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  • Unexpected server restart - Windows 2003 SP2 fully patched

    - by PCTech
    I'm having problems with a server that has been restarting itself randomly for the past 3 months. The server is windows 2003 with SP2 Domain Controller and it is fully patched. I have seen the following errors in event log: Source: USER32 Category: None Type: Information Event ID: 1074 User: Domain\Administrator The process winlogon.exe has initiated the restart of computer (server name) on behalf of user domainname\Administrator for the following reason: No title for this reason could be found Reason Code: 0x840000ff Shutdown Type: restart I have ran out of ideas as to what might be causing this issue. The system is clean and not infected. There are no scheduled tasks responsible for the restart either. I'm considering moving the backup (Backup Exec 12.5) to a different server but I'm almost certain that this is not the issue as the restart times vary and do not match the scheduled backup jobs. Any suggestions to help me resolve this issue would be appreciated, thanks.

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  • dynamic routing between openvpn tunnels

    - by pQd
    i'm thinking about using dynamic routing [ OSPF or RIP ] via OpenVPN tunnels. right now i have few offices connected in full mesh, but this is not scalable solution as we add more locations. i would like to avoid situation when plenty of internal traffic is affected if one of two vpn termination points that i plan to use is down. do you have similar configuration working in production? if so - what routing daemon did you use - quagga? something else? did you encounter any problems? thanks!

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  • Why is C++ backward compatibility important / necessary?

    - by Giorgio
    As far as understand it is a well-established opinion within the C++ community that C is an obsolete language that was useful 20 years ago but cannot support many modern good programming practices, or even encourages bad practices; certain features that were typical of C++ (C with classes) during the nineties are also obsolete and considered bad practice in modern C++ (e.g., new and delete should be replaced by smart pointer primitives). In view of this, I often wonder why backward compatibility with C and obsolete C++ features is still considered important: to my knowledge there is no 100% compatibility, but most of C and C++ are contained in C++11 as a subset. Of course, there is a lot of legacy code and libraries (possibly containing templates) that are written using a previous standard of the language and which still need to be maintained or used in connection with new code. Nevertheless, maybe it would still be possible to drop obsolete C and C++ features (e.g. the mentioned new / delete) from a future C++ standard so that it is impossible to use them in new code. In this way, old and dangerous programming practices would be quickly banned from new code, and modern, better programming practices would be enforced by the compiler. Legacy code could still be maintained using separate compilation (having C alongside C++ source files is already a common practice). Developers would have to choose between one compiler supporting the old-style C++ that was common during the nineties and a compiler supporting the modern C++? style (the question mark indicates a future, hypothetical revision). Only mixing the two styles would be forbidden. Would this be a viable strategy for encouraging the adoption of modern C++ practices? Are there conceptual reasons or technical problems (e.g. compiling existing templates) that make such a change undesirable or even impossible? Has such a development been proposed in the C++ community. If there has been some extended discussion on the topic, is there any material on-line?

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  • SQL SERVER – Concurrency Basics – Guest Post by Vinod Kumar

