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• protect form hijacking hack

  - by Karem

  Yes hello today I discovered a hack for my site. When you write a msg on a users wall (in my communitysite) it runs a ajax call, to insert the msg to the db and will then on success slide down and show it. Works fine with no problem. So I was rethinking alittle, I am using POST methods for this and if it was GET method you could easily do ?msg=haxmsg&usr=12345679. But what could you do to come around the POST method? I made a new html document, made a form and on action i set "site.com/insertwall.php" (the file that normally are being used in ajax), i made some input fields with names exactly like i am doing with the ajaxcall (msg, uID (userid), BuID (by userid) ) and made a submit button. I know I have a page_protect() function on which requires you to login and if you arent you will be header to index.php. So i logged in (started session on my site.com) and then I pressed on this submit button. And then wops I saw on my site that it has made a new message. I was like wow, was it so easy to hijack POST method i thought maybe it was little more secure or something. I would like to know what could I do to prevent this hijacking? As i wouldnt even want to know what real hackers could do with this "hole". The page_protect secures that the sessions are from the same http user agent and so, and this works fine (tried to run the form without logging in, and it just headers me to startpage) but yea wouldnt take long time to figure out to log in first and then run it. Any advices are appreciated alot. I would like to keep my ajax calls most secure as possible and all of them are running on the POST method. What could I do to the insertwall.php, to check that it comes from the server or something.. Thank you

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• MediaWiki: how to hide users from the user list?

  - by Dave Everitt

  I've set up Mediawiki 1.15.1 for a client who has added two users by mistake. They now want to hide these users from the user list. It seems this is done via the $wgGroupPermissions array with $wgGroupPermissions['suppress']['hideuser'] = true;, but it isn't at all clear what entry this needs for the hiding to work, or whether a new group ('hidden' or whatever) has to be created first with $wgAddGroups['bureaucrat'] = true;. For now, I've added the two users to be hidden to the 'Oversight' group which explains 'Block a username, hiding it from the public (hideuser)', but they still appear on the Special:ListUsers page. At a loss as to how the MediWiki arrays alter options displayed in the interface, so far I've added this to LocalSettings.php: $wgGroupPermissions['suppress']['hideuser'] = true; $wgAddGroups['supress'] = true; Or - since they haven't actually added anything to the wiki - could they simply be removed from the MySQL users table - although MediaWiki warns against this? Has anyone else done this successfully? Update - this is a hole in MediaWiki admin (although there are workarounds). See this thread on MediaWIki Users and the note to the reply below.

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• Apache Cordova (Phonegap): is jsop needed for cross-site scripting?

  - by DEX

  I've just started using Apache Cordova. I have an library that makes calls (via ajax) to a soap server. When I run these on my local machine in chrome, I get cross site scripting errors when trying to make calls to the service. When I run the same exact code using the Cordova browser in the iOS emulator, the scripts seem to hit the server fine and the response data is received properly. So my question is how is the Cordova browser able to make these requests without cross-site scripting permissions & JSONP ? One thing I noticed is that when the request is sent from iOS, there is no "Origin" header. Is this allowing the Cordova browser to stealthily circumvent cross-site scripting requirements? Is it possible that the node.js server on the device (I believe this is how Cordova works) is manipulating the headers to allow this? I'd like to avoid enabling cross-site scripting on my site so I think this "feature" is nice, but I'm wondering if it's a security hole as well. Anyone have experience with this?

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• PHP Mailer Class - Securing Email Credentials

  - by Alan A

  I am using the php mailer class to send email via my scripts. The structure is as follows: $mail = new PHPMailer; $mail->IsSMTP(); // Set mailer to use SMTP $mail->Host = 'myserver.com'; // Specify main and backup server $mail->SMTPAuth = true; // Enable SMTP authentication $mail->Username = '[email protected]'; // SMTP username $mail->Password = 'user123'; // SMTP password $mail->SMTPSecure = 'pass123'; It seems to me to be a bit of a security hole having the mailbox credentials in plain view. So I thought I might put these in an external file outside of the web root. My question is how would I then assign the $mail object these values. I of course no how to use include and/or requires... would it simple be a case of.... $mail->IsSMTP(); // Set mailer to use SMTP $mail->Host = 'myserver.com'; // Specify main and backup server $mail->SMTPAuth = true; // Enable SMTP authentication includes '../locationOutsideWebroot/emailCredntials.php'; $mail->SMTPSecure = 'pass123'; Then emailCredentails.php: <?php $mail->Username = '[email protected]'; $mail->Password = 'user123'; ?> Would this be sufficient and secure enough? Thanks, Alan.

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• Flash Player, security: If a URL starts with "http://" will the SWF always be loaded into REMOTE san

  - by Pavel

  Seems to be a question for a Flash security guru. Suppose we are loading an external SWF movie with MovieClipLoader.loadMovie(url:String) Is it safe to assume that if url starts with "http://", the movie will be loaded in REMOTE sandbox? We need to tell local SWFs from remote ones to close a security hole. If you need the context read on. We have developed a Projector, written in C++ embedding Flash Player ActiveX. Our Flash application runs inside the Projector. Soon we want to give our users a way to create plugins for the application. The plugins are obviously will be SWF movies. The case I'm afraid of is the following. A bad person creates a malicious evil.swf pretending it to be nice plugin for our app. In case evil.swf is loaded from the local file system it is granted an access to the whole MovieClip tree and Projector API, opening C++ file access operations. On the other hand if evil.swf is loaded from the internet, remotely, it will be locked in REMOTE sandbox by Flash security model. Because of this, we need a reliable way to tell local SWF from remote one before loading it. And we must not make a mistake. So again, is it safe to assume that if url begins with "http://", the clip will be loaded inside REMOTE sandbox?

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• Modifying Django's pre_save/post_save Data

  - by Rodrogo

  Hi, I'm having a hard time to grasp this post_save/pre_save signals from django. What happens is that my model has a field called status and when a entry to this model is added/saved, it's status must be changed accordingly with some condition. My model looks like this: class Ticket(models.Model): (...) status = models.CharField(max_length=1,choices=OFFERT_STATUS, default='O') And my signal handler, configured for pre_save: def ticket_handler(sender, **kwargs): ticket = kwargs['instance'] (...) if someOtherCondition: ticket.status = 'C' Now, what happens if I put aticket.save() just bellow this last line if statement is a huge iteration black hole, since this action calls the signal itself. And this problem happens in both pre_save and post_save. Well... I guess that the capability of altering a entry before (or even after) saving it is pretty common in django's universe. So, what I'm doing wrong here? Is the Signals the wrong approach or I'm missing something else here? Also, would it be possible to, once this pre_save/post_save function is triggered, to access another model's instance and change a specific row entry on that? Thanks

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• T-SQL Tuesday #33: Trick Shots: Undocumented, Underdocumented, and Unknown Conspiracies!

  - by Most Valuable Yak (Rob Volk)

