snapshot replication on demand and waits for its completion. This is something that you can’t do with out of the box functionality. While configuring the snapshot replication two SQL Agent Jobs are created, one for the creation of the snapshot and one for the distribution of the snapshot. Unfortunately these jobs are  asynchronous which means that if you execute them they immediately report back if the job started successfully or not, they do not wait for completion and report its result afterwards. So I had to create an SSIS package that executes the jobs and waits for their completion before the rest of the ETL process continues. Fortunately I was able to create the SSIS package with the desired functionality. I have made a step-by-step guide that will help you configure the snapshot replication and I have uploaded the SSIS package you need to execute it. Configure snapshot replication   The first step is to create a publication on the database you want to replicate. Connect to SQL Server Management Studio and right-click Replication, choose for New.. Publication…   The New Publication Wizard appears, click Next Choose your “source” database and click Next Choose Snapshot publication and click Next   You can now select tables and other objects that you want to publish Expand Tables and select the tables that are needed in your ETL process In the next screen you can add filters on the selected tables which can be very useful. Think about selecting only the last x days of data for example. Its possible to filter out rows and/or columns. In this example I did not apply any filters. Schedule the Snapshot Agent to run at a desired time, by doing this a SQL Agent Job is created which we need to execute from a SSIS package later on. Next you need to set the Security Settings for the Snapshot Agent. Click on the Security Settings button.   In this example I ran the Agent under the SQL Server Agent service account. This is not recommended as a security best practice. Fortunately there is an excellent article on TechNet which tells you exactly how to set up the security for replication services. Read it here and make sure you follow the guidelines!   On the next screen choose to create the publication at the end of the wizard Give the publication a name (SnapshotTest) and complete the wizard   The publication is created and the articles (tables in this case) are added Now the publication is created successfully its time to create a new subscription for this publication.   Expand the Replication folder in SSMS and right click Local Subscriptions, choose New Subscriptions   The New Subscription Wizard appears   Select the publisher on which you just created your publication and select the database and publication (SnapshotTest)   You can now choose where the Distribution Agent should run. If it runs at the distributor (push subscriptions) it causes extra processing overhead. If you use a separate server for your ETL process and databases choose to run each agent at its subscriber (pull subscriptions) to reduce the processing overhead at the distributor. Of course we need a database for the subscription and fortunately the Wizard can create it for you. Choose for New database   Give the database the desired name, set the desired options and click OK You can now add multiple SQL Server Subscribers which is not necessary in this case but can be very useful.   You now need to set the security settings for the Distribution Agent. Click on the …. button Again, in this example I ran the Agent under the SQL Server Agent service account. Read the security best practices here   Click Next   Make sure you create a synchronization job schedule again. This job is also necessary in the SSIS package later on. Initialize the subscription at first synchronization Select the first box to create the subscription when finishing this wizard Complete the wizard by clicking Finish The subscription will be created In SSMS you see a new database is created, the subscriber. There are no tables or other objects in the database available yet because the replication jobs did not ran yet. Now expand the SQL Server Agent, go to Jobs and search for the job that creates the snapshot:   Rename this job to “CreateSnapshot” Now search for the job that distributes the snapshot:   Rename this job to “DistributeSnapshot” Create an SSIS package that executes the snapshot replication We now need an SSIS package that will take care of the execution of both jobs. The CreateSnapshot job needs to execute and finish before the DistributeSnapshot job runs. After the DistributeSnapshot job has started the package needs to wait until its finished before the package execution finishes. The Execute SQL Server Agent Job Task is designed to execute SQL Agent Jobs from SSIS. Unfortunately this SSIS task only executes the job and reports back if the job started succesfully or not, it does not report if the job actually completed with success or failure. This is because these jobs are asynchronous. The SSIS package I’ve created does the following: It runs the CreateSnapshot job It checks every 5 seconds if the job is completed with a for loop When the CreateSnapshot job is completed it starts the DistributeSnapshot job And again it waits until the snapshot is delivered before the package will finish successfully Quite simple and the package is ready to use as standalone extract mechanism. After executing the package the replicated tables are added to the subscriber database and are filled with data:   Download the SSIS package here (SSIS 2008) Conclusion In this example I only replicated 5 tables, I could create a SSIS package that does the same in approximately the same amount of time. But if I replicated all the 70+ AdventureWorks tables I would save a lot of time and boring work! With replication services you also benefit from the feature that schema changes are applied automatically which means your entire extract phase wont break. Because a snapshot is created using the bcp utility (bulk copy) it’s also quite fast, so the performance will be quite good. Disadvantages of using snapshot replication as extraction tool is the limitation on source systems. You can only choose SQL Server or Oracle databases to act as a publisher. So if you plan to build an extract phase for your ETL process that will invoke a lot of tables think about replication services, it would save you a lot of time and thanks to the Extract SSIS package I’ve created you can perfectly fit it in your usual SSIS ETL process.

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  • The DOS DEBUG Environment