    - by pinaldave
    This guest post is by Vinod Kumar. Vinod Kumar has worked with SQL Server extensively since joining the industry over a decade ago. Working on various versions from SQL Server 7.0, Oracle 7.3 and other database technologies – he now works with the Microsoft Technology Center (MTC) as a Technology Architect. Let us read the blog post in Vinod’s own voice. Learning is always fun when it comes to SQL Server and learning the basics again can be more fun. I did write about Transaction Logs and recovery over my blogs and the concept of simplifying the basics is a challenge. In the real world we always see checks and queues for a process – say railway reservation, banks, customer supports etc there is a process of line and queue to facilitate everyone. Shorter the queue higher is the efficiency of system (a.k.a higher is the concurrency). Every database does implement this using checks like locking, blocking mechanisms and they implement the standards in a way to facilitate higher concurrency. In this post, let us talk about the topic of Concurrency and what are the various aspects that one needs to know about concurrency inside SQL Server. Let us learn the concepts as one-liners: Concurrency can be defined as the ability of multiple processes to access or change shared data at the same time. The greater the number of concurrent user processes that can be active without interfering with each other, the greater the concurrency of the database system. Concurrency is reduced when a process that is changing data prevents other processes from reading that data or when a process that is reading data prevents other processes from changing that data. Concurrency is also affected when multiple processes are attempting to change the same data simultaneously. Two approaches to managing concurrent data access: Optimistic Concurrency Model Pessimistic Concurrency Model Concurrency Models Pessimistic Concurrency Default behavior: acquire locks to block access to data that another process is using. Assumes that enough data modification operations are in the system that any given read operation is likely affected by a data modification made by another user (assumes conflicts will occur). Avoids conflicts by acquiring a lock on data being read so no other processes can modify that data. Also acquires locks on data being modified so no other processes can access the data for either reading or modifying. Readers block writer, writers block readers and writers. Optimistic Concurrency Assumes that there are sufficiently few conflicting data modification operations in the system that any single transaction is unlikely to modify data that another transaction is modifying. Default behavior of optimistic concurrency is to use row versioning to allow data readers to see the state of the data before the modification occurs. Older versions of the data are saved so a process reading data can see the data as it was when the process started reading and not affected by any changes being made to that data. Processes modifying the data is unaffected by processes reading the data because the reader is accessing a saved version of the data rows. Readers do not block writers and writers do not block readers, but, writers can and will block writers. Transaction Processing A transaction is the basic unit of work in SQL Server. Transaction consists of SQL commands that read and update the database but the update is not considered final until a COMMIT command is issued (at least for an explicit transaction: marked with a BEGIN TRAN and the end is marked by a COMMIT TRAN or ROLLBACK TRAN). Transactions must exhibit all the ACID properties of a transaction. ACID Properties Transaction processing must guarantee the consistency and recoverability of SQL Server databases. Ensures all transactions are performed as a single unit of work regardless of hardware or system failure. A – Atomicity C – Consistency I – Isolation D- Durability Atomicity: Each transaction is treated as all or nothing – it either commits or aborts. Consistency: ensures that a transaction won’t allow the system to arrive at an incorrect logical state – the data must always be logically correct.  Consistency is honored even in the event of a system failure. Isolation: separates concurrent transactions from the updates of other incomplete transactions. SQL Server accomplishes isolation among transactions by locking data or creating row versions. Durability: After a transaction commits, the durability property ensures that the effects of the transaction persist even if a system failure occurs. If a system failure occurs while a transaction is in progress, the transaction is completely undone, leaving no partial effects on data. Transaction Dependencies In addition to supporting all four ACID properties, a transaction might exhibit few other behaviors (known as dependency problems or consistency problems). Lost Updates: Occur when two processes read the same data and both manipulate the data, changing its value and then both try to update the original data to the new value. The second process might overwrite the first update completely. Dirty Reads: Occurs when a process reads uncommitted data. If one process has changed data but not yet committed the change, another process reading the data will read it in an inconsistent state. Non-repeatable Reads: A read is non-repeatable if a process might get different values when reading the same data in two reads within the same transaction. This can happen when another process changes the data in between the reads that the first process is doing. Phantoms: Occurs when membership in a set changes. It occurs if two SELECT operations using the same predicate in the same transaction return a different number of rows. Isolation Levels SQL Server supports 5 isolation levels that control the behavior of read operations. Read Uncommitted All behaviors except for lost updates are possible. Implemented by allowing the