  Mike Fal (b | t) is hosting this month's T-SQL Tuesday on Trick Shots.  I love this choice because I've been preoccupied with sneaky/tricky/evil SQL Server stuff for a long time and have been presenting on it for the past year.  Mike's directives were "Show us a cool trick or process you developed…It doesn’t have to be useful", which most of my blogging definitely fits, and "Tell us what you learned from this trick…tell us how it gave you insight in to how SQL Server works", which is definitely a new concept.  I've done a lot of reading and watching on SQL Server Internals and even attended training, but sometimes I need to go explore on my own, using my own tools and techniques.  It's an itch I get every few months, and, well, it sure beats workin'. I've found some people to be intimidated by SQL Server's internals, and I'll admit there are A LOT of internals to keep track of, but there are tons of excellent resources that clearly document most of them, and show how knowing even the basics of internals can dramatically improve your database's performance.  It may seem like rocket science, or even brain surgery, but you don't have to be a genius to understand it. Although being an "evil genius" can help you learn some things they haven't told you about. ;) This blog post isn't a traditional "deep dive" into internals, it's more of an approach to find out how a program works.  It utilizes an extremely handy tool from an even more extremely handy suite of tools, Sysinternals.  I'm not the only one who finds Sysinternals useful for SQL Server: Argenis Fernandez (b | t), Microsoft employee and former T-SQL Tuesday host, has an excellent presentation on how to troubleshoot SQL Server using Sysinternals, and I highly recommend it.  Argenis didn't cover the Strings.exe utility, but I'll be using it to "hack" the SQL Server executable (DLL and EXE) files. Please note that I'm not promoting software piracy or applying these techniques to attack SQL Server via internal knowledge. This is strictly educational and doesn't reveal any proprietary Microsoft information.  And since Argenis works for Microsoft and demonstrated Sysinternals with SQL Server, I'll just let him take the blame for it. :P (The truth is I've used Strings.exe on SQL Server before I ever met Argenis.) Once you download and install Strings.exe you can run it from the command line.  For our purposes we'll want to run this in the Binn folder of your SQL Server instance (I'm referencing SQL Server 2012 RTM): cd "C:\Program Files\Microsoft SQL Server\MSSQL11\MSSQL\Binn" C:\Program Files\Microsoft SQL Server\MSSQL11\MSSQL\Binn> strings *sql*.dll > sqldll.txt C:\Program Files\Microsoft SQL Server\MSSQL11\MSSQL\Binn> strings *sql*.exe > sqlexe.txt   I've limited myself to DLLs and EXEs that have "sql" in their names.  There are quite a few more but I haven't examined them in any detail. (Homework assignment for you!) If you run this yourself you'll get 2 text files, one with all the extracted strings from every SQL DLL file, and the other with the SQL EXE strings.  You can open these in Notepad, but you're better off using Notepad++, EditPad, Emacs, Vim or another more powerful text editor, as these will be several megabytes in size. And when you do open it…you'll find…a TON of gibberish.  (If you think that's bad, just try opening the raw DLL or EXE file in Notepad.  And by the way, don't do this in production, or even on a running instance of SQL Server.)  Even if you don't clean up the file, you can still use your editor's search function to find a keyword like "SELECT" or some other item you expect to be there.  As dumb as this sounds, I sometimes spend my lunch break just scanning the raw text for anything interesting.  I'm boring like that. Sometimes though, having these files available can lead to some incredible learning experiences.  For me the most recent time was after reading Joe Sack's post on non-parallel plan reasons.  He mentions a new SQL Server 2012 execution plan element called NonParallelPlanReason, and demonstrates a query that generates "MaxDOPSetToOne".  Joe (formerly on the Microsoft SQL Server product team, so he knows this stuff) mentioned that this new element was not currently documented and tried a few more examples to see what other reasons could be generated. Since I'd already run Strings.exe on the SQL Server DLLs and EXE files, it was easy to run grep/find/findstr for MaxDOPSetToOne on those extracts.  Once I found which files it belonged to (sqlmin.dll) I opened the text to see if the other reasons were listed.  As you can see in my comment on Joe's blog, there were about 20 additional non-parallel reasons.  And while it's not "documentation" of this underdocumented feature, the names are pretty self-explanatory about what can prevent parallel processing. I especially like the ones about cursors – more ammo! - and am curious about the PDW compilation and Cloud DB replication reasons. One reason completely stumped me: NoParallelHekatonPlan.  What the heck is a hekaton?  Google and Wikipedia were vague, and the top results were not in English.  I found one reference to Greek, stating "hekaton" can be translated as "hundredfold"; with a little more Wikipedia-ing this leads to hecto, the prefix for "one hundred" as a unit of measure.  I'm not sure why Microsoft chose hekaton for such a plan name, but having already learned some Greek I figured I might as well dig some more in the DLL text for hekaton.  Here's what I found: hekaton_slow_param_passing Occurs when a Hekaton procedure call dispatch goes to slow parameter passing code path The reason why Hekaton parameter passing code took the slow code path hekaton_slow_param_pass_reason sp_deploy_hekaton_database sp_undeploy_hekaton_database sp_drop_hekaton_database sp_checkpoint_hekaton_database sp_restore_hekaton_database e:\sql11_main_t\sql\ntdbms\hekaton\sqlhost\sqllang\hkproc.cpp e:\sql11_main_t\sql\ntdbms\hekaton\sqlhost\sqllang\matgen.cpp e:\sql11_main_t\sql\ntdbms\hekaton\sqlhost\sqllang\matquery.cpp e:\sql11_main_t\sql\ntdbms\hekaton\sqlhost\sqllang\sqlmeta.cpp e:\sql11_main_t\sql\ntdbms\hekaton\sqlhost\sqllang\resultset.cpp Interesting!  The first 4 entries (in red) mention parameters and "slow code".  Could this be the foundation of the mythical DBCC RUNFASTER command?  Have I been passing my parameters the slow way all this time? And what about those sp_xxxx_hekaton_database procedures (in blue)? Could THEY be the secret to a faster SQL Server? Could they promise a "hundredfold" improvement in performance?  Are these special, super-undocumented DIB (databases in black)? I decided to look in the SQL Server system views for any objects with hekaton in the name, or references to them, in hopes of discovering some new code that would answer all my questions: SELECT name FROM sys.all_objects WHERE name LIKE '%hekaton%' SELECT name FROM sys.all_objects WHERE object_definition(OBJECT_ID) LIKE '%hekaton%' Which revealed: name ------------------------ (0 row(s) affected) name ------------------------ sp_createstats sp_recompile sp_updatestats (3 row(s) affected)   Hmm.  Well that didn't find much.  Looks like these procedures are seriously undocumented, unknown, perhaps forbidden knowledge. Maybe a part of some unspeakable evil? (No, I'm not paranoid, I just like mysteries and thought that punching this up with that kind of thing might keep you reading.  I know I'd fall asleep without it.) OK, so let's check out those 3 procedures and see what they reveal when I search for "Hekaton": sp_createstats: -- filter out local temp tables, Hekaton tables, and tables for which current user has no permissions -- Note that OBJECTPROPERTY returns NULL on type="IT" tables, thus we only call it on type='U' tables   OK, that's interesting, let's go looking down a little further: ((@table_type<>'U') or (0 = OBJECTPROPERTY(@table_id, 'TableIsInMemory'))) and -- Hekaton table   Wellllll, that tells us a few new things: There's such a thing as Hekaton tables (UPDATE: I'm not the only one to have found them!) They are not standard user tables and probably not in memory UPDATE: I misinterpreted this because I didn't read all the code when I wrote this blog post. The OBJECTPROPERTY function has an undocumented TableIsInMemory option Let's check out sp_recompile: -- (3) Must not be a Hekaton procedure.   And once again go a little further: if (ObjectProperty(@objid, 'IsExecuted') <> 0 AND ObjectProperty(@objid, 'IsInlineFunction') = 0 AND ObjectProperty(@objid, 'IsView') = 0 AND -- Hekaton procedure cannot be recompiled -- Make them go through schema version bumping branch, which will fail ObjectProperty(@objid, 'ExecIsCompiledProc') = 0)   And now we learn that hekaton procedures also exist, they can't be recompiled, there's a "schema version bumping branch" somewhere, and OBJECTPROPERTY has another undocumented option, ExecIsCompiledProc.  (If you experiment with this you'll find this option returns null, I think it only works when called from a system object.) This is neat! Sadly sp_updatestats doesn't reveal anything new, the comments about hekaton are the same as sp_createstats.  But we've ALSO discovered undocumented features for the OBJECTPROPERTY function, which we can now search for: SELECT name, object_definition(OBJECT_ID) FROM sys.all_objects WHERE object_definition(OBJECT_ID) LIKE '%OBJECTPROPERTY(%'   I'll leave that to you as more homework.  I should add that searching the system procedures was recommended long ago by the late, great Ken Henderson, in his Guru's Guide books, as a great way to find undocumented features.  That seems to be really good advice! Now if you're a programmer/hacker, you've probably been drooling over the last 5 entries for hekaton (in green), because these are the names of source code files for SQL Server!  Does this mean we can access the source code for SQL Server?  As The Oracle suggested to Neo, can we return to The Source??? Actually, no. Well, maybe a little bit.  While you won't get the actual source code from the compiled DLL and EXE files, you'll get references to source files, debugging symbols, variables and module names, error messages, and even the startup flags for SQL Server.  And if you search for "DBCC" or "CHECKDB" you'll find a really nice section listing all the DBCC commands, including the undocumented ones.  Granted those are pretty easy to find online, but you may be surprised what those web sites DIDN'T tell you! (And neither will I, go look for yourself!)  And as we saw earlier, you'll also find execution plan elements, query processing rules, and who knows what else.  It's also instructive to see how Microsoft organizes their source directories, how various components (storage engine, query processor, Full Text, AlwaysOn/HADR) are split into smaller modules. There are over 2000 source file references, go do some exploring! So what did we learn?  We can pull strings out of executable files, search them for known items, browse them for unknown items, and use the results to examine internal code to learn even more things about SQL Server.  We've even learned how to use command-line utilities!  We are now 1337 h4X0rz!  (Not really.  I hate that leetspeak crap.) Although, I must confess I might've gone too far with the "conspiracy" part of this post.  I apologize for that, it's just my overactive imagination.  There's really no hidden agenda or conspiracy regarding SQL Server internals.  It's not The Matrix.  It's not like you'd find anything like that in there: Attach Matrix Database DM_MATRIX_COMM_PIPELINES MATRIXXACTPARTICIPANTS dm_matrix_agents   Alright, enough of this paranoid ranting!  Microsoft are not really evil!  It's not like they're The Borg from Star Trek: ALTER FEDERATION DROP ALTER FEDERATION SPLIT DROP FEDERATION   #tsql2sday

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• SQL SERVER – Why Do We Need Data Quality Services – Importance and Significance of Data Quality Services (DQS)

  - by pinaldave

  Databases are awesome.  I’m sure my readers know my opinion about this – I have made SQL Server my life’s work after all!  I love technology and all things computer-related.  Of course, even with my love for technology, I have to admit that it has its limits.  For example, it takes a human brain to notice that data has been input incorrectly.  Computer “brains” might be faster than humans, but human brains are still better at pattern recognition.  For example, a human brain will notice that “300” is a ridiculous age for a human to be, but to a computer it is just a number.  A human will also notice similarities between “P. Dave” and “Pinal Dave,” but this would stump most computers. In a database, these sorts of anomalies are incredibly important.  Databases are often used by multiple people who rely on this data to be true and accurate, so data quality is key.  That is why the improved SQL Server features Master Data Management talks about Data Quality Services.  This service has the ability to recognize and flag anomalies like out of range numbers and similarities between data.  This allows a human brain with its pattern recognition abilities to double-check and ensure that P. Dave is the same as Pinal Dave. A nice feature of Data Quality Services is that once you set the rules for the program to follow, it will not only keep your data organized in the future, but go to the past and “fix up” any data that has already been entered.  It also allows you do combine data from multiple places and it will apply these rules across the board, so that you don’t have any weird issues that crop up when trying to fit a round peg into a square hole. There are two parts of Data Quality Services that help you accomplish all these neat things.  The first part is DQL Server, which you can think of as the hardware component of the system.  It is installed on the side of (it needs to install separately after SQL Server is installed) SQL Server and runs quietly in the background, performing all its cleanup services. DQS Client is the user interface that you can interact with to set the rules and check over your data.  There are three main aspects of Client: knowledge base management, data quality projects and administration.  Knowledge base management is the part of the system that allows you to set the rules, or program the “knowledge base,” so that your database is clean and consistent. Data Quality projects are what run in the background and clean up the data that is already present.  The administration allows you to check out what DQS Client is doing, change rules, and generally oversee the entire process.  The whole process is user-friendly and a pleasure to use.  I highly recommend implementing Data Quality Services in your database. Here are few of my blog posts which are related to Data Quality Services and I encourage you to try this out. SQL SERVER – Installing Data Quality Services (DQS) on SQL Server 2012 SQL SERVER – Step by Step Guide to Beginning Data Quality Services in SQL Server 2012 – Introduction to DQS SQL SERVER – DQS Error – Cannot connect to server – A .NET Framework error occurred during execution of user-defined routine or aggregate “SetDataQualitySessions” – SetDataQualitySessionPhaseTwo SQL SERVER – Configuring Interactive Cleansing Suggestion Min Score for Suggestions in Data Quality Services (DQS) – Sensitivity of Suggestion SQL SERVER – Unable to DELETE Project in Data Quality Projects (DQS) Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: Data Quality Services, DQS

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• broken upgrade from 10.04 to 12.04 on a VPS - recoverable?