    - by MarkPearl
    Today I thought I would go back in time and have a look at the DEBUG command that has been available since the beginning of dawn in DOS, MS-DOS and Microsoft Windows. up to today I always knew it was there, but had no clue on how to use it so for those that are interested this might be a great geek party trick to pull out when you want the awe the younger generation and want to show them what “real” programming is about. But wait, you will have to do it relatively quickly as it seems like DEBUG was finally dumped from the Windows group in Windows 7. Not to worry, pull out that Windows XP box which will get you even more geek points and you can still poke DEBUG a bit. So, for those that are interested and want to find out a bit about the history of DEBUG read the wiki link here. That all put aside, lets get our hands dirty.. How to Start DEBUG in Windows Make sure your version of Windows supports DEBUG. Open up a console window Make a directory where you want to play with debug – in my instance I called it C221 Enter the directory and type Debug You will get a response with a – as illustrated in the image below…   The commands available in DEBUG There are several commands available in DEBUG. The most common ones are A (Assemble) R (Register) T (Trace) G (Go) D (Dump or Display) U (Unassemble) E (Enter) P (Proceed) N (Name) L (Load) W (Write) H (Hexadecimal) I (Input) O (Output) Q (Quit) I am not going to cover all these commands, but what I will do is go through a few of them briefly. A is for Assemble Command (to write code) The A command translates assembly language statements into machine code. It is quite useful for writing small assembly programs. Below I have written a very basic assembly program. The code typed out is as follows mov ax,0015 mov cx,0023 sub cx,ax mov [120],al mov cl,[120]A nop R is for Register (to jump to a point in memory) The r command turns out to be one of the most frequent commands you will use in DEBUG. It allows you to view the contents of registers and to change their values. It can be used with the following combinations… R – Displays the contents of all the registers R f – Displays the flags register R register_name – Displays the contents of a specific register All three methods are illustrated in the image above T is for Trace (To execute a program step by step) The t command allows us to execute the program step by step. Before we can trace the program we need to point back to the beginning of the program. We do this by typing in r ip, which moves us back to memory point 100. We then type trace which executes the first line of code (line 100) (As shown in the image below starting from the red arrow). You can see from the above image that the register AX now contains 0015 as per our instruction mov ax,0015 You can also see that the IP points to line 0103 which has the MOV CX,0023 command If we type t again it will now execute the second line of the program which moves 23 in the cx register. Again, we can see that the line of code was executed and that the CX register now holds the value of 23. What I would like to highlight now is the section underlined in red. These are the status flags. The ones we are going to look at now are 1st (NV), 4th (PL), 5th (NZ) & 8th (NC) NV means no overflow, the alternate would be OV PL means that the sign of the previous arithmetic operation was Plus, the alternate would be NG (Negative) NZ means that the results of the previous arithmetic operation operation was Not Zero, the alternate would be ZR NC means that No final Carry resulted from the previous arithmetic operation. CY means that there was a final Carry. We could now follow this process of entering the t command until the entire program is executed line by line. G is for Go (To execute a program up to a certain line number) So we have looked at executing a program line by line, which is fine if your program is minuscule BUT totally unpractical if we have any decent sized program. A quicker way to run some lines of code is to use the G command. The ‘g’ command executes a program up to a certain specified point. It can be used in connection with the the reset IP command. You would set your initial point and then run the G command with the line you want to end on. P is for Proceed (Similar to trace but slightly more streamlined) Another command similar to trace is the proceed command. All that the p command does is if it is called and it encounters a CALL, INT or LOOP command it terminates the program execution. In the example below I modified our example program to include an int 20 at the end of it as illustrated in the image below… Then when executing the code when I encountered the int 20 command I typed the P command and the program terminated normally (illustrated below). D is for Dump (or for those more polite Display) So, we have all these assembly lines of code, but if you have ever opened up an exe or com file in a text/hex editor, it looks nothing like assembly code. The D command is a way that we can see what our code looks like in memory (or in a hex editor). If we examined the image above, we can see that Debug is storing our assembly code with each instruction following immediately after the previous one. For instance in memory address 110 we have int and 111 we have 20. If we examine the dump of memory we can see at memory point 110 CD is stored and at memory point 111 20 is stored. U is for Unassemble (or Convert Machine code to Assembly Code) So up to now we have gone through a bunch of commands, but probably one of the most useful is the U command. Let’s say we don’t understand machine code so well and so instead we want to see it in its equivalent assembly code. We can type the U command followed by the start memory point, followed by the end memory point and it will show us the assembly code equivalent of the machine code. E is for a bunch of things… The E command can be used for a bunch of things… One example is to enter data or machine code instructions directly into memory. It can also be used to display the contents of memory locations. I am not going to worry to much about it in this post. N / L / W is for Name, Load & Write So we have written out assembly code in debug, and now we want to save it to disk, or write it as a com file or load it. This is where the N, L & W command come in handy. The n command is used to give a name to the executable program file and is pretty simple to use. The w command is a bit trickier. It saves to disk all the memory between point bx and point cx so you need to specify the bx memory address and the cx memory address for it to write your code. Let’s look at an example illustrated below. You do this by calling the r command followed by the either bx or cx. We can then go to the directory where we were working and will see the new file with the name we specified. The L command is relatively simple. You would first specify the name of the file you would like to load using the N command, and then call the L command. Q is for Quit The last command that I am going to write about in this post is the Q command. Simply put, calling the Q command exits DEBUG. Commands we did not Cover Out of the standard DEBUG commands we covered A, T, G, D, U, E, P, R, N, L & W. The ones we did not cover were H, I & O – I might make mention of these in a later post, but for the basics they are not really needed. Some Useful Resources Please note this post is based on the COS2213 handouts for UNISA A Guide to DEBUG - http://mirror.href.com/thestarman/asm/debug/debug.htm#NT

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  • Using Lightbox with _Screen

