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• Unable to Sign in to the Microsoft Online Services Signin application from Windows 7 client located behind ISA firewall

  - by Ravindra Pamidi

  A while ago i helped a customer troubleshoot authentication problem with Microsoft Online Services Signin application.  This customer was evaluating Microsoft BPOS (Business Productivity Online Services) and was having trouble using the single sign on application behind ISA 2004 firewall.The network structure is fairly simple with single Windows 2003 Active Directory domain and Windows 7 clients. On a successful logon to the Microsoft Online Services Signin application, this application provides single signon functionality to all of Microsoft online services in the BPOS package. Symptoms:When trying to signin it fails with error "The service is currently unavailable. Please try again later. If problems continue, contact your service administrator". If ISA 2004 firewall is removed from the picture the authentication succeeds.Troubleshooting: Enabled ISA Server firewall logging along with Microsoft Network Monitor tool on the Windows 7 Client while reproducing the issue. Analysis of the ISA Server Firewall logs and Microsoft Network capture revealed that the Microsoft Online Services Sign In application when sending request to ISA Server does not send the domain credentials and as a result ISA Server responds with an error code of HTTP 407 Proxy authentication required listing out the supported authentication mechanisms.  The application in question is expected to send the credentials of the domain user in response to this request. However in this case, it fails to send the logged on user's domain credentials. Bit of researching on the Internet revealed that The "Microsoft Online Services Sign In" application by default does not support Outbound Internet Proxy authentication. In order for it to send the logged on user's domain credentials we had to make  changes to its configuration file "SignIn.exe.config" located under "Program Files\Microsoft Online Services\Sign In" folder. Step by Step details to configure the configuration file are documented on Microsoft TechNet website given below.  Configure your outbound authenticating proxy serverhttp://www.microsoft.com/online/help/en-us/helphowto/cc54100d-d149-45a9-8e96-f248ecb1b596.htm After the above problem was addressed we were still not able to use the "Microsoft Online Services Sign In" application and it failed with the same error.  Analysis of another network capture revealed that the application in question is now sending the required credentials and the connection seems to terminate at a later stage. Enabled verbose logging for the "Microsoft Online Services Sign In" application and then reproduced the problem. Analysis of the logs revealed a time difference between the local client and Microsoft Online services server of around seven minutes which is above the acceptable time skew of five minutes. Excerpt from Microsoft Online Services Sign In application verbose log:  1/26/2012 1:57:51 PM Verbose SingleSignOn.GetSSOGenericInterface SSO Interface URL: https://signinservice.apac.microsoftonline.com/ssoservice/UID1/26/2012 1:57:52 PM Exception SSOSignIn.SignIn The security timestamp is invalid because its creation time ('2012-01-26T08:34:52.767Z') is in the future. Current time is '2012-01-26T08:27:52.987Z' and allowed clock skew is '00:05:00'.1/26/2012 1:57:52 PM Exception SSOSignIn.SignIn  Although the Windows 7 Clients successfully synchronized time to the domain controller for the domain, the domain controller was not configured to synchronize time with external NTP servers. This caused a gradual drift in time on the network thus resulting in the above issue. Reconfigured the domain controller holding the PDC FSMO role to synchronize time with external time source ( time.nist.gov ) and edited the system policy on the ISA server firewall to allow NTP traffic to time.nist.gov Configure the time source for the forest:Windows Time Servicehttp://technet.microsoft.com/en-us/library/cc794937(WS.10).aspx Forced synchronization of Windows time using the command w32tm /resync on the domain controller and later on the clients each of which had corrected the seven minutes difference. This resolved the problem with logon to Microsoft Online Services Sign In.