  - by HorusKol

  I have a VPS hosted 1500 km away. It originally came with 9.10 - and this morning I decided that I really should get to an LTS release, and figured I'd jump to 12.04. Researching, I discovered that there is no direct path between 9.10 and 12.04, but that I could upgrade via 10.04. After backing up my data, I dove in. The upgrade to 10.04 was successful, and I proceeded to upgrade to 12.04. Things started to go wrong. First, I got an error with GLIBC - I retried and got the same error. That's when I stopped the upgrade. I then tried another round of apt-get update && apt-get upgrade and got a list of "unmet dependencies": apt: Depends: ubuntu-keyring but it is not going to be installed Depends: libc6 (>= 2.15) but 2.11.1-0ubuntu7.11 is to be installed Depends: libstdc++6 (>= 4.6) but 4.4.3-4ubuntu5.1 is to be installed PreDepends: dpkg (>= 1.15.7.2) but 1.15.5.6ubuntu4.6 is to be installed apt-utils: Depends: libapt-pkg-libc6.10-6-4.8 libapt-inst1.4: Depends: libc6 (>= 2.14) but 2.11.1-0ubuntu7.11 is to be installed libapt-pkg4.12: Depends: libc6 (>= 2.15) but 2.11.1-0ubuntu7.11 is to be installed Depends: libstdc++6 (>= 4.6) but 4.4.3-4ubuntu5.1 is to be installed libc6: Depends: libc-bin (= 2.11.1-0ubuntu7.11) but 2.15-0ubuntu10.2 is to be installed libept0: Depends: libapt-pkg-libc6.10-6-4.8 libnih-dbus1: Depends: libnih1 (= 1.0.3-4ubuntu9) but 1.0.1-1 is to be installed I tried to see if I could do something about these - using apt-get -f install. This told me that I would need to upgrade my kernel. I found instructions on how to do this, but when I ran apt-get to install the new linux headers, I got the same dependency errors. I found another answer here where someone else had had an interruption in their upgrade - and tried the solution that worked for them: sudo apt-get -f dist-upgrade This resulted in the error: E: Could not perform immediate configuration on 'python2.7-minimal'.Please see man 5 apt.conf under APT::Immediate-Configure for details. (2) I tried to resolve this by: apt-get install -o APT::Immediate-Configure=false -f apt python-minimal But this simply ended up with this last list of dependency errors: apt: Depends: ubuntu-keyring but it is not going to be installed Depends: libc6 (>= 2.15) but 2.11.1-0ubuntu7.11 is to be installed Depends: libstdc++6 (>= 4.6) but 4.4.3-4ubuntu5.1 is to be installed PreDepends: dpkg (>= 1.15.7.2) but 1.15.5.6ubuntu4.6 is to be installed apt-utils: Depends: libapt-pkg-libc6.10-6-4.8 libapt-inst1.4: Depends: libc6 (>= 2.14) but 2.11.1-0ubuntu7.11 is to be installed libapt-pkg4.12: Depends: libc6 (>= 2.15) but 2.11.1-0ubuntu7.11 is to be installed Depends: libstdc++6 (>= 4.6) but 4.4.3-4ubuntu5.1 is to be installed libc6: Depends: libc-bin (= 2.11.1-0ubuntu7.11) but 2.15-0ubuntu10.2 is to be installed libept0: Depends: libapt-pkg-libc6.10-6-4.8 libnih-dbus1: Depends: libnih1 (= 1.0.3-4ubuntu9) but 1.0.1-1 is to be installed python: Depends: python-minimal (= 2.6.5-0ubuntu1) but 2.7.3-0ubuntu2 is to be installed python-apt: Depends: libapt-pkg-libc6.10-6-4.8 python-minimal: Depends: python2.7-minimal (>= 2.7.3) but it is not going to be installed Breaks: python-support (< 1.0.10ubuntu2) but 1.0.4ubuntu1 is to be installed synaptic: Depends: libapt-pkg-libc6.10-6-4.8 Any ideas on how to dig out of this hole?

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• Hosted Monitoring

  - by Grant Fritchey

  The concept of using services to take the place of writing a lot of your own code goes way, way back in computing history. The fundamentals of the concept go back to the dawn of computing with places like IBM hosting time-shares for computing power that you could rent for short periods of time. But things really took off with the building of the Web. Now, all the growth with virtual machines, hosted machines, hosted services from vendors like Amazon and Microsoft, the need to keep all of your software locally on physical boxes is just going the way of the dodo. There will likely always be some pieces of software that you keep on machines on your property or on your person, but the concept of keeping fundamental services locally is going away. As someone put it to me once, if you were starting a business right now, would you bother setting up an Exchange server to manage your email or would you just go to one of the external mail services for everything? For most of us (who are not Exchange admins) the answer is pretty easy. With all this momentum to having external services manage more and more of the infrastructure that’s not business unique, why would you burn up a server and license instance setting up monitoring for your SQL Servers? Of course, some of you are dealing with hyper-sensitive data that might require, through law or treaty, that you lock it down and never expose it to the intertubes, but most of us are not. So, what if someone else took on the basic hassle of setting up monitoring on your systems? That’s what we’re working on here at Red Gate. Right now it’s a private test, but we’re growing it and developing it and it’ll be going to a public beta, probably (hopefully) this year. I’m running it on my machines right now. The concept is pretty simple. You put a relay on your server, poke a hole in your firewall for it, and we start monitoring your server using SQL Monitor. It’s actually shocking how easy it is to get going. You still have to adjust your alerting thresholds, but that’s a standard part of alerting. Your pain threshold and my pain threshold for any given alert may be different. But from there, we do all the heavy lifting, keeping your data online and available, providing you with access to the information about how your servers are behaving, everything. Maybe it’s just me, but I’m really excited by this. I think we’re getting to a place where we can really help the small and medium sized businesses get a monitoring solution in place, quickly and easily. All you crazy busy, and possibly accidental, DBAs and system admins finally can set up monitoring without taking all the time to configure systems, run installs, and all the rest. You just have to tweak your alerts and you’re ready to run. If you are interested in checking it out, you can apply for the closed beta through the Monitor web page.

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• Need help making site available externally

  - by White Island

  I'm trying to open a hole in the firewall (ASA 5505, v8.2) to allow external access to a Web application. Via ASDM (6.3?), I've added the server as a Public Server, which creates a static NAT entry [I'm using the public IP that is assigned to 'dynamic NAT--outgoing' for the LAN, after confirming on the Cisco forums that it wouldn't bring everyone's access crashing down] and an incoming rule "any... public_ip... https... allow" but traffic is still not getting through. When I look at the log viewer, it says it's denied by access-group outside_access_in, implicit rule, which is "any any ip deny" I haven't had much experience with Cisco management. I can't see what I'm missing to allow this connection through, and I'm wondering if there's anything else special I have to add. I tried adding a rule (several variations) within that access-group to allow https to the server, but it never made a difference. Maybe I haven't found the right combination? :P I also made sure the Windows firewall is open on port 443, although I'm pretty sure the current problem is Cisco, because of the logs. :) Any ideas? If you need more information, please let me know. Thanks Edit: First of all, I had this backward. (Sorry) Traffic is being blocked by access-group "inside_access_out" which is what confused me in the first place. I guess I confused myself again in the midst of typing the question. Here, I believe, is the pertinent information. Please let me know what you see wrong. access-list acl_in extended permit tcp any host PUBLIC_IP eq https access-list acl_in extended permit icmp CS_WAN_IPs 255.255.255.240 any access-list acl_in remark Allow Vendor connections to LAN access-list acl_in extended permit tcp host Vendor any object-group RemoteDesktop access-list acl_in remark NetworkScanner scan-to-email incoming (from smtp.mail.microsoftonline.com to PCs) access-list acl_in extended permit object-group TCPUDP any object-group Scan-to-email host NetworkScanner object-group Scan-to-email access-list acl_out extended permit icmp any any access-list acl_out extended permit tcp any any access-list acl_out extended permit udp any any access-list SSLVPNSplitTunnel standard permit LAN_Subnet 255.255.255.0 access-list nonat extended permit ip VPN_Subnet 255.255.255.0 LAN_Subnet 255.255.255.0 access-list nonat extended permit ip LAN_Subnet 255.255.255.0 VPN_Subnet 255.255.255.0 access-list inside_access_out remark NetworkScanner Scan-to-email outgoing (from scanner to Internet) access-list inside_access_out extended permit object-group TCPUDP host NetworkScanner object-group Scan-to-email any object-group Scan-to-email access-list inside_access_out extended permit tcp any interface outside eq https static (inside,outside) PUBLIC_IP LOCAL_IP[server object] netmask 255.255.255.255 I wasn't sure if I needed to reverse that "static" entry, since I got my question mixed up... and also with that last access-list entry, I tried interface inside and outside - neither proved successful... and I wasn't sure about whether it should be www, since the site is running on https. I assumed it should only be https.

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• Disable Acer eRecovery system

  - by Joel Coehoorn

  The meat of this question is that I'm looking for a way to either require a password before using a recovery partition or "break" the recovery partition (specifically, Acer eRecovery) in a way that I can later "unbreak" only by booting normally into windows first. Here's the full details: I have a set of new Acer Veriton n260g machines in a computer lab. A lot work went into setting up this lab to work well - for example, Office 2007 and other programs needed by the students were installed, all windows updates are applied, and a default desktop is setup. All in all it's several hours work to fully set up one machine. Unfortunately, I don't currently have the ability to easily image these machines, and even if I did I would want to avoid downtime even while an image is restored. Therefore, I've taken steps to lock them down — namely DeepFreeze and a bios password to prevent booting from anywhere but the frozen hard drive. DeepFreeze is an amazing product — as long as you boot from the frozen hard drive, there is no way to actually make permanent changes to that hard drive. Anything you do is wiped after the machine restarts. It lets me give students the leeway to do what they want on lab computers without worrying about them breaking something. The problem is that even with the bios locked and set to only boot from the hard drive, these Acers still have a simple way to choose a different boot source: shut them down and put a paper click in a little hole at the top while you turn it on again. This puts them into the "Acer eRecovery" mode. This by itself is no big deal — you can still power cycle with no impact. But if you then click through the menu to reset the machine (we're now past the point of curiosity and on to intent) it will wipe the hard drive and restore it to the original state. Of course, a few students have already figured this out and reset a couple machines. That's unfortunate, but inevitable. I don't want to destroy the ability to do this entirely (which I could by repartitioning the drives to remove the recovery partition) but I would like a way to require a password first, or "break" the recovery system in a way that I can "unbreak" only if I first un-freeze the hard drive in DeepFreeze. Any ideas?