    Although, I have to admit that I discovered Bernard Bout's ideas and concepts about implementing a lightbox in Visual FoxPro quite a while ago, there was no "spare" time in active projects that allowed me to have a closer look into his solution(s). Luckily, these days I received a demand to focus a little bit more on this. This article describes the steps about how to integrate and make use of Bernard's lightbox class in combination with _Screen in Visual FoxPro. The requirement in this project was to be able to visually lock the whole application (_Screen area) and guide the user to an information that should not be ignored easily. Depending on the importance any current user activity should be interrupted and focus put onto the notification. Getting the "meat", eh, source code Please check out Bernard's blog on Foxite directly in order to get the latest and greatest version. As time of writing this article I use version 6.0 as described in this blog entry: The Fastest Lightbox Ever The Lightbox class is sub-classed from the imgCanvas class from the GdiPlusX project on VFPx and therefore you need to have the source code of GdiPlusX as well, and integrate it into your development environment. The version I use is available here: Release GDIPlusX 1.20 As soon as you open the bbGdiLightbox class the first it, VFP might ask you to update the reference to the gdiplusx.vcx. As we have the sources, no problem and you have access to Bernard's code. The class itself is pretty easy to understand, some properties that you do not need to change and three methods: Setup(), ShowLightbox() and BeforeDraw() The challenge - _Screen or not? Reading Bernard's article about the fastest lightbox ever, he states the following: "The class will only work on a form. It will not support any other containers" Really? And what about _Screen? Isn't that a form class, too? Yes, of course it is but nonetheless trying to use _Screen directly will fail. Well, let's have look at the code to see why: WITH This .Left = 0 .Top = 0 .Height = ThisForm.Height .Width = ThisForm.Width .ZOrder(0) .Visible = .F.ENDWITH During the setup of the lightbox as well as while capturing the image as replacement for your forms and controls, the object reference Thisform is used. Which is a little bit restrictive to my opinion but let's continue. The second issue lies in the method ShowLightbox() and introduced by the call of .Bitmap.FromScreen(): Lparameters tlVisiblilty* tlVisiblilty - show or hide (T/F)* grab a screen dump with controlsIF tlVisiblilty Local loCaptureBmp As xfcBitmap Local lnTitleHeight, lnLeftBorder, lnTopBorder, lcImage, loImage lnTitleHeight = IIF(ThisForm.TitleBar = 1,Sysmetric(9),0) lnLeftBorder = IIF(ThisForm.BorderStyle < 2,0,Sysmetric(3)) lnTopBorder = IIF(ThisForm.BorderStyle < 2,0,Sysmetric(4)) With _Screen.System.Drawing loCaptureBmp = .Bitmap.FromScreen(ThisForm.HWnd,; lnLeftBorder,; lnTopBorder+lnTitleHeight,; ThisForm.Width ,; ThisForm.Height) ENDWITH * save it to a property This.capturebmp = loCaptureBmp ThisForm.SetAll("Visible",.F.) This.DraW() This.Visible = .T.ELSE ThisForm.SetAll("Visible",.T.) This.Visible = .F.ENDIF My first trials in using the class ended in an exception - GdiPlusError:OutOfMemory - thrown by the Bitmap object. Frankly speaking, this happened mainly because of my lack of knowledge about GdiPlusX. After reading some documentation, especially about the FromScreen() method I experimented a little bit. Capturing the visible area of _Screen actually was not the real problem but the dimensions I specified for the bitmap. The modifications - step by step First of all, it is to get rid of restrictive object references on Thisform and to change them into either This.Parent or more generic into This.oForm (even better: This.oControl). The Lightbox.Setup() method now sets the necessary object reference like so: *====================================================================* Initial setup* Default value: This.oControl = "This.Parent"* Alternative: This.oControl = "_Screen"*====================================================================With This .oControl = Evaluate(.oControl) If Vartype(.oControl) == T_OBJECT .Anchor = 0 .Left = 0 .Top = 0 .Width = .oControl.Width .Height = .oControl.Height .Anchor = 15 .ZOrder(0) .Visible = .F. EndIfEndwith Also, based on other developers' comments in Bernard articles on his lightbox concept and evolution I found the source code to handle the differences between a form and _Screen and goes into Lightbox.ShowLightbox() like this: *====================================================================* tlVisibility - show or hide (T/F)* grab a screen dump with controls*====================================================================Lparameters tlVisibility Local loControl m.loControl = This.oControl If m.tlVisibility Local loCaptureBmp As xfcBitmap Local lnTitleHeight, lnLeftBorder, lnTopBorder, lcImage, loImage lnTitleHeight = Iif(m.loControl.TitleBar = 1,Sysmetric(9),0) lnLeftBorder = Iif(m.loControl.BorderStyle < 2,0,Sysmetric(3)) lnTopBorder = Iif(m.loControl.BorderStyle < 2,0,Sysmetric(4)) With _Screen.System.Drawing If Upper(m.loControl.Name) == Upper("Screen") loCaptureBmp = .Bitmap.FromScreen(m.loControl.HWnd) Else loCaptureBmp = .Bitmap.FromScreen(m.loControl.HWnd,; lnLeftBorder,; lnTopBorder+lnTitleHeight,; m.loControl.Width ,; m.loControl.Height) EndIf Endwith * save it to a property This.CaptureBmp = loCaptureBmp m.loControl.SetAll("Visible",.F.) This.Draw() This.Visible = .T. Else This.CaptureBmp = .Null. m.loControl.SetAll("Visible",.T.) This.Visible = .F. Endif {loadposition content_adsense} Are we done? Almost... Although, Bernard says it clearly in his article: "Just drop the class on a form and call it as shown." It did not come clear to my mind in the first place with _Screen, but, yeah, he is right. Dropping the class on a form provides a permanent link between those two classes, it creates a valid This.Parent object reference. Bearing in mind that the lightbox class can not be "dropped" on the _Screen, we have to create the same type of binding during runtime execution like so: *====================================================================* Create global lightbox component*==================================================================== Local llOk, loException As Exception m.llOk = .F. m.loException = .Null. If Not Vartype(_Screen.Lightbox) == "O" Try _Screen.AddObject("Lightbox", "bbGdiLightbox") Catch To m.loException Assert .F. Message m.loException.Message EndTry EndIf m.llOk = (Vartype(_Screen.Lightbox) == "O")Return m.llOk Through runtime instantiation we create a valid binding to This.Parent in the lightbox object and the code works as expected with _Screen. Ease your life: Use properties instead of constants Having a closer look at the BeforeDraw() method might wet your appetite to simplify the code a little bit. Looking at the sample screenshots in Bernard's article you see several forms in different colors. This got me to modify the code like so: *====================================================================* Apply the actual lightbox effect on the captured bitmap.*====================================================================If Vartype(This.CaptureBmp) == T_OBJECT Local loGfx As xfcGraphics loGfx = This.oGfx With _Screen.System.Drawing loGfx.DrawImage(This.CaptureBmp,This.Rectangle,This.Rectangle,.GraphicsUnit.Pixel) * change the colours as needed here * possible colours are (220,128,0,0),(220,0,0,128) etc. loBrush = .SolidBrush.New(.Color.FromArgb( ; This.Opacity, .Color.FromRGB(This.BorderColor))) loGfx.FillRectangle(loBrush,This.Rectangle) EndwithEndif Create an additional property Opacity to specify the grade of translucency you would like to have without the need to change the code in each instance of the class. This way you only need to change the values of Opacity and BorderColor to tweak the appearance of your lightbox. This could be quite helpful to signalize different levels of importance (ie. green, yellow, orange, red, etc...) of notifications to the users of the application. Final thoughts Using the lightbox concept in combination with _Screen instead of forms is possible. Already Jim Wiggins comments in Bernard's article to loop through the _Screen.Forms collection in order to cascade the lightbox visibility to all active forms. Good idea. But honestly, I believe that instead of looping all forms one could use _Screen.SetAll("ShowLightbox", .T./.F., "Form") with Form.ShowLightbox_Access method to gain more speed. The modifications described above might provide even more features to your applications while consuming less resources and performance. Additionally, the restrictions to capture only forms does not exist anymore. Using _Screen you are able to capture and cover anything. The captured area of _Screen does not include any toolbars, docked windows, or menus. Therefore, it is advised to take this concept on a higher level and to combine it with additional classes that handle the state of toolbars, docked windows and menus. Which I did for the customer's project.