read operations to not take any locks, and because of this, it won’t be blocked by conflicting locks acquired by other processes. The process can read data that another process has modified but not yet committed. When using the read uncommitted isolation level and scanning an entire table, SQL Server can decide to do an allocation order scan (in page-number order) instead of a logical order scan (following page pointers). If another process doing concurrent operations changes data and move rows to a new location in the table, the allocation order scan can end up reading the same row twice. Also can happen if you have read a row before it is updated and then an update moves the row to a higher page number than your scan encounters later. Performing an allocation order scan under Read Uncommitted can cause you to miss a row completely – can happen when a row on a high page number that hasn’t been read yet is updated and moved to a lower page number that has already been read. Read Committed Two varieties of read committed isolation: optimistic and pessimistic (default). Ensures that a read never reads data that another application hasn’t committed. If another transaction is updating data and has exclusive locks on data, your transaction will have to wait for the locks to be released. Your transaction must put share locks on data that are visited, which means that data might be unavailable for others to use. A share lock doesn’t prevent others from reading but prevents them from updating. Read committed (snapshot) ensures that an operation never reads uncommitted data, but not by forcing other processes to wait. SQL Server generates a version of the changed row with its previous committed values. Data being changed is still locked but other processes can see the previous versions of the data as it was before the update operation began. Repeatable Read This is a Pessimistic isolation level. Ensures that if a transaction revisits data or a query is reissued the data doesn’t change. That is, issuing the same query twice within a transaction cannot pickup any changes to data values made by another user’s transaction because no changes can be made by other transactions. However, this does allow phantom rows to appear. Preventing non-repeatable read is a desirable safeguard but cost is that all shared locks in a transaction must be held until the completion of the transaction. Snapshot Snapshot Isolation (SI) is an optimistic isolation level. Allows for processes to read older versions of committed data if the current version is locked. Difference between snapshot and read committed has to do with how old the older versions have to be. It’s possible to have two transactions executing simultaneously that give us a result that is not possible in any serial execution. Serializable This is the strongest of the pessimistic isolation level. Adds to repeatable read isolation level by ensuring that if a query is reissued rows were not added in the interim, i.e, phantoms do not appear. Preventing phantoms is another desirable safeguard, but cost of this extra safeguard is similar to that of repeatable read – all shared locks in a transaction must be held until the transaction completes. In addition serializable isolation level requires that you lock data that has been read but also data that doesn’t exist. Ex: if a SELECT returned no rows, you want it to return no. rows when the query is reissued. This is implemented in SQL Server by a special kind of lock called the key-range lock. Key-range locks require that there be an index on the column that defines the range of values. If there is no index on the column, serializable isolation requires a table lock. Gets its name from the fact that running multiple serializable transactions at the same time is equivalent of running them one at a time. Now that we understand the basics of what concurrency is, the subsequent blog posts will try to bring out the basics around locking, blocking, deadlocks because they are the fundamental blocks that make concurrency possible. Now if you are with me – let us continue learning for SQL Server Locking Basics. 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 Tagged: Concurrency

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  • MOSS 2007 SP2 - Error while provisioning SSP.

    - by Tim
    This is a brand new installation I am trying to provision the first SSP for MOSS and I keep getting the following error: (Provisioning failed: A transport-level error has occurred when receiving results from the server. (provider: TCP Provider, error: 0 - The semaphore timeout period has expired.)) The error also keeps appearing in the Application Event Log as event ID 7888. Google searches tell me its a connection between the Sharepoint server and the SQL server however, this is a production SQL Server which has several databases on it that do not experience any problems. These databases also include the Central Admin and Web Application databases for Sharepoint which are all working fine. Any guidance would be greatly appreciated. Thanks in advance.

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  • Unable to authenticate Windows XP clients agains Snow Leopard Server PDC after 10.6.2 upgrade

    - by Roland
    I have setup a Snow Leopard Server 10.6.1 as a PDC without problems to authenticate Windows XP clients. Joining a Windows XP client to the SLS PDC Domain and log in from a Windows XP client to the SLS PDC Domain are working. After the update to Snow Leopard Server 10.6.2 the authentication is broken. opendirectory_smb_pwd_check_ntlmv1 gave -14090 [eDSAuthFailed] By changing the Windows XP "Network security: LAN Manager authentication level" policy to NTVLM2 responses only the authentication agains a SMB share is possible, but trying to join SLS PDC Domain is still not possible. opendirectory_smb_pwd_check_ntlmv2 gave -14090 [eDSAuthFailed] Any ideas? Is anyone else having similar authentication difficulties?

