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  • Which program is locking all my executable files?

    - by Tom Wijsman
    When updating any software product, as well as manually trying to replace .exe files, it says that access is denied to the file and in fact the System process is holding a handle to the file when I check it with Process Explorer. This must be a driver or something that is malfunctioning was my first though, but now I wonder how I figure out which driver / program is doing this and why it is so. Unlocker doesn't seem to be working for me, unless someone can tell me how to use it properly other than making it appear a magical wand in the notification area.... This is what Unlocker puts in my event log: The description for Event ID 1060 from source Application Popup cannot be found. Either the component that raises this event is not installed on your local computer or the installation is corrupted. You can install or repair the component on the local computer. If the event originated on another computer, the display information had to be saved with the event. The following information was included with the event: \??\C:\Program Files (x86)\Unlocker\UnlockerDriver5.sys the message resource is present but the message is not found in the string/message table Upon searching event 1060 I get: <file name> has been blocked from loading due to incompatibility with this system. Perhaps it is because I have 64 bit?

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  • Uninstall Glassfish and metro completely

    - by user775829
    I thought of updating my Glassfish server from 2.1 to 3.1.1 in a Linux machine. I downloaded the .ZIP package. However during uninstalling of Glassfish v2.1 I did not find the uninstall.sh file in "bin" directory. Following are a few steps which I did... I removed the glassfish folder (rm -rf ...) After removing files in the end it gave me a notification that it could not remove 2 files used by Metro. I cant recollect those file names, but I manually deleted that folder. I made a mistake by first not uninstalling Metro. I uninstalled metro completely after that. but it seemed pointless (it uninstalled successfully :P ) I transfered the Glassfish 3.1.1 ZIP file and unzipped and configured it. FOllow are a few Problems I am facing I cannot deploy any of my WAR file. Its giving errors saying " Error creating bean,Instantiation of bean failed etc etc." (However the WAR file is getting deployed successfully in other Linux Machine) When I try installing Metro v2.1 separately, it does not show the admin console or it timesout while starting the domain. The Log File of the Domain says it has started the domain successfully and the process is also created. But after running the command (asadmin) it takes like forever and times out without showing Domain Started Successfully, There is no uninstall.sh in Glassfishv3.1.1 bin directory. How do I completely uninstall Glassfish v 3.1.1 and Metro 2.1 ??? What are the files which I will have to manually remove?

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  • VNC Server that can be used from command line?

    - by jesusiniesta
    I'm looking for a replacement for a custom vnc server that we have been using in my company for a long time. I need a simple executable that can be run from command line by an IT Support software without the user noticing it (our application will warn the user, we don't want him to see we are using that VNC sever). I need it to support Windows and preferably also OSX. The only option I've found is UltraVNC, but I can't configure it from command line to accept loopback connections without authentication. We have already a whole VNC Viewer + VNC Repeater + Bouncers architecture, and the only missing piece is the VNC Server. Do you know any solution you could suggest me? I'm afraid I'll end up developing a new VNC server myself, may be based on an open source one. EDIT: When I said I don't want the user to notice this VNC server, I should have added that I don't want him even noticing the installation. So better if it can be installed silently or can be executed as a portable executalbe (for instance, ultravnc can be installed and ran as a service from command line, or simply executed quietly, with only a notification icon; its problem is that I can't run it without authentication).

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  • Software for RAID Failure Alerts?

    - by QF_Developer
    I have two 256 GB Samsung 840 Pro SSD disks in a RAID 1 array. I would like to receive a notification if one of the disks in the array fails. Can anybody recommend an application I can install on the server to fire an email if such an event occurs? Here are some additional specs: Supermicro X9SCM-IIF motherboard utilising the hardware RAID controller. OS = Windows 2012 Standard Also is it possible to simulate a disk failure by pulling it out of the bay? SSDs appear to fail close together when in a mirrored config so I'd like to know ASAP if one goes down so I can swap them out with minimum delay. UPDATE 26th June 2013 ------------------------ None of the software that ships with the Supermicro X9SCM-* motherboards offer support for RAID monitoring. As has been pointed out here, these boards are built on an Intel chipset for RAID and so I installed Intel Rapid Storage Technology that supports automated email notifications on RAID failure http://www.intel.com/support/chipsets/imsm/sb/cs-020784.htm One small issue, the software only allows you to send email notifications without SMTP authentication. There's a bunch of different workarounds here: http://communities.intel.com/thread/30771

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  • Server 2008 R2 boot is at 2 hours and counting. What now?

    - by Jesse
    This morning, we rebooted our Server 2008 R2 box. No problem, came right back up. Then we shut it down and let it install windows updates. While it was off, we added some RAM. Then we turned it back on. The system came right back up to the "press ctrl-alt-delete" screen, so far, so good. I logged in. The system got as far as "Applying Group Policy" -- then spent almost an hour applying drive mappings. Finally finished that, and has now spent 30 minutes on waiting for the Event Notification Service. I still haven't been able to log in. Remote desktop service doesn't appear to be running yet. I tried viewing the event log from another machine. I see that the box is writing to the Security log, but there are no events in System or Application in the last 45 minutes. Digging through the System log of events from 45 minutes ago, I see a bunch of timeouts: A timeout (30000 milliseconds) was reached while waiting for a transaction response from the ShellHWDetection service. [lots of these] A timeout (30000 milliseconds) was reached while waiting for a transaction response from the wuauserv service. A timeout (30000 milliseconds) was reached while waiting for a transaction response from the SessionEnv service. A timeout (30000 milliseconds) was reached while waiting for a transaction response from the Schedule service. A timeout (30000 milliseconds) was reached while waiting for a transaction response from the CertPropSvc service. What can I do? Should I try shutting it down remotely, or will that do more damage?

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  • How does KMS (Windows Server 2008 R2) differentiate clients?

    - by Joe Taylor
    I have recently installed a KMS Server in our domain and deployed 75 new Windows 7 machines using an image I made using Acronis True Image. There are 2 variations of this image rolled out currently. When I go to activate the machines it returns that the KMS count is not sufficient. On the server with a slmgr /dlv it shows: Key Management Service is enabled on this machine. Current count: 2 Listening on Port: 1688 DNS publishing enabled KMS Priority: Normal KMS cumulative requests received from clients: 366 Failed requests received: 2 Requests with License status unlicensed: 0 Requests with License status licensed: 0 Requests with License status Initial Grace period: 1 Requests with License statusLicense expired or hardware out of tolerance: 0 Requests with License status Non genuine grace period: 0 Requests with License status Notification: 363 Is it to do with the fact that I've used the same image for all the PC's? If so how do I get round this. Would changing the SID help? OK knowing I've been thick whats the best way to rectify the situation. Can I sysprep the machines to OOBE on each individual machine? Or would NewSID work?

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  • What is a good replacement for StumbleUpon's Share feature?

    - by Mofoo
    I've been using Firefox + StumbleUpon's Share feature with my friends for years now. It is a perfect way of sharing links directly with your friends. You first need to be Following each other and then on the SU toolbar, you can "Share" with your list of friends. You can even include a personal message. The friend will receive a notification with # of pending shares in their toolbar (bold & red). They click the stumble button and it will navigate to the site plus show a yellow bar with your message. I literally use it daily. But then Chrome came along and beat the tar out of Firefox (and other browsers) in terms of usability and performance. But it doesn't (and never will according to Google) allow toolbars. StumbleUpon's solution in Chrome is a fake toolbar (html) that gets injected into the page you're viewing. It's buggy and performance is low. Overall it's not an acceptable solution. I'm looking for a replacement with something that is just as easy to send/receive links. I was thinking of Twitter DM's and using a bookmarklet, but I wanted to survey the collective for other options Thanks in advance for your input!

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  • how do you make a "concurrent queue safe" lazy loader (singleton manager) in objective-c

    - by Rich
    Hi, I made this class that turns any object into a singleton, but I know that it's not "concurrent queue safe." Could someone please explain to me how to do this, or better yet, show me the code. To be clear I want to know how to use this with operation queues and dispatch queues (NSOperationQueue and Grand Central Dispatch) on iOS. Thanks in advance, Rich EDIT: I had an idea for how to do it. If someone could confirm it for me I'll do it and post the code. The idea is that proxies make queues all on their own. So if I make a mutable proxy (like Apple does in key-value coding/observing) for any object that it's supposed to return, and always return the same proxy for the same object/identifier pair (using the same kind of lazy loading technique as I used to create the singletons), the proxies would automatically queue up the any messages to the singletons, and make it totally thread safe. IMHO this seems like a lot of work to do, so I don't want to do it if it's not gonna work, or if it's gonna slow my apps down to a crawl. Here's my non-thread safe code: RMSingletonCollector.h // // RMSingletonCollector.h // RMSingletonCollector // // Created by Rich Meade-Miller on 2/11/11. // Copyright 2011 Rich Meade-Miller. All rights reserved. // #import <Foundation/Foundation.h> #import "RMWeakObjectRef.h" struct RMInitializerData { // The method may take one argument. // required SEL designatedInitializer; // data to pass to the initializer or nil. id data; }; typedef struct RMInitializerData RMInitializerData; RMInitializerData RMInitializerDataMake(SEL initializer, id data); @interface NSObject (SingletonCollector) // Returns the selector and data to pass to it (if the selector takes an argument) for use when initializing the singleton. // If you override this DO NOT call super. + (RMInitializerData)designatedInitializerForIdentifier:(NSString *)identifier; @end @interface RMSingletonCollector : NSObject { } + (id)collectionObjectForType:(NSString *)className identifier:(NSString *)identifier; + (id<RMWeakObjectReference>)referenceForObjectOfType:(NSString *)className identifier:(NSString *)identifier; + (void)destroyCollection; + (void)destroyCollectionObjectForType:(NSString *)className identifier:(NSString *)identifier; @end // ==--==--==--==--==Notifications==--==--==--==--== extern NSString *const willDestroySingletonCollection; extern NSString *const willDestroySingletonCollectionObject; RMSingletonCollector.m // // RMSingletonCollector.m // RMSingletonCollector // // Created by Rich Meade-Miller on 2/11/11. // Copyright 2011 Rich Meade-Miller. All rights reserved. // #import "RMSingletonCollector.h" #import <objc/objc-runtime.h> NSString *const willDestroySingletonCollection = @"willDestroySingletonCollection"; NSString *const willDestroySingletonCollectionObject = @"willDestroySingletonCollectionObject"; RMInitializerData RMInitializerDataMake(SEL initializer, id data) { RMInitializerData newData; newData.designatedInitializer = initializer; newData.data = data; return newData; } @implementation NSObject (SingletonCollector) + (RMInitializerData)designatedInitializerForIdentifier:(NSString *)identifier { return RMInitializerDataMake(@selector(init), nil); } @end @interface RMSingletonCollector () + (NSMutableDictionary *)singletonCollection; + (void)setSingletonCollection:(NSMutableDictionary *)newSingletonCollection; @end @implementation RMSingletonCollector static NSMutableDictionary *singletonCollection = nil; + (NSMutableDictionary *)singletonCollection { if (singletonCollection != nil) { return singletonCollection; } NSMutableDictionary *collection = [[NSMutableDictionary alloc] initWithCapacity:1]; [self setSingletonCollection:collection]; [collection release]; return singletonCollection; } + (void)setSingletonCollection:(NSMutableDictionary *)newSingletonCollection { if (newSingletonCollection != singletonCollection) { [singletonCollection release]; singletonCollection = [newSingletonCollection retain]; } } + (id)collectionObjectForType:(NSString *)className identifier:(NSString *)identifier { id obj; NSString *key; if (identifier) { key = [className stringByAppendingFormat:@".%@", identifier]; } else { key = className; } if (obj = [[self singletonCollection] objectForKey:key]) { return obj; } // dynamic creation. // get a class for Class classForName = NSClassFromString(className); if (classForName) { obj = objc_msgSend(classForName, @selector(alloc)); // if the initializer takes an argument... RMInitializerData initializerData = [classForName designatedInitializerForIdentifier:identifier]; if (initializerData.data) { // pass it. obj = objc_msgSend(obj, initializerData.designatedInitializer, initializerData.data); } else { obj = objc_msgSend(obj, initializerData.designatedInitializer); } [singletonCollection setObject:obj forKey:key]; [obj release]; } else { // raise an exception if there is no class for the specified name. NSException *exception = [NSException exceptionWithName:@"com.RMDev.RMSingletonCollector.failed_to_find_class" reason:[NSString stringWithFormat:@"SingletonCollector couldn't find class for name: %@", [className description]] userInfo:nil]; [exception raise]; [exception release]; } return obj; } + (id<RMWeakObjectReference>)referenceForObjectOfType:(NSString *)className identifier:(NSString *)identifier { id obj = [self collectionObjectForType:className identifier:identifier]; RMWeakObjectRef *objectRef = [[RMWeakObjectRef alloc] initWithObject:obj identifier:identifier]; return [objectRef autorelease]; } + (void)destroyCollection { NSDictionary *userInfo = [singletonCollection copy]; [[NSNotificationCenter defaultCenter] postNotificationName:willDestroySingletonCollection object:self userInfo:userInfo]; [userInfo release]; // release the collection and set it to nil. [self setSingletonCollection:nil]; } + (void)destroyCollectionObjectForType:(NSString *)className identifier:(NSString *)identifier { NSString *key; if (identifier) { key = [className stringByAppendingFormat:@".%@", identifier]; } else { key = className; } [[NSNotificationCenter defaultCenter] postNotificationName:willDestroySingletonCollectionObject object:[singletonCollection objectForKey:key] userInfo:nil]; [singletonCollection removeObjectForKey:key]; } @end RMWeakObjectRef.h // // RMWeakObjectRef.h // RMSingletonCollector // // Created by Rich Meade-Miller on 2/12/11. // Copyright 2011 Rich Meade-Miller. All rights reserved. // // In order to offset the performance loss from always having to search the dictionary, I made a retainable, weak object reference class. #import <Foundation/Foundation.h> @protocol RMWeakObjectReference <NSObject> @property (nonatomic, assign, readonly) id objectRef; @property (nonatomic, retain, readonly) NSString *className; @property (nonatomic, retain, readonly) NSString *objectIdentifier; @end @interface RMWeakObjectRef : NSObject <RMWeakObjectReference> { id objectRef; NSString *className; NSString *objectIdentifier; } - (RMWeakObjectRef *)initWithObject:(id)object identifier:(NSString *)identifier; - (void)objectWillBeDestroyed:(NSNotification *)notification; @end RMWeakObjectRef.m // // RMWeakObjectRef.m // RMSingletonCollector // // Created by Rich Meade-Miller on 2/12/11. // Copyright 2011 Rich Meade-Miller. All rights reserved. // #import "RMWeakObjectRef.h" #import "RMSingletonCollector.h" @implementation RMWeakObjectRef @dynamic objectRef; @synthesize className, objectIdentifier; - (RMWeakObjectRef *)initWithObject:(id)object identifier:(NSString *)identifier { if (self = [super init]) { NSString *classNameForObject = NSStringFromClass([object class]); className = classNameForObject; objectIdentifier = identifier; objectRef = object; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(objectWillBeDestroyed:) name:willDestroySingletonCollectionObject object:object]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(objectWillBeDestroyed:) name:willDestroySingletonCollection object:[RMSingletonCollector class]]; } return self; } - (id)objectRef { if (objectRef) { return objectRef; } objectRef = [RMSingletonCollector collectionObjectForType:className identifier:objectIdentifier]; return objectRef; } - (void)objectWillBeDestroyed:(NSNotification *)notification { objectRef = nil; } - (void)dealloc { [[NSNotificationCenter defaultCenter] removeObserver:self]; [className release]; [super dealloc]; } @end