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  • Using SQL Execution Plans to discover the Swedish alphabet

    - by Rob Farley
    SQL Server is quite remarkable in a bunch of ways. In this post, I’m using the way that the Query Optimizer handles LIKE to keep it SARGable, the Execution Plans that result, Collations, and PowerShell to come up with the Swedish alphabet. SARGability is the ability to seek for items in an index according to a particular set of criteria. If you don’t have SARGability in play, you need to scan the whole index (or table if you don’t have an index). For example, I can find myself in the phonebook easily, because it’s sorted by LastName and I can find Farley in there by moving to the Fs, and so on. I can’t find everyone in my suburb easily, because the phonebook isn’t sorted that way. I can’t even find people who have six letters in their last name, because also the book is sorted by LastName, it’s not sorted by LEN(LastName). This is all stuff I’ve looked at before, including in the talk I gave at SQLBits in October 2010. If I try to find everyone who’s names start with F, I can do that using a query a bit like: SELECT LastName FROM dbo.PhoneBook WHERE LEFT(LastName,1) = 'F'; Unfortunately, the Query Optimizer doesn’t realise that all the entries that satisfy LEFT(LastName,1) = 'F' will be together, and it has to scan the whole table to find them. But if I write: SELECT LastName FROM dbo.PhoneBook WHERE LastName LIKE 'F%'; then SQL is smart enough to understand this, and performs an Index Seek instead. To see why, I look further into the plan, in particular, the properties of the Index Seek operator. The ToolTip shows me what I’m after: You’ll see that it does a Seek to find any entries that are at least F, but not yet G. There’s an extra Predicate in there (a Residual Predicate if you like), which checks that each LastName is really LIKE F% – I suppose it doesn’t consider that the Seek Predicate is quite enough – but most of the benefit is seen by its working out the Seek Predicate, filtering to just the “at least F but not yet G” section of the data. This got me curious though, particularly about where the G comes from, and whether I could leverage it to create the Swedish alphabet. I know that in the Swedish language, there are three extra letters that appear at the end of the alphabet. One of them is ä that appears in the word Västerås. It turns out that Västerås is quite hard to find in an index when you’re looking it up in a Swedish map. I talked about this briefly in my five-minute talk on Collation from SQLPASS (the one which was slightly less than serious). So by looking at the plan, I can work out what the next letter is in the alphabet of the collation used by the column. In other words, if my alphabet were Swedish, I’d be able to tell what the next letter after F is – just in case it’s not G. It turns out it is… Yes, the Swedish letter after F is G. But I worked this out by using a copy of my PhoneBook table that used the Finnish_Swedish_CI_AI collation. I couldn’t find how the Query Optimizer calculates the G, and my friend Paul White (@SQL_Kiwi) tells me that it’s frustratingly internal to the QO. He’s particularly smart, even if he is from New Zealand. To investigate further, I decided to do some PowerShell, leveraging the Get-SqlPlan function that I blogged about recently (make sure you also have the SqlServerCmdletSnapin100 snap-in added). I started by indicating that I was going to use Finnish_Swedish_CI_AI as my collation of choice, and that I’d start whichever letter cam straight after the number 9. I figure that this is a cheat’s way of guessing the first letter of the alphabet (but it doesn’t actually work in Unicode – luckily I’m using varchar not nvarchar. Actually, there are a few aspects of this code that only work using ASCII, so apologies if you were wanting to apply it to Greek, Japanese, etc). I also initialised my $alphabet variable. $collation = 'Finnish_Swedish_CI_AI'; $firstletter = '9'; $alphabet = ''; Now I created the table for my test. A single field would do, and putting a Clustered Index on it would suffice for the Seeks. Invoke-Sqlcmd -server . -data tempdb -query "create table dbo.collation_test (col varchar(10) collate $collation primary key);" Now I get into the looping. $c = $firstletter; $stillgoing = $true; while ($stillgoing) { I construct the query I want, seeking for entries which start with whatever $c has reached, and get the plan for it: $query = "select col from dbo.collation_test where col like '$($c)%';"; [xml] $pl = get-sqlplan $query "." "tempdb"; At this point, my $pl variable is a scary piece of XML, representing the execution plan. A bit of hunting through it showed me that the EndRange element contained what I was after, and that if it contained NULL, then I was done. $stillgoing = ($pl.ShowPlanXML.BatchSequence.Batch.Statements.StmtSimple.QueryPlan.RelOp.IndexScan.SeekPredicates.SeekPredicateNew.SeekKeys.EndRange -ne $null); Now I could grab the value out of it (which came with apostrophes that needed stripping), and append that to my $alphabet variable.   if ($stillgoing)   {  $c=$pl.ShowPlanXML.BatchSequence.Batch.Statements.StmtSimple.QueryPlan.RelOp.IndexScan.SeekPredicates.SeekPredicateNew.SeekKeys.EndRange.RangeExpressions.ScalarOperator.ScalarString.Replace("'","");     $alphabet += $c;   } Finally, finishing the loop, dropping the table, and showing my alphabet! } Invoke-Sqlcmd -server . -data tempdb -query "drop table dbo.collation_test;"; $alphabet; When I run all this, I see that the Swedish alphabet is ABCDEFGHIJKLMNOPQRSTUVXYZÅÄÖ, which matches what I see at Wikipedia. Interesting to see that the letters on the end are still there, even with Case Insensitivity. Turns out they’re not just “letters with accents”, they’re letters in their own right. I’m sure you gave up reading long ago, and really aren’t that fazed about the idea of doing this using PowerShell. I chose PowerShell because I’d already come up with an easy way of grabbing the estimated plan for a query, and PowerShell does allow for easy navigation of XML. I find the most interesting aspect of this as the fact that the Query Optimizer uses the next letter of the alphabet to maintain the SARGability of LIKE. I’m hoping they do something similar for a whole bunch of operations. Oh, and the fact that you know how to find stuff in the IKEA catalogue. Footnote: If you are interested in whether this works in other languages, you might want to consider the following screenshot, which shows that in principle, it should work with Japanese. It might be a bit harder to run this in PowerShell though, as I’m not sure how it translates. In Hiragana, the Japanese alphabet starts ?, ?, ?, ?, ?, ...