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• Email server can send internal, but messages never arrive at external recipients

  - by Chase Florell

  I'm running MailEnable on my server, and have been for many years. Recently we had an attack on our server, and I was able to close the hole. Since then, our mail server doesn't seem to be sending mail out. If I send an email from myself to another account hosted on the server, the email arrives as expected. If I send an email from my gmail account to my business account, the email also arrives as expected The problem comes when I send from my business account to an external domain I tried the following Gmail.com Hotmail.com Shaw.ca When I send to any of the above The message leaves my client as expected, The logs appear to accept and forward on the message The SMTP outbound que is empty The message never arrives I have checked our domain with mxtoolbox.com senderbase.org And neither of them are reporting any problems with our domain. I have ensured that port 25 is open (along with the other standard ports) Here is one of the log entries from the SMTP connector 11/05/13 12:10:00 SMTP-IN 494C0AF55CD0400FB90FD5E6525BC885.MAI 1312 127.0.0.1 220 mx1.example.com ESMTP MailEnable Service, Version: 6.81--6.81 ready at 11/05/13 12:10:00 0 0 11/05/13 12:10:00 SMTP-IN 494C0AF55CD0400FB90FD5E6525BC885.MAI 1312 127.0.0.1 EHLO EHLO ASSP.nospam 250-mx1.example.com [127.0.0.1], this server offers 6 extensions 159 18 11/05/13 12:10:00 SMTP-IN 494C0AF55CD0400FB90FD5E6525BC885.MAI 1312 127.0.0.1 EHLO EHLO ASSP.nospam 250-mx1.example.com [127.0.0.1], this server offers 6 extensions 159 18 11/05/13 12:10:01 SMTP-IN 494C0AF55CD0400FB90FD5E6525BC885.MAI 1312 127.0.0.1 AUTH AUTH LOGIN 334 VXNlcm5hbWU6 18 12 11/05/13 12:10:01 SMTP-IN 494C0AF55CD0400FB90FD5E6525BC885.MAI 1312 127.0.0.1 AUTH {blank} 334 UGFzc3dvcmQ6 18 26 [email protected] 11/05/13 12:10:01 SMTP-IN 494C0AF55CD0400FB90FD5E6525BC885.MAI 1312 127.0.0.1 AUTH Y29sb25lbGZhY2U= 235 Authenticated 19 18 [email protected] 11/05/13 12:10:01 SMTP-IN 494C0AF55CD0400FB90FD5E6525BC885.MAI 1312 127.0.0.1 MAIL MAIL FROM:<[email protected]> 250 Requested mail action okay, completed 43 31 [email protected] 11/05/13 12:10:01 SMTP-IN 494C0AF55CD0400FB90FD5E6525BC885.MAI 1312 127.0.0.1 RCPT RCPT TO:<[email protected]> 250 Requested mail action okay, completed 43 35 [email protected] 11/05/13 12:10:01 SMTP-IN 494C0AF55CD0400FB90FD5E6525BC885.MAI 1312 127.0.0.1 DATA DATA 354 Start mail input; end with <CRLF>.<CRLF> 46 6 [email protected] Here are the headers of the sent message X-Assp-Version: 1.7.5.7(1.0.07) on ASSP.nospam X-Assp-ID: ASSP.nospam 78601-04523 X-Assp-Intended-For: [email protected] X-Assp-Envelope-From: [email protected] Received: from [10.10.1.101] ([68.147.245.149] helo=[10.10.1.101]) with IPv4:587 by ASSP.nospam; 5 Nov 2013 12:10:00 -0700 From: Chase Florell <[email protected]> Content-Type: text/plain Content-Transfer-Encoding: 7bit Subject: Test Message Message-Id: <[email protected]> Date: Tue, 5 Nov 2013 12:10:18 -0700 To: Chase Florell <[email protected]> Mime-Version: 1.0 (Mac OS X Mail 7.0 \(1816\)) X-Mailer: Apple Mail (2.1816) . Where else can I check to see if there is something broken? What could cause a problem like this whereby the message appears to send, but never arrives, and never returns a bounce?

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• "Hostile" network in the company - please comment on a security setup

  - by TomTom

  I have a little specific problem here that I want (need) to solve in a satisfactory way. My company has multiple (IPv4) networks that are controlled by our router sitting in the middle. Typical smaller shop setup. There is now one additional network that has an IP Range OUTSIDE of our control, connected to the internet with another router OUTSIDE of our control. Call it a project network that is part of another companies network and combined via VPN they set up. This means: They control the router that is used for this network and They can reconfigure things so that they can access the machines in this network. The network is physically split on our end through some VLAN capable switches as it covers three locations. At one end there is the router the other company controls. I Need / want to give the machines used in this network access to my company network. In fact, it may be good to make them part of my active directory domain. The people working on those machines are part of my company. BUT - I need to do so without compromising the security of my company network from outside influence. Any sort of router integration using the externally controlled router is out by this idea So, my idea is this: We accept the IPv4 address space and network topology in this network is not under our control. We seek alternatives to integrate those machines into our company network. The 2 concepts I came up with are: Use some sort of VPN - have the machines log into VPN. Thanks to them using modern windows, this could be transparent DirectAccess. This essentially treats the other IP space not different than any restaurant network a laptop of the company goes in. Alternatively - establish IPv6 routing to this ethernet segment. But - and this is a trick - block all IPv6 packets in the switch before they hit the third party controlled router, so that even IF they turn on IPv6 on that thing (not used now, but they could do it) they would get not a single packet. The switch can nicely do that by pulling all IPv6 traffic coming to that port into a separate VLAN (based on ethernet protocol type). Anyone sees a problem with using he switch to isolate the outer from IPv6? Any security hole? It is sad we have to treat this network as hostile - would be a lot easier - but the support personnel there is of "known dubious quality" and the legal side is clear - we can not fulfill our obligations when we integrate them into our company while they are under a jurisdiction we don't have a say in.

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• PHPMyAdmin works with https Only (not http)

  - by 01010011

  Hi I've been having a problem getting phpmyadmin to work consistently on my XP desktop and laptop computers for months now. When I type into Chrome's browser on both machines, localhost/phpmyadmin, I kept getting Error #1045 Access Denied for user at root@localhost (using password yes). Eventually, I realized that I had two (2) versions of mysql installed (XAMPP and MySQL Server 5.1) on both machines. So I uninstalled the MySQL Server 5.1I from the desktop and phpmyadmin worked. But when I uninstalled MySQL Server 5.1 from my laptop, it did not work. But I realized I could still get into MySQL Commandline Client using my password and that my databases were still intact. So I uninstalled and reinstalled XAMPP on the laptop and phpmyadmin worked after that. Now I have a new problem. On phpMyAdmin's home page has a message at the bottom: Your configuration file contains settings (root with no password) that correspond to the default MySQL privileged account. Your MySQL server is running with this default, is open to intrusion, and you really should fix this security hole by setting a password for user 'root'. So I located the following lines in config.inc.php file: /* Authentication type and info */ $cfg['Servers'][$i]['auth_type'] = 'config'; $cfg['Servers'][$i]['user'] = 'root'; $cfg['Servers'][$i]['password'] = ''; $cfg['Servers'][$i]['AllowNoPassword'] = true; and I just changed the last 2 lines as follows: $cfg['Servers'][$i]['password'] = 'mypassword'; $cfg['Servers'][$i]['AllowNoPassword'] = false; As soon as I did that and I tried to access phpmyadmin again, I got the Error #1045 message again, but when I tried https://localhost/phpmyadmin/ I got a red page saying this sites certificate is not trusted would you like to proceed anyway. And now it only works using https. I would really like to settle all my phpmyadmin problems once and for all so here are my questions: 1. Why does my laptop only access phpmyadmin via https? 2. How do I change my password in my configuration file? Also, if you have any other tips regarding phpMyAdmin, they are very welcome. Thanks in advance

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• What's up with OCFS2?