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  • SQL Server 2012 - AlwaysOn

    - by Claus Jandausch
    Ich war nicht nur irritiert, ich war sogar regelrecht schockiert - und für einen kurzen Moment sprachlos (was nur selten der Fall ist). Gerade eben hatte mich jemand gefragt "Wann Oracle denn etwas Vergleichbares wie AlwaysOn bieten würde - und ob überhaupt?" War ich hier im falschen Film gelandet? Ich konnte nicht anders, als meinen Unmut kundzutun und zu erklären, dass die Fragestellung normalerweise anders herum läuft. Zugegeben - es mag vielleicht strittige Punkte geben im Vergleich zwischen Oracle und SQL Server - bei denen nicht unbedingt immer Oracle die Nase vorn haben muss - aber das Thema Clustering für Hochverfügbarkeit (HA), Disaster Recovery (DR) und Skalierbarkeit gehört mit Sicherheit nicht dazu. Dieses Erlebnis hakte ich am Nachgang als Einzelfall ab, der so nie wieder vorkommen würde. Bis ich kurz darauf eines Besseren belehrt wurde und genau die selbe Frage erneut zu hören bekam. Diesmal sogar im Exadata-Umfeld und einem Oracle Stretch Cluster. Einmal ist keinmal, doch zweimal ist einmal zu viel... Getreu diesem alten Motto war mir klar, dass man das so nicht länger stehen lassen konnte. Ich habe keine Ahnung, wie die Microsoft Marketing Abteilung es geschafft hat, unter dem AlwaysOn Brading eine innovative Technologie vermuten zu lassen - aber sie hat ihren Job scheinbar gut gemacht. Doch abgesehen von einem guten Marketing, stellt sich natürlich die Frage, was wirklich dahinter steckt und wie sich das Ganze mit Oracle vergleichen lässt - und ob überhaupt? Damit wären wir wieder bei der ursprünglichen Frage angelangt.  So viel zum Hintergrund dieses Blogbeitrags - von meiner Antwort handelt der restliche Blog. "Windows was the God ..." Um den wahren Unterschied zwischen Oracle und Microsoft verstehen zu können, muss man zunächst das bedeutendste Microsoft Dogma kennen. Es lässt sich schlicht und einfach auf den Punkt bringen: "Alles muss auf Windows basieren." Die Überschrift dieses Absatzes ist kein von mir erfundener Ausspruch, sondern ein Zitat. Konkret stammt es aus einem längeren Artikel von Kurt Eichenwald in der Vanity Fair aus dem August 2012. Er lautet Microsoft's Lost Decade und sei jedem ans Herz gelegt, der die "Microsoft-Maschinerie" unter Steve Ballmer und einige ihrer Kuriositäten besser verstehen möchte. "YOU TALKING TO ME?" Microsoft C.E.O. Steve Ballmer bei seiner Keynote auf der 2012 International Consumer Electronics Show in Las Vegas am 9. Januar   Manche Dinge in diesem Artikel mögen überspitzt dargestellt erscheinen - sind sie aber nicht. Vieles davon kannte ich bereits aus eigener Erfahrung und kann es nur bestätigen. Anderes hat sich mir erst so richtig erschlossen. Insbesondere die folgenden Passagen führten zum Aha-Erlebnis: “Windows was the god—everything had to work with Windows,” said Stone... “Every little thing you want to write has to build off of Windows (or other existing roducts),” one software engineer said. “It can be very confusing, …” Ich habe immer schon darauf hingewiesen, dass in einem SQL Server Failover Cluster die Microsoft Datenbank eigentlich nichts Nenneswertes zum Geschehen beiträgt, sondern sich voll und ganz auf das Windows Betriebssystem verlässt. Deshalb muss man auch die Windows Server Enterprise Edition installieren, soll ein Failover Cluster für den SQL Server eingerichtet werden. Denn hier werden die Cluster Services geliefert - nicht mit dem SQL Server. Er ist nur lediglich ein weiteres Server Produkt, für das Windows in Ausfallszenarien genutzt werden kann - so wie Microsoft Exchange beispielsweise, oder Microsoft SharePoint, oder irgendein anderes Server Produkt das auf Windows gehostet wird. Auch Oracle kann damit genutzt werden. Das Stichwort lautet hier: Oracle Failsafe. Nur - warum sollte man das tun, wenn gleichzeitig eine überlegene Technologie wie die Oracle Real Application Clusters (RAC) zur Verfügung steht, die dann auch keine Windows Enterprise Edition voraussetzen, da Oracle die eigene Clusterware liefert. Welche darüber hinaus für kürzere Failover-Zeiten sorgt, da diese Cluster-Technologie Datenbank-integriert ist und sich nicht auf "Dritte" verlässt. Wenn man sich also schon keine technischen Vorteile mit einem SQL Server Failover Cluster erkauft, sondern zusätzlich noch versteckte Lizenzkosten durch die Lizenzierung der Windows Server Enterprise Edition einhandelt, warum hat Microsoft dann in den vergangenen Jahren seit SQL Server 2000 nicht ebenfalls an einer neuen und innovativen Lösung gearbeitet, die mit Oracle RAC mithalten kann? Entwickler hat Microsoft genügend? Am Geld kann es auch nicht liegen? Lesen Sie einfach noch einmal die beiden obenstehenden Zitate und sie werden den Grund verstehen. Anders lässt es sich ja auch gar nicht mehr erklären, dass AlwaysOn aus zwei unterschiedlichen Technologien besteht, die beide jedoch wiederum auf dem Windows Server Failover Clustering (WSFC) basieren. Denn daraus ergeben sich klare Nachteile - aber dazu später mehr. Um AlwaysOn zu verstehen, sollte man sich zunächst kurz in Erinnerung rufen, was Microsoft bisher an HA/DR (High Availability/Desaster Recovery) Lösungen für SQL Server zur Verfügung gestellt hat. Replikation Basiert auf logischer Replikation und Pubisher/Subscriber Architektur Transactional Replication Merge Replication Snapshot Replication Microsoft's Replikation ist vergleichbar mit Oracle GoldenGate. Oracle GoldenGate stellt jedoch die umfassendere Technologie dar und bietet High Performance. Log Shipping Microsoft's Log Shipping stellt eine einfache Technologie dar, die vergleichbar ist mit Oracle Managed Recovery in Oracle Version 7. Das Log Shipping besitzt folgende Merkmale: Transaction Log Backups werden von Primary nach Secondary/ies geschickt Einarbeitung (z.B. Restore) auf jedem Secondary individuell Optionale dritte Server Instanz (Monitor Server) für Überwachung und Alarm Log Restore Unterbrechung möglich für Read-Only Modus (Secondary) Keine Unterstützung von Automatic Failover Database Mirroring Microsoft's Database Mirroring wurde verfügbar mit SQL Server 2005, sah aus wie Oracle Data Guard in Oracle 9i, war funktional jedoch nicht so umfassend. Für ein HA/DR Paar besteht eine 1:1 Beziehung, um die produktive Datenbank (Principle DB) abzusichern. Auf der Standby Datenbank (Mirrored DB) werden alle Insert-, Update- und Delete-Operationen nachgezogen. Modi Synchron (High-Safety Modus) Asynchron (High-Performance Modus) Automatic Failover Unterstützt im High-Safety Modus (synchron) Witness Server vorausgesetzt     Zur Frage der Kontinuität Es stellt sich die Frage, wie es um diesen Technologien nun im Zusammenhang mit SQL Server 2012 bestellt ist. Unter Fanfaren seinerzeit eingeführt, war Database Mirroring das erklärte Mittel der Wahl. Ich bin kein Produkt Manager bei Microsoft und kann hierzu nur meine Meinung äußern, aber zieht man den SQL AlwaysOn Team Blog heran, so sieht es nicht gut aus für das Database Mirroring - zumindest nicht langfristig. "Does AlwaysOn Availability Group replace Database Mirroring going forward?” “The short answer is we recommend that you migrate from the mirroring configuration or even mirroring and log shipping configuration to using Availability Group. Database Mirroring will still be available in the Denali release but will be phased out over subsequent releases. Log Shipping will continue to be available in future releases.” Damit wären wir endlich beim eigentlichen Thema angelangt. Was ist eine sogenannte Availability Group und was genau hat es mit der vielversprechend klingenden Bezeichnung AlwaysOn auf sich?   SQL Server 2012 - AlwaysOn Zwei HA-Features verstekcne sich hinter dem “AlwaysOn”-Branding. Einmal das AlwaysOn Failover Clustering aka SQL Server Failover Cluster Instances (FCI) - zum Anderen die AlwaysOn Availability Groups. Failover Cluster Instances (FCI) Entspricht ungefähr dem Stretch Cluster Konzept von Oracle Setzt auf Windows Server Failover Clustering (WSFC) auf Bietet HA auf Instanz-Ebene AlwaysOn Availability Groups (Verfügbarkeitsgruppen) Ähnlich der Idee von Consistency Groups, wie in Storage-Level Replikations-Software von z.B. EMC SRDF Abhängigkeiten zu Windows Server Failover Clustering (WSFC) Bietet HA auf Datenbank-Ebene   Hinweis: Verwechseln Sie nicht eine SQL Server Datenbank mit einer Oracle Datenbank. Und auch nicht eine Oracle Instanz mit einer SQL Server Instanz. Die gleichen Begriffe haben hier eine andere Bedeutung - nicht selten ein Grund, weshalb Oracle- und Microsoft DBAs schnell aneinander vorbei reden. Denken Sie bei einer SQL Server Datenbank eher an ein Oracle Schema, das kommt der Sache näher. So etwas wie die SQL Server Northwind Datenbank ist vergleichbar mit dem Oracle Scott Schema. Wenn Sie die genauen Unterschiede kennen möchten, finden Sie eine detaillierte Beschreibung in meinem Buch "Oracle10g Release 2 für Windows und .NET", erhältich bei Lehmanns, Amazon, etc.   Windows Server Failover Clustering (WSFC) Wie man sieht, basieren beide AlwaysOn Technologien wiederum auf dem Windows Server Failover Clustering (WSFC), um einerseits Hochverfügbarkeit auf Ebene der Instanz zu gewährleisten und andererseits auf der Datenbank-Ebene. Deshalb nun eine kurze Beschreibung der WSFC. Die WSFC sind ein mit dem Windows Betriebssystem geliefertes Infrastruktur-Feature, um HA für Server Anwendungen, wie Microsoft Exchange, SharePoint, SQL Server, etc. zu bieten. So wie jeder andere Cluster, besteht ein WSFC Cluster aus einer Gruppe unabhängiger Server, die zusammenarbeiten, um die Verfügbarkeit einer Applikation oder eines Service zu erhöhen. Falls ein Cluster-Knoten oder -Service ausfällt, kann der auf diesem Knoten bisher gehostete Service automatisch oder manuell auf einen anderen im Cluster verfügbaren Knoten transferriert werden - was allgemein als Failover bekannt ist. Unter SQL Server 2012 verwenden sowohl die AlwaysOn Avalability Groups, als auch die AlwaysOn Failover Cluster Instances die WSFC als Plattformtechnologie, um Komponenten als WSFC Cluster-Ressourcen zu registrieren. Verwandte Ressourcen werden in eine Ressource Group zusammengefasst, die in Abhängigkeit zu anderen WSFC Cluster-Ressourcen gebracht werden kann. Der WSFC Cluster Service kann jetzt die Notwendigkeit zum Neustart der SQL Server Instanz erfassen oder einen automatischen Failover zu einem anderen Server-Knoten im WSFC Cluster auslösen.   Failover Cluster Instances (FCI) Eine SQL Server Failover Cluster Instanz (FCI) ist eine einzelne SQL Server Instanz, die in einem Failover Cluster betrieben wird, der aus mehreren Windows Server Failover Clustering (WSFC) Knoten besteht und so HA (High Availability) auf Ebene der Instanz bietet. Unter Verwendung von Multi-Subnet FCI kann auch Remote DR (Disaster Recovery) unterstützt werden. Eine weitere Option für Remote DR besteht darin, eine unter FCI gehostete Datenbank in einer Availability Group zu betreiben. Hierzu später mehr. FCI und WSFC Basis FCI, das für lokale Hochverfügbarkeit der Instanzen genutzt wird, ähnelt der veralteten Architektur eines kalten Cluster (Aktiv-Passiv). Unter SQL Server 2008 wurde diese Technologie SQL Server 2008 Failover Clustering genannt. Sie nutzte den Windows Server Failover Cluster. In SQL Server 2012 hat Microsoft diese Basistechnologie unter der Bezeichnung AlwaysOn zusammengefasst. Es handelt sich aber nach wie vor um die klassische Aktiv-Passiv-Konfiguration. Der Ablauf im Failover-Fall ist wie folgt: Solange kein Hardware-oder System-Fehler auftritt, werden alle Dirty Pages im Buffer Cache auf Platte geschrieben Alle entsprechenden SQL Server Services (Dienste) in der Ressource Gruppe werden auf dem aktiven Knoten gestoppt Die Ownership der Ressource Gruppe wird auf einen anderen Knoten der FCI transferriert Der neue Owner (Besitzer) der Ressource Gruppe startet seine SQL Server Services (Dienste) Die Connection-Anforderungen einer Client-Applikation werden automatisch auf den neuen aktiven Knoten mit dem selben Virtuellen Network Namen (VNN) umgeleitet Abhängig vom Zeitpunkt des letzten Checkpoints, kann die Anzahl der Dirty Pages im Buffer Cache, die noch auf Platte geschrieben werden müssen, zu unvorhersehbar langen Failover-Zeiten führen. Um diese Anzahl zu drosseln, besitzt der SQL Server 2012 eine neue Fähigkeit, die Indirect Checkpoints genannt wird. Indirect Checkpoints ähnelt dem Fast-Start MTTR Target Feature der Oracle Datenbank, das bereits mit Oracle9i verfügbar war.   