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  • Functions inside page using Razor View Engine – ASP.NET MVC

    - by hajan
    As we already know, Razor is probably the best view engine for ASP.NET MVC so far. It keeps your code fluid and very expressive. Besides the other functionalities Razor has, it also supports writing local functions. If you want to write a function, you can’t just open new @{ } razor block and write it there… it won’t work. Instead, you should specify @functions { } so that inside the brackets you will write your own C#/VB.NET functions/methods. Lets see an example: 1. I have the following loop that prints data using Razor <ul> @{     int N = 10;     for (int i = 1; i<=N; i++)     {         <li>Number @i</li>     }     } </ul> This code will print the numbers from 1 to 10: Number 1 Number 2 Number 3 Number 4 Number 5 Number 6 Number 7 Number 8 Number 9 Number 10 So, now lets write a function that will check if current number is even, if yes… add Even before Number word. Function in Razor @functions{     public bool isEven(int number)     {         return number % 2 == 0 ? true : false;     } } The modified code which creates unordered list is: <ul> @{     int N = 10;     for (int i = 1; i<=N; i++)     {         if (isEven(@i)) {             <li>Even number @i</li>         }         else {             <li>Number @i</li>         }                 }             } </ul> As you can see, in the modified code we use the isEven(@i) function to check if the current number is even or not… The result is: Number 1 Even number 2 Number 3 Even number 4 Number 5 Even number 6 Number 7 Even number 8 Number 9 Even number 10 So, the main point of this blog was to show how you can define your own functions inside page using Razor View Engine. Of course you can define multiple functions inside the same @functions { } defined razor statement. The complete code: @{     Layout = null; } <!DOCTYPE html> <html> <head>     <title>ASP.NET MVC - Razor View Engine :: Functions</title> </head> <body>     <div>         <ul>         @{             int N = 10;             for (int i = 1; i<=N; i++)             {                 if (isEven(@i)) {                     <li>Even number @i</li>                 }                 else {                     <li>Number @i</li>                 }                         }                     }         </ul>         @functions{             public bool isEven(int number)             {                 return number % 2 == 0 ? true : false;             }         }     </div> </body> </html> Hope you like it. Regards, Hajan

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  • Lessons from rewriting POP Forums for MVC, open source-like

    - by Jeff
    It has been a ton of work, interrupted over the last two years by unemployment, moving, a baby, failing to sell houses and other life events, but it's really exciting to see POP Forums v9 coming together. I'm not even sure when I decided to really commit to it as an open source project, but working on the same team as the CodePlex folks probably had something to do with it. Moving along the roadmap I set for myself, the app is now running on a quasi-production site... we launched MouseZoom last weekend. (That's a post-beta 1 build of the forum. There's also some nifty Silverlight DeepZoom goodness on that site.)I have to make a point to illustrate just how important starting over was for me. I started this forum thing for my sites in old ASP more than ten years ago. What a mess that stuff was, including SQL injection vulnerabilities and all kinds of crap. It went to ASP.NET in 2002, but even then, it felt a little too much like script. More than a year later, in 2003, I did an honest to goodness rewrite. If you've been in this business of writing code for any amount of time, you know how much you hate what you wrote a month ago, so just imagine that with seven years in between. The subsequent versions still carried a fair amount of crap, and that's why I had to start over, to make a clean break. Mind you, much of that crap is still running on some of my production sites in a stable manner, but it's a pain in the ass to maintain.So with that clean break, there is much that I have learned. These are a few of those lessons, in no particular order...Avoid shiny object syndromeOver the years, I've embraced new things without bothering to ask myself why. I remember spending the better part of a year trying to adapt this app to use the membership and profile API's in ASP.NET, just because they were there. They didn't solve any known problem. Early on in this version, I dabbled in exotic ORM's, even though I already had the fundamental SQL that I knew worked. I bloated up the client side code with all kinds of jQuery UI and plugins just because, and it got in the way. All the new shiny can be distracting, and I've come to realize that I've allowed it to be a distraction most of my professional life.Just query what you needI've spent a lot of time over-thinking how to query data. In the SQL world, this means exotic joins, special caches, the read-update-commit loop of ORM's, etc. There are times when you have to remind yourself that you aren't Facebook, you'll never be Facebook, and that databases are in fact intended to serve data. In a lot of projects, back in the day, I used to have these big, rich data objects and pass them all over the place, through various application tiers, when in reality, all I needed was some ID from the entity. I try to be mindful of how many queries hit the database on a given request, but I don't obsess over it. I just get what I need.Don't spend too much time worrying about your unit testsIf you've looked at any of the tests for POP Forums, you might offer an audible WTF. That's OK. There's a whole lot of mocking going on. In some cases, it points out where you're doing too much, and that's good for improving your design. In other cases it shows where your design sucks. But the biggest trap of unit testing is that you worry it should be prettier. That's a waste of time. When you write a test, in many cases before the production code, the important part is that you're testing the right thing. If you have to mock up a bunch of stuff to test the outcome, so be it, but it's not wasted time. You're still doing up the typical arrange-action-assert deal, and you'll be able to read that later if you need to.Get back to your HTTP rootsASP.NET Webforms did a reasonably decent job at abstracting us away from the stateless nature of the Web. A lot of people criticize it, but I think it all worked pretty well. These days, with MVC, jQuery, REST services, and what not, we've gone back to thinking about the wire. The nuts and bolts passing between our Web browser and server matters. This doesn't make things harder, in my opinion, it makes them easier. There is something incredibly freeing about how we approach development of Web apps now. HTTP is a really simple protocol, and the stuff we push through it, in particular HTML and JSON, are pretty simple too. The debugging points are really easy to trap and trace.Premature optimization is prematureI'll go back to the data thing for a moment. I've been known to look at a particular action or use case and stress about the number of calls that are made to the database. I'm not suggesting that it's a bad thing to keep these in mind, but if you worry about it outside of the context of the actual impact, you're wasting time. For example, I query the database for last read times in a forum separately of the user and the list of forums. The impact on performance barely exists. If I put it under load, exceeding the kind of load I expect, it still barely has an impact. Then consider it only counts for logged in users. The context of this "inefficient" action is that it doesn't matter. Did I mention I won't be Facebook?Solve your own problems firstThis is another trap I've fallen into. I've often thought about what other people might need for some feature or aspect of the app. In other words, I was willing to make design decisions based on non-existent data. How stupid is that? When I decided to truly open source this thing, building for myself first was a stated design goal. This app has to server the audiences of CoasterBuzz, MouseZoom and other sites first. In this development scenario, you don't have access to mountains of usability studies or user focus groups. You have to start with what you know.I'm sure there are other points I could make too. It has been a lot of fun to work on, and I look forward to evolving the UI as time goes on. That's where I hope to see more magic in the future.