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• User password rejected on login screen but accepted on text console login

  - by MadsirR

  I had to force shutdown my Ubuntu 12.04 64-bit, after which I restarted and tried to log in as a normal user, which was rejected several times. I then logged in as guest and tty to my regular account with use of my normal password, which succeeded. (So the password is still valid.) How can I gain access again via the normal login procedure (welcome screen)? Update: When I tried to log on with my new password, it again was denied. When I deliberately tried to log on with a faulty password, an error message came back, saying: Access denied - wrong password. I suppose, the first time the password was not rejected, but the procedure was aborted for some reason. Some additional info after trying to find a solution: I am conviced it is a Compiz-issue. Why? before this happened, all sessions came to a grinding halt, regardless of being logged on in a 2D or 3d environment. I found a link saying that I should remove Compiz and proceed in a 2D environment, which initiall worked without a glitch, until my system went into a state of total obivium. Only after that, the above mentioned troubles appeared. In the meantime I have happened to find a thread with reference 17381, describing exactly what I have experienced. For now, I will try to cure this situation (later this week) and revert with the results, hopefully to close this post. In the meantime I cordially thank you all, even if you didn't kill the problem; you gave me the inspiration to look further and find a possible cure. Update2: After 15 hrs of trial-and-error I callled it quits (When I decided to tackle this problem, I've given myself 12 hrs, to avoid massive loss of time.) I decided to re-install Precise, since the "point 1" version has become availabe. Log-in is back to normal, as is the graphic environment. Response to mouse input is stil appalling, especially when I have a series of screens open as "children"of a "parent" screen. It still completely locks up. I have installed Enlightenment, Gnome classic, Gnome 3, Cinnamon and they all behave in a similar fashion. FOR THOSE WHO NEED A WAY-OUT IN SITUATIONS OF THE LIKE: Open a terminal with [Ctrl+Alt+F2]. Type [sudo killall Firefox] (or whatever application you wish to terminate). Key in your password. Return to your graphical screen with [Ctrl+Alt+F7], and Bob's your uncle. Just re-open Firefox like nothing happened. Next time you are stuck: [Ctrl+Alt+F2], upward arrow till you meet the command of your desire, [Ctrl+Alt+F7], etcetera. Hope this is of help. My next move will be to upgrade the kernel to 3.4 from the repositories for 12.10. However, since this entails a totally new situation, I will start a new thread on this site to avoid topic pollution I will keep you posted. Still.

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• Package management system corrupted. Cannot install or remove packages. U12.04LTS

  - by user271490

  Having read other posts, I believe that this may be less about samba than about update system. Below is the log file of the failed installation of Samba. I have been trying without success to install/outstall samba so that I could install anything else ... I cannot either install or remove samba using either update-manager or apt-get (nor indeed Software Centre). One of the errors that I have had to correct is the presence after "removal" (failed) of /usr/share/system-config-samba directory which finally allowed itself to be deleted. That, however was then ... I have U12.04LTS. running on release 63 because I allowed the upgrade to 64 this morning which fell over - no output to monitor - obviously even less support for my graphic chip than I am suffering already (see other posts in this forum). According to my interpretation of the dpkg returned errors there may be some problem with the package files, but if this is the case then it is on servers 'main', 'nantes uni fr' and 'best fr' at the very least if not everywhere. The suggestions offered at Package operation failed and elsewhere have not worked for me. This linked post suggests that a similar error is present in other packages, or that the error is in the 'update system' I have tried ... sudo apt-get remove samba ... autoremove ... install samba ... clean ... update -f all of the above In update-manager I have tried the "reload packages list" which fails to terminate because of the error. I have tried to install and remove samba from the software centre ... :( I am at a loss ... I need help, please! Firstly to recover my apt-get/update-manager/Software Centre so that I can at least carry on with my continuing installation - up to communicating with home network hence need for samba - which brings me to my second requirement ... samba. PS is the issue about "MaxReports" associated or apart? UPDATE! Being heartily sick of restarting FF every 5 seconds I thought I'd try again with Chromium ... and got the same errors from dpkg about corrupt compressed package - coincidence? Of course this was no longer in clipboard when I got here because apport has just errored ... AAARRRGGGH!!! Why does every error clear the clipboard? Thanks for any and all help!! installArchives() failed: Preconfiguring packages ... ... snip (Reading database ... ... snip (Reading database ... 184858 files and directories currently installed.) Unpacking samba (from .../samba_2%3a3.6.3-2ubuntu2.10_i386.deb) ... dpkg-deb (subprocess): data: internal gzip read error: ': data error' dpkg-deb: error: subprocess returned error exit status 2 dpkg: error processing /var/cache/apt/archives/samba_2%3a3.6.3-2ubuntu2.10_i386.deb (--unpack): subprocess dpkg-deb --fsys-tarfile returned error exit status 2 No apport report written because MaxReports is reached already Selecting previously unselected package system-config-samba. Unpacking system-config-samba (from .../system-config-samba_1.2.63-0ubuntu5_all.deb) ... Processing triggers for ureadahead ... ureadahead will be reprofiled on next reboot Processing triggers for ufw ... Processing triggers for man-db ... Processing triggers for bamfdaemon ... Rebuilding /usr/share/applications/bamf.index... Processing triggers for desktop-file-utils ... Processing triggers for gnome-menus ... Processing triggers for hicolor-icon-theme ... Errors were encountered while processing: /var/cache/apt/archives/samba_2%3a3.6.3-2ubuntu2.10_i386.deb Error in function: dpkg: dependency problems prevent configuration of system-config-samba: system-config-samba depends on samba; however: Package samba is not installed. dpkg: error processing system-config-samba (--configure): dependency problems - leaving unconfigured