  - by wcoekaer

  On Linux there are many filesystem choices and even from Oracle we provide a number of filesystems, all with their own advantages and use cases. Customers often confuse ACFS with OCFS or OCFS2 which then causes assumptions to be made such as one replacing the other etc... I thought it would be good to write up a summary of how OCFS2 got to where it is, what we're up to still, how it is different from other options and how this really is a cool native Linux cluster filesystem that we worked on for many years and is still widely used. Work on a cluster filesystem at Oracle started many years ago, in the early 2000's when the Oracle Database Cluster development team wrote a cluster filesystem for Windows that was primarily focused on providing an alternative to raw disk devices and help customers with the deployment of Oracle Real Application Cluster (RAC). Oracle RAC is a cluster technology that lets us make a cluster of Oracle Database servers look like one big database. The RDBMS runs on many nodes and they all work on the same data. It's a Shared Disk database design. There are many advantages doing this but I will not go into detail as that is not the purpose of my write up. Suffice it to say that Oracle RAC expects all the database data to be visible in a consistent, coherent way, across all the nodes in the cluster. To do that, there were/are a few options : 1) use raw disk devices that are shared, through SCSI, FC, or iSCSI 2) use a network filesystem (NFS) 3) use a cluster filesystem(CFS) which basically gives you a filesystem that's coherent across all nodes using shared disks. It is sort of (but not quite) combining option 1 and 2 except that you don't do network access to the files, the files are effectively locally visible as if it was a local filesystem. So OCFS (Oracle Cluster FileSystem) on Windows was born. Since Linux was becoming a very important and popular platform, we decided that we would also make this available on Linux and thus the porting of OCFS/Windows started. The first version of OCFS was really primarily focused on replacing the use of Raw devices with a simple filesystem that lets you create files and provide direct IO to these files to get basically native raw disk performance. The filesystem was not designed to be fully POSIX compliant and it did not have any where near good/decent performance for regular file create/delete/access operations. Cache coherency was easy since it was basically always direct IO down to the disk device and this ensured that any time one issues a write() command it would go directly down to the disk, and not return until the write() was completed. Same for read() any sort of read from a datafile would be a read() operation that went all the way to disk and return. We did not cache any data when it came down to Oracle data files. So while OCFS worked well for that, since it did not have much of a normal filesystem feel, it was not something that could be submitted to the kernel mail list for inclusion into Linux as another native linux filesystem (setting aside the Windows porting code ...) it did its job well, it was very easy to configure, node membership was simple, locking was disk based (so very slow but it existed), you could create regular files and do regular filesystem operations to a certain extend but anything that was not database data file related was just not very useful in general. Logfiles ok, standard filesystem use, not so much. Up to this point, all the work was done, at Oracle, by Oracle developers. Once OCFS (1) was out for a while and there was a lot of use in the database RAC world, many customers wanted to do more and were asking for features that you'd expect in a normal native filesystem, a real "general purposes cluster filesystem". So the team sat down and basically started from scratch to implement what's now known as OCFS2 (Oracle Cluster FileSystem release 2). Some basic criteria were : Design it with a real Distributed Lock Manager and use the network for lock negotiation instead of the disk Make it a Linux native filesystem instead of a native shim layer and a portable core Support standard Posix compliancy and be fully cache coherent with all operations Support all the filesystem features Linux offers (ACL, extended Attributes, quotas, sparse files,...) Be modern, support large files, 32/64bit, journaling, data ordered journaling, endian neutral, we can mount on both endian /cross architecture,.. Needless to say, this was a huge development effort that took many years to complete. A few big milestones happened along the way... OCFS2 was development in the open, we did not have a private tree that we worked on without external code review from the Linux Filesystem maintainers, great folks like Christopher Hellwig reviewed the code regularly to make sure we were not doing anything out of line, we submitted the code for review on lkml a number of times to see if we were getting close for it to be included into the mainline kernel. Using this development model is standard practice for anyone that wants to write code that goes into the kernel and having any chance of doing so without a complete rewrite or.. shall I say flamefest when submitted. It saved us a tremendous amount of time by not having to re-fit code for it to be in a Linus acceptable state. Some other filesystems that were trying to get into the kernel that didn't follow an open development model had a lot harder time and a lot harsher criticism. March 2006, when Linus released 2.6.16, OCFS2 officially became part of the mainline kernel, it was accepted a little earlier in the release candidates but in 2.6.16. OCFS2 became officially part of the mainline Linux kernel tree as one of the many filesystems. It was the first cluster filesystem to make it into the kernel tree. Our hope was that it would then end up getting picked up by the distribution vendors to make it easy for everyone to have access to a CFS. Today the source code for OCFS2 is approximately 85000 lines of code. We made OCFS2 production with full support for customers that ran Oracle database on Linux, no extra or separate support contract needed. OCFS2 1.0.0 started being built for RHEL4 for x86, x86-64, ppc, s390x and ia64. For RHEL5 starting with OCFS2 1.2. SuSE was very interested in high availability and clustering and decided to build and include OCFS2 with SLES9 for their customers and was, next to Oracle, the main contributor to the filesystem for both new features and bug fixes. Source code was always available even prior to inclusion into mainline and as of 2.6.16, source code was just part of a Linux kernel download from kernel.org, which it still is, today. So the latest OCFS2 code is always the upstream mainline Linux kernel. OCFS2 is the cluster filesystem used in Oracle VM 2 and Oracle VM 3 as the virtual disk repository filesystem. Since the filesystem is in the Linux kernel it's released under the GPL v2 The release model has always been that new feature development happened in the mainline kernel and we then built consistent, well tested, snapshots that had versions, 1.2, 1.4, 1.6, 1.8. But these releases were effectively just snapshots in time that were tested for stability and release quality. OCFS2 is very easy to use, there's a simple text file that contains the node information (hostname, node number, cluster name) and a file that contains the cluster heartbeat timeouts. It is very small, and very efficient. As Sunil Mushran wrote in the manual : OCFS2 is an efficient, easily configured, quickly installed, fully integrated and compatible, feature-rich, architecture and endian neutral, cache coherent, ordered data journaling, POSIX-compliant, shared disk cluster file system. Here is a list of some of the important features that are included : Variable Block and Cluster sizes Supports block sizes ranging from 512 bytes to 4 KB and cluster sizes ranging from 4 KB to 1 MB (increments in power of 2). Extent-based Allocations Tracks the allocated space in ranges of clusters making it especially efficient for storing very large files. Optimized Allocations Supports sparse files, inline-data, unwritten extents, hole punching and allocation reservation for higher performance and efficient storage. File Cloning/snapshots REFLINK is a feature which introduces copy-on-write clones of files in a cluster coherent way. Indexed Directories Allows efficient access to millions of objects in a directory. Metadata Checksums Detects silent corruption in inodes and directories. Extended Attributes Supports attaching an unlimited number of name:value pairs to the file system objects like regular files, directories, symbolic links, etc. Advanced Security Supports POSIX ACLs and SELinux in addition to the traditional file access permission model. Quotas Supports user and group quotas. Journaling Supports both ordered and writeback data journaling modes to provide file system consistency in the event of power failure or system crash. Endian and Architecture neutral Supports a cluster of nodes with mixed architectures. Allows concurrent mounts on nodes running 32-bit and 64-bit, little-endian (x86, x86_64, ia64) and big-endian (ppc64) architectures. In-built Cluster-stack with DLM Includes an easy to configure, in-kernel cluster-stack with a distributed lock manager. Buffered, Direct, Asynchronous, Splice and Memory Mapped I/Os Supports all modes of I/Os for maximum flexibility and performance. Comprehensive Tools Support Provides a familiar EXT3-style tool-set that uses similar parameters for ease-of-use. The filesystem was distributed for Linux distributions in separate RPM form and this had to be built for every single kernel errata release or every updated kernel provided by the vendor. We provided builds from Oracle for Oracle Linux and all kernels released by Oracle and for Red Hat Enterprise Linux. SuSE provided the modules directly for every kernel they shipped. With the introduction of the Unbreakable Enterprise Kernel for Oracle Linux and our interest in reducing the overhead of building filesystem modules for every minor release, we decide to make OCFS2 available as part of UEK. There was no more need for separate kernel modules, everything was built-in and a kernel upgrade automatically updated the filesystem, as it should. UEK allowed us to not having to backport new upstream filesystem code into an older kernel version, backporting features into older versions introduces risk and requires extra testing because the code is basically partially rewritten. The UEK model works really well for continuing to provide OCFS2 without that extra overhead. Because the RHEL kernel did not contain OCFS2 as a kernel module (it is in the source tree but it is not built by the vendor in kernel module form) we stopped adding the extra packages to Oracle Linux and its RHEL compatible kernel and for RHEL. Oracle Linux customers/users obviously get OCFS2 included as part of the Unbreakable Enterprise Kernel, SuSE customers get it by SuSE distributed with SLES and Red Hat can decide to distribute OCFS2 to their customers if they chose to as it's just a matter of compiling the module and making it available. OCFS2 today, in the mainline kernel is pretty much feature complete in terms of integration with every filesystem feature Linux offers and it is still actively maintained with Joel Becker being the primary maintainer. Since we use OCFS2 as part of Oracle VM, we continue to look at interesting new functionality to add, REFLINK was a good example, and as such we continue to enhance the filesystem where it makes sense. Bugfixes and any sort of code that goes into the mainline Linux kernel that affects filesystems, automatically also modifies OCFS2 so it's in kernel, actively maintained but not a lot of new development happening at this time. We continue to fully support OCFS2 as part of Oracle Linux and the Unbreakable Enterprise Kernel and other vendors make their own decisions on support as it's really a Linux cluster filesystem now more than something that we provide to customers. It really just is part of Linux like EXT3 or BTRFS etc, the OS distribution vendors decide. Do not confuse OCFS2 with ACFS (ASM cluster Filesystem) also known as Oracle Cloud Filesystem. ACFS is a filesystem that's provided by Oracle on various OS platforms and really integrates into Oracle ASM (Automatic Storage Management). It's a very powerful Cluster Filesystem but it's not distributed as part of the Operating System, it's distributed with the Oracle Database product and installs with and lives inside Oracle ASM. ACFS obviously is fully supported on Linux (Oracle Linux, Red Hat Enterprise Linux) but OCFS2 independently as a native Linux filesystem is also, and continues to also be supported. ACFS is very much tied into the Oracle RDBMS, OCFS2 is just a standard native Linux filesystem with no ties into Oracle products. Customers running the Oracle database and ASM really should consider using ACFS as it also provides storage/clustered volume management. Customers wanting to use a simple, easy to use generic Linux cluster filesystem should consider using OCFS2. To learn more about OCFS2 in detail, you can find good documentation on http://oss.oracle.com/projects/ocfs2 in the Documentation area, or get the latest mainline kernel from http://kernel.org and read the source. One final, unrelated note - since I am not always able to publicly answer or respond to comments, I do not want to selectively publish comments from readers. Sometimes I forget to publish comments, sometime I publish them and sometimes I would publish them but if for some reason I cannot publicly comment on them, it becomes a very one-sided stream. So for now I am going to not publish comments from anyone, to be fair to all sides. You are always welcome to email me and I will do my best to respond to technical questions, questions about strategy or direction are sometimes not possible to answer for obvious reasons.