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  • Stuck removing ffmpeg from system due to package problems

    - by Michiel
    I'd be very grateful to get a bit of support on the following situation: Using Ubuntu 12.04, and I used the PPA of Jon Severinson for ffmpeg. I had a problem playing movies with mplayer, so I decided to remove the PPA and try to use libav only after I read this article about libav vs ffmpeg. I first removed the PPA from the list, then apt-get update, etc. But I couldn't remove ffmpeg due to dependency-errors and got stuck in what seemed some kind of loop. Then I found a suggestion here. I followed the steps, and ended up force-removing libavcodec-extra-53. Because, apparently that was "what got stuff moving again". At the moment I can't. Now Ubuntu is reporting a broken package (BrokenCount 0). Errors: De afhankelijkheden van de volgende pakketten konden niet geïnstalleerd worden: audacious-plugins: Depends: audacious-plugins-data (= 3.2.1-4ubuntu1) maar 3.2.1-4ubuntu1 is geïnstalleerd Depends: libavcodec-extra-53 (= 4:0.8-1~) maar het is niet geïnstalleerd Depends: libavformat-extra-53 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libavutil-extra-51 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libcurl3-gnutls (= 7.16.2-1) maar 7.22.0-3ubuntu4 is geïnstalleerd Depends: libgcc1 (= 1:4.1.1) maar 1:4.6.3-1ubuntu5 is geïnstalleerd Depends: libpulse0 (= 1:0.99.1) maar 1:1.1-0ubuntu15.1 is geïnstalleerd Depends: libstdc++6 (= 4.6) maar 4.6.3-1ubuntu5 is geïnstalleerd Depends: libwavpack1 (= 4.40.0) maar 4.60.1-2 is geïnstalleerd Depends: libxcomposite1 (= 1:0.3-1) maar 1:0.4.3-2build1 is geïnstalleerd Depends: zlib1g (= 1:1.1.4) maar 1:1.2.3.4.dfsg-3ubuntu4 is geïnstalleerd libavfilter-extra-2: Depends: libavcodec-extra-53 (= 6:0.10.4.0ubuntu0jon2.2) maar het is niet geïnstalleerd Depends: libavcodec-extra-53 (< 6:0.10.4.0ubuntu0jon2.2-99) maar het is niet geïnstalleerd Depends: libavformat-extra-53 (= 6:0.10.4.0ubuntu0jon2.2) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libavutil-extra-51 (= 6:0.10.4.0ubuntu0jon2.2) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libswresample-extra-0 (= 6:0.10.4.0ubuntu0jon2.2) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libswscale-extra-2 (= 6:0.10.4.0ubuntu0jon2.2) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd libavformat-extra-53: Depends: libavcodec-extra-53 (= 6:0.10.4.0ubuntu0jon2.2) maar het is niet geïnstalleerd Depends: libavcodec-extra-53 (< 6:0.10.4.0ubuntu0jon2.2-99) maar het is niet geïnstalleerd Depends: libavutil-extra-51 (= 6:0.10.4.0ubuntu0jon2.2) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd libk3b6-extracodecs: Depends: libavcodec-extra-53 (= 4:0.8-1~) maar het is niet geïnstalleerd Depends: libavformat-extra-53 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libavutil-extra-51 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libc6 (= 2.14) maar 2.15-0ubuntu10 is geïnstalleerd Depends: libkdecore5 (= 4:4.4.4) maar 4:4.8.4a-0ubuntu0.2 is geïnstalleerd Depends: libkio5 (= 4:4.4.4) maar 4:4.8.4a-0ubuntu0.2 is geïnstalleerd Depends: libqtcore4 (= 4:4.7.0~beta1) maar 4:4.8.1-0ubuntu4.2 is geïnstalleerd Depends: libstdc++6 (= 4.1.1) maar 4.6.3-1ubuntu5 is geïnstalleerd libquicktime2: Depends: libavcodec-extra-53 (= 4:0.8~beta2-2) maar het is niet geïnstalleerd Depends: libswscale-extra-2 (= 4:0.8~beta2-2) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd libxine1-ffmpeg: Depends: libavcodec-extra-53 (= 4:0.7.3-1) maar het is niet geïnstalleerd Depends: libavutil-extra-51 (= 4:0.7.3-1) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libc6 (= 2.4) maar 2.15-0ubuntu10 is geïnstalleerd Depends: libpostproc-extra-52 (= 4:0.7.3-1) maar het is niet geïnstalleerd Depends: libxine1-bin (= 1.1.20-2build1) maar 1.1.20-2build1 is geïnstalleerd mencoder: Depends: libavcodec-extra-53 (= 4:0.8-1~) maar het is niet geïnstalleerd Depends: libavformat-extra-53 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libavutil-extra-51 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libpostproc-extra-52 (= 4:0.8-1~) maar het is niet geïnstalleerd Depends: libswscale-extra-2 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd mplayer: Depends: libavcodec-extra-53 (= 4:0.8-1~) maar het is niet geïnstalleerd Depends: libavformat-extra-53 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libavutil-extra-51 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libpostproc-extra-52 (= 4:0.8-1~) maar het is niet geïnstalleerd Depends: libswscale-extra-2 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd vlc: Depends: vlc-nox (= 2.0.3-0ubuntu0.12.04.1) maar 2.0.3-0ubuntu0.12.04.1 is geïnstalleerd Depends: libavcodec-extra-53 (= 4:0.8-1~) maar het is niet geïnstalleerd Depends: libavutil-extra-51 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libc6 (= 2.15) maar 2.15-0ubuntu10 is geïnstalleerd Depends: libfreetype6 (= 2.2.1) maar 2.4.8-1ubuntu2 is geïnstalleerd Depends: libgcc1 (= 1:4.1.1) maar 1:4.6.3-1ubuntu5 is geïnstalleerd Depends: libqtcore4 (= 4:4.8.0) maar 4:4.8.1-0ubuntu4.2 is geïnstalleerd Depends: libqtgui4 (= 4:4.7.0~beta1) maar 4:4.8.1-0ubuntu4.2 is geïnstalleerd Depends: libstdc++6 (= 4.6) maar 4.6.3-1ubuntu5 is geïnstalleerd Depends: zlib1g (= 1:1.2.3.3.dfsg) maar 1:1.2.3.4.dfsg-3ubuntu4 is geïnstalleerd vlc-nox: Depends: libavcodec-extra-53 (= 4:0.8-1~) maar het is niet geïnstalleerd Depends: libavformat-extra-53 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libavutil-extra-51 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libc6 (= 2.15) maar 2.15-0ubuntu10 is geïnstalleerd Depends: libfontconfig1 (= 2.8.0) maar 2.8.0-3ubuntu9.1 is geïnstalleerd Depends: libfreetype6 (= 2.2.1) maar 2.4.8-1ubuntu2 is geïnstalleerd Depends: libgcc1 (= 1:4.1.1) maar 1:4.6.3-1ubuntu5 is geïnstalleerd Depends: libgnutls26 (= 2.12.6.1-0) maar 2.12.14-5ubuntu3.1 is geïnstalleerd Depends: libmpcdec6 (= 1:0.1~r435) maar 2:0.1~r459-1ubuntu1 is geïnstalleerd Depends: libncursesw5 (= 5.6+20070908) maar 5.9-4 is geïnstalleerd Depends: libpostproc-extra-52 (= 4:0.8-1~) maar het is niet geïnstalleerd Depends: libsmbclient (= 3.0.24) maar 2:3.6.3-2ubuntu2.3 is geïnstalleerd Depends: libstdc++6 (= 4.6) maar 4.6.3-1ubuntu5 is geïnstalleerd Depends: libswscale-extra-2 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libudev0 (= 147) maar 175-0ubuntu9.1 is geïnstalleerd Depends: libxml2 (= 2.7.4) maar 2.7.8.dfsg-5.1ubuntu4.1 is geïnstalleerd Depends: zlib1g (= 1:1.2.0.2) maar 1:1.2.3.4.dfsg-3ubuntu4 is geïnstalleerd xbmc-bin: Depends: libavcodec-extra-53 (= 4:0.8-1~) maar het is niet geïnstalleerd Depends: libavfilter-extra-2 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libavformat-extra-53 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libavutil-extra-51 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd Depends: libpostproc-extra-52 (= 4:0.8-1~) maar het is niet geïnstalleerd Depends: libswscale-extra-2 (= 4:0.8-1~) maar 6:0.10.4.0ubuntu0jon2.2 is geïnstalleerd And apt-get is reporting: root@LAPTOP:~# apt-get -f install Pakketlijsten worden ingelezen... Klaar Boom van vereisten wordt opgebouwd De status informatie wordt gelezen... Klaar Vereisten worden gecorrigeerd... mislukt. De volgende pakketten hebben niet-voldane vereisten: audacious-plugins : Vereisten: libavcodec53 (= 4:0.8-1~) maar het is niet geïnstalleerd of libavcodec-extra-53 (= 4:0.8-1~) maar het is niet geïnstalleerd libavfilter-extra-2 : Vereisten: libavcodec-extra-53 (= 6:0.10.4.0ubuntu0jon2.2) maar het is niet geïnstalleerd Vereisten: libavcodec-extra-53 (< 6:0.10.4.0ubuntu0jon2.2-99) maar het is niet geïnstalleerd libavformat-extra-53 : Vereisten: libavcodec-extra-53 (= 6:0.10.4.0ubuntu0jon2.2) maar het is niet geïnstalleerd Vereisten: libavcodec-extra-53 (< 6:0.10.4.0ubuntu0jon2.2-99) maar het is niet geïnstalleerd libk3b6-extracodecs : Vereisten: libavcodec53 (= 4:0.8-1~) maar het is niet geïnstalleerd of libavcodec-extra-53 (= 4:0.8-1~) maar het is niet geïnstalleerd libquicktime2 : Vereisten: libavcodec53 (= 4:0.8~beta2-2) maar het is niet geïnstalleerd of libavcodec-extra-53 (= 4:0.8~beta2-2) maar het is niet geïnstalleerd libxine1-ffmpeg : Vereisten: libavcodec53 (= 4:0.7.3-1) maar het is niet geïnstalleerd of libavcodec-extra-53 (= 4:0.7.3-1) maar het is niet geïnstalleerd mencoder : Vereisten: libavcodec53 (= 4:0.8-1~) maar het is niet geïnstalleerd of libavcodec-extra-53 (= 4:0.8-1~) maar het is niet geïnstalleerd mplayer : Vereisten: libavcodec53 (= 4:0.8-1~) maar het is niet geïnstalleerd of libavcodec-extra-53 (= 4:0.8-1~) maar het is niet geïnstalleerd vlc : Vereisten: libavcodec53 (= 4:0.8-1~) maar het is niet geïnstalleerd of libavcodec-extra-53 (= 4:0.8-1~) maar het is niet geïnstalleerd vlc-nox : Vereisten: libavcodec53 (= 4:0.8-1~) maar het is niet geïnstalleerd of libavcodec-extra-53 (= 4:0.8-1~) maar het is niet geïnstalleerd xbmc-bin : Vereisten: libavcodec53 (= 4:0.8-1~) maar het is niet geïnstalleerd of libavcodec-extra-53 (= 4:0.8-1~) maar het is niet geïnstalleerd E: Fout, pkgProblemResolver::Resolve maakte scheidingen aan, dit kan veroorzaakt worden door vastgehouden pakketten. E: Kan vereisten niet corrigeren How to proceed?? Thanks in advance, Michiel

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  • How to use Azure storage for uploading and displaying pictures.