SQL Server Multi-Subnet Clustering Ein SQL Server Multi-Subnet Failover Cluster entspricht vom Konzept her einem Oracle RAC Stretch Cluster. Doch dies ist nur auf den ersten Blick der Fall. Im Gegensatz zu RAC ist in einem lokalen SQL Server Failover Cluster jeweils nur ein Knoten aktiv für eine Datenbank. Für die Datenreplikation zwischen geografisch entfernten Sites verlässt sich Microsoft auf 3rd Party Lösungen für das Storage Mirroring.     Die Verbesserung dieses Szenario mit einer SQL Server 2012 Implementierung besteht schlicht darin, dass eine VLAN-Konfiguration (Virtual Local Area Network) nun nicht mehr benötigt wird, so wie dies bisher der Fall war. Das folgende Diagramm stellt dar, wie der Ablauf mit SQL Server 2012 gehandhabt wird. In Site A und Site B wird HA jeweils durch einen lokalen Aktiv-Passiv-Cluster sichergestellt.     Besondere Aufmerksamkeit muss hier der Konfiguration und dem Tuning geschenkt werden, da ansonsten völlig inakzeptable Failover-Zeiten resultieren. Dies liegt darin begründet, weil die Downtime auf Client-Seite nun nicht mehr nur von der reinen Failover-Zeit abhängt, sondern zusätzlich von der Dauer der DNS Replikation zwischen den DNS Servern. (Rufen Sie sich in Erinnerung, dass wir gerade von Multi-Subnet Clustering sprechen). Außerdem ist zu berücksichtigen, wie schnell die Clients die aktualisierten DNS Informationen abfragen. Spezielle Konfigurationen für Node Heartbeat, HostRecordTTL (Host Record Time-to-Live) und Intersite Replication Frequeny für Active Directory Sites und Services werden notwendig. Default TTL für Windows Server 2008 R2: 20 Minuten Empfohlene Einstellung: 1 Minute DNS Update Replication Frequency in Windows Umgebung: 180 Minuten Empfohlene Einstellung: 15 Minuten (minimaler Wert)   Betrachtet man diese Werte, muss man feststellen, dass selbst eine optimale Konfiguration die rigiden SLAs (Service Level Agreements) heutiger geschäftskritischer Anwendungen für HA und DR nicht erfüllen kann. Denn dies impliziert eine auf der Client-Seite erlebte Failover-Zeit von insgesamt 16 Minuten. Hierzu ein Auszug aus der SQL Server 2012 Online Dokumentation: Cons: If a cross-subnet failover occurs, the client recovery time could be 15 minutes or longer, depending on your HostRecordTTL setting and the setting of your cross-site DNS/AD replication schedule.    Wir sind hier an einem Punkt unserer Überlegungen angelangt, an dem sich erklärt, weshalb ich zuvor das "Windows was the God ..." Zitat verwendet habe. Die unbedingte Abhängigkeit zu Windows wird zunehmend zum Problem, da sie die Komplexität einer Microsoft-basierenden Lösung erhöht, anstelle sie zu reduzieren. Und Komplexität ist das Letzte, was sich CIOs heutzutage wünschen.  Zur Ehrenrettung des SQL Server 2012 und AlwaysOn muss man sagen, dass derart lange Failover-Zeiten kein unbedingtes "Muss" darstellen, sondern ein "Kann". Doch auch ein "Kann" kann im unpassenden Moment unvorhersehbare und kostspielige Folgen haben. Die Unabsehbarkeit ist wiederum Ursache vieler an der Implementierung beteiligten Komponenten und deren Abhängigkeiten, wie beispielsweise drei Cluster-Lösungen (zwei von Microsoft, eine 3rd Party Lösung). Wie man die Sache auch dreht und wendet, kommt man an diesem Fakt also nicht vorbei - ganz unabhängig von der Dauer einer Downtime oder Failover-Zeiten. Im Gegensatz zu AlwaysOn und der hier vorgestellten Version eines Stretch-Clusters, vermeidet eine entsprechende Oracle Implementierung eine derartige Komplexität, hervorgerufen duch multiple Abhängigkeiten. Den Unterschied machen Datenbank-integrierte Mechanismen, wie Fast Application Notification (FAN) und Fast Connection Failover (FCF). Für Oracle MAA Konfigurationen (Maximum Availability Architecture) sind Inter-Site Failover-Zeiten im Bereich von Sekunden keine Seltenheit. Wenn Sie dem Link zur Oracle MAA folgen, finden Sie außerdem eine Reihe an Customer Case Studies. Auch dies ist ein wichtiges Unterscheidungsmerkmal zu AlwaysOn, denn die Oracle Technologie hat sich bereits zigfach in höchst kritischen Umgebungen bewährt.   Availability Groups (Verfügbarkeitsgruppen) Die sogenannten Availability Groups (Verfügbarkeitsgruppen) sind - neben FCI - der weitere Baustein von AlwaysOn.   Hinweis: Bevor wir uns näher damit beschäftigen, sollten Sie sich noch einmal ins Gedächtnis rufen, dass eine SQL Server Datenbank nicht die gleiche Bedeutung besitzt, wie eine Oracle Datenbank, sondern eher einem Oracle Schema entspricht. So etwas wie die SQL Server Northwind Datenbank ist vergleichbar mit dem Oracle Scott Schema.   Eine Verfügbarkeitsgruppe setzt sich zusammen aus einem Set mehrerer Benutzer-Datenbanken, die im Falle eines Failover gemeinsam als Gruppe behandelt werden. Eine Verfügbarkeitsgruppe unterstützt ein Set an primären Datenbanken (primäres Replikat) und einem bis vier Sets von entsprechenden sekundären Datenbanken (sekundäre Replikate).       Es können jedoch nicht alle SQL Server Datenbanken einer AlwaysOn Verfügbarkeitsgruppe zugeordnet werden. Der SQL Server Spezialist Michael Otey zählt in seinem SQL Server Pro Artikel folgende Anforderungen auf: Verfügbarkeitsgruppen müssen mit Benutzer-Datenbanken erstellt werden. System-Datenbanken können nicht verwendet werden Die Datenbanken müssen sich im Read-Write Modus befinden. Read-Only Datenbanken werden nicht unterstützt Die Datenbanken in einer Verfügbarkeitsgruppe müssen Multiuser Datenbanken sein Sie dürfen nicht das AUTO_CLOSE Feature verwenden Sie müssen das Full Recovery Modell nutzen und es muss ein vollständiges Backup vorhanden sein Eine gegebene Datenbank kann sich nur in einer einzigen Verfügbarkeitsgruppe befinden und diese Datenbank düerfen nicht für Database Mirroring konfiguriert sein Microsoft empfiehl außerdem, dass der Verzeichnispfad einer Datenbank auf dem primären und sekundären Server identisch sein sollte Wie man sieht, eignen sich Verfügbarkeitsgruppen nicht, um HA und DR vollständig abzubilden. Die Unterscheidung zwischen der Instanzen-Ebene (FCI) und Datenbank-Ebene (Availability Groups) ist von hoher Bedeutung. Vor kurzem wurde mir gesagt, dass man mit den Verfügbarkeitsgruppen auf Shared Storage verzichten könne und dadurch Kosten spart. So weit so gut ... Man kann natürlich eine Installation rein mit Verfügbarkeitsgruppen und ohne FCI durchführen - aber man sollte sich dann darüber bewusst sein, was man dadurch alles nicht abgesichert hat - und dies wiederum für Desaster Recovery (DR) und SLAs (Service Level Agreements) bedeutet. Kurzum, um die Kombination aus beiden AlwaysOn Produkten und der damit verbundene Komplexität kommt man wohl in der Praxis nicht herum.    Availability Groups und WSFC AlwaysOn hängt von Windows Server Failover Clustering (WSFC) ab, um die aktuellen Rollen der Verfügbarkeitsreplikate einer Verfügbarkeitsgruppe zu überwachen und zu verwalten, und darüber zu entscheiden, wie ein Failover-Ereignis die Verfügbarkeitsreplikate betrifft. Das folgende Diagramm zeigt de Beziehung zwischen Verfügbarkeitsgruppen und WSFC:   Der Verfügbarkeitsmodus ist eine Eigenschaft jedes Verfügbarkeitsreplikats. Synychron und Asynchron können also gemischt werden: Availability Modus (Verfügbarkeitsmodus) Asynchroner Commit-Modus Primäres replikat schließt Transaktionen ohne Warten auf Sekundäres Synchroner Commit-Modus Primäres Replikat wartet auf Commit von sekundärem Replikat Failover Typen Automatic Manual Forced (mit möglichem Datenverlust) Synchroner Commit-Modus Geplanter, manueller Failover ohne Datenverlust Automatischer Failover ohne Datenverlust Asynchroner Commit-Modus Nur Forced, manueller Failover mit möglichem Datenverlust   Der SQL Server kennt keinen separaten Switchover Begriff wie in Oracle Data Guard. Für SQL Server werden alle Role Transitions als Failover bezeichnet. Tatsächlich unterstützt der SQL Server keinen Switchover für asynchrone Verbindungen. Es gibt nur die Form des Forced Failover mit möglichem Datenverlust. Eine ähnliche Fähigkeit wie der Switchover unter Oracle Data Guard ist so nicht gegeben.   SQL Sever FCI mit Availability Groups (Verfügbarkeitsgruppen) Neben den Verfügbarkeitsgruppen kann eine zweite Failover-Ebene eingerichtet werden, indem SQL Server FCI (auf Shared Storage) mit WSFC implementiert wird. Ein Verfügbarkeitesreplikat kann dann auf einer Standalone Instanz gehostet werden, oder einer FCI Instanz. Zum Verständnis: Die Verfügbarkeitsgruppen selbst benötigen kein Shared Storage. Diese Kombination kann verwendet werden für lokale HA auf Ebene der Instanz und DR auf Datenbank-Ebene durch Verfügbarkeitsgruppen. Das folgende Diagramm zeigt dieses Szenario:   Achtung! Hier handelt es sich nicht um ein Pendant zu Oracle RAC plus Data Guard, auch wenn das Bild diesen Eindruck vielleicht vermitteln mag - denn alle sekundären Knoten im FCI sind rein passiv. Es existiert außerdem eine weitere und ernsthafte Einschränkung: SQL Server Failover Cluster Instanzen (FCI) unterstützen nicht das automatische AlwaysOn Failover für Verfügbarkeitsgruppen. Jedes unter FCI gehostete Verfügbarkeitsreplikat kann nur für manuelles Failover konfiguriert werden.   Lesbare Sekundäre Replikate Ein oder mehrere Verfügbarkeitsreplikate in einer Verfügbarkeitsgruppe können für den lesenden Zugriff konfiguriert werden, wenn sie als sekundäres Replikat laufen. Dies ähnelt Oracle Active Data Guard, jedoch gibt es Einschränkungen. Alle Abfragen gegen die sekundäre Datenbank werden automatisch auf das Snapshot Isolation Level abgebildet. Es handelt sich dabei um eine Versionierung der Rows. Microsoft versuchte hiermit die Oracle MVRC (Multi Version Read Consistency) nachzustellen. Tatsächlich muss man die SQL Server Snapshot Isolation eher mit Oracle Flashback vergleichen. Bei der Implementierung des Snapshot Isolation Levels handelt sich um ein nachträglich aufgesetztes Feature und nicht um einen inhärenten Teil des Datenbank-Kernels, wie im Falle Oracle. (Ich werde hierzu in Kürze einen weiteren Blogbeitrag verfassen, wenn ich mich mit der neuen SQL Server 2012 Core Lizenzierung beschäftige.) Für die Praxis entstehen aus der Abbildung auf das Snapshot Isolation Level ernsthafte Restriktionen, derer man sich für den Betrieb in der Praxis bereits vorab bewusst sein sollte: Sollte auf der primären Datenbank eine aktive Transaktion zu dem Zeitpunkt existieren, wenn ein lesbares sekundäres Replikat in die Verfügbarkeitsgruppe aufgenommen wird, werden die Row-Versionen auf der korrespondierenden sekundären Datenbank nicht sofort vollständig verfügbar sein. Eine aktive Transaktion auf dem primären Replikat muss zuerst abgeschlossen (Commit oder Rollback) und dieser Transaktions-Record auf dem sekundären Replikat verarbeitet werden. Bis dahin ist das Isolation Level Mapping auf der sekundären Datenbank unvollständig und Abfragen sind temporär geblockt. Microsoft sagt dazu: "This is needed to guarantee that row versions are available on the secondary replica before executing the query under snapshot isolation as all isolation levels are implicitly mapped to snapshot isolation." (SQL Storage Engine Blog: AlwaysOn: I just enabled Readable Secondary but my query is blocked?)  