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  • Android “open for embedded”? Must-read Ars Technica article

    - by terrencebarr
    A few days ago ars technica published an article “Google’s iron grip on Android: Controlling open source by any means necessary”. If you are considering Android for embedded this article is a must-read to understand the severe ramifications of Google’s tight (and tightening) control on the Android technology and ecosystem. Some quotes from the ars technica article: “Android is open – except for all the good parts“ “Android actually falls into two categories: the open parts from the Android Open Source Project (AOSP) … and the closed source parts, which are all the Google-branded apps” “Android open source apps … turn into abandonware by moving all continuing development to a closed source model.” “Joining the OHA requires a company to sign its life away and promise to not build a device that runs a competing Android fork.” “Google Play Services is a closed source app owned by Google … to turn the “Android App Ecosystem” into the “Google Play Ecosystem” “You’re allowed to contribute to Android and allowed to use it for little hobbies, but in nearly every area, the deck is stacked against anyone trying to use Android without Google’s blessing“ Compare this with a recent Wired article “Oracle Makes Java More Relevant Than Ever”: “Oracle has actually opened up Java even more — getting rid of some of the closed-door machinations that used to be part of the Java standards-making process. Java has been raked over the coals for security problems over the past few years, but Oracle has kept regular updates coming. And it’s working on a major upgrade to Java, due early next year.” Cheers, – Terrence Filed under: Embedded, Mobile & Embedded Tagged: Android, embedded, Java Embedded, Open Source

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  • Can't access network share with name defined in hosts file

    - by Einar Egilsson
    I have a network share on a machine that I can only reach by IP address. I then defined an alias for the IP in my hosts file so I could use that instead of the IP but then I can't log on to the share, I just get the logon prompt again and again. So basically this: \\172.17.0.48\SomeShare works but this \\myalias\SomeShare doesn't. myalias is defined in c:\windows\system32\drivers\etc\hosts as 172.17.0.48 myalias And I can use the alias for remote desktop without problems. Can anyone tell me why this doesn't work for fileshares?

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  • Desktop Fun: Sci-Fi Icons Packs Series 2

    - by Asian Angel
    If you loved our first sci-fi icon packs collection then get ready for more icon goodness with the selection in our second sci-fi series. Sneak Preview As always we have an example desktop full of icon goodness to share with you. Here you can see a Star Trek themed desktop using the “Borg-green” set shown below. Note: Wallpaper can be found here. Our new desktop icons up close… Borg-green *.png format only Download Trek Insignia *.ico format only Download Star Trek Elite Force X *.ico format only Download Starships X *.ico format only Download If I Were A Thief In The 24th Century 1.0 *.ico format only Download Star Wars: Attack of the Clones *.ico format only Download BSG: Frakking Toasters *.ico format only Download Doctor Who *.ico format only Download TRON *.ico format only Download Alien vs Predator Icons *.ico and .png format Download 2001: A Space Odyssey 1.0 *.ico format only Download To the Moon *.ico format only, also has bonus set of wallpapers included! This is what the bonus wallpaper looks like…it comes in the following sizes: 1024*768, 1280*854, 1280*1024, 1440*900, 1600*1200, & 1920*1200. Download Space Icons *.ico and .png format Download Matrix Documentations *.ico format only Download Matrix Rebooted *.ico format only Download If you loved this collection of sci-fi icons then head on over to see our first sci-fi series here. Also, be certain to visit our new Desktop Fun section for more customization goodness! Similar Articles Productive Geek Tips Desktop Customization: Sci-Fi Icon PacksRestore Missing Desktop Icons in Windows 7 or VistaDesktop Fun: Adventure Icon PacksDesktop Fun: Star Trek WallpapersCreate a Keyboard Shortcut to Access Hidden Desktop Icons and Files TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Microsoft’s “How Do I ?” Videos Home Networks – How do they look like & the problems they cause Check Your IMAP Mail Offline In Thunderbird Follow Finder Finds You Twitter Users To Follow Combine MP3 Files Easily QuicklyCode Provides Cheatsheets & Other Programming Stuff

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  • Windows 2k3 server as a KVM client

    - by Peter NUnn
    Just wondering if anyone else has had issues installing Windows 2K3 server under KVM. I have tried a few times tonight and keep getting "not a supported platform" when the installation first boots. I've used i686, had acpi and apic off and on, given it 4GB ram, 200GB hard disk and it fails every time. I've done some hunting around, but can't find anything conclusive on google. It is listed as a supported client on the KVM site. Host is Ubuntu 10.04 64Bit, qemu-kmv hypervisor. Drivers, I'm not sure what your asking for there, but the disk is a standard (I believe) 32 bit Win2K3 server. I'm trying to install a bulk standard server install. I've done it with win2K8 no problems, but this 2k3 install is failing every time.

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  • KB980408: Fix for Explorer freezing: does anyone know what apps cause it?

    - by Ian Boyd
    Microsoft released an update for Windows 7 today: KB980408: The April 2010 stability and reliability update for Windows 7 and Windows Server 2008 R2 is available. The update fixes, among other things: Windows Explorer may stop responding for 30 seconds when a file or a directory is created or renamed after certain applications are installed. i'm not experiencing it on my own Windows 7 machine, but two colleagues at work were experiencing the problem. i would really like to know what applications were causing problems. Microsoft will never call out the misbehaving applications. i want to know what software i should be ridiculing and insulting. And avoid in the future. Did anyone who was experiencing this problem isolate the applications?

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  • Exporting 3DS Max animated biped character into Assimp

    - by Doug Kavendek
    I've been having some trouble with MD5 meshes exported from 3DS Max into my C++ program, using Assimp to import the model and its skeletal animation. If the models were rigged manually with bones, the export and animations work perfectly, but if they were rigged as a biped character, the animation hits a "deadly import error" and all the bones appear to get smooshed together into a big pile. This seems like it might just be a limitation of the MD5 exporter (we're currently using the one found here. Our plan is to try out a different MD5 exporter (this one), and if that still has problems, then try switching from MD5 to COLLADA. Our modeler won't be able to make time to try out these other exporters for a few days, so in the meantime I wanted to see if there were any better methods out there for getting biped rigged models from 3DS Max into our app via Assimp. Out of Assimp's supported formats, I need to figure out which will support the following: Skeletal animations Exportable from 3DS Max biped rigged models Failing that, an alternative would be a way to convert a biped character to its corresponding bones before exporting. We did find one script to do that, but it only seems meant as a starting point for modeling -- it doesn't carry over any hierarchy, skinning, or animation -- so it can't be used solely during export.