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• The long road to bug-free software

  - by Tony Davis

  The past decade has seen a burgeoning interest in functional programming languages such as Haskell or, in the Microsoft world, F#. Though still on the periphery of mainstream programming, functional programming concepts are gradually seeping into the imperative C# language (for example, Lambda expressions have their root in functional programming). One of the more interesting concepts from functional programming languages is the use of formal methods, the lofty ideal behind which is bug-free software. The idea is that we write a specification that describes exactly how our function (say) should behave. We then prove that our function conforms to it, and in doing so have proved beyond any doubt that it is free from bugs. All programmers already use one form of specification, specifically their programming language's type system. If a value has a specific type then, in a type-safe language, the compiler guarantees that value cannot be an instance of a different type. Many extensions to existing type systems, such as generics in Java and .NET, extend the range of programs that can be type-checked. Unfortunately, type systems can only prevent some bugs. To take a classic problem of retrieving an index value from an array, since the type system doesn't specify the length of the array, the compiler has no way of knowing that a request for the "value of index 4" from an array of only two elements is "unsafe". We restore safety via exception handling, but the ideal type system will prevent us from doing anything that is unsafe in the first place and this is where we start to borrow ideas from a language such as Haskell, with its concept of "dependent types". If the type of an array includes its length, we can ensure that any index accesses into the array are valid. The problem is that we now need to carry around the length of arrays and the values of indices throughout our code so that it can be type-checked. In general, writing the specification to prove a positive property, even for a problem very amenable to specification, such as a simple sorting algorithm, turns out to be very hard and the specification will be different for every program. Extend this to writing a specification for, say, Microsoft Word and we can see that the specification would end up being no simpler, and therefore no less buggy, than the implementation. Fortunately, it is easier to write a specification that proves that a program doesn't have certain, specific and undesirable properties, such as infinite loops or accesses to the wrong bit of memory. If we can write the specifications to prove that a program is immune to such problems, we could reuse them in many places. The problem is the lack of specification "provers" that can do this without a lot of manual intervention (i.e. hints from the programmer). All this might feel a very long way off, but computing power and our understanding of the theory of "provers" advances quickly, and Microsoft is doing some of it already. Via their Terminator research project they have started to prove that their device drivers will always terminate, and in so doing have suddenly eliminated a vast range of possible bugs. This is a huge step forward from saying, "we've tested it lots and it seems fine". What do you think? What might be good targets for specification and verification? SQL could be one: the cost of a bug in SQL Server is quite high given how many important systems rely on it, so there's a good incentive to eliminate bugs, even at high initial cost. [Many thanks to Mike Williamson for guidance and useful conversations during the writing of this piece] Cheers, Tony.