Grundlegend bedeutet dies, dass ein aktives lesbares Replikat nicht in die Verfügbarkeitsgruppe aufgenommen werden kann, ohne das primäre Replikat vorübergehend stillzulegen. Da Leseoperationen auf das Snapshot Isolation Transaction Level abgebildet werden, kann die Bereinigung von Ghost Records auf dem primären Replikat durch Transaktionen auf einem oder mehreren sekundären Replikaten geblockt werden - z.B. durch eine lang laufende Abfrage auf dem sekundären Replikat. Diese Bereinigung wird auch blockiert, wenn die Verbindung zum sekundären Replikat abbricht oder der Datenaustausch unterbrochen wird. Auch die Log Truncation wird in diesem Zustant verhindert. Wenn dieser Zustand längere Zeit anhält, empfiehlt Microsoft das sekundäre Replikat aus der Verfügbarkeitsgruppe herauszunehmen - was ein ernsthaftes Downtime-Problem darstellt. Die Read-Only Workload auf den sekundären Replikaten kann eingehende DDL Änderungen blockieren. Obwohl die Leseoperationen aufgrund der Row-Versionierung keine Shared Locks halten, führen diese Operatioen zu Sch-S Locks (Schemastabilitätssperren). DDL-Änderungen durch Redo-Operationen können dadurch blockiert werden. Falls DDL aufgrund konkurrierender Lese-Workload blockiert wird und der Schwellenwert für 'Recovery Interval' (eine SQL Server Konfigurationsoption) überschritten wird, generiert der SQL Server das Ereignis sqlserver.lock_redo_blocked, welches Microsoft zum Kill der blockierenden Leser empfiehlt. Auf die Verfügbarkeit der Anwendung wird hierbei keinerlei Rücksicht genommen.   Keine dieser Einschränkungen existiert mit Oracle Active Data Guard.   Backups auf sekundären Replikaten  Über die sekundären Replikate können Backups (BACKUP DATABASE via Transact-SQL) nur als copy-only Backups einer vollständigen Datenbank, Dateien und Dateigruppen erstellt werden. Das Erstellen inkrementeller Backups ist nicht unterstützt, was ein ernsthafter Rückstand ist gegenüber der Backup-Unterstützung physikalischer Standbys unter Oracle Data Guard. Hinweis: Ein möglicher Workaround via Snapshots, bleibt ein Workaround. Eine weitere Einschränkung dieses Features gegenüber Oracle Data Guard besteht darin, dass das Backup eines sekundären Replikats nicht ausgeführt werden kann, wenn es nicht mit dem primären Replikat kommunizieren kann. Darüber hinaus muss das sekundäre Replikat synchronisiert sein oder sich in der Synchronisation befinden, um das Beackup auf dem sekundären Replikat erstellen zu können.   Vergleich von Microsoft AlwaysOn mit der Oracle MAA Ich komme wieder zurück auf die Eingangs erwähnte, mehrfach an mich gestellte Frage "Wann denn - und ob überhaupt - Oracle etwas Vergleichbares wie AlwaysOn bieten würde?" und meine damit verbundene (kurze) Irritation. Wenn Sie diesen Blogbeitrag bis hierher gelesen haben, dann kennen Sie jetzt meine darauf gegebene Antwort. Der eine oder andere Punkt traf dabei nicht immer auf Jeden zu, was auch nicht der tiefere Sinn und Zweck meiner Antwort war. Wenn beispielsweise kein Multi-Subnet mit im Spiel ist, sind alle diesbezüglichen Kritikpunkte zunächst obsolet. Was aber nicht bedeutet, dass sie nicht bereits morgen schon wieder zum Thema werden könnten (Sag niemals "Nie"). In manch anderes Fettnäpfchen tritt man wiederum nicht unbedingt in einer Testumgebung, sondern erst im laufenden Betrieb. Erst recht nicht dann, wenn man sich potenzieller Probleme nicht bewusst ist und keine dedizierten Tests startet. Und wer AlwaysOn erfolgreich positionieren möchte, wird auch gar kein Interesse daran haben, auf mögliche Schwachstellen und den besagten Teufel im Detail aufmerksam zu machen. Das ist keine Unterstellung - es ist nur menschlich. Außerdem ist es verständlich, dass man sich in erster Linie darauf konzentriert "was geht" und "was gut läuft", anstelle auf das "was zu Problemen führen kann" oder "nicht funktioniert". Wer will schon der Miesepeter sein? Für mich selbst gesprochen, kann ich nur sagen, dass ich lieber vorab von allen möglichen Einschränkungen wissen möchte, anstelle sie dann nach einer kurzen Zeit der heilen Welt schmerzhaft am eigenen Leib erfahren zu müssen. Ich bin davon überzeugt, dass es Ihnen nicht anders geht. Nachfolgend deshalb eine Zusammenfassung all jener Punkte, die ich im Vergleich zur Oracle MAA (Maximum Availability Architecture) als unbedingt Erwähnenswert betrachte, falls man eine Evaluierung von Microsoft AlwaysOn in Betracht zieht. 1. AlwaysOn ist eine komplexe Technologie Der SQL Server AlwaysOn Stack ist zusammengesetzt aus drei verschiedenen Technlogien: Windows Server Failover Clustering (WSFC) SQL Server Failover Cluster Instances (FCI) SQL Server Availability Groups (Verfügbarkeitsgruppen) Man kann eine derartige Lösung nicht als nahtlos bezeichnen, wofür auch die vielen von Microsoft dargestellten Einschränkungen sprechen. Während sich frühere SQL Server Versionen in Richtung eigener HA/DR Technologien entwickelten (wie Database Mirroring), empfiehlt Microsoft nun die Migration. Doch weshalb dieser Schwenk? Er führt nicht zu einem konsisten und robusten Angebot an HA/DR Technologie für geschäftskritische Umgebungen.  Liegt die Antwort in meiner These begründet, nach der "Windows was the God ..." noch immer gilt und man die Nachteile der allzu engen Kopplung mit Windows nicht sehen möchte? Entscheiden Sie selbst ... 2. Failover Cluster Instanzen - Kein RAC-Pendant Die SQL Server und Windows Server Clustering Technologie basiert noch immer auf dem veralteten Aktiv-Passiv Modell und führt zu einer Verschwendung von Systemressourcen. In einer Betrachtung von lediglich zwei Knoten erschließt sich auf Anhieb noch nicht der volle Mehrwert eines Aktiv-Aktiv Clusters (wie den Real Application Clusters), wie er von Oracle bereits vor zehn Jahren entwickelt wurde. Doch kennt man die Vorzüge der Skalierbarkeit durch einfaches Hinzufügen weiterer Cluster-Knoten, die dann alle gemeinsam als ein einziges logisches System zusammenarbeiten, versteht man was hinter dem Motto "Pay-as-you-Grow" steckt. In einem Aktiv-Aktiv Cluster geht es zwar auch um Hochverfügbarkeit - und ein Failover erfolgt zudem schneller, als in einem Aktiv-Passiv Modell - aber es geht eben nicht nur darum. An dieser Stelle sei darauf hingewiesen, dass die Oracle 11g Standard Edition bereits die Nutzung von Oracle RAC bis zu vier Sockets kostenfrei beinhaltet. Möchten Sie dazu Windows nutzen, benötigen Sie keine Windows Server Enterprise Edition, da Oracle 11g die eigene Clusterware liefert. Sie kommen in den Genuss von Hochverfügbarkeit und Skalierbarkeit und können dazu die günstigere Windows Server Standard Edition nutzen. 3. SQL Server Multi-Subnet Clustering - Abhängigkeit zu 3rd Party Storage Mirroring  Die SQL Server Multi-Subnet Clustering Architektur unterstützt den Aufbau eines Stretch Clusters, basiert dabei aber auf dem Aktiv-Passiv Modell. Das eigentlich Problematische ist jedoch, dass man sich zur Absicherung der Datenbank auf 3rd Party Storage Mirroring Technologie verlässt, ohne Integration zwischen dem Windows Server Failover Clustering (WSFC) und der darunterliegenden Mirroring Technologie. Wenn nun im Cluster ein Failover auf Instanzen-Ebene erfolgt, existiert keine Koordination mit einem möglichen Failover auf Ebene des Storage-Array. 4. Availability Groups (Verfügbarkeitsgruppen) - Vier, oder doch nur Zwei? Ein primäres Replikat erlaubt bis zu vier sekundäre Replikate innerhalb einer Verfügbarkeitsgruppe, jedoch nur zwei im Synchronen Commit Modus. Während dies zwar einen Vorteil gegenüber dem stringenten 1:1 Modell unter Database Mirroring darstellt, fällt der SQL Server 2012 damit immer noch weiter zurück hinter Oracle Data Guard mit bis zu 30 direkten Stanbdy Zielen - und vielen weiteren durch kaskadierende Ziele möglichen. Damit eignet sich Oracle Active Data Guard auch für die Bereitstellung einer Reader-Farm Skalierbarkeit für Internet-basierende Unternehmen. Mit AwaysOn Verfügbarkeitsgruppen ist dies nicht möglich. 5. Availability Groups (Verfügbarkeitsgruppen) - kein asynchrones Switchover  Die Technologie der Verfügbarkeitsgruppen wird auch als geeignetes Mittel für administrative Aufgaben positioniert - wie Upgrades oder Wartungsarbeiten. Man muss sich jedoch einem gravierendem Defizit bewusst sein: Im asynchronen Verfügbarkeitsmodus besteht die einzige Möglichkeit für Role Transition im Forced Failover mit Datenverlust! Um den Verlust von Daten durch geplante Wartungsarbeiten zu vermeiden, muss man den synchronen Verfügbarkeitsmodus konfigurieren, was jedoch ernstzunehmende Auswirkungen auf WAN Deployments nach sich zieht. Spinnt man diesen Gedanken zu Ende, kommt man zu dem Schluss, dass die Technologie der Verfügbarkeitsgruppen für geplante Wartungsarbeiten in einem derartigen Umfeld nicht effektiv genutzt werden kann. 6. Automatisches Failover - Nicht immer möglich Sowohl die SQL Server FCI, als auch Verfügbarkeitsgruppen unterstützen automatisches Failover. Möchte man diese jedoch kombinieren, wird das Ergebnis kein automatisches Failover sein. Denn ihr Zusammentreffen im Failover-Fall führt zu Race Conditions (Wettlaufsituationen), weshalb diese Konfiguration nicht länger das automatische Failover zu einem Replikat in einer Verfügbarkeitsgruppe erlaubt. Auch hier bestätigt sich wieder die tiefere Problematik von AlwaysOn, mit einer Zusammensetzung aus unterschiedlichen Technologien und der Abhängigkeit zu Windows. 7. Problematische RTO (Recovery Time Objective) Microsoft postioniert die SQL Server Multi-Subnet Clustering Architektur als brauchbare HA/DR Architektur. Bedenkt man jedoch die Problematik im Zusammenhang mit DNS Replikation und den möglichen langen Wartezeiten auf Client-Seite von bis zu 16 Minuten, sind strenge RTO Anforderungen (Recovery Time Objectives) nicht erfüllbar. Im Gegensatz zu Oracle besitzt der SQL Server keine Datenbank-integrierten Technologien, wie Oracle Fast Application Notification (FAN) oder Oracle Fast Connection Failover (FCF). 8. Problematische RPO (Recovery Point Objective) SQL Server ermöglicht Forced Failover (erzwungenes Failover), bietet jedoch keine Möglichkeit zur automatischen Übertragung der letzten Datenbits von einem alten zu einem neuen primären Replikat, wenn der Verfügbarkeitsmodus asynchron war. Oracle Data Guard hingegen bietet diese Unterstützung durch das Flush Redo Feature. Dies sichert "Zero Data Loss" und beste RPO auch in erzwungenen Failover-Situationen. 9. Lesbare Sekundäre Replikate mit Einschränkungen Aufgrund des Snapshot Isolation Transaction Level für lesbare sekundäre Replikate, besitzen diese Einschränkungen mit Auswirkung auf die primäre Datenbank. Die Bereinigung von Ghost Records auf der primären Datenbank, wird beeinflusst von lang laufenden Abfragen auf der lesabaren sekundären Datenbank. Die lesbare sekundäre Datenbank kann nicht in die Verfügbarkeitsgruppe aufgenommen werden, wenn es aktive Transaktionen auf der primären Datenbank gibt. Zusätzlich können DLL Änderungen auf der primären Datenbank durch Abfragen auf der sekundären blockiert werden. Und imkrementelle Backups werden hier nicht unterstützt.   Keine dieser Restriktionen existiert unter Oracle Data Guard.