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  • Need Tech Support? Call the Star Wars Help Desk! [Video Classic]

    - by Asian Angel
    Having problems with the Tractor Beam? Did a weapons malfunction bring your computer system down? Is the Replicator making your Earl Grey Tea taste odd? Wait…what??!! Just call the Star Wars Help Desk to get the personalized help you need. Star Wars Help Desk [YouTube] Latest Features How-To Geek ETC How to Enable User-Specific Wireless Networks in Windows 7 How to Use Google Chrome as Your Default PDF Reader (the Easy Way) How To Remove People and Objects From Photographs In Photoshop Ask How-To Geek: How Can I Monitor My Bandwidth Usage? Internet Explorer 9 RC Now Available: Here’s the Most Interesting New Stuff Here’s a Super Simple Trick to Defeating Fake Anti-Virus Malware Comix is an Awesome Comics Archive Viewer for Linux Get the MakeUseOf eBook Guide to Speeding Up Windows for Free Need Tech Support? Call the Star Wars Help Desk! [Video Classic] Reclaim Vertical UI Space by Adding a Toolbar to the Left or Right Side of Firefox Androidify Turns You into an Android-style Avatar Reader for Android Updates; Now with Feed Widgets and More

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  • Need some advice regarding collision detection with the sprite changing its width and height

    - by Frank Scott
    So I'm messing around with collision detection in my tile-based game and everything works fine and dandy using this method. However, now I am trying to implement sprite sheets so my character can have a walking and jumping animation. For one, I'd like to to be able to have each frame of variable size, I think. I want collision detection to be accurate and during a jumping animation the sprite's height will be shorter (because of the calves meeting the hamstrings). Again, this also works fine at the moment. I can get the character to animate properly each frame and cycle through animations. The problems arise when the width and height of the character change. Often times its position will be corrected by the collision detection system and the character will be rubber-banded to random parts of the map or even go outside the map bounds. For some reason with the linked collision detection algorithm, when the width or height of the sprite is changed on the fly, the entire algorithm breaks down. The solution I found so far is to have a single width and height of the sprite that remains constant, and only adjust the source rectangle for drawing. However, I'm not sure exactly what to set as the sprite's constant bounding box because it varies so much with the different animations. So now I'm not sure what to do. I'm toying with the idea of pixel-perfect collision detection but I'm not sure if it would really be worth it. Does anyone know how Braid does their collision detection? My game is also a 2D sidescroller and I was quite impressed with how it was handled in that game. Thanks for reading.

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  • Find which config file Apache uses to find virtual host

    - by eje211
    I have a rather complicated Apache setup: some config files have to be manually written and some have to be automatically generated. So far, I've had no problems. But now, I've just tried to set a site at: newsubdomain.mydomain.com and Apache directs it to the data for: www.someotherdomain.com I've looking into all the many config files and can't find anything wrong. All is pointing where it should and no definitions, as far as I can tell, overlap. So what I'm wondering is: is there a way to see which config files or config instructions Apache is using to match a URL to a directory? Tanks.

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  • Time Machine + Ubee Router?

    - by Charlie
    I can't for the life of me figure this out. I recently had TWC installed in my house, and wanted to disable the NAT and router functions of it. I have a Time Machine hooked up to it from LAN1 (on the Ubee) to the WAN port on the TM. The problems started occurring here. I figured the settings would be these: Ubee Configuration mode: Bridge DHCP: Off TM IPv4: 192.168.100.2 Subnet Mask: 255.255.255.0 Router Address: 192.168.100.1 DNS Servers: 8.8.8.8, 8.8.4.4 Router Mode: DHCP and NAT But using those settings, my TM says "Double NAT", so I have to change it all around to the default settings of the Ubee using NAT. This leads me to believe bridge mode doesn't actually turn off NAT...

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  • MacBookPro RAM: CL7 or CL9

    - by chris_l
    Hi, I want to increase the RAM in my MacBookPro 15", 2.53 GHz, Mid-2009. I currently have 4GB, and I want 6GB (and upgrade to 8GB later - I think this should work with my model: http://forums.macrumors.com/showthread.php?t=573906) Now I see two offers: 1x4GB DDR3 1333 CL9 9-9 (149 EUR) 1x4GB DDR3 1066 CL7 7-7 (192 EUR). Both are from the same brand (Transcend), both are labeled "For MacBook/MacBookPro". Now I have no idea, which of these would work better with the 2GB RAM module from my currently installed memory (Running at 1067 MHz, according to System Profiler - but with what CL setting?) Would the 1333 CL9 RAM be set to CL7 when running at 1066 MHz? Thanks, Chris PS Should I expect problems when I later upgrade to 8GB with a different module (in case the same module won't be produced anymore)?

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  • Option Trading: Getting the most out of the event session options