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• Dynamically load and call delegates based on source data

  - by makerofthings7

  Assume I have a stream of records that need to have some computation. Records will have a combination of these functions run Sum, Aggregate, Sum over the last 90 seconds, or ignore. A data record looks like this: Date;Data;ID Question Assuming that ID is an int of some kind, and that int corresponds to a matrix of some delegates to run, how should I use C# to dynamically build that launch map? I'm sure this idea exists... it is used in Windows Forms which has many delegates/events, most of which will never actually be invoked in a real application. The sample below includes a few delegates I want to run (sum, count, and print) but I don't know how to make the quantity of delegates fire based on the source data. (say print the evens, and sum the odds in this sample) using System; using System.Threading; using System.Collections.Generic; internal static class TestThreadpool { delegate int TestDelegate(int parameter); private static void Main() { try { // this approach works is void is returned. //ThreadPool.QueueUserWorkItem(new WaitCallback(PrintOut), "Hello"); int c = 0; int w = 0; ThreadPool.GetMaxThreads(out w, out c); bool rrr =ThreadPool.SetMinThreads(w, c); Console.WriteLine(rrr); // perhaps the above needs time to set up6 Thread.Sleep(1000); DateTime ttt = DateTime.UtcNow; TestDelegate d = new TestDelegate(PrintOut); List<IAsyncResult> arDict = new List<IAsyncResult>(); int count = 1000000; for (int i = 0; i < count; i++) { IAsyncResult ar = d.BeginInvoke(i, new AsyncCallback(Callback), d); arDict.Add(ar); } for (int i = 0; i < count; i++) { int result = d.EndInvoke(arDict[i]); } // Give the callback time to execute - otherwise the app // may terminate before it is called //Thread.Sleep(1000); var res = DateTime.UtcNow - ttt; Console.WriteLine("Main program done----- Total time --> " + res.TotalMilliseconds); } catch (Exception e) { Console.WriteLine(e); } Console.ReadKey(true); } static int PrintOut(int parameter) { // Console.WriteLine(Thread.CurrentThread.ManagedThreadId + " Delegate PRINTOUT waited and printed this:"+parameter); var tmp = parameter * parameter; return tmp; } static int Sum(int parameter) { Thread.Sleep(5000); // Pretend to do some math... maybe save a summary to disk on a separate thread return parameter; } static int Count(int parameter) { Thread.Sleep(5000); // Pretend to do some math... maybe save a summary to disk on a separate thread return parameter; } static void Callback(IAsyncResult ar) { TestDelegate d = (TestDelegate)ar.AsyncState; //Console.WriteLine("Callback is delayed and returned") ;//d.EndInvoke(ar)); } }

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• Problem in udp socket programing in c

  - by Md. Talha

  I complile the following C code of UDP client after I run './udpclient localhost 9191' in terminal.I put "Enter Text= " as Hello, but it is showing error in sendto as below: Enter text: hello hello : error in sendto()guest-1SDRJ2@md-K42F:~/Desktop$ " Note: I open 1st the server port as below in other terminal ./server 9191. I beleive there is no error in server code. The udp client is not passing message to server. If I don't use thread , the message is passing .But I have to do it by thread. UDP client Code: /* simple UDP echo client */ #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <netdb.h> #include <stdio.h> #include <pthread.h> #define STRLEN 1024 static void *readdata(void *); static void *writedata(void *); int sockfd, n, slen; struct sockaddr_in servaddr; char sendline[STRLEN], recvline[STRLEN]; int main(int argc, char *argv[]) { pthread_t readid,writeid; struct sockaddr_in servaddr; struct hostent *h; if(argc != 3) { printf("Usage: %s <proxy server ip> <port>\n", argv[0]); exit(0); } /* create hostent structure from user entered host name*/ if ( (h = gethostbyname(argv[1])) == NULL) { printf("\n%s: error in gethostbyname()", argv[0]); exit(0); } /* create server address structure */ bzero(&servaddr, sizeof(servaddr)); /* initialize it */ servaddr.sin_family = AF_INET; memcpy((char *) &servaddr.sin_addr.s_addr, h->h_addr_list[0], h->h_length); servaddr.sin_port = htons(atoi(argv[2])); /* get the port number from argv[2]*/ /* create a UDP socket: SOCK_DGRAM */ if ( (sockfd = socket(AF_INET,SOCK_DGRAM, 0)) < 0) { printf("\n%s: error in socket()", argv[0]); exit(0); } pthread_create(&readid,NULL,&readdata,NULL); pthread_create(&writeid,NULL,&writedata,NULL); while(1) { }; close(sockfd); } static void * writedata(void *arg) { /* get user input */ printf("\nEnter text: "); do { if (fgets(sendline, STRLEN, stdin) == NULL) { printf("\n%s: error in fgets()"); exit(0); } /* send a text */ if (sendto(sockfd, sendline, sizeof(sendline), 0, (struct sockaddr *) &servaddr, sizeof(servaddr)) < 0) { printf("\n%s: error in sendto()"); exit(0); } }while(1); } static void * readdata(void *arg) { /* wait for echo */ slen = sizeof(servaddr); if ( (n = recvfrom(sockfd, recvline, STRLEN, 0, (struct sockaddr *) &servaddr, &slen)) < 0) { printf("\n%s: error in recvfrom()"); exit(0); } /* null terminate the string */ recvline[n] = 0; fputs(recvline, stdout); }