    - by Magnus Karlsson
    Basic set up of Azure storage for local development and production. This is a somewhat completion of the following guide from http://www.windowsazure.com/en-us/develop/net/how-to-guides/blob-storage/ that also involves a practical example that I believe is commonly used, i.e. upload and present an image from a user.   First we set up for local storage and then we configure for them to work on a web role. Steps: 1. Configure connection string locally. 2. Configure model, controllers and razor views.   1. Setup connectionsstring 1.1 Right click your web role and choose “Properties”. 1.2 Click Settings. 1.3 Add setting. 1.4 Name your setting. This will be the name of the connectionstring. 1.5 Click the ellipsis to the right. (the ellipsis appear when you mark the area. 1.6 The following window appears- Select “Windows Azure storage emulator” and click ok.   Now we have a connection string to use. To be able to use it we need to make sure we have windows azure tools for storage. 2.1 Click Tools –> Library Package manager –> Manage Nuget packages for solution. 2.2 This is what it looks like after it has been added.   Now on to what the code should look like. 3.1 First we need a view which collects images to upload. Here Index.cshtml. 1: @model List<string> 2:  3: @{ 4: ViewBag.Title = "Index"; 5: } 6:  7: <h2>Index</h2> 8: <form action="@Url.Action("Upload")" method="post" enctype="multipart/form-data"> 9:  10: <label for="file">Filename:</label> 11: <input type="file" name="file" id="file1" /> 12: <br /> 13: <label for="file">Filename:</label> 14: <input type="file" name="file" id="file2" /> 15: <br /> 16: <label for="file">Filename:</label> 17: <input type="file" name="file" id="file3" /> 18: <br /> 19: <label for="file">Filename:</label> 20: <input type="file" name="file" id="file4" /> 21: <br /> 22: <input type="submit" value="Submit" /> 23: 24: </form> 25:  26: @foreach (var item in Model) { 27:  28: <img src="@item" alt="Alternate text"/> 29: } 3.2 We need a controller to receive the post. Notice the “containername” string I send to the blobhandler. I use this as a folder for the pictures for each user. If this is not a requirement you could just call it container or anything with small characters directly when creating the container. 1: public ActionResult Upload(IEnumerable<HttpPostedFileBase> file) 2: { 3: BlobHandler bh = new BlobHandler("containername"); 4: bh.Upload(file); 5: var blobUris=bh.GetBlobs(); 6: 7: return RedirectToAction("Index",blobUris); 8: } 3.3 The handler model. I’ll let the comments speak for themselves. 1: public class BlobHandler 2: { 3: // Retrieve storage account from connection string. 4: CloudStorageAccount storageAccount = CloudStorageAccount.Parse( 5: CloudConfigurationManager.GetSetting("StorageConnectionString")); 6: 7: private string imageDirecoryUrl; 8: 9: /// <summary> 10: /// Receives the users Id for where the pictures are and creates 11: /// a blob storage with that name if it does not exist. 12: /// </summary> 13: /// <param name="imageDirecoryUrl"></param> 14: public BlobHandler(string imageDirecoryUrl) 15: { 16: this.imageDirecoryUrl = imageDirecoryUrl; 17: // Create the blob client. 18: CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient(); 19: 20: // Retrieve a reference to a container. 21: CloudBlobContainer container = blobClient.GetContainerReference(imageDirecoryUrl); 22: 23: // Create the container if it doesn't already exist. 24: container.CreateIfNotExists(); 25: 26: //Make available to everyone 27: container.SetPermissions( 28: new BlobContainerPermissions 29: { 30: PublicAccess = BlobContainerPublicAccessType.Blob 31: }); 32: } 33: 34: public void Upload(IEnumerable<HttpPostedFileBase> file) 35: { 36: // Create the blob client. 37: CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient(); 38: 39: // Retrieve a reference to a container. 40: CloudBlobContainer container = blobClient.GetContainerReference(imageDirecoryUrl); 41: 42: if (file != null) 43: { 44: foreach (var f in file) 45: { 46: if (f != null) 47: { 48: CloudBlockBlob blockBlob = container.GetBlockBlobReference(f.FileName); 49: blockBlob.UploadFromStream(f.InputStream); 50: } 51: } 52: } 53: } 54: 55: public List<string> GetBlobs() 56: { 57: // Create the blob client. 58: CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient(); 59: 60: // Retrieve reference to a previously created container. 61: CloudBlobContainer container = blobClient.GetContainerReference(imageDirecoryUrl); 62: 63: List<string> blobs = new List<string>(); 64: 65: // Loop over blobs within the container and output the URI to each of them 66: foreach (var blobItem in container.ListBlobs()) 67: blobs.Add(blobItem.Uri.ToString()); 68: 69: return blobs; 70: } 71: } 3.4 So, when the files have been uploaded we will get them to present them to out user in the index page. Pretty straight forward. In this example we only present the image by sending the Uri’s to the view. A better way would be to save them up in a view model containing URI, metadata, alternate text, and other relevant information but for this example this is all we need.   4. Now press F5 in your solution to try it out. You can see the storage emulator UI here:     4.1 If you get any exceptions or errors I suggest to first check if the service Is running correctly. I had problem with this and they seemed related to the installation and a reboot fixed my problems.     5. Set up for Cloud storage. To do this we need to add configuration for cloud just as we did for local in step one. 5.1 We need our keys to do this. Go to the windows Azure menagement portal, select storage icon to the right and click “Manage keys”. (Image from a different blog post though).   5.2 Do as in step 1.but replace step 1.6 with: 1.6 Choose “Manually entered credentials”. Enter your account name. 1.7 Paste your Account Key from step 5.1. and click ok.   5.3. Save, publish and run! Please feel free to ask any questions using the comments form at the bottom of this page. I will get back to you to help you solve any questions. Our consultancy agency also provides services in the Nordic regions if you would like any further support.

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  • Movement prediction for non-shooters

    - by ShadowChaser
    I'm working on an isometric 2D game with moderate-scale multiplayer, approximately 20-30 players connected at once to a persistent server. I've had some difficulty getting a good movement prediction implementation in place. Physics/Movement The game doesn't have a true physics implementation, but uses the basic principles to implement movement. Rather than continually polling input, state changes (ie/ mouse down/up/move events) are used to change the state of the character entity the player is controlling. The player's direction (ie/ north-east) is combined with a constant speed and turned into a true 3D vector - the entity's velocity. In the main game loop, "Update" is called before "Draw". The update logic triggers a "physics update task" that tracks all entities with a non-zero velocity uses very basic integration to change the entities position. For example: entity.Position += entity.Velocity.Scale(ElapsedTime.Seconds) (where "Seconds" is a floating point value, but the same approach would work for millisecond integer values). The key point is that no interpolation is used for movement - the rudimentary physics engine has no concept of a "previous state" or "current state", only a position and velocity. State Change and Update Packets When the velocity of the character entity the player is controlling changes, a "move avatar" packet is sent to the server containing the entity's action type (stand, walk, run), direction (north-east), and current position. This is different from how 3D first person games work. In a 3D game the velocity (direction) can change frame to frame as the player moves around. Sending every state change would effectively transmit a packet per frame, which would be too expensive. Instead, 3D games seem to ignore state changes and send "state update" packets on a fixed interval - say, every 80-150ms. Since speed and direction updates occur much less frequently in my game, I can get away with sending every state change. Although all of the physics simulations occur at the same speed and are deterministic, latency is still an issue. For that reason, I send out routine position update packets (similar to a 3D game) but much less frequently - right now every 250ms, but I suspect with good prediction I can easily boost it towards 500ms. The biggest problem is that I've now deviated from the norm - all other documentation, guides, and samples online send routine updates and interpolate between the two states. It seems incompatible with my architecture, and I need to come up with a better movement prediction algorithm that is closer to a (very basic) "networked physics" architecture. The server then receives the packet and determines the players speed from it's movement type based on a script (Is the player able to run? Get the player's running speed). Once it has the speed, it combines it with the direction to get a vector - the entity's velocity. Some cheat detection and basic validation occurs, and the entity on the server side is updated with the current velocity, direction, and position. Basic throttling is also performed to prevent players from flooding the server with movement requests. After updating its own entity, the server broadcasts an "avatar position update" packet to all other players within range. The position update packet is used to update the client side physics simulations (world state) of the remote clients and perform prediction and lag compensation. Prediction and Lag Compensation As mentioned above, clients are authoritative for their own position. Except in cases of cheating or anomalies, the client's avatar will never be repositioned by the server. No extrapolation ("move now and correct later") is required for the client's avatar - what the player sees is correct. However, some sort of extrapolation or interpolation is required for all remote entities that are moving. Some sort of prediction and/or lag-compensation is clearly required within the client's local simulation / physics engine. Problems I've been struggling with various algorithms, and have a number of questions and problems: Should I be extrapolating, interpolating, or both? My "gut feeling" is that I should be using pure extrapolation based on velocity. State change is received by the client, client computes a "predicted" velocity that compensates for lag, and the regular physics system does the rest. However, it feels at odds to all other sample code and articles - they all seem to store a number of states and perform interpolation without a physics engine. When a packet arrives, I've tried interpolating the packet's position with the packet's velocity over a fixed time period (say, 200ms). I then take the difference between the interpolated position and the current "error" position to compute a new vector and place that on the entity instead of the velocity that was sent. However, the assumption is that another packet will arrive in that time interval, and it's incredibly difficult to "guess" when the next packet will arrive - especially since they don't all arrive on fixed intervals (ie/ state changes as well). Is the concept fundamentally flawed, or is it correct but needs some fixes / adjustments? What happens when a remote player stops? I can immediately stop the entity, but it will be positioned in the "wrong" spot until it moves again. If I estimate a vector or try to interpolate, I have an issue because I don't store the previous state - the physics engine has no way to say "you need to stop after you reach position X". It simply understands a velocity, nothing more complex. I'm reluctant to add the "packet movement state" information to the entities or physics engine, since it violates basic design principles and bleeds network code across the rest of the game engine. What should happen when entities collide? There are three scenarios - the controlling player collides locally, two entities collide on the server during a position update, or a remote entity update collides on the local client. In all cases I'm uncertain how to handle the collision - aside from cheating, both states are "correct" but at different time periods. In the case of a remote entity it doesn't make sense to draw it walking through a wall, so I perform collision detection on the local client and cause it to "stop". Based on point #2 above, I might compute a "corrected vector" that continually tries to move the entity "through the wall" which will never succeed - the remote avatar is stuck there until the error gets too high and it "snaps" into position. How do games work around this?