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• .NET Security Part 2

  - by Simon Cooper

  So, how do you create partial-trust appdomains? Where do you come across them? There are two main situations in which your assembly runs as partially-trusted using the Microsoft .NET stack: Creating a CLR assembly in SQL Server with anything other than the UNSAFE permission set. The permissions available in each permission set are given here. Loading an assembly in ASP.NET in any trust level other than Full. Information on ASP.NET trust levels can be found here. You can configure the specific permissions available to assemblies using ASP.NET policy files. Alternatively, you can create your own partially-trusted appdomain in code and directly control the permissions and the full-trust API available to the assemblies you load into the appdomain. This is the scenario I’ll be concentrating on in this post. Creating a partially-trusted appdomain There is a single overload of AppDomain.CreateDomain that allows you to specify the permissions granted to assemblies in that appdomain – this one. This is the only call that allows you to specify a PermissionSet for the domain. All the other calls simply use the permissions of the calling code. If the permissions are restricted, then the resulting appdomain is referred to as a sandboxed domain. There are three things you need to create a sandboxed domain: The specific permissions granted to all assemblies in the domain. The application base (aka working directory) of the domain. The list of assemblies that have full-trust if they are loaded into the sandboxed domain. The third item is what allows us to have a fully-trusted API that is callable by partially-trusted code. I’ll be looking at the details of this in a later post. Granting permissions to the appdomain Firstly, the permissions granted to the appdomain. This is encapsulated in a PermissionSet object, initialized either with no permissions or full-trust permissions. For sandboxed appdomains, the PermissionSet is initialized with no permissions, then you add permissions you want assemblies loaded into that appdomain to have by default: PermissionSet restrictedPerms = new PermissionSet(PermissionState.None); // all assemblies need Execution permission to run at all restrictedPerms.AddPermission( new SecurityPermission(SecurityPermissionFlag.Execution)); // grant general read access to C:\config.xml restrictedPerms.AddPermission( new FileIOPermission(FileIOPermissionAccess.Read, @"C:\config.xml")); // grant permission to perform DNS lookups restrictedPerms.AddPermission( new DnsPermission(PermissionState.Unrestricted)); It’s important to point out that the permissions granted to an appdomain, and so to all assemblies loaded into that appdomain, are usable without needing to go through any SafeCritical code (see my last post if you’re unsure what SafeCritical code is). That is, partially-trusted code loaded into an appdomain with the above permissions (and so running under the Transparent security level) is able to create and manipulate a FileStream object to read from C:\config.xml directly. It is only for operations requiring permissions that are not granted to the appdomain that partially-trusted code is required to call a SafeCritical method that then asserts the missing permissions and performs the operation safely on behalf of the partially-trusted code. The application base of the domain This is simply set as a property on an AppDomainSetup object, and is used as the default directory assemblies are loaded from: AppDomainSetup appDomainSetup = new AppDomainSetup { ApplicationBase = @"C:\temp\sandbox", }; If you’ve read the documentation around sandboxed appdomains, you’ll notice that it mentions a security hole if this parameter is set correctly. I’ll be looking at this, and other pitfalls, that will break the sandbox when using sandboxed appdomains, in a later post. Full-trust assemblies in the appdomain Finally, we need the strong names of the assemblies that, when loaded into the appdomain, will be run as full-trust, irregardless of the permissions specified on the appdomain. These assemblies will contain methods and classes decorated with SafeCritical and Critical attributes. I’ll be covering the details of creating full-trust APIs for partial-trust appdomains in a later post. This is how you get the strongnames of an assembly to be executed as full-trust in the sandbox: // get the Assembly object for the assembly Assembly assemblyWithApi = ... // get the StrongName from the assembly's collection of evidence StrongName apiStrongName = assemblyWithApi.Evidence.GetHostEvidence<StrongName>(); Creating the sandboxed appdomain So, putting these three together, you create the appdomain like so: AppDomain sandbox = AppDomain.CreateDomain( "Sandbox", null, appDomainSetup, restrictedPerms, apiStrongName); You can then load and execute assemblies in this appdomain like any other. For example, to load an assembly into the appdomain and get an instance of the Sandboxed.Entrypoint class, implementing IEntrypoint, you do this: IEntrypoint o = (IEntrypoint)sandbox.CreateInstanceFromAndUnwrap( "C:\temp\sandbox\SandboxedAssembly.dll", "Sandboxed.Entrypoint"); // call method the Execute method on this object within the sandbox o.Execute(); The second parameter to CreateDomain is for security evidence used in the appdomain. This was a feature of the .NET 2 security model, and has been (mostly) obsoleted in the .NET 4 model. Unless the evidence is needed elsewhere (eg. isolated storage), you can pass in null for this parameter. Conclusion That’s the basics of sandboxed appdomains. The most important object is the PermissionSet that defines the permissions available to assemblies running in the appdomain; it is this object that defines the appdomain as full or partial-trust. The appdomain also needs a default directory used for assembly lookups as the ApplicationBase parameter, and you can specify an optional list of the strongnames of assemblies that will be given full-trust permissions if they are loaded into the sandboxed appdomain. Next time, I’ll be looking closer at full-trust assemblies running in a sandboxed appdomain, and what you need to do to make an API available to partial-trust code.

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• Database Owner Conundrum

  - by Johnm

  Have you ever restored a database from a production environment on Server A into a development environment on Server B and had some items, such as Service Broker, mysteriously cease functioning? You might want to consider reviewing the database owner property of the database. The Scenario Recently, I was developing some messaging functionality that utilized the Service Broker feature of SQL Server in a development environment. Within the instance of the development environment resided two databases: One was a restored version of a production database that we will call "RestoreDB". The second database was a brand new database that has yet to exist in the production environment that we will call "DevDB". The goal is to setup a communication path between RestoreDB and DevDB that will later be implemented into the production database. After implementing all of the Service Broker objects that are required to communicate within a database as well as between two databases on the same instance I found myself a bit confounded. My testing was showing that the communication was successful when it was occurring internally within DevDB; but the communication between RestoreDB and DevDB did not appear to be working. Profiler to the rescue After carefully reviewing my code for any misspellings, missing commas or any other minor items that might be a syntactical cause of failure, I decided to launch Profiler to aid in the troubleshooting. After simulating the cross database messaging, I noticed the following error appearing in Profiler: An exception occurred while enqueueing a message in the target queue. Error: 33009, State: 2. The database owner SID recorded in the master database differs from the database owner SID recorded in database '[Database Name Here]'. You should correct this situation by resetting the owner of database '[Database Name Here]' using the ALTER AUTHORIZATION statement. Now, this error message is a helpful one. Not only does it identify the issue in plain language, it also provides a potential solution. An execution of the following query that utilizes the catalog view sys.transmission_queue revealed the same error message for each communication attempt: SELECT     * FROM        sys.transmission_queue; Seeing the situation as a learning opportunity I dove a bit deeper. Reviewing the database properties  The owner of a specific database can be easily viewed by right-clicking the database in SQL Server Management Studio and selecting the "properties" option. The owner is listed on the "General" page of the properties screen. In my scenario, the database in the production server was created by Frank the DBA; therefore his server login appeared as the owner: "ServerName\Frank". While this is interesting information, it certainly doesn't tell me much in regard to the SID (security identifier) and its existence, or lack thereof, in the master database as the error suggested. I pulled together the following query to gather more interesting information: SELECT     a.name     , a.owner_sid     , b.sid     , b.name     , b.type_desc FROM        master.sys.databases a     LEFT OUTER JOIN master.sys.server_principals b         ON a.owner_sid = b.sid WHERE     a.name not in ('master','tempdb','model','msdb'); This query also helped identify how many other user databases in the instance were experiencing the same issue. In this scenario, I saw that there were no matching SIDs in server_principals to the owner SID for my database. What login should be used as the database owner instead of Frank's? The system stored procedure sp_helplogins will provide a list of the valid logins that can be used. Here is an example of its use, revealing all available logins: EXEC sp_helplogins;  Fixing a hole The error message stated that the recommended solution was to execute the ALTER AUTHORIZATION statement. The full statement for this scenario would appear as follows: ALTER AUTHORIZATION ON DATABASE:: [Database Name Here] TO [Login Name]; Another option is to execute the following statement using the sp_changedbowner system stored procedure; but please keep in mind that this stored procedure has been deprecated and will likely disappear in future versions of SQL Server: EXEC dbo.sp_changedbowner @loginname = [Login Name]; .And They Lived Happily Ever After Upon changing the database owner to an existing login and simulating the inner and cross database messaging the errors have ceased. More importantly, all messages sent through this feature now successfully complete their journey. I have added the ownership change to my restoration script for the development environment.

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• Use your own domain email and tired of SPAM? SPAMfighter FTW

  - by Dave Campbell

  I wouldn't post this if I hadn't tried it... and I paid for it myself, so don't anybody be thinking I'm reviewing something someone sent me! Long ago and far away I got very tired of local ISPs and 2nd phone lines and took the plunge and got hooked up to cable... yeah I know the 2nd phone line concept may be hard for everyone to understand, but that's how it was in 'the old days'. To avoid having to change email addresses all the time, I decided to buy a domain name, get minimal hosting, and use that for all email into the house. That way if I changed providers, all the email addresses wouldn't have to change. Of course, about a dozen domains later, I have LOTS of pop email addresses and even an exchange address to my client's server... times have changed. What also has changed is the fact that we get SPAM... 'back in the day' when I was a beta tester for the first ISP in Phoenix, someone tried sending an ad to all of us, and what he got in return for his trouble was a bunch of core dumps that locked up his email... if you don't know what a core dump is, ask your grandfather. But in today's world, we're all much more civilized than that, and as with many things, the criminals seem to have much more rights than we do, so we get inundated with email offering all sorts of wild schemes that you'd have to be brain-dead to accept, but yet... if people weren't accepting them, they'd stop sending them. I keep hoping that survival of the smartest would weed out the mental midgets that respond and then the jumk email stop, but that hasn't happened yet anymore than finding high-quality hearing aids at the checkout line of Safeway because of all the dimwits playing music too loud inside their car... but that's another whole topic and I digress. So what's the solution for all the spam? And I mean *all*... on that old personal email address, I am now getting over 150 spam messages a day! Yes I know that's why God invented the delete key, but I took it on as a challenge, and it's a matter of principle... why should I switch email addresses, or convert from [email protected] to something else, or have all my email filtered through some service just because some A-Hole somewhere has a site up trying to phish Ma & Pa Kettle (ask your grandfather about that too) out of their retirement money? Well... I got an email from my cousin the other day while I was writing yet another email rule, and there was a banner on the bottom of his email that said he was protected by SPAMfighter. SPAMfighter huh.... so I took a look at their site, and found yet one more of the supposed tools to help us. But... I read that they're a Microsoft Gold Partner... and that doesn't come lightly... so I took a gamble and here's what I found: I installed it, and had to do a couple things: 1) SPAMfighter stuffed the SPAMfighter folder into my client's exchange address... I deleted it, made a new SPAMfighter folder where I wanted it to go, then in the SPAMfighter Clients settings for Outlook, I told it to put all spam there. 2) It didn't seem to be doing anything. There's a ribbon button that you can select "Block", and I did that, wondering if I was 'training' it, but it wasn't picking up duplicates 3) I sent email to support, and wrote a post on the forum (not to self: reply to that post). By the time the folks from the home office responded, it was the next day, and first up, SPAMfighter knocked down everything that came through when Outlook opend... two thumbs up! I disabled my 'garbage collection' rule from Outlook, and told Outlook not to use the junk folder thinking it was interfering. 4) Day 2 seemed to go about like Day 1... but I hung in there. 5) Day 3 is now a whole new day... I had left Outlook open and hadn't looked at the PC since sometime late yesterday afternoon, and when I looked this morning, *every bit* of spam was in the SPAMfighter folder!! I'm a new paying customer After watching SPAMfighter work this morning, I've purchased a 1-year license, and I now can sit and watch as emails come in and disappear from my inbox into the SPAMfighter folder. No more continual tweaking of the rules. I've got SPAMfighter set to 'Very Hard' filtering... personally I'd rather pull the few real emails out of the SPAMfighter folder than pull spam out of the real folders. Yes this is simply another way of using the delete key, but you know what? ... it feels good :) Here's a screenshot of the stats after just about 48 hours of being onboard: Note that all the ones blocked by me were during Day 1 and 2... I've blocked none today, and everything is blocked. Stay in the 'Light!