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  • Cannot login to Ubuntu 14.04 returns to the login screen

    - by Safder
    I updated to 14.04 from 12.04.03. I was using cinammon at that time. When I upgraded to 14.04 ,I got a serious problem. I was unable to login, as whenever I hit enter after entering password, it is taking me straight to login screen again.I unable to login like Guest even. So, here is my .xsession-errors file. possibly anyone could help. Thanks in advance. Script for ibus started at run_im. Script for auto started at run_im. Script for default started at run_im. init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd respawning too fast, stopped init: gnome-settings-daemon main process (14717) killed by TRAP signal init: gnome-settings-daemon main process ended, respawning init: update-notifier-crash (/var/crash/_usr_bin_gnome-session.1000.crash) main process (14607) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_lib_ibus_ibus-x11.1000.crash) main process (14623) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_lib_x86_64-linux-gnu_bamf_bamfdaemon.1000.crash) main process (14663) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_lib_ibus_ibus-ui-gtk3.1000.crash) main process (14620) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_lib_gnome-session_gnome-session-check-accelerated.1000.crash) main process (14612) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_lib_gnome-settings-daemon_gnome-settings-daemon.1000.crash) main process (14616) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_lib_unity_unity-panel-service.1000.crash) main process (14629) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_lib_unity-settings-daemon_unity-settings-daemon.1000.crash) main process (14625) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_lib_update-notifier_system-crash-notification.1000.crash) main process (14662) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_lib_gnome-session_gnome-session-check-accelerated.127.crash) main process (14613) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_share_apport_apport-gtk.1000.crash) main process (14665) terminated with status 133 init: update-notifier-crash (/var/crash/linux-image-3.13.0-24-generic.0.crash) main process (14606) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_bin_Xorg.0.crash) main process (14609) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_lib_ibus_ibus-x11.127.crash) main process (14624) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_lib_ibus_ibus-ui-gtk3.127.crash) main process (14622) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_lib_gnome-settings-daemon_gnome-settings-daemon.127.crash) main process (14618) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_lib_unity-settings-daemon_unity-settings-daemon.127.crash) main process (14628) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_lib_x86_64-linux-gnu_bamf_bamfdaemon.127.crash) main process (14664) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_bin_gnome-session.127.crash) main process (14608) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_lib_unity_unity-panel-service.127.crash) main process (14634) terminated with status 133 init: update-notifier-crash (/var/crash/_usr_share_apport_apport-gtk.127.crash) main process (14667) terminated with status 133 init: gnome-settings-daemon main process (14843) killed by TRAP signal init: gnome-settings-daemon main process ended, respawning init: gnome-settings-daemon main process (14850) killed by TRAP signal init: gnome-settings-daemon main process ended, respawning init: gnome-session (GNOME) main process (14727) killed by TRAP signal init: gnome-settings-daemon main process (14859) killed by TRAP signal init: logrotate main process (14570) killed by TERM signal init: upstart-dbus-session-bridge main process (14683) terminated with status 1 init: Disconnected from notified D-Bus bus

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  • OAM OVD integration - Error Encounterd while performance test "LDAP response read timed out, timeout used:2000ms"

    - by siddhartha_sinha
    While working on OAM OVD integration for one of my client, I have been involved in the performance test of the products wherein I encountered OAM authentication failures while talking to OVD during heavy load. OAM logs revealed the following: oracle.security.am.common.policy.common.response.ResponseException: oracle.security.am.engines.common.identity.provider.exceptions.IdentityProviderException: OAMSSA-20012: Exception in getting user attributes for user : dummy_user1, idstore MyIdentityStore with exception javax.naming.NamingException: LDAP response read timed out, timeout used:2000ms.; remaining name 'ou=people,dc=oracle,dc=com' at oracle.security.am.common.policy.common.response.IdentityValueProvider.getUserAttribute(IdentityValueProvider.java:271) ... During the authentication and authorization process, OAM complains that the LDAP repository is taking too long to return user attributes.The default value is 2 seconds as can be seen from the exception, "2000ms". While troubleshooting the issue, it was found that we can increase the ldap read timeout in oam-config.xml.  For reference, the attribute to add in the oam-config.xml file is: <Setting Name="LdapReadTimeout" Type="xsd:string">2000</Setting> However it is not recommended to increase the time out unless it is absolutely necessary and ensure that back-end directory servers are working fine. Rather I took the path of tuning OVD in the following manner: 1) Navigate to ORACLE_INSTANCE/config/OPMN/opmn folder and edit opmn.xml. Search for <data id="java-options" ………> and edit the contents of the file with the highlighted items: <category id="start-options"><data id="java-bin" value="$ORACLE_HOME/jdk/bin/java"/><data id="java-options" value="-server -Xms1024m -Xmx1024m -Dvde.soTimeoutBackend=0 -Didm.oracle.home=$ORACLE_HOME -Dcommon.components.home=$ORACLE_HOME/../oracle_common -XX:+PrintGCDetails -XX:+PrintGCDateStamps -Xloggc:/opt/bea/Middleware/asinst_1/diagnostics/logs/OVD/ovd1/ovdGClog.log -XX:+UseConcMarkSweepGC -Doracle.security.jps.config=$ORACLE_INSTANCE/config/JPS/jps-config-jse.xml"/><data id="java-classpath" value="$ORACLE_HOME/ovd/jlib/vde.jar$:$ORACLE_HOME/jdbc/lib/ojdbc6.jar"/></category></module-data><stop timeout="120"/><ping interval="60"/></process-type> When the system is busy, a ping from the Oracle Process Manager and Notification Server (OPMN) to Oracle Virtual Directory may fail. As a result, OPMN will restart Oracle Virtual Directory after 20 seconds (the default ping interval). To avoid this, consider increasing the ping interval to 60 seconds or more. 2) Navigate to ORACLE_INSTANCE/config/OVD/ovd1 folder.Open listeners.os_xml file and perform the following changes: · Search for <ldap id=”Ldap Endpoint”…….> and point the cursor to that line. · Change threads count to 200. · Change anonymous bind to Deny. · Change workQueueCapacity to 8096. Add a new parameter <useNIO> and set its value to false viz: <useNIO>false</useNio> Snippet: <ldap version="8" id="LDAP Endpoint"> ....... .......  <socketOptions><backlog>128</backlog>         <reuseAddress>false</reuseAddress>         <keepAlive>false</keepAlive>         <tcpNoDelay>true</tcpNoDelay>         <readTimeout>0</readTimeout>      </socketOptions> <useNIO>false</useNIO></ldap> Restart OVD server. For more information on OVD tuneup refer to http://docs.oracle.com/cd/E25054_01/core.1111/e10108/ovd.htm. Please Note: There were few patches released from OAM side for performance tune-up as well. Will provide the updates shortly !!!

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  • Hierarchical View/ViewModel/Presenters in MVPVM

    - by Brian Flynn
    I've been working with MVVM for a while, but I've recently started using MVPVM and I want to know how to create hierarchial View/ViewModel/Presenter app using this pattern. In MVVM I would typically build my application using a hierarchy of Views and corresponding ViewModels e.g. I might define 3 views as follows: The View Models for these views would be as follows: public class AViewModel { public string Text { get { return "This is A!"; } } public object Child1 { get; set; } public object Child2 { get; set; } } public class BViewModel { public string Text { get { return "This is B!"; } } } public class CViewModel { public string Text { get { return "This is C!"; } } } In would then have some data templates to say that BViewModel and CViewModel should be presented using View B and View C: <DataTemplate DataType="{StaticResource local:BViewModel}"> <local:BView/> </DataTemplate> <DataTemplate DataType="{StaticResource local:CViewModel}"> <local:CView/> </DataTemplate> The final step would be to put some code in AViewModel that would assign values to Child1 and Child2: public AViewModel() { this.Child1 = new AViewModel(); this.Child2 = new BViewModel(); } The result of all this would be a screen that looks something like: Doing this in MVPVM would be fairly simple - simply moving the code in AViewModel's constructor to APresenter: public class APresenter { .... public void WireUp() { ViewModel.Child1 = new BViewModel(); ViewModel.Child2 = new CViewModel(); } } But If I want to have business logic for BViewModel and CViewModel I would need to have a BPresenter and a CPresenter - the problem is, Im not sure where the best place to put these are. I could store references to the presenter for AViewModel.Child1 and AViewModel.Child2 in APresenter i.e.: public class APresenter : IPresenter { private IPresenter child1Presenter; private IPresenter child2Presenter; public void WireUp() { child1Presenter = new BPresenter(); child1Presenter.WireUp(); child2Presenter = new CPresenter(); child2Presenter.WireUp(); ViewModel.Child1 = child1Presenter.ViewModel; ViewModel.Child2 = child2Presenter.ViewModel; } } But this solution seems inelegant compared to the MVVM approach. I have to keep track of both the presenter and the view model and ensure they stay in sync. If, for example, I wanted a button on View A, which, when clicked swapped the View's in Child1 and Child2, I might have a command that did the following: var temp = ViewModel.Child1; ViewModel.Child1 = ViewModel.Child2; ViewModel.Child2 = temp; This would work as far as swapping the view's on screen (assuming the correct Property Change notification code is in place), but now my APresenter.child1Presenter is pointing to the presenter for AViewModel.Child2, and APresenter.child2Presenter is pointing to the presenter for AViewModel.Child1. If something accesses APresenter.child1Presenter, any changes will actually happen to AViewModel.Child2. I can imagine this leading to all sorts of debugging fun. I know that I may be misunderstanding the pattern, and if this is the case a clarification of what Im doing wrong would be appreciated.