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• Application using JOGL stays in Limbo when closing

  - by Roy T.

  I'm writing a game using Java and OpenGL using the JOGL bindings. I noticed that my game doesn't terminate properly when closing the window even though I've set the closing operation of the JFrame to EXIT_ON_CLOSE. I couldn't track down where the problem was so I've made a small reproduction case. Note that on some computers the program terminates normally when closing the window but on other computers (notably my own) something in the JVM keeps lingering, this causes the JFrame to never be disposed and the application to never exit. I haven't found something in common between the computers that had difficulty terminating. All computers had Windows 7, Java 7 and the same version of JOGL and some terminated normally while others had this problem. The test case is as follows: public class App extends JFrame implements GLEventListener { private GLCanvas canvas; @Override public void display(GLAutoDrawable drawable) { GL3 gl = drawable.getGL().getGL3(); gl.glClearColor(0.0f, 0.0f, 0.0f, 0.0f); gl.glClear(GL3.GL_COLOR_BUFFER_BIT); gl.glFlush(); } // The overrides for dispose (the OpenGL one), init and reshape are empty public App(String title, boolean full_screen, int width, int height) { //snipped setting the width and height of the JFRAME GLProfile profile = GLProfile.get(GLProfile.GL3); GLCapabilities capabilities = new GLCapabilities(profile); canvas = new GLCanvas(capabilities); canvas.addGLEventListener(this); canvas.setSize(getWidth(), getHeight()); add(canvas); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //!!! setVisible(true); } @Override public void dispose() { System.out.println("HELP"); // } public static void main( String[] args ) { new App("gltut 01", false, 1280, 720); } } As you can see this doesn't do much more than adding a GLCanvas to the frame and registering the main class as the GLEventListener. So what keeps lingering? I'm not sure. I've made some screenshots. The application running normally. The application after the JFrame is closed, note that the JVM still hasn't exited or printed a return code. The application after it was force closed. Note the return code -1, so it wasnt just the JVM standing by or something the application really hadn't exited yet. So what is keeping the application in Limbo? Might it be the circular reference between the GLCanvas and the JFrame? I thought the GC could figure that out. If so how should I deal with that when I want to exit? Is there any other clean-up required when using JOGL? I've tried searching but it doesn't seem to be necessary. Edit, to clarify: there are 2 dispose functions dispose(GLAutoDrawable arg) which is a member of GLEventListener and dispose() which is a member of JFrame. The first one is called correctly (but I wouldn't know what to there, destroying the GLAutoDrawable or the GLCanvas gives an infinite exception loop) the second one is never called.

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• The long road to bug-free software