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• Hiring New IT Employees versus Promoting Internally for IT Positions

  Recently I was asked my opinion regarding the hiring of IT professionals in regards to the option of hiring new IT employees versus promoting internally for IT positions. After thinking a little more about this question regarding staffing, specifically pertaining to promoting internally verses new employees; I think my answer to this question is that it truly depends on the situation. However, in most cases I would side with promoting internally. The key factors in this decision should be based on a company/department’s current values, culture, attitude, and existing priorities.  For example if a company values retaining all of its hard earned business knowledge then they would tend to promote existing employees internal over hiring a new employee. Moreover, the company will have to pay to train an existing employee to learn a new technology and the learning curve for some technologies can be very steep. Conversely, if a company values new technologies and technical proficiency over business knowledge then a company would tend to hire new employees because they may already have experience with a technology that the company is planning on using. In this scenario, the company would have to take on the additional overhead of allowing a new employee to learn how the business operates prior to them being fully effective. To illustrate my points above let us look at contractor that builds in ground pools for example.  He has the option to hire employees that are very strong but use small shovels to dig, or employees weak in physical strength but use large shovels to dig. Which employee should the contractor use to dig a hole for a new in ground pool? If we compare the possible candidates for this job we will find that they are very similar to hiring someone internally verses a new hire. The first example represents the existing workers that are very strong regarding the understanding how the business operates and the reasons why in a specific manner. However this employee could be potentially weaker than an outsider pertaining to specific technologies and would need some time to build their technical prowess for a new position much like the strong worker upgrading their shovels in order to remove more dirt at once when digging. The other employee is very similar to hiring a new person that may already have the large shovel but will need to increase their strength in order to use the shovel properly and efficiently so that they can move a maximum amount of dirt in a minimal amount of time. This can be compared to new employ learning how a business operates before they can be fully functional and integrated in the company/department. Another key factor in this dilemma pertains to existing employee and their passion for their work, their ability to accept new responsibility when given, and the willingness to take on responsibilities when they see a need in the business. As much as possible should be considered in this decision down to the mood of the team, the quality of existing staff, learning cure for both technology and business, and the potential side effects of the existing staff.  In addition, there are many more consideration based on the current team/department/companies culture and mood. There are several factors that need to be considered when promoting an individual or hiring new blood for a team. They both can provide great benefits as well as create controversy to a group. Personally, staffing especially in the IT world is like building a large scale system in that all of the components and modules must fit together and preform as one cohesive system in the same way a team must come together using their individually acquired skills so that they can work as one team.  If a module is out of place or is nonexistent then the rest of the team will suffer until the all of its issues are addressed and resolved. Benefits of Promoting Internally Internal promotions give employees a reason to constantly upgrade their technology, business, and communication skills if they want to further their career Employees can control their own destiny based on personal desires Employee already knows how the business operates Companies can save money by promoting internally because the initial overhead of allowing new hires to learn how a company operates is very expensive Newly promoted employees can assist in training their replacements while transitioning to their new role within a company. Existing employees already have a proven track record in regards fitting in with the business culture; this is always an unknown with all new hires Benefits of a New Hire New employees can energize and excite existing employees New employees can bring new ideas and advancements in technology New employees can offer a different perspective on existing issues based on their past experience. As you can see the decision to promote an existing employee from within a company verses hiring a new person should be based on several factors that should ultimately place the business in the best possible situation for the immediate and long term future. How would you handle this situation? Would you hire a new employee or promote from within?

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• Rebuilding CoasterBuzz, Part II: Hot data objects

  - by Jeff

  This is the second post, originally from my personal blog, in a series about rebuilding one of my Web sites, which has been around for 12 years. More: Part I: Evolution, and death to WCF After the rush to get moving on stuff, I temporarily lost interest. I went almost two weeks without touching the project, in part because the next thing on my backlog was doing up a bunch of administrative pages. So boring. Unfortunately, because most of the site's content is user-generated, you need some facilities for editing data. CoasterBuzz has a database full of amusement parks and roller coasters. The entities enjoy the relationships that you would expect, though they're further defined by "instances" of a coaster, to define one that has moved between parks as one, with different names and operational dates. And of course, there are pictures and news items, too. It's not horribly complex, except when you have to account for a name change and display just the newest name. In all previous versions, data access was straight SQL. As so much of the old code was rooted in 2003, with some changes in 2008, there wasn't much in the way of ORM frameworks going on then. Let me rephrase that, I mostly wasn't interested in ORM's. Since that time, I used a little LINQ to SQL in some projects, and a whole bunch of nHibernate while at Microsoft. Through all of that experience, I have to admit that these frameworks are often a bigger pain in the ass than not. They're great for basic crud operations, but when you start having all kinds of exotic relationships, they get difficult, and generate all kinds of weird SQL under the covers. The black box can quickly turn into a black hole. Sometimes you end up having to build all kinds of new expertise to do things "right" with a framework. Still, despite my reservations, I used the newer version of Entity Framework, with the "code first" modeling, in a science project and I really liked it. Since it's just a right-click away with NuGet, I figured I'd give it a shot here. My initial effort was spent defining the context class, which requires a bit of work because I deviate quite a bit from the conventions that EF uses, starting with table names. Then throw some partial querying of certain tables (where you'll find image data), and you're splitting tables across several objects (navigation properties). I won't go into the details, because these are all things that are well documented around the Internet, but there was a minor learning curve there. The basics of reading data using EF are fantastic. For example, a roller coaster object has a park associated with it, as well as a number of instances (if it was ever relocated), and there also might be a big banner image for it. This is stupid easy to use because it takes one line of code in your repository class, and by the time you pass it to the view, you have a rich object graph that has everything you need to display stuff. Likewise, editing simple data is also, well, simple. For this goodness, thank the ASP.NET MVC framework. The UpdateModel() method on the controllers is very elegant. Remember the old days of assigning all kinds of properties to objects in your Webforms code-behind? What a time consuming mess that used to be. Even if you're not using an ORM tool, having hydrated objects come off the wire is such a time saver. Not everything is easy, though. When you have to persist a complex graph of objects, particularly if they were composed in the user interface with all kinds of AJAX elements and list boxes, it's not just a simple matter of submitting the form. There were a few instances where I ended up going back to "old-fashioned" SQL just in the interest of time. It's not that I couldn't do what I needed with EF, it's just that the efficiency, both my own and that of the generated SQL, wasn't good. Since EF context objects expose a database connection object, you can use that to do the old school ADO.NET stuff you've done for a decade. Using various extension methods from POP Forums' data project, it was a breeze. You just have to stick to your decision, in this case. When you start messing with SQL directly, you can't go back in the same code to messing with entities because EF doesn't know what you're changing. Not really a big deal. There are a number of take-aways from using EF. The first is that you write a lot less code, which has always been a desired outcome of ORM's. The other lesson, and I particularly learned this the hard way working on the MSDN forums back in the day, is that trying to retrofit an ORM framework into an existing schema isn't fun at all. The CoasterBuzz database isn't bad, but there are design decisions I'd make differently if I were starting from scratch. Now that I have some of this stuff done, I feel like I can start to move on to the more interesting things on the backlog. There's a lot to do, but at least it's fun stuff, and not more forms that will be used infrequently.