    - by extended_events
    You can control different aspects of how an event session behaves by setting the event session options as part of the CREATE EVENT SESSION DDL. The default settings for the event session options are designed to handle most of the common event collection situations so I generally recommend that you just use the defaults. Like everything in the real world though, there are going to be a handful of “special cases” that require something different. This post focuses on identifying the special cases and the correct use of the options to accommodate those cases. There is a reason it’s called Default The default session options specify a total event buffer size of 4 MB with a 30 second latency. Translating this into human terms; this means that our default behavior is that the system will start processing events from the event buffer when we reach about 1.3 MB of events or after 30 seconds, which ever comes first. Aside: What’s up with the 1.3 MB, I thought you said the buffer was 4 MB?The Extended Events engine takes the total buffer size specified by MAX_MEMORY (4MB by default) and divides it into 3 equally sized buffers. This is done so that a session can be publishing events to one buffer while other buffers are being processed. There are always at least three buffers; how to get more than three is covered later. Using this configuration, the Extended Events engine can “keep up” with most event sessions on standard workloads. Why is this? The fact is that most events are small, really small; on the order of a couple hundred bytes. Even when you start considering events that carry dynamically sized data (eg. binary, text, etc.) or adding actions that collect additional data, the total size of the event is still likely to be pretty small. This means that each buffer can likely hold thousands of events before it has to be processed. When the event buffers are finally processed there is an economy of scale achieved since most targets support bulk processing of the events so they are processed at the buffer level rather than the individual event level. When all this is working together it’s more likely that a full buffer will be processed and put back into the ready queue before the remaining buffers (remember, there are at least three) are full. I know what you’re going to say: “My server is exceptional! My workload is so massive it defies categorization!” OK, maybe you weren’t going to say that exactly, but you were probably thinking it. The point is that there are situations that won’t be covered by the Default, but that’s a good place to start and this post assumes you’ve started there so that you have something to look at in order to determine if you do have a special case that needs different settings. So let’s get to the special cases… What event just fired?! How about now?! Now?! If you believe the commercial adage from Heinz Ketchup (Heinz Slow Good Ketchup ad on You Tube), some things are worth the wait. This is not a belief held by most DBAs, particularly DBAs who are looking for an answer to a troubleshooting question fast. If you’re one of these anxious DBAs, or maybe just a Program Manager doing a demo, then 30 seconds might be longer than you’re comfortable waiting. If you find yourself in this situation then consider changing the MAX_DISPATCH_LATENCY option for your event session. This option will force the event buffers to be processed based on your time schedule. This option only makes sense for the asynchronous targets since those are the ones where we allow events to build up in the event buffer – if you’re using one of the synchronous targets this option isn’t relevant. Avoid forgotten events by increasing your memory Have you ever had one of those days where you keep forgetting things? That can happen in Extended Events too; we call it dropped events. In order to optimizes for server performance and help ensure that the Extended Events doesn’t block the server if to drop events that can’t be published to a buffer because the buffer is full. You can determine if events are being dropped from a session by querying the dm_xe_sessions DMV and looking at the dropped_event_count field. Aside: Should you care if you’re dropping events?Maybe not – think about why you’re collecting data in the first place and whether you’re really going to miss a few dropped events. For example, if you’re collecting query duration stats over thousands of executions of a query it won’t make a huge difference to miss a couple executions. Use your best judgment. If you find that your session is dropping events it means that the event buffer is not large enough to handle the volume of events that are being published. There are two ways to address this problem. First, you could collect fewer events – examine you session to see if you are over collecting. Do you need all the actions you’ve specified? Could you apply a predicate to be more specific about when you fire the event? Assuming the session is defined correctly, the next option is to change the MAX_MEMORY option to a larger number. Picking the right event buffer size might take some trial and error, but a good place to start is with the number of dropped events compared to the number you’ve collected. Aside: There are three different behaviors for dropping events that you specify using the EVENT_RETENTION_MODE option. The default is to allow single event loss and you should stick with this setting since it is the best choice for keeping the impact on server performance low.You’ll be tempted to use the setting to not lose any events (NO_EVENT_LOSS) – resist this urge since it can result in blocking on the server. If you’re worried that you’re losing events you should be increasing your event buffer memory as described in this section. Some events are too big to fail A less common reason for dropping an event is when an event is so large that it can’t fit into the event buffer. Even though most events are going to be small, you might find a condition that occasionally generates a very large event. You can determine if your session is dropping large events by looking at the dm_xe_sessions DMV once again, this time check the largest_event_dropped_size. If this value is larger than the size of your event buffer [remember, the size of your event buffer, by default, is max_memory / 3] then you need a large event buffer. To specify a large event buffer you set the MAX_EVENT_SIZE option to a value large enough to fit the largest event dropped based on data from the DMV. When you set this option the Extended Events engine will create two buffers of this size to accommodate these large events. As an added bonus (no extra charge) the large event buffer will also be used to store normal events in the cases where the normal event buffers are all full and waiting to be processed. (Note: This is just a side-effect, not the intended use. If you’re dropping many normal events then you should increase your normal event buffer size.) Partitioning: moving your events to a sub-division Earlier I alluded to the fact that you can configure your event session to use more than the standard three event buffers – this is called partitioning and is controlled by the MEMORY_PARTITION_MODE option. The result of setting this option is fairly easy to explain, but knowing when to use it is a bit more art than science. First the science… You can configure partitioning in three ways: None, Per NUMA Node & Per CPU. This specifies the location where sets of event buffers are created with fairly obvious implication. There are rules we follow for sub-dividing the total memory (specified by MAX_MEMORY) between all the event buffers that are specific to the mode used: None: 3 buffers (fixed)Node: 3 * number_of_nodesCPU: 2.5 * number_of_cpus Here are some examples of what this means for different Node/CPU counts: Configuration None Node CPU 2 CPUs, 1 Node 3 buffers 3 buffers 5 buffers 6 CPUs, 2 Node 3 buffers 6 buffers 15 buffers 40 CPUs, 5 Nodes 3 buffers 15 buffers 100 buffers   Aside: Buffer size on multi-processor computersAs the number of Nodes or CPUs increases, the size of the event buffer gets smaller because the total memory is sub-divided into more pieces. The defaults will hold up to this for a while since each buffer set is holding events only from the Node or CPU that it is associated with, but at some point the buffers will get too small and you’ll either see events being dropped or you’ll get an error when you create your session because you’re below the minimum buffer size. Increase the MAX_MEMORY setting to an appropriate number for the configuration. The most likely reason to start partitioning is going to be related to performance. If you notice that running an event session is impacting the performance of your server beyond a reasonably expected level [Yes, there is a reasonably expected level of work required to collect events.] then partitioning might be an answer. Before you partition you might want to check a few other things: Is your event retention set to NO_EVENT_LOSS and causing blocking? (I told you not to do this.) Consider changing your event loss mode or increasing memory. Are you over collecting and causing more work than necessary? Consider adding predicates to events or removing unnecessary events and actions from your session. Are you writing the file target to the same slow disk that you use for TempDB and your other high activity databases? <kidding> <not really> It’s always worth considering the end to end picture – if you’re writing events to a file you can be impacted by I/O, network; all the usual stuff. Assuming you’ve ruled out the obvious (and not so obvious) issues, there are performance conditions that will be addressed by partitioning. For example, it’s possible to have a successful event session (eg. no dropped events) but still see a performance impact because you have many CPUs all attempting to write to the same free buffer and having to wait in line to finish their work. This is a case where partitioning would relieve the contention between the different CPUs and likely reduce the performance impact cause by the event session. There is no DMV you can check to find these conditions – sorry – that’s where the art comes in. This is  largely a matter of experimentation. On the bright side you probably won’t need to to worry about this level of detail all that often. The performance impact of Extended Events is significantly lower than what you may be used to with SQL Trace. You will likely only care about the impact if you are trying to set up a long running event session that will be part of your everyday workload – sessions used for short term troubleshooting will likely fall into the “reasonably expected impact” category. Hey buddy – I think you forgot something OK, there are two options I didn’t cover: STARTUP_STATE & TRACK_CAUSALITY. If you want your event sessions to start automatically when the server starts, set the STARTUP_STATE option to ON. (Now there is only one option I didn’t cover.) I’m going to leave causality for another post since it’s not really related to session behavior, it’s more about event analysis. - Mike Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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  • Recover Data Like a Forensics Expert Using an Ubuntu Live CD