  - by Tony Davis

  The past decade has seen a burgeoning interest in functional programming languages such as Haskell or, in the Microsoft world, F#. Though still on the periphery of mainstream programming, functional programming concepts are gradually seeping into the imperative C# language (for example, Lambda expressions have their root in functional programming). One of the more interesting concepts from functional programming languages is the use of formal methods, the lofty ideal behind which is bug-free software. The idea is that we write a specification that describes exactly how our function (say) should behave. We then prove that our function conforms to it, and in doing so have proved beyond any doubt that it is free from bugs. All programmers already use one form of specification, specifically their programming language's type system. If a value has a specific type then, in a type-safe language, the compiler guarantees that value cannot be an instance of a different type. Many extensions to existing type systems, such as generics in Java and .NET, extend the range of programs that can be type-checked. Unfortunately, type systems can only prevent some bugs. To take a classic problem of retrieving an index value from an array, since the type system doesn't specify the length of the array, the compiler has no way of knowing that a request for the "value of index 4" from an array of only two elements is "unsafe". We restore safety via exception handling, but the ideal type system will prevent us from doing anything that is unsafe in the first place and this is where we start to borrow ideas from a language such as Haskell, with its concept of "dependent types". If the type of an array includes its length, we can ensure that any index accesses into the array are valid. The problem is that we now need to carry around the length of arrays and the values of indices throughout our code so that it can be type-checked. In general, writing the specification to prove a positive property, even for a problem very amenable to specification, such as a simple sorting algorithm, turns out to be very hard and the specification will be different for every program. Extend this to writing a specification for, say, Microsoft Word and we can see that the specification would end up being no simpler, and therefore no less buggy, than the implementation. Fortunately, it is easier to write a specification that proves that a program doesn't have certain, specific and undesirable properties, such as infinite loops or accesses to the wrong bit of memory. If we can write the specifications to prove that a program is immune to such problems, we could reuse them in many places. The problem is the lack of specification "provers" that can do this without a lot of manual intervention (i.e. hints from the programmer). All this might feel a very long way off, but computing power and our understanding of the theory of "provers" advances quickly, and Microsoft is doing some of it already. Via their Terminator research project they have started to prove that their device drivers will always terminate, and in so doing have suddenly eliminated a vast range of possible bugs. This is a huge step forward from saying, "we've tested it lots and it seems fine". What do you think? What might be good targets for specification and verification? SQL could be one: the cost of a bug in SQL Server is quite high given how many important systems rely on it, so there's a good incentive to eliminate bugs, even at high initial cost. [Many thanks to Mike Williamson for guidance and useful conversations during the writing of this piece] Cheers, Tony.

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• How to know the source of certain TCP traffic on AIX

  - by A.Rashad

  We have two AIX boxes, one for production system and another for testing. both systems are running ATM machine switches, where the ATM device is connected via TCP socket. we had an issue on production system where the machine would power off or get disconnected but the netstat -na | grep <IP of machine > would still mention that the socket is up when simulated that case on the UAT environment, the problem did not happen, where the socket would terminate in 3 to 5 minutes. when sniffed on the traffic between the machine and ATM we found that no traffic takes place on production while there is some sort of heartbeat on UAT. but it is not initiated by the application. $>tcpdump | grep -v "10.2.2.71" | grep -v "HSRP" | grep "10.3.1.30" tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on en6, link-type 1, capture size 96 bytes 09:08:13.323421 IP server073.afs3-callback > 10.3.1.30.impera: . 278204201:278204202(1) ack 3307884029 win 164 09:08:13.335334 IP 10.3.1.30.impera > server073.afs3-callback: . ack 1 win 64180 09:08:23.425771 IP 10.3.1.30.impera > server073.afs3-callback: . 1:2(1) ack 1 win 64180 09:08:23.425789 IP server073.afs3-callback > 10.3.1.30.impera: . ack 2 win 65535 09:09:13.628985 IP server073.afs3-callback > 10.3.1.30.impera: . 0:1(1) ack 1 win 164 09:09:13.633900 IP 10.3.1.30.impera > server073.afs3-callback: . ack 1 win 64180 09:09:23.373634 IP 10.3.1.30.impera > server073.afs3-callback: . 1:2(1) ack 1 win 64180 09:09:23.373647 IP server073.afs3-callback > 10.3.1.30.impera: . ack 2 win 65535 while on production, that traffic is not there. we want to know where this traffic is initiated from to implement on production to sense disconnection our comms parameters are: tcp_keepcnt = 2 tcp_keepidle = 100 tcp_keepinit = 150 tcp_keepintvl = 150 tcp_finwait2 = 1200 can anyone help? Editing Question: One point I missed because I was rushing to a meeting. the difference between the Production and UAT in setup is that in Production we have an application called F5 working as load balancer between the ATMs and the AIX box, while it is a direct connection through MPLS in case of UAT. note: we had one MPLS and one GPRS connected ATMs on UAT, and both connections terminated when unplugged in about 4 minutes Edit 2 the no -o tcp_timewait command returns 1 in both Production and UAT

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• Persistent Issues on small business network using Cisco 871W and Catalyst Express 500