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  • MongoDB usage best practices

    - by andresv
    The project I'm working on uses MongoDB for some stuff so I'm creating some documents to help developers speedup the learning curve and also avoid mistakes and help them write clean & reliable code. This is my first version of it, so I'm pretty sure I will be adding more stuff to it, so stay tuned! C# Official driver notes The 10gen official MongoDB driver should always be referenced in projects by using NUGET. Do not manually download and reference assemblies in any project. C# driver quickstart guide: http://www.mongodb.org/display/DOCS/CSharp+Driver+Quickstart Reference links C# Language Center: http://www.mongodb.org/display/DOCS/CSharp+Language+Center MongoDB Server Documentation: http://www.mongodb.org/display/DOCS/Home MongoDB Server Downloads: http://www.mongodb.org/downloads MongoDB client drivers download: http://www.mongodb.org/display/DOCS/Drivers MongoDB Community content: http://www.mongodb.org/display/DOCS/CSharp+Community+Projects Tutorials Tutorial MongoDB con ASP.NET MVC - Ejemplo Práctico (Spanish):http://geeks.ms/blogs/gperez/archive/2011/12/02/tutorial-mongodb-con-asp-net-mvc-ejemplo-pr-225-ctico.aspx MongoDB and C#:http://www.codeproject.com/Articles/87757/MongoDB-and-C C# driver LINQ tutorial:http://www.mongodb.org/display/DOCS/CSharp+Driver+LINQ+Tutorial C# driver reference: http://www.mongodb.org/display/DOCS/CSharp+Driver+Tutorial Safe Mode Connection The C# driver supports two connection modes: safe and unsafe. Safe connection mode (only applies to methods that modify data in a database like Inserts, Deletes and Updates. While the current driver defaults to unsafe mode (safeMode == false) it's recommended to always enable safe mode, and force unsafe mode on specific things we know aren't critical. When safe mode is enabled, the driver internal code calls the MongoDB "getLastError" function to ensure the last operation is completed before returning control the the caller. For more information on using safe mode and their implicancies on performance and data reliability see: http://www.mongodb.org/display/DOCS/getLastError+Command If safe mode is not enabled, all data modification calls to the database are executed asynchronously (fire & forget) without waiting for the result of the operation. This mode could be useful for creating / updating non-critical data like performance counters, usage logging and so on. It's important to know that not using safe mode implies that data loss can occur without any notification to the caller. As with any wait operation, enabling safe mode also implies dealing with timeouts. For more information about C# driver safe mode configuration see: http://www.mongodb.org/display/DOCS/CSharp+getLastError+and+SafeMode The safe mode configuration can be specified at different levels: Connection string: mongodb://hostname/?safe=true Database: when obtaining a database instance using the server.GetDatabase(name, safeMode) method Collection: when obtaining a collection instance using the database.GetCollection(name, safeMode) method Operation: for example, when executing the collection.Insert(document, safeMode) method Some useful SafeMode article: http://stackoverflow.com/questions/4604868/mongodb-c-sharp-safemode-official-driver Exception Handling The driver ensures that an exception will be thrown in case of something going wrong, in case of using safe mode (as said above, when not using safe mode no exception will be thrown no matter what the outcome of the operation is). As explained here https://groups.google.com/forum/?fromgroups#!topic/mongodb-user/mS6jIq5FUiM there is no need to check for any returned value from a driver method inserting data. With updates the situation is similar to any other relational database: if an update command doesn't affect any records, the call will suceed anyway (no exception thrown) and you manually have to check for something like "records affected". For MongoDB, an Update operation will return an instance of the "SafeModeResult" class, and you can verify the "DocumentsAffected" property to ensure the intended document was indeed updated. Note: Please remember that an Update method might return a null instance instead of an "SafeModeResult" instance when safe mode is not enabled. Useful Community Articles Comments about how MongoDB works and how that might affect your application: http://ethangunderson.com/blog/two-reasons-to-not-use-mongodb/ FourSquare using MongoDB had serious scalability problems: http://mashable.com/2010/10/07/mongodb-foursquare/ Is MongoDB a replacement for Memcached? http://www.quora.com/Is-MongoDB-a-good-replacement-for-Memcached/answer/Rick-Branson MongoDB Introduction, shell, when not to use, maintenance, upgrade, backups, memory, sharding, etc: http://www.markus-gattol.name/ws/mongodb.html MongoDB Collection level locking support: https://jira.mongodb.org/browse/SERVER-1240 MongoDB performance tips: http://www.quora.com/MongoDB/What-are-some-best-practices-for-optimal-performance-of-MongoDB-particularly-for-queries-that-involve-multiple-documents Lessons learned migrating from SQL Server to MongoDB: http://www.wireclub.com/development/TqnkQwQ8CxUYTVT90/read MongoDB replication performance: http://benshepheard.blogspot.com.ar/2011/01/mongodb-replication-performance.html

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  • POP Forums v9 Beta 1 for ASP.NET MVC 3 posted to CodePlex!

    - by Jeff
    As promised, I posted a beta build of my forum app for ASP.NET MVC 3. Get the new goodies here: http://popforums.codeplex.com/releases/view/58228 This is the first beta for the ASP.NET MVC 3 version of POP Forums. It is nearly feature complete, and ready for testing and feedback. For previous release notes, look here, here and here.Check out the live preview: http://preview.popforums.com/ForumsSetup instructions are on the home page of this project. The new hotness in the beta, or what has been done since the last preview: All views converted to use Razor E-mail subscription/notification of new posts New post indicators/mark read buttons Permalinks to posts Jump to newest post (from new post indicators) Recent topics Favorite topics Moderator functions for topics (pin/close/delete, plus move and rename) Search, ported from v8. Not a ton of optimization here, or new unit testing, but the old version worked pretty well User posts (topics the user posted in) Forgot password Vanity items (signatures and avatars) Hide vanity items per user preference Some minor data caching where appropriate A little bit of UI refinement Lots-o-bug fixes Lots-o-unit tests What's next? The plan between now and the next beta is as follows: Continue working through features/tasks, and fix bugs as they're reported Integrate the forum into a real, production site Refine the UI Refactor as much as possible... the code organization is not entirely logical in some places After the second beta, a release candidate will follow, with a real "final" release after that. Subsequent releases should come relatively frequently and without a lot of risk. The trick in building this thing has been that it mostly tossed the previous WebForms version, which was all full of crusties. The time table for this is a little harder to pin down, as day jobs and families will have their effect. Other notes Refactoring will be a priority. As the features of MVC have evolved, so have my desires to use it in a fashion that makes things clear and easy to follow. I don't even know if anyone will ever start mucking around in the code, but on the off chance they do, I'd like what they find to not suck. Other nice-to-haves are builds to target Windows Azure and SQL CE. A nice setup UI would be super too. I think the ASP.NET MVC world has gone long enough without a decent forum.The biggest challenge that I've found is making the forum something that can be dropped in any app. While it does rope its views into an area, areas are mostly just routing details. I haven't thought of a clever way yet to limit dependency injection, for example, to just the forum bits. I mean, everyone should be using Ninject, but how realistic is that? ;)How much time and effort should you spend on POP Forums in its current state? Change is inevitable, but at this point I'm reasonably committed to not changing the database schema. I really think it will stay as-is. All bets are off for the various interfaces throughout the app, but the data should generally resist change. It's not even that different from v8, which was one of the original goals because I didn't want to rewrite SQL or introduce a new ORM or whatever. My point is that if you wanted to build a site around this today, even though it's not entirely functional, I think it's low risk in terms of data loss. I can't vouch for whether or not you know what you're doing.I've been having some chats with people lately about quoting posts, and honestly there has to be something better and straight forward. That continues to be a holy grail of mine, and some day, I hope to find it.Enjoy... it's starting to feel more real every day!

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  • Fusion Concepts: Fusion Database Schemas

    - by Vik Kumar
    You often read about FUSION and FUSION_RUNTIME users while dealing with Fusion Applications. There is one more called FUSION_DYNAMIC. Here are some details on the difference between these three and the purpose of each type of schema. FUSION: It can be considered as an Administrator of the Fusion Applications with all the corresponding rights and powers such as owning tables and objects, providing grants to FUSION_RUNTIME.  It is used for patching and has grants to many internal DBMS functions. FUSION_RUNTIME: Used to run the Applications.  Contains no DB objects. FUSION_DYNAMIC: This schema owns the objects that are created dynamically through ADM_DDL. ADM_DDL is a package that acts as a wrapper around the DDL statement. ADM_DDL support operations like truncate table, create index etc. As the above statements indicate that FUSION owns the tables and objects including FND tables so using FUSION to run applications is insecure. It would be possible to modify security policies and other key information in the base tables (like FND) to break the Fusion Applications security via SQL injection etc. Other possibilities would be to write a logon DB trigger and steal credentials etc. Thus, to make Fusion Applications secure FUSION_RUNTIME is granted privileges to execute DMLs only on APPS tables. Another benefit of having separate users is achieving Separation of Duties (SODs) at schema level which is required by auditors. Below are the roles and privileges assigned to FUSION, FUSION_RUNTIME and FUSION_DYNAMIC schema: FUSION It has the following privileges: Create SESSION Do all types of DDL owned by FUSION. Additionally, some specific priveleges on other schemas is also granted to FUSION. EXECUTE ON various EDN_PUBLISH_EVENT It has the following roles: CTXAPP for managing Oracle Text Objects AQ_SER_ROLE and AQ_ADMINISTRATOR_ROLE for managing Advanced Queues (AQ) FUSION_RUNTIME It has the following privileges: CREATE SESSION CHANGE NOTIFICATION EXECUTE ON various EDN_PUBLISH_EVENT It has the following roles: FUSION_APPS_READ_WRITE for performing DML (Select, Insert, Delete) on Fusion Apps tables FUSION_APPS_EXECUTE for performing execute on objects such as procedures, functions, packages etc. AQ_SER_ROLE and AQ_ADMINISTRATOR_ROLE for managing Advanced Queues (AQ) FUSION_DYNAMIC It has following privileges: CREATE SESSION, PROCEDURE, TABLE, SEQUENCE, SYNONYM, VIEW UNLIMITED TABLESPACE ANALYZE ANY CREATE MINING MODEL EXECUTE on specific procedure, function or package and SELECT on specific tables. This depends on the objects identified by product teams that ADM_DDL needs to have access  in order to perform dynamic DDL statements. There is one more role FUSION_APPS_READ_ONLY which is not attached to any user and has only SELECT privilege on all the Fusion objects. FUSION_RUNTIME does not have any synonyms defined to access objects owned by FUSION schema. A logon trigger is defined in FUSION_RUNTIME which sets the current schema to FUSION and eliminates the need of any synonyms.   What it means for developers? Fusion Application developers should be using FUSION_RUNTIME for testing and running Fusion Applications UI, BC and to connect to any SQL front end like SQL *PLUS, SQL Loader etc. For testing ADFbc using AM tester while using FUSION_RUNTIME you may hit the following error: oracle.jbo.JboException: JBO-29000: Unexpected exception caught: java.sql.SQLException, msg=invalid name pattern: FUSION.FND_TABLE_OF_VARCHAR2_255 The fix is to add the below JVM parameter in the Run/Debug client property in the Model project properties -Doracle.jdbc.createDescriptorUseCurrentSchemaForSchemaName=true More details are discussed in this forum thread for it.

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

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

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  • Dual boot Ubuntu and Windows 7, I Can only boot ubuntu through recovery mode

    - by Alec
    I want to become a new user of Ubuntu, however this problem is preventing me. I have/had Window 7 professional on my computer. I recently looked into getting linux. I discovered dual-booting and decided to give it a try. First I created a bootable flash drive with ubuntu 12.10 64 bit. I then followed the instructions on: https://help.ubuntu.com/community/WindowsDualBoot after I finished going through the setup, my computer rebooted. After the reboot I was able to select Ubuntu, advanced options for Ubuntu, 2 memory tests, and windows 7 (loader). So I chose Windows ( honestly i was more concerned that i still had everything on windows at this point). I then rebooted again and selected Ubuntu. When i selected Ubuntu, the background screen of Grub (the crimson/burgandy color) stayed for a few seconds then the screen went black: video here http://www.youtube.com/watch?v=6kKcG4sT7Lg&feature=plcp I tried again with the same results. so i redid the ubuntu install differently using http://www.liberiangeek.net/2012/10/dual-booting-windows-7-and-ubuntu-12-10-quantal-quetzal/. After rebooting the same thing happened. After that i was stumped, so i figured it could hurt to experiment. after all i backed up my windows 7 stuff, and i have the software disk. I tried booting in recovery mode under "advanced options for Ubuntu" and sure enough, after selecting continue to normal reboot it worked. So i updated and everything but when i rebooted it still wouldn't boot under Ubuntu. It would always boot after recovery mode. So i try installing 12.10 32 bit Ubuntu. the same problem keeps happening. I can still get to Ubuntu through recovery mode. so i went online and tried using the terminal (in ubuntu that i booted through recovery mode) when i was using it i discovered that "Error in sitecustomize; set PYTHONVERBOSE for traceback: EOFError: EOF read where not expected" kept showing up. also i noticed a notification in the top right corner that looked like a do not enter sign. it said "an error occured, please run package manager from the right-click menu or apt-get in a terminal to see what is wrong. the error message was: 'ror in sitecustomize;set PYTHONVERBOSE for traceback: EOFError: EOF read where not expected traceback (most recent called last): File "/usr/bin/lsb_release EOFError: EOF read where not expected 39;0' this usually means that your installed packages have unmet dependencies" Naturally i assumed this was what was causing my boot problems. I downloaded synaptic and updated everything and the error went away. but my boot problem was still a problem. so i go online find some things that have worked for others, like this Try to do this (in your terminal: sudo nano /etc/default/grub Look for: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" Change it too : GRUB_CMDLINE_LINUX_DEFAULT="quiet" And update Grub: sudo update-grub This should fix stuff.) I did this and i still have the problem. sorry for the excessive explanation, please help.