    - by Trevor Bekolay
    There are lots of utilities to recover deleted files, but what if you can’t boot up your computer, or the whole drive has been formatted? We’ll show you some tools that will dig deep and recover the most elusive deleted files, or even whole hard drive partitions. We’ve shown you simple ways to recover accidentally deleted files, even a simple method that can be done from an Ubuntu Live CD, but for hard disks that have been heavily corrupted, those methods aren’t going to cut it. In this article, we’ll examine four tools that can recover data from the most messed up hard drives, regardless of whether they were formatted for a Windows, Linux, or Mac computer, or even if the partition table is wiped out entirely. Note: These tools cannot recover data that has been overwritten on a hard disk. Whether a deleted file has been overwritten depends on many factors – the quicker you realize that you want to recover a file, the more likely you will be able to do so. Our setup To show these tools, we’ve set up a small 1 GB hard drive, with half of the space partitioned as ext2, a file system used in Linux, and half the space partitioned as FAT32, a file system used in older Windows systems. We stored ten random pictures on each hard drive. We then wiped the partition table from the hard drive by deleting the partitions in GParted. Is our data lost forever? Installing the tools All of the tools we’re going to use are in Ubuntu’s universe repository. To enable the repository, open Synaptic Package Manager by clicking on System in the top-left, then Administration > Synaptic Package Manager. Click on Settings > Repositories and add a check in the box labelled “Community-maintained Open Source software (universe)”. Click Close, and then in the main Synaptic Package Manager window, click the Reload button. Once the package list has reloaded, and the search index rebuilt, search for and mark for installation one or all of the following packages: testdisk, foremost, and scalpel. Testdisk includes TestDisk, which can recover lost partitions and repair boot sectors, and PhotoRec, which can recover many different types of files from tons of different file systems. Foremost, originally developed by the US Air Force Office of Special Investigations, recovers files based on their headers and other internal structures. Foremost operates on hard drives or drive image files generated by various tools. Finally, scalpel performs the same functions as foremost, but is focused on enhanced performance and lower memory usage. Scalpel may run better if you have an older machine with less RAM. Recover hard drive partitions If you can’t mount your hard drive, then its partition table might be corrupted. Before you start trying to recover your important files, it may be possible to recover one or more partitions on your drive, recovering all of your files with one step. Testdisk is the tool for the job. Start it by opening a terminal (Applications > Accessories > Terminal) and typing in: sudo testdisk If you’d like, you can create a log file, though it won’t affect how much data you recover. Once you make your choice, you’re greeted with a list of the storage media on your machine. You should be able to identify the hard drive you want to recover partitions from by its size and label. TestDisk asks you select the type of partition table to search for. In most cases (ext2/3, NTFS, FAT32, etc.) you should select Intel and press Enter. Highlight Analyse and press enter. In our case, our small hard drive has previously been formatted as NTFS. Amazingly, TestDisk finds this partition, though it is unable to recover it. It also finds the two partitions we just deleted. We are able to change their attributes, or add more partitions, but we’ll just recover them by pressing Enter. If TestDisk hasn’t found all of your partitions, you can try doing a deeper search by selecting that option with the left and right arrow keys. We only had these two partitions, so we’ll recover them by selecting Write and pressing Enter. Testdisk informs us that we will have to reboot. Note: If your Ubuntu Live CD is not persistent, then when you reboot you will have to reinstall any tools that you installed earlier. After restarting, both of our partitions are back to their original states, pictures and all. Recover files of certain types For the following examples, we deleted the 10 pictures from both partitions and then reformatted them. PhotoRec Of the three tools we’ll show, PhotoRec is the most user-friendly, despite being a console-based utility. To start recovering files, open a terminal (Applications > Accessories > Terminal) and type in: sudo photorec To begin, you are asked to select a storage device to search. You should be able to identify the right device by its size and label. Select the right device, and then hit Enter. PhotoRec asks you select the type of partition to search. In most cases (ext2/3, NTFS, FAT, etc.) you should select Intel and press Enter. You are given a list of the partitions on your selected hard drive. If you want to recover all of the files on a partition, then select Search and hit enter. However, this process can be very slow, and in our case we only want to search for pictures files, so instead we use the right arrow key to select File Opt and press Enter. PhotoRec can recover many different types of files, and deselecting each one would take a long time. Instead, we press “s” to clear all of the selections, and then find the appropriate file types – jpg, gif, and png – and select them by pressing the right arrow key. Once we’ve selected these three, we press “b” to save these selections. Press enter to return to the list of hard drive partitions. We want to search both of our partitions, so we highlight “No partition” and “Search” and then press Enter. PhotoRec prompts for a location to store the recovered files. If you have a different healthy hard drive, then we recommend storing the recovered files there. Since we’re not recovering very much, we’ll store it on the Ubuntu Live CD’s desktop. Note: Do not recover files to the hard drive you’re recovering from. PhotoRec is able to recover the 20 pictures from the partitions on our hard drive! A quick look in the recup_dir.1 directory that it creates confirms that PhotoRec has recovered all of our pictures, save for the file names. Foremost Foremost is a command-line program with no interactive interface like PhotoRec, but offers a number of command-line options to get as much data out of your had drive as possible. For a full list of options that can be tweaked via the command line, open up a terminal (Applications > Accessories > Terminal) and type in: foremost –h In our case, the command line options that we are going to use are: -t, a comma-separated list of types of files to search for. In our case, this is “jpeg,png,gif”. -v, enabling verbose-mode, giving us more information about what foremost is doing. -o, the output folder to store recovered files in. In our case, we created a directory called “foremost” on the desktop. -i, the input that will be searched for files. This can be a disk image in several different formats; however, we will use a hard disk, /dev/sda. Our foremost invocation is: sudo foremost –t jpeg,png,gif –o foremost –v –i /dev/sda Your invocation will differ depending on what you’re searching for and where you’re searching for it. Foremost is able to recover 17 of the 20 files stored on the hard drive. Looking at the files, we can confirm that these files were recovered relatively well, though we can see some errors in the thumbnail for 00622449.jpg. Part of this may be due to the ext2 filesystem. Foremost recommends using the –d command-line option for Linux file systems like ext2. We’ll run foremost again, adding the –d command-line option to our foremost invocation: sudo foremost –t jpeg,png,gif –d –o foremost –v –i /dev/sda This time, foremost is able to recover all 20 images! A final look at the pictures reveals that the pictures were recovered with no problems. Scalpel Scalpel is another powerful program that, like Foremost, is heavily configurable. Unlike Foremost, Scalpel requires you to edit a configuration file before attempting any data recovery. Any text editor will do, but we’ll use gedit to change the configuration file. In a terminal window (Applications > Accessories > Terminal), type in: sudo gedit /etc/scalpel/scalpel.conf scalpel.conf contains information about a number of different file types. Scroll through this file and uncomment lines that start with a file type that you want to recover (i.e. remove the “#” character at the start of those lines). Save the file and close it. Return to the terminal window. Scalpel also has a ton of command-line options that can help you search quickly and effectively; however, we’ll just define the input device (/dev/sda) and the output folder (a folder called “scalpel” that we created on the desktop). Our invocation is: sudo scalpel /dev/sda –o scalpel Scalpel is able to recover 18 of our 20 files. A quick look at the files scalpel recovered reveals that most of our files were recovered successfully, though there were some problems (e.g. 00000012.jpg). Conclusion In our quick toy example, TestDisk was able to recover two deleted partitions, and PhotoRec and Foremost were able to recover all 20 deleted images. Scalpel recovered most of the files, but it’s very likely that playing with the command-line options for scalpel would have enabled us to recover all 20 images. These tools are lifesavers when something goes wrong with your hard drive. If your data is on the hard drive somewhere, then one of these tools will track it down! Similar Articles Productive Geek Tips Recover Deleted Files on an NTFS Hard Drive from a Ubuntu Live CDUse an Ubuntu Live CD to Securely Wipe Your PC’s Hard DriveReset Your Ubuntu Password Easily from the Live CDBackup Your Windows Live Writer SettingsAdding extra Repositories on Ubuntu TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Awe inspiring, inter-galactic theme (Win 7) Case Study – How to Optimize Popular Wordpress Sites Restore Hidden Updates in Windows 7 & Vista Iceland an Insurance Job? Find Downloads and Add-ins for Outlook Recycle !