  - by Ben Campbell

  Being the most qualified (read: still not qualified) to solve our persistant network issues, I've turned to serverfault for guidance. I've done some searching, reading related documentation on cisco.com and tried a bit of troubleshooting. Here is the config: 100mb synchronous connection from a business internet provider (tested multiple times at 100meg at the source) Cisco 871W wireless point & router is where the WAN connection starts (this serves all our wireless). The only wired connection in the 871W is the Catalyst switch listed below. Cisco Catalyst Express 500 (24TT) is where all the wired connections terminate. About 20 Windows workstations and servers (AD/Webservers only). Some services in EC2 including mail and other web servers/apps. I've been TOLD cabling internally should be gigabit-ready. Here are the problems: generally slow download rates from the internet to the desktop/laptop frequent "page cannot be displayed" errors in browsers-sometimes 3 or 4 reloads are necessary... often times CSS wont load or other content requiring the browser to connect to a different server. slow speed within the LAN from workstation to workstation copying files. I would expect extremely fast data transfer workstation to workstation / server to workstation in this simple network. Several things I need to admit: I'm not primarily a network guy. Funding is relatively low, I need to be the guy that finds the solution. I understand most of the terminology and most of the technology. Implementation is where I fail due to lack of experience. Getting to the point: I'm wondering whether experienced network admins think that our small network should be sufficiently served with our current hardware if configured properly... or if we should purchase new equipment and start fresh? If starting fresh is the plan, whatever that new equipment may be is a likely different question entirely. If I haven't provided enough information, I will happily do some troubleshooting and update with the results. I have experience using wireshark and some other tools. Please let me know what you think would be most helpful and thanks in advance. EDIT: I forgot to add that the Cisco applicance will not finish loading the SDM Express console. It hangs every time at the "populating modules... DHCP". It eventually crashes and closes. I've rebooted the hardware and this still happens.

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• Vagrant-aws not provisioning

  - by SuperCabbage

  I'm trying to spin up and provision an EC2 instance with Vagrant, it successfully creates the instance up and I can then use vagrant ssh to SSH into the it but Puppet doesn't seem to carry out any provisioning. Upon running vagrant up --provider=aws --provision I get the following output Bringing machine 'default' up with 'aws' provider... WARNING: Nokogiri was built against LibXML version 2.8.0, but has dynamically loaded 2.9.1 [default] Warning! The AWS provider doesn't support any of the Vagrant high-level network configurations (`config.vm.network`). They will be silently ignored. [default] Launching an instance with the following settings... [default] -- Type: m1.small [default] -- AMI: ami-a73264ce [default] -- Region: us-east-1 [default] -- Keypair: banderton [default] -- Block Device Mapping: [] [default] -- Terminate On Shutdown: false [default] Waiting for SSH to become available... [default] Machine is booted and ready for use! [default] Rsyncing folder: /Users/benanderton/development/projects/my-project/aws/ => /vagrant [default] Rsyncing folder: /Users/benanderton/development/projects/my-project/aws/manifests/ => /tmp/vagrant-puppet/manifests [default] Rsyncing folder: /Users/benanderton/development/projects/my-project/aws/modules/ => /tmp/vagrant-puppet/modules-0 [default] Running provisioner: puppet... An error occurred while executing multiple actions in parallel. Any errors that occurred are shown below. An error occurred while executing the action on the 'default' machine. Please handle this error then try again: No error message I can then SSH into the instance by using vagrant ssh but none of my provisioning has taken place, so I'm assuming that errors have occured but I'm not being given any useful information relating to them. My Vagrantfile is as following; Vagrant.configure("2") do |config| config.vm.box = "ubuntu_aws" config.vm.box_url = "https://github.com/mitchellh/vagrant-aws/raw/master/dummy.box" config.vm.provider :aws do |aws, override| aws.access_key_id = "REDACTED" aws.secret_access_key = "REDACTED" aws.keypair_name = "banderton" override.ssh.private_key_path = "~/.ssh/banderton.pem" override.ssh.username = "ubuntu" aws.ami = "ami-a73264ce" end config.vm.provision :puppet do |puppet| puppet.manifests_path = "manifests" puppet.module_path = "modules" puppet.options = ['--verbose'] end end My Puppet manifest is as following; package { [ 'build