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  • Detecting Process Shutdown/Startup Events through ActivationAgents

    - by Ramkumar Menon
    @10g - This post is motivated by one of my close friends and colleague - who wanted to proactively know when a BPEL process shuts down/re-activates. This typically happens when you have a BPEL Process that has an inbound polling adapter, when the adapter loses connectivity to the source system. Or whatever causes it. One valuable suggestion came in from one of my colleagues - he suggested I write my own ActivationAgent to do the job. Well, it really worked. Here is a sample ActivationAgent that you can use. There are few methods you need to override from BaseActivationAgent, and you are on your way to receiving notifications/what not, whenever the shutdown/startup events occur. In the example below, I am retrieving the emailAddress property [that is specified in your bpel.xml activationAgent section] and use that to send out an email notification on the activation agent initialization. You could choose to do different things. But bottomline is that you can use the below-mentioned API to access the very same properties that you specify in the bpel.xml. package com.adapter.custom.activation; import com.collaxa.cube.activation.BaseActivationAgent; import com.collaxa.cube.engine.ICubeContext; import com.oracle.bpel.client.BPELProcessId; import java.util.Date; import java.util.Properties; public class LifecycleManagerActivationAgent extends BaseActivationAgent { public BPELProcessId getBPELProcessId() { return super.getBPELProcessId(); } private void handleInit() throws Exception { //Write initialization code here System.err.println("Entered initialization code...."); //e.g. String emailAddress = getActivationAgentDescriptor().getPropertyValue(emailAddress); //send an email sendEmail(emailAddress); } private void handleLoad() throws Exception { //Write load code here System.err.println("Entered load code...."); } private void handleUnload() throws Exception { //Write unload code here System.err.println("Entered unload code...."); } private void handleUninit() throws Exception { //Write uninitialization code here System.err.println("Entered uninitialization code...."); } public void init(ICubeContext icubecontext) throws Exception { super.init(icubecontext); System.err.println("Initializing LifecycleManager Activation Agent ....."); handleInit(); } public void unload(ICubeContext icubecontext) throws Exception { super.unload(icubecontext); System.err.println("Unloading LifecycleManager Activation Agent ....."); handleUnload(); } public void uninit(ICubeContext icubecontext) throws Exception{ super.uninit(icubecontext); System.err.println("Uninitializing LifecycleManager Activation Agent ....."); handleUninit(); } public String getName() { return "Lifecyclemanageractivationagent"; } public void onStateChanged(int i, ICubeContext iCubeContext) { } public void onLifeCycleChanged(int i, ICubeContext iCubeContext) { } public void onUndeployed(ICubeContext iCubeContext) { } public void onServerShutdown() { } } Once you compile this code, generate a jar file and ensure you add it to the server startup classpath. The library is ready for use after the server restarts. To use this activationAgent, add an additional activationAgent entry in the bpel.xml for the BPEL Process that you wish to monitor. After you deploy the process, the ActivationAgent object will be called back whenever the events mentioned in the overridden methods are raised. [init(), load(), unload(), uninit()]. Subsequently, your custom code is executed. Sample bpel.xml illustrating activationAgent definition and property definition. <?xml version="1.0" encoding="UTF-8"? <BPELSuitcase timestamp="1291943469921" revision="1.0" <BPELProcess wsdlPort="{http://xmlns.oracle.com/BPELTest}BPELTestPort" src="BPELTest.bpel" wsdlService="{http://xmlns.oracle.com/BPELTest}BPELTest" id="BPELTest" <partnerLinkBindings <partnerLinkBinding name="client" <property name="wsdlLocation"BPELTest.wsdl</property </partnerLinkBinding <partnerLinkBinding name="test" <property name="wsdlLocation"test.wsdl</property </partnerLinkBinding </partnerLinkBindings <activationAgents <activationAgent className="oracle.tip.adapter.fw.agent.jca.JCAActivationAgent" partnerLink="test" <property name="portType"Read_ptt</property </activationAgent <activationAgent className="com.oracle.bpel.activation.LifecycleManagerActivationAgent" partnerLink="test" <property name="emailAddress"[email protected]</property </activationAgent </activationAgents </BPELProcess </BPELSuitcase em

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  • SQL SERVER – Basic Calculation and PEMDAS Order of Operation

    - by pinaldave
    After thinking a long time, I have decided to write about this blog post. I had no plan to create a blog post about this subject but the amount of conversation this one has created on my Facebook page, I decided to bring up a few of the question and concerns discussed on the Facebook page. There are more than 10,000 comments here so far. There are lots of discussion about what should be the answer. Well, as far as I can tell there is a big debate going on on Facebook, for educational purpose you should go ahead and read some of the comments. They are very interesting and for sure teach some new stuff. Even though some of the comments are clearly wrong they have made some good points and I believe it for sure develops some logic. Here is my take on this subject. I believe the answer is 9 as I follow PEMDAS  Order of Operation. PEMDAS stands for  parentheses, exponents, multiplication, division, addition, subtraction. PEMDAS is commonly known as BODMAS in India. BODMAS stands for Brackets, Orders (ie Powers and Square Roots, etc), Division, Multiplication,  Addition and Subtraction. PEMDAS and BODMAS are almost same and both of them follow the operation order from LEFT to RIGHT. Let us try to simplify above statement using the PEMDAS or BODMAS (whatever you prefer to call). Step 1: 6 ÷ 2 (1+2) (parentheses first) Step 2: = 6 ÷ 2 * (1+2) (adding multiplication sign for further clarification) Step 3: = 6 ÷ 2* (3) (single digit in parentheses – simplify using operator) Step 4: = 6 ÷ 2 * 3 (Remember next Operation should be LEFT to RIGHT) Step 5: = 3 * 3 (because 6 ÷ 2 = 3; remember LEFT to RIGHT) Step 6: = 9 (final answer) Some often find Step 4 confusing and often ended up multiplying 2 and 3 resulting Step 5 to be 6 ÷ 6, this is incorrect because in this case we did not follow the order of LEFT to RIGHT. When we do not follow the order of operation from LEFT to RIGHT we end up with the answer 1 which is incorrect. Let us see what SQL Server returns as a result. I executed following statement in SQL Server Management Studio SELECT 6/2*(1+2) It is clear that SQL Server also thinks that the answer should be 9. Let us go ahead and ask Google what will be the answer of above question in Google I have searched for the following term: 6/2(1+2) The result also says the answer should be 9. If you want a further reference here is a great video which describes why the answer should be 9 and not 1. And here is a fantastic conversation on Google Groups. Well, now what is your take on this subject? You are welcome to share constructive feedback and your answer may be different from my answer. NOTE: A healthy conversation about this subject is indeed encouraged but if there is a single bad word or comment is flaming it will be deleted without any notification (it does not matter how valuable information it contains). Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: About Me, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • no launcher, no dash, no unity, how to get back to my desktop?

    - by Numan Syed
    FYI, I have tried these, but none worked as of yet! Please help! I must not want to reinstall Ubuntu precise: AskUbuntu:Unity Launcher missing AskUbuntu: Unity doesn't load Youtube:Restore missing launcher AskUbuntu:Unity 3D no longer works! Is there any other way to find a solution, any help is highly appreciated! Please do ask for any further info u may need to point me to a better direction. Edit: I have still the opportunity to use ctrl+Alt+T for the terminal. And from there I used firefox & to get the browser on. Edit 2: Tried to find more; found more explained situation http://askubuntu.com/q/260578/176470. Edit 3:@Adithya: tried that no luck! Here is what my terminal gave me so far... [1447:22] (~) bash $ unity --reset WARNING: Unity currently default profile, so switching to metacity while resetting the values unity-panel-service: no process found Checking if settings need to be migrated ...no Checking if internal files need to be migrated ...no Backend : gconf Integration : true Profile : unity Adding plugins Initializing core options...done compiz (core) - Warn: failed to receive ConfigureNotify event on 0x1600004 compiz (core) - Warn: failed to receive ConfigureNotify event on 0x30000b8 compiz (core) - Warn: failed to receive ConfigureNotify event on 0x2c00fc1 Initializing composite options...done Initializing opengl options...done Initializing decor options...done Initializing vpswitch options...done Initializing snap options...done Initializing mousepoll options...done Initializing resize options...done Initializing place options...done Initializing move options...done Initializing wall options...done Initializing grid options...done Initializing session options...done Initializing gnomecompat options...done Initializing animation options...done Initializing fade options...done compiz (core) - Error: Couldn't load plugin '/usr/lib/compiz/libunitymtgrabhandles.so' : /usr/lib/compiz/libunitymtgrabhandles.so: undefined symbol: _ZN10CompOption7setNameEPKcNS_4TypeE compiz (core) - Error: Couldn't load plugin 'unitymtgrabhandles' Initializing workarounds options...done Initializing scale options...done compiz (expo) - Warn: failed to bind image to texture Initializing expo options...done Initializing ezoom options...done compiz (core) - Error: Couldn't load plugin '/usr/lib/compiz/libunityshell.so' : /usr/lib/compiz/libunityshell.so: undefined symbol: _ZN10CompOption7setNameEPKcNS_4TypeE compiz (core) - Error: Couldn't load plugin 'unityshell' compiz (core) - Warn: unhandled ConfigureNotify on 0xc000a0! compiz (core) - Warn: this should never happen. you should probably file a bug about this. compiz (core) - Warn: unhandled ConfigureNotify on 0xc000a3! compiz (core) - Warn: this should never happen. you should probably file a bug about this. compiz (core) - Warn: unhandled ConfigureNotify on 0xc000a6! compiz (core) - Warn: this should never happen. you should probably file a bug about this. Initializing addhelper options...done Initializing animationaddon options...done Initializing annotate options...done Initializing bench options...done Initializing blur options...done Initializing clone options...done Initializing colorfilter options...done Initializing commands options...done Initializing crashhandler options...done Initializing cube options...done Initializing cubeaddon options...done Initializing extrawm options...done Initializing fadedesktop options...done Initializing firepaint options...done Initializing group options...done Initializing imgjpeg options...done Initializing kdecompat options...done Initializing loginout options...done Initializing mag options...done Initializing maximumize options...done Initializing mblur options...done Initializing neg options...done Initializing notification options...done Initializing obs options...done Initializing opacify options...done Initializing put options...done Initializing reflex options...done Initializing resizeinfo options...done Initializing ring options...done Initializing rotate options...done Initializing scaleaddon options...done Initializing scalefilter options...done Initializing screenshot options...done Initializing shelf options...done Initializing shift options...done Initializing showdesktop options...done Initializing showmouse options...done Initializing splash options...done Initializing staticswitcher options...done Initializing switcher options...done Initializing td options...done Initializing thumbnail options...done Initializing trailfocus options...done Initializing unitymtgrabhandles options...done Initializing unityshell options...done Initializing wallpaper options...done Initializing water options...done Initializing widget options...done Initializing winrules options...done Initializing wobbly options...done Setting Update "main_menu_key" Setting Update "run_key" Anything suspicious herein?

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  • User interfirance, themes, Broken, Unreadable parts

    - by Adames
    Arther going on a customizing spree my the desktop themes on unity got messed up I had installed Ubuntu tweak and unsettings so I removed them but the default themes and custom ones are still messed up I ran unity --reset and this is what I get: WARNING: Unity currently default profile, so switching to metacity while resetting the values unity-panel-service: no process found Checking if settings need to be migrated ...no Checking if internal files need to be migrated ...no Backend : gconf Integration : true Profile : unity Adding plugins Initializing core options...done compiz (core) - Warn: failed to receive ConfigureNotify event on 0x1200004 compiz (core) - Warn: failed to receive ConfigureNotify event on 0x38000af compiz (core) - Warn: failed to receive ConfigureNotify event on 0x32000ad Initializing composite options...done Initializing opengl options...done Initializing decor options...done Initializing vpswitch options...done Initializing snap options...done Initializing mousepoll options...done Initializing resize options...done Initializing place options...done Initializing move options...done Initializing wall options...done Initializing grid options...done Initializing session options...done Initializing gnomecompat options...done Initializing animation options...done Initializing fade options...done Initializing unitymtgrabhandles options...done Initializing workarounds options...done Initializing scale options...done compiz (expo) - Warn: failed to bind image to texture Initializing expo options...done Initializing ezoom options...done (compiz:4749): GConf-CRITICAL **: gconf_client_add_dir: assertion `gconf_valid_key (dirname, NULL)' failed Initializing unityshell options...done compiz (core) - Warn: unhandled ConfigureNotify on 0xc0009e! compiz (core) - Warn: this should never happen. you should probably file a bug about this. compiz (core) - Warn: unhandled ConfigureNotify on 0xc000a1! compiz (core) - Warn: this should never happen. you should probably file a bug about this. compiz (core) - Warn: unhandled ConfigureNotify on 0xc000a1! compiz (core) - Warn: this should never happen. you should probably file a bug about this. compiz (core) - Warn: unhandled ConfigureNotify on 0xc000a4! compiz (core) - Warn: this should never happen. you should probably file a bug about this. WARN 2012-07-02 19:51:42 unity.libindicator <unknown>:0 Desktop file '/usr/share/applications/google-chrome.desktop' is using a deprecated format for its actions that will be dropped soon. WARN 2012-07-02 19:51:42 unity.libindicator <unknown>:0 Desktop file '/usr/share/applications/firefox.desktop' is using a deprecated format for its actions that will be dropped soon. WARN 2012-07-02 19:51:42 unity.libindicator <unknown>:0 Desktop file '/usr/share/applications/libreoffice-writer.desktop' is using a deprecated format for its actions that will be dropped soon. WARN 2012-07-02 19:51:42 unity.libindicator <unknown>:0 Desktop file '/usr/share/applications/libreoffice-calc.desktop' is using a deprecated format for its actions that will be dropped soon. WARN 2012-07-02 19:51:42 unity.libindicator <unknown>:0 Desktop file '/usr/share/applications/libreoffice-impress.desktop' is using a deprecated format for its actions that will be dropped soon. Initializing addhelper options...done Initializing animationaddon options...done Initializing annotate options...done Initializing bench options...done Initializing blur options...done Initializing clone options...done Initializing colorfilter options...done Initializing commands options...done Initializing crashhandler options...done Initializing cube options...done Initializing cubeaddon options...done Initializing extrawm options...done Initializing fadedesktop options...done Initializing firepaint options...done Initializing group options...done Initializing imgjpeg options...done Initializing kdecompat options...done Initializing loginout options...done Initializing mag options...done Initializing maximumize options...done Initializing mblur options...done Initializing neg options...done Initializing notification options...done Initializing obs options...done Initializing opacify options...done Initializing put options...done Initializing reflex options...done Initializing resizeinfo options...done Initializing ring options...done Initializing rotate options...done Initializing scaleaddon options...done Initializing scalefilter options...done Initializing screenshot options...done Initializing shelf options...done Initializing shift options...done Initializing showdesktop options...done Initializing showmouse options...done Initializing splash options...done Initializing staticswitcher options...done Initializing switcher options...done Initializing td options...done Initializing thumbnail options...done Initializing trailfocus options...done Initializing wallpaper options...done Initializing water options...done Initializing widget options...done Initializing winrules options...done Initializing wobbly options...done ERROR 2012-07-02 19:51:43 unity.glib-gobject <unknown>:0 g_object_unref: assertion `G_IS_OBJECT (object)' failed Setting Update "main_menu_key" Setting Update "run_key" Setting Update "autoraise" Setting Update "autoraise_delay" Any Ideas? this is very inconvenient some of the text like in additional drivers are unreadable because they come out White