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• Performance triage

  - by Dave

  Folks often ask me how to approach a suspected performance issue. My personal strategy is informed by the fact that I work on concurrency issues. (When you have a hammer everything looks like a nail, but I'll try to keep this general). A good starting point is to ask yourself if the observed performance matches your expectations. Expectations might be derived from known system performance limits, prototypes, and other software or environments that are comparable to your particular system-under-test. Some simple comparisons and microbenchmarks can be useful at this stage. It's also useful to write some very simple programs to validate some of the reported or expected system limits. Can that disk controller really tolerate and sustain 500 reads per second? To reduce the number of confounding factors it's better to try to answer that question with a very simple targeted program. And finally, nothing beats having familiarity with the technologies that underlying your particular layer. On the topic of confounding factors, as our technology stacks become deeper and less transparent, we often find our own technology working against us in some unexpected way to choke performance rather than simply running into some fundamental system limit. A good example is the warm-up time needed by just-in-time compilers in Java Virtual Machines. I won't delve too far into that particular hole except to say that it's rare to find good benchmarks and methodology for java code. Another example is power management on x86. Power management is great, but it can take a while for the CPUs to throttle up from low(er) frequencies to full throttle. And while I love "turbo" mode, it makes benchmarking applications with multiple threads a chore as you have to remember to turn it off and then back on otherwise short single-threaded runs may look abnormally fast compared to runs with higher thread counts. In general for performance characterization I disable turbo mode and fix the power governor at "performance" state. Another source of complexity is the scheduler, which I've discussed in prior blog entries. Lets say I have a running application and I want to better understand its behavior and performance. We'll presume it's warmed up, is under load, and is an execution mode representative of what we think the norm would be. It should be in steady-state, if a steady-state mode even exists. On Solaris the very first thing I'll do is take a set of "pstack" samples. Pstack briefly stops the process and walks each of the stacks, reporting symbolic information (if available) for each frame. For Java, pstack has been augmented to understand java frames, and even report inlining. A few pstack samples can provide powerful insight into what's actually going on inside the program. You'll be able to see calling patterns, which threads are blocked on what system calls or synchronization constructs, memory allocation, etc. If your code is CPU-bound then you'll get a good sense where the cycles are being spent. (I should caution that normal C/C++ inlining can diffuse an otherwise "hot" method into other methods. This is a rare instance where pstack sampling might not immediately point to the key problem). At this point you'll need to reconcile what you're seeing with pstack and your mental model of what you think the program should be doing. They're often rather different. And generally if there's a key performance issue, you'll spot it with a moderate number of samples. I'll also use OS-level observability tools to lock for the existence of bottlenecks where threads contend for locks; other situations where threads are blocked; and the distribution of threads over the system. On Solaris some good tools are mpstat and too a lesser degree, vmstat. Try running "mpstat -a 5" in one window while the application program runs concurrently. One key measure is the voluntary context switch rate "vctx" or "csw" which reflects threads descheduling themselves. It's also good to look at the user; system; and idle CPU percentages. This can give a broad but useful understanding if your threads are mostly parked or mostly running. For instance if your program makes heavy use of malloc/free, then it might be the case you're contending on the central malloc lock in the default allocator. In that case you'd see malloc calling lock in the stack traces, observe a high csw/vctx rate as threads block for the malloc lock, and your "usr" time would be less than expected. Solaris dtrace is a wonderful and invaluable performance tool as well, but in a sense you have to frame and articulate a meaningful and specific question to get a useful answer, so I tend not to use it for first-order screening of problems. It's also most effective for OS and software-level performance issues as opposed to HW-level issues. For that reason I recommend mpstat & pstack as my the 1st step in performance triage. If some other OS-level issue is evident then it's good to switch to dtrace to drill more deeply into the problem. Only after I've ruled out OS-level issues do I switch to using hardware performance counters to look for architectural impediments.

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• Data Binding to Attached Properties

  - by Chris Gardner

  Originally posted on: http://geekswithblogs.net/freestylecoding/archive/2013/06/14/data-binding-to-attached-properties.aspx When I was working on my C#/XAML game framework, I discovered I wanted to try to data bind my sprites to background objects. That way, I could update my objects and the draw functionality would take care of the work for me. After a little experimenting and web searching, it appeared this concept was an impossible dream. Of course, when has that ever stopped me? In my typical way, I started to massively dive down the rabbit hole. I created a sprite on a canvas, and I bound it to a background object. <Canvas Name="GameField" Background="Black"> <Image Name="PlayerStrite" Source="Assets/Ship.png" Width="50" Height="50" Canvas.Left="{Binding X}" Canvas.Top="{Binding Y}"/> </Canvas> Now, we wire the UI item to the background item. public MainPage() { this.InitializeComponent(); this.Loaded += StartGame; }   void StartGame( object sender, RoutedEventArgs e ) { BindingPlayer _Player = new BindingPlayer(); _Player.X = Window.Current.Bounds.Height - PlayerSprite.Height; _Player.X = ( Window.Current.Bounds.Width - PlayerSprite.Width ) / 2.0; } Of course, now we need to actually have our background object. public class BindingPlayer : INotifyPropertyChanged { private double m_X; public double X { get { return m_X; } set { m_X = value; NotifyPropertyChanged(); } }   private double m_Y; public double Y { get { return m_Y; } set { m_Y = value; NotifyPropertyChanged(); } }   public event PropertyChangedEventHandler PropertyChanged; protected void NotifyPropertyChanged( [CallerMemberName] string p_PropertyName = null ) { if( PropertyChanged != null ) PropertyChanged( this, new PropertyChangedEventArgs( p_PropertyName ) ); } } I fired this baby up, and my sprite was correctly positioned on the screen. Maybe the sky wasn't falling after all. Wouldn't it be great if that was the case? I created some code to allow me to move the sprite, but nothing happened. This seems odd. So, I start debugging the application and stepping through code. Everything appears to be working. Time to dig a little deeper. After much profanity was spewed, I stumbled upon a breakthrough. The code only looked like it was working. What was really happening is that there was an exception being thrown in the background thread that I never saw. Apparently, the key call was the one to PropertyChanged. If PropertyChanged is not called on the UI thread, the UI thread ignores the call. Actually, it throws an exception and the background thread silently crashes. Of course, you'll never see this unless you're looking REALLY carefully. This seemed to be a simple problem. I just need to marshal this to the UI thread. Unfortunately, this object has no knowledge of this mythical UI Thread in which we speak. So, I had to pull the UI Thread out of thin air. Let's change our PropertyChanged call to look this. public event PropertyChangedEventHandler PropertyChanged; protected void NotifyPropertyChanged( [CallerMemberName] string p_PropertyName = null ) { if( PropertyChanged != null ) Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync( Windows.UI.Core.CoreDispatcherPriority.Normal, new Windows.UI.Core.DispatchedHandler( () => { PropertyChanged( this, new PropertyChangedEventArgs( p_PropertyName ) ); } ) ); } Now, we raised our notification on the UI thread. Everything is fine, people are happy, and the world moves on. You may have noticed that I didn't await my call to the dispatcher. This was intentional. If I am trying to update a slew of sprites, I don't want thread being hung while I wait my turn. Thus, I send the message and move on. It is worth nothing that this is NOT the most efficient way to do this for game programming. We'll get to that in another blog post. However, it is perfectly acceptable for a business app that is running a background task that would like to notify the UI thread of progress on a periodic basis. It is worth noting that this code was written for a Windows Store App. You can do the same thing with WP8 and WPF. The call to the marshaler changes, but it is the same idea.

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• Is One Tool or a Suite of Tools Better for Scrum?

  - by Rob Wells

  G'day, Edit: We've been using Scrum very successfully for several years on several projects of varying sizes. In fact, our team developed the successful iPlayer project for the BBC using a classical Scrum approach. After using various combinations of tools, some high-tech, some low-tech, across these projects we now wish to try adopting a suitable tool suite. Our manager is to some extent attempting to force the adoption of a single suite of tools for Scrum. I've looked at the SO question "Best Scrum tools" and most people seem to recommend either: a suite of low-tech solutions, e.g. whiteboards, post-its, index cards, etc., or a monolithic tool that tries to satisfy as much as possible of the process, e.g. Agilo, Mingle, ScrumWorks, Target Process, etc. Our team is currently evaluating several different Scrum tools. However, we are looking at selecting a single, monolithic tool, e.g. Agilo. All of the "one-stop" solutions have their strengths and weaknesses with the serious enterprise type solutions being the best sort of fit. But all have some short comings. After reading the paper "Peer Code Review: An Agile Process" over at SmartBear I started wondering if we were trying to force adoption of a tool on a "best fit" basis. I think you can take a couple of reference artefacts of the Scrum development process, say user stories, epics and themes, and the code base which must use a well-known SCM, e.g. SVN, Hg, etc. Then if we take that as the common reference points for the tools employed then we would be able to use a group of tools to handle the different aspects of the Scrum process rather than try forcing a fit of a single tool would is a bit like forcing a square peg into the round hole. In this way, providing you've agreed your common reference points, you can use several tools, each performing their role better than a could be done by a single component in a monolithic tool suite. Is this a more sensible approach? Are the two reference points I mentioned above suitable, or is their a better choice of points where the tools would meet? cheers,

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• Stata - Multiple rotated plots on graph (including distributions on sides of axes)

  - by meerak

  I would like to produce a single graph containing both: (1) a scatter plot (2) either histograms or kernel density functions of the Y and X variables to the left of the Y axis and below the X axis. I found a graph that does this in MATLAB -- I would just like to produce something similar in Stata: That graph was produced using the following MATLAB code: n = 1000; rho = .7; Z = mvnrnd([0 0], [1 rho; rho 1], n); U = normcdf(Z); X = [gaminv(U(:,1),2,1) tinv(U(:,2),5)]; [n1,ctr1] = hist(X(:,1),20); [n2,ctr2] = hist(X(:,2),20); subplot(2,2,2); plot(X(:,1),X(:,2),'.'); axis([0 12 -8 8]); h1 = gca; title('1000 Simulated Dependent t and Gamma Values'); xlabel('X1 ~ Gamma(2,1)'); ylabel('X2 ~ t(5)'); subplot(2,2,4); bar(ctr1,-n1,1); axis([0 12 -max(n1)*1.1 0]); axis('off'); h2 = gca; subplot(2,2,1); barh(ctr2,-n2,1); axis([-max(n2)*1.1 0 -8 8]); axis('off'); h3 = gca; set(h1,'Position',[0.35 0.35 0.55 0.55]); set(h2,'Position',[.35 .1 .55 .15]); set(h3,'Position',[.1 .35 .15 .55]); colormap([.8 .8 1]); UPDATE: The Stata13 manual entry for "graph combine" has precisely this example (http://www.stata.com/manuals13/g-2graphcombine.pdf). Here is the code: use http://www.stata-press.com/data/r13/lifeexp, clear generate loggnp = log10(gnppc) label var loggnp "Log base 10 of GNP per capita" scatter lexp loggnp, ysca(alt) xsca(alt) xlabel(, grid gmax) fysize(25) saving(yx) twoway histogram lexp, fraction xsca(alt reverse) horiz fxsize(25) saving(hy) twoway histogram loggnp, fraction ysca(alt reverse) ylabel(,nogrid) xlabel(,grid gmax) saving(hx) graph combine hy.gph yx.gph hx.gph, hole(3) imargin(0 0 0 0) graphregion(margin(l=22 r=22)) title("Life expectancy at birth vs. GNP per capita") note("Source: 1998 data from The World Bank Group")

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