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  • XNA: Rotating Bones

    - by MLM
    XNA 4.0 I am trying to learn how to rotate bones on a very simple tank model I made in Cinema 4D. It is rigged by 3 bones, Root - Main - Turret - Barrel I have binded all of the objects to the bones so that all translations/rotations work as planned in C4D. I exported it as .fbx I based my test project after: http://create.msdn.com/en-US/education/catalog/sample/simple_animation I can build successfully with no errors but all the rotations I try to do to my bones have no effect. I can transform my Root successfully using below but the bone transforms have no effect: myModel.Root.Transform = world; Matrix turretRotation = Matrix.CreateRotationY(MathHelper.ToRadians(37)); Matrix barrelRotation = Matrix.CreateRotationX(barrelRotationValue); MainBone.Transform = MainTransform; TurretBone.Transform = turretRotation * TurretTransform; BarrelBone.Transform = barrelRotation * BarrelTransform; I am wondering if my model is just not right or something important I am missing in the code. Here is my Game1.cs using System; using System.Collections.Generic; using System.Linq; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Audio; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.GamerServices; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Input; using Microsoft.Xna.Framework.Media; namespace ModelTesting { /// <summary> /// This is the main type for your game /// </summary> public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; SpriteBatch spriteBatch; float aspectRatio; Tank myModel; public Game1() { graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; } /// <summary> /// Allows the game to perform any initialization it needs to before starting to run. /// This is where it can query for any required services and load any non-graphic /// related content. Calling base.Initialize will enumerate through any components /// and initialize them as well. /// </summary> protected override void Initialize() { // TODO: Add your initialization logic here myModel = new Tank(); base.Initialize(); } /// <summary> /// LoadContent will be called once per game and is the place to load /// all of your content. /// </summary> protected override void LoadContent() { // Create a new SpriteBatch, which can be used to draw textures. spriteBatch = new SpriteBatch(GraphicsDevice); // TODO: use this.Content to load your game content here myModel.Load(Content); aspectRatio = graphics.GraphicsDevice.Viewport.AspectRatio; } /// <summary> /// UnloadContent will be called once per game and is the place to unload /// all content. /// </summary> protected override void UnloadContent() { // TODO: Unload any non ContentManager content here } /// <summary> /// Allows the game to run logic such as updating the world, /// checking for collisions, gathering input, and playing audio. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> protected override void Update(GameTime gameTime) { // Allows the game to exit if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed) this.Exit(); // TODO: Add your update logic here float time = (float)gameTime.TotalGameTime.TotalSeconds; // Move the pieces /* myModel.TurretRotation = (float)Math.Sin(time * 0.333f) * 1.25f; myModel.BarrelRotation = (float)Math.Sin(time * 0.25f) * 0.333f - 0.333f; */ base.Update(gameTime); } /// <summary> /// This is called when the game should draw itself. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue); // Calculate the camera matrices. float time = (float)gameTime.TotalGameTime.TotalSeconds; Matrix rotation = Matrix.CreateRotationY(MathHelper.ToRadians(45)); Matrix view = Matrix.CreateLookAt(new Vector3(2000, 500, 0), new Vector3(0, 150, 0), Vector3.Up); Matrix projection = Matrix.CreatePerspectiveFieldOfView(MathHelper.PiOver4, graphics.GraphicsDevice.Viewport.AspectRatio, 10, 10000); // TODO: Add your drawing code here myModel.Draw(rotation, view, projection); base.Draw(gameTime); } } } And here is my tank class: using System; using System.Collections.Generic; using System.Linq; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Audio; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.GamerServices; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Input; using Microsoft.Xna.Framework.Media; namespace ModelTesting { public class Tank { Model myModel; // Array holding all the bone transform matrices for the entire model. // We could just allocate this locally inside the Draw method, but it // is more efficient to reuse a single array, as this avoids creating // unnecessary garbage. public Matrix[] boneTransforms; // Shortcut references to the bones that we are going to animate. // We could just look these up inside the Draw method, but it is more // efficient to do the lookups while loading and cache the results. ModelBone MainBone; ModelBone TurretBone; ModelBone BarrelBone; // Store the original transform matrix for each animating bone. Matrix MainTransform; Matrix TurretTransform; Matrix BarrelTransform; // current animation positions float turretRotationValue; float barrelRotationValue; /// <summary> /// Gets or sets the turret rotation amount. /// </summary> public float TurretRotation { get { return turretRotationValue; } set { turretRotationValue = value; } } /// <summary> /// Gets or sets the barrel rotation amount. /// </summary> public float BarrelRotation { get { return barrelRotationValue; } set { barrelRotationValue = value; } } /// <summary> /// Load the model /// </summary> public void Load(ContentManager Content) { // TODO: use this.Content to load your game content here myModel = Content.Load<Model>("Models\\simple_tank02"); MainBone = myModel.Bones["Main"]; TurretBone = myModel.Bones["Turret"]; BarrelBone = myModel.Bones["Barrel"]; MainTransform = MainBone.Transform; TurretTransform = TurretBone.Transform; BarrelTransform = BarrelBone.Transform; // Allocate the transform matrix array. boneTransforms = new Matrix[myModel.Bones.Count]; } public void Draw(Matrix world, Matrix view, Matrix projection) { myModel.Root.Transform = world; Matrix turretRotation = Matrix.CreateRotationY(MathHelper.ToRadians(37)); Matrix barrelRotation = Matrix.CreateRotationX(barrelRotationValue); MainBone.Transform = MainTransform; TurretBone.Transform = turretRotation * TurretTransform; BarrelBone.Transform = barrelRotation * BarrelTransform; myModel.CopyAbsoluteBoneTransformsTo(boneTransforms); // Draw the model, a model can have multiple meshes, so loop foreach (ModelMesh mesh in myModel.Meshes) { // This is where the mesh orientation is set foreach (BasicEffect effect in mesh.Effects) { effect.World = boneTransforms[mesh.ParentBone.Index]; effect.View = view; effect.Projection = projection; effect.EnableDefaultLighting(); } // Draw the mesh, will use the effects set above mesh.Draw(); } } } }

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