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  • Windows 7 Machine Makes Router Drop -All- Wireless Connections

    - by Hammer Bro.
    Some background: My home network consists of my Desktop, a two-month old Windows 7 (x64) machine which is online most frequently (N-spec), as well as three other Windows XP laptops (all G) that only connect every now and then (one for work, one for Netflix, and the other for infrequent regular laptop uses). I used to have a Belkin F5D8236-4 wireless router, and everything worked great. A week ago, however, I found out that the Belkin absolutely in no way would establish a VPN connection, something that has become important for work. So I bought a Netgear WNR3500v2/U/L. The wireless was acting a little sketchy at first for just the Windows 7 machine, but I thought it had something to do with 802.11N and I was in a hurry so I just fished up an ethernet cable and disabled the computer's wireless. It has now become apparent, though, that whenever the Windows 7 machine is connected to the router, all wireless connections become unstable. I was using my work laptop for a solid six hours today with no trouble, having multiple SSH connections open over VPN and streaming internet radio in the background. Then, within two minutes of turning on this Windows 7 box, I had lost all connectivity over the wireless. And I was two feet away from the router. The same sort of thing happens on all of the other laptops -- Netflix can be playing stuff all weekend, but if I come up here and do things on this (W7) computer, the streaming will be dead within ten minutes. So here are my basic observations: If the Windows 7 machine is off, then all connections will have a Signal Strength of Very Good or Excellent and a Speed of 48-54 Mbps for an indefinite amount of time. Shortly after the Windows 7 machine is turned on, all wireless connections will experience a consistent decline in Speed down to 1.0 Mbps, eventually losing their connection entirely. These machines will continue to maintain 70% signal strength, as observed by themselves and router. Once dropped, a wireless connection will have difficulty reconnecting. And, if a connection manages to become established, it will quickly drop off again. The Windows 7 machine itself will continue to function just fine if it's using a wired connection, although it will experience these same issues over the wireless. All of the drivers and firmwares are up to date, and this happened both with the stock Netgear firmware as well as the (current) DD-WRT. What I've tried: Making sure each computer is being assigned a distinct IP. (They are.) Disabling UPnP and Stateful Packet Inspection on the router. Disabling Network Sharing, SSDP Discovery, TCP/IP NetBios Helper and Computer Browser services on the Windows 7 machine. Disabling QoS Packet Scheduler, IPv6, and Link Layer Topology Discovery options on my ethernet controller (leaving only Client for Microsoft Networks, File and Printer Sharing, and IPv4 enabled). What I think: It seems awfully similar to the problems discussed in detail at http://social.msdn.microsoft.com/Forums/en/wsk/thread/1064e397-9d9b-4ae2-bc8e-c8798e591915 (which was both the most relevant and concrete information I could dig up on the internet). I still think that something the Windows 7 IP stack (or just Operating System itself) is doing is giving the router fits. However, I could be wrong, because I have two key differences. One is that most instances of this problem are reported as the entire router dying or restarting, and mine still works just fine over the wired connection. The other is that it's a new router, tested with both the factory firmware and the (I assume) well-maintained DD-WRT project. Even if Windows 7 is still secretly sending IPv6 packets or the TCP Window Scaling implementation that I hear Vista caused some trouble with (even though I've tried my best to disable anything fancy), this router should support those functions. I don't want to get a new or a replacement router unless someone can convince me that this is a defective unit. But the problem seems too specific and predictable by my instincts to be a hardware hiccup. And I don't want to deal with the inevitable problems that always seem to take half a day to resolve when getting a new router, since I'm frantically working (including tomorrow) to complete a project by next week's deadline. Plus, I think in the worst case scenario, I could keep this router connected directly to the modem, disable its wireless entirely, and connect the old Belkin to it directly. That should allow me to still use VPN (although I'll have to plug my work laptop directly into that router), and then maintain wireless connections for all of the other computers. But that feels so wrong to me. Anyone have any ideas what the cause and possible solution could be? Clarifications: The Windows 7 machine is directly connected via an ethernet cable to the router for everything above. But while it is online, all other computers' wireless connections become unusable. It is not an issue of signal strength or interference -- no other devices within scanning range are using Channel 1, and the problem will affect computers that are literally feet away from the router with 95% signal strength.

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  • Using CheckPoint SNX with RSA SecurID Software Token to connect to VPN

    - by Vinnie
    I have a fairly specific issue that I'm hoping someone else out in the community has had to tackle with success. My company uses CheckPoint VPN clients on Windows XP machines with RSA SecurID software to generate the tokens. The beauty is that once you generate a token code on the software, you can enter it into any machine trying to connect via VPN and with your username get connected. So, I've got Ubuntu 10.10 32bit on a tower and formerly on a laptop. Through several posts around the web, I was able to get SNX installed on the laptop, plug in my server connection information and be asked for a password only to have the connection fail. I used to debug mode and was able to see that the application was trying to and failing at writing a registry value, but I believe that to be a symptom of a different issue, even though I tried to find a way to remedy that. I'm wondering if anyone out there is on a similar configuration and was able to connect with SNX using an RSA token? If so, what steps did you take to setup and what problems/solutions did you encounter?

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  • Setting CATALINA_OPTS for tomcat6 on windows doesn’t work.

    - by Ben
    (I've copied this from Stack Overflow here, after someone suggested I post the question here) Hi, I'm trying to setup Tomcat6 to work with JMX on Windows Vista 64. To do that I need to pass the parameters below to Tomcat6. What I do in command prompt. (that doesn't work) set CATALINA_OPTS="-Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=9898 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false" tomcat6.exe What I do that does work (but causes other problems) java -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=9898 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false -jar bootstrap.jar It seems as if tomcat is just ignoring the environment variable CATALINA_OPTS. Am I doing something wrong? I've also tried to edit catalina.bat and define the variable CATALINA_OPTS there. No success. (tried adding the parameters to JAVA_OPTS too, no success either) Thanks in Advance!!

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  • Check if root ca certificate is installed

    - by Zulakis
    We are having a custom CA for our local-domains. The Root CA certificate is installed on all the corporate machines by default, but sometimes it happens that we have someone here who doesn't have it installed. If the user a) accesses our intranet using http or b) accepts the server-certificate I would like to redirect the user to a site which tells it what happened and how they can install the root CA. The only solution I found was the following: <img src="https://the_site/the_image" onerror="redirectToCertPage()"> This is barely a work-around and not really a solution. It can be triggered by other problems then the missing certificate. Are there any better solutions on how to solve this problem?

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  • iTunes 9.2 OS X - iTunes DJ not functioning correctly

    - by David Sykes
    I have been using iTunes on my Mac for 4 years now without any problems at all. Recently, however, the iTunes DJ function has started misbehaving. Instead of showing the 5 previously played songs, and 15 upcoming songs randomly selected from the playlist I have defined in the settings, it instead shows the 5 previously played songs, plus many more than 15 upcoming songs. In addition, the upcoming songs are not from the playlist, they are from about 7 or so albums, in album order. I have changed settings, change the source playlist, restarted iTunes, rebooted the machine. All with no change. Does anybody have any idea how to get this working again? Thanks, Dave

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  • Dolby Digital Live (DDL) on Asus Rampage II Gene (Creative X-Fi Extreme)

    - by kevyn
    Hi there, I have an Asus Rampage II Gene motherboard which has X-Fi extreme built in. I can get it to work with Windows 7 ok using the Creative drivers, however when I try and install the DDL/DTS add on pack from Creative I get the error message: "There are no supported audio device available. You need to close the application. Click OK to close the application now" I don't understand it because I have the Creative software installed ok and supporting the sound without any problems. In Device manager the audio device comes up as 'High definition audio device' and uses driver: 6.1.7600.16385 from Microsoft. I tried using the Creative drivers which show up as 'soundmax HD audio' however these do not allow any of the Creative products to run properly. Please can anyone offer any help? Or even just confirm that DDL can work with my onboard sound? Windows 7 Ultimate 64 bit 6GB DDR3 XFX GS8800 384mb Asus Rampage II Gene Intel i7 920 (2.66)

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