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  • Using Live Data in Database Development Work

    - by Phil Factor
    Guest Editorial for Simple-Talk Newsletter... in which Phil Factor reacts with some exasperation when coming across a report that a majority of companies were still using financial and personal data for both developing and testing database applications. If you routinely test your development work using real production data that contains personal or financial information, you are probably being irresponsible, and at worst, risking a heavy financial penalty for your company. Surprisingly, over 80% of financial companies still do this. Plenty of data breaches and fraud have happened from the use of real data for testing, and a data breach is a nightmare for any organisation that suffers one. The cost of each data breach averages out at around $7.2 million in the US in notification, escalation, credit monitoring, fines, litigation, legal costs, and lost business due to customer churn, £1.9 million in the UK. 70% of data breaches are done from within the organisation. Real data can be exploited in a number of ways for malicious or criminal purposes. It isn't just the obvious use of items such as name and address, date of birth, social security number, and credit card and bank account numbers: Data can be exploited in many subtle ways, so there are excellent reasons to ensure that a high priority is given to the detection and prevention of any data breaches. You'll never successfully guess all the ways that real data can be exploited maliciously, or the ease with which it can be accessed. It would be silly to argue that developers never need access to a copy of the database containing live data. Developers sometimes need to track a bug that can only be replicated on the data from the live database. However, it has to be done in a very restrictive harness. The law makes no distinction between development and production databases when a data breach occurs, so the data has to be held with all appropriate security measures in place. In Europe, the use of personal data for testing requires the explicit consent of the people whose data is being held. There are federal standards such as GLBA, PCI DSS and HIPAA, and most US States have privacy legislation. The task of ensuring compliance and tight security in such circumstances is an expensive and time-consuming overhead. The developer is likely to suffer investigation if a data breach occurs, even if the company manages to stay in business. Ironically, the use of copies of live data isn't usually the most effective way to develop or test your data. Data is usually time-specific and isn't usually current by the time it is used for testing, Existing data doesn't help much for new functionality, and every time the data is refreshed from production, any test data is likely to be overwritten. Also, it is not always going to test all the 'edge' conditions that are likely to flush out bugs. You still have the task of simulating the dynamics of actual usage of the database, and here you have no alternative to creating 'spoofed' data. Because of the complexities of relational data, It used to be that there was no realistic alternative to developing and testing with live data. However, this is no longer the case. Real data can be obfuscated, or it can be created entirely from scratch. The latter process used to be impractical, now that there are plenty of third-party tools to choose from. The process of obfuscation isn't risk free. The process must access the live data, and the success of the obfuscation process has to be carefully monitored. Database data security isn't an exciting topic to you or I, but to a hacker it can be an all-consuming obsession, especially if there is financial or political gain involved. This is not the sort of adversary one would wish for and it is far better to accept, and work with, security restrictions that exist for using live data in database development work, especially when the tools exist to create large realistic database test data that can be better for several aspects of testing.

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  • Use Case Actors - Primary versus Secondary

    - by Dave Burke
    The Unified Modeling Language (UML1) defines an Actor (from UseCases) as: An actor specifies a role played by a user or any other system that interacts with the subject. In Alistair Cockburn’s book “Writing Effective Use Cases” (2) Actors are further defined as follows: Primary Actor: The primary actor of a use case is the stakeholder that calls on the system to deliver one of its services. It has a goal with respect to the system – one that can be satisfied by its operation. The primary actor is often, but not always, the actor who triggers the use case. Supporting Actors: A supporting actor in a use case in an external actor that provides a service to the system under design. It might be a high-speed printer, a web service, or humans that have to do some research and get back to us. In a 2006 article (3) Cockburn refined the definitions slightly to read: Primary Actors: The Actor(s) using the system to achieve a goal. The Use Case documents the interactions between the system and the actors to achieve the goal of the primary actor. Secondary Actors: Actors that the system needs assistance from to achieve the primary actor’s goal. Finally, the Oracle Unified Method (OUM) concurs with the UML definition of Actors, along with Cockburn’s refinement, but OUM also includes the following: Secondary actors may or may not have goals that they expect to be satisfied by the use case, the primary actor always has a goal, and the use case exists to satisfy the primary actor. Now that we are on the same “page”, let’s consider two examples: A bank loan officer wants to review a loan application from a customer, and part of the process involves a real-time credit rating check. Use Case Name: Review Loan Application Primary Actor: Loan Officer Secondary Actors: Credit Rating System A Human Resources manager wants to change the job code of an employee, and as part of the process, automatically notify several other departments within the company of the change. Use Case Name: Maintain Job Code Primary Actor: Human Resources Manager Secondary Actors: None The first example is quite straight forward; we need to define the Secondary Actor because without the “Credit Rating System” we cannot successfully complete the Use Case. In other words, the goal of the Primary Actor is to successfully complete the Loan Application, but they need the explicit “help” of the Secondary Actor (Credit Rating System) to achieve this goal. The second example is where people sometimes get confused. Within OUM we would not include the “other departments” as Secondary Actors and therefore not include them on the Use Case diagram for the following reasons: The other departments are not required for the successful completion of the Use Case We are not expecting any response from the other departments (at least within the bounds of the Use Case under discussion) Having said that, within the detail of the Use Case Specification Main Success Scenario, we would include something like: “The system sends a notification to the related department heads (ref. Business Rule BR101)” Now let’s consider one final example. A Procurement Manager wants to place a “bid” for some goods using an On-Line Trading Community (B2B version of eBay) Use Case Name: Create Bid Primary Actor: Procurement Manager Secondary Actors: On-Line Trading Community You might wonder why the Trading Community is listed as a Secondary Actor, i.e. if all we are going to do is place a bid for a specific quantity of goods at a given price and send that off to the Trading Community, then why would the Trading Community need to “assist” in that Use Case? Well, once again, it comes back to the “User Experience” and how we want to optimize that when we think about our Use Case, and ultimately, when the developer comes to assembling some code. In this final example, the Procurement Manager cannot successfully complete the “Create Bid” Use Case until they receive an affirmative confirmation back from the Trading Community that the Bid has been accepted. Therefore, the Trading Community must become a Secondary Actor and be referenced both on the Use Case diagram and Use Case Specification. Any astute readers who are wondering about the “single sitting” rule will have to wait for a follow-up Blog entry to find out how that consideration can be factored in!!! Happy Use Case writing! (1) OMG Unified Modeling LanguageTM (OMG UML), Superstructure Version 2.4.1 (2) Cockburn, A, 2000, Writing Effective Use Case, Addison-Wesley Professional; Edition 1 (3) Cockburn, A, 2006 “Use Case fundamentals” viewed 20th March 2012, http://alistair.cockburn.us/Use+case+fundamentals

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  • Attachments in Oracle BPM 11g – Create a BPM Process Instance by passing an Attachment

    - by Venugopal Mangipudi
    Problem Statement: On a recent engagement I had  a requirement where we needed to create BPM instances using a message start event. The challenge was that the instance needed to be created after polling a file location and attaching the picked up file (pdf) as an attachment to the instance. Proposed Solution: I was contemplating using process API to accomplish this,but came up with a solution which involves a BPEL process to pickup the file and send a notification to the BPM process by passing the attachment as a payload. The following are some of the brief steps that were used to build the solution: BPM Process to receive an attachment as part of the payload: The BPM Process is a very simple process which has a Message Start event that accepts the attachment as an argument and a Simple User Task that the user can use to view the attachment (as part of the OOTB attachment panel). The Input payload is based on AttachmentPayload.xsd.  The 3 key elements of the the payload are: <xsd:element name="filename" type="xsd:string"/> <xsd:element name="mimetype" type="xsd:string"/> <xsd:element name="content" type="xsd:base64Binary"/> A screenshot of the Human task data assignment that need to performed to attach the file is provided here. Once the process and the UI project (default generated UI) are deployed to the SOA server, copy the wsdl location of the process service (from EM). This WSDL would be used in the BPEL project to create the Instances in the BPM process after a file is polled. BPEL Process to Poll for File and create instances in the BPM process: For the BPEL process a File adapter was configured as a Read service (File Streaming option and keeping the Schema as Opaque). Once a location and the file pattern to poll are provided the Readservice Partner Link was wired to Invoke the BPEL Process. Also, using the BPM Process WSDL, we can create the Webservice reference and can invoke the start operation. Before we do the assignment for the Invoke operation, a global variable should be created to hold the value of the fileName of the file. The mapping to the global variable can be done on the Receive activity properties (jca.file.FileName).  So for the assign operation before we invoke the BPM process service, we can get the content of the file from the receive input variable and the fileName from the jca.file.FileName property. The mimetype needs to be hard coded to the mime-type of the file: application/pdf (I am still researching ways to derive the mime type as it is not available as part of the jca.file properties).  The screenshot of the BPEL process can be found here and the Assign activity can be found here. The project source can be found at the following location. A sample pdf file to test the project and a screenshot of the BPM Human task screen after the successful creation of the instance can be found here. References: [1] https://blogs.oracle.com/fmwinaction/entry/oracle_bpm_adding_an_attachment

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  • Launch 7:Windows Phone 7 Style Live Tiles On Android Mobiles

    - by Gopinath
    Android is a great mobile OS but one thought that lingers in the mind of few Android owners is: Am I using a cheap iPhone? This is valid thought for many low end Android users as their phones runs sluggish and the user interface of Android looks like an imitation of iOS. When it comes to Windows Phone 7 users, even though their operating system features are not as great as iPhone/Android but it has its unique user interface; Windows Phone 7 user interface is a very intuitive and fresh, it’s constantly updating Live Tiles show all the required information on the home screen. Android has best mobile operating system features except UI and Windows Phone 7 has excellent user interface. How about porting Windows Phone 7 Tiles interface on an Android? That should be great. Launch 7 app brings the best of Windows Phone 7 look and feel to Android OS. Once the Launcher 7 app is installed and activated, it brings Live Tiles or constantly updating controls that show information on Android home screen. Apart from simple and smooth tiles, there are handful of customization options provided. Users can change colour of the tiles, add new tiles, enable/disable transitions. The reviews on Android Market are on the positive side with 4.4 stars by 10,000 + reviewers. Here are few user reviews 1. Does what it says. only issue for me is that the app drawer doesn’t rotate. And I would like the UI to rotate when my KB is opened. HTC desire z – Jonathan 2. Works great on atrix.Kudos to developers. Awesome. Though needs: Better notification bar More stock images of tiles Better fitting of widgets on tiles – Manny 3. Looks really good like it much more than I thought I would runs real smooth running royal ginger 2.1 – Jay 4. Omg amazing i am definetly keeping it as my default best of android and windows – Devon 5. Man! An update every week! Very very responsive developer! – Andrew You can read more reviews on Android Market here.  There is no doubt that this application is receiving rave reviews. After scanning a while through the reviews, few complaints throw light on the negative side: Battery drains a bit faster & Low end mobile run a bit sluggish. The application is available in two versions – an ad supported free version and $1.41 ad free version. Download Launcher 7 from Android Market This article titled,Launch 7:Windows Phone 7 Style Live Tiles On Android Mobiles, was originally published at Tech Dreams. Grab our rss feed or fan us on Facebook to get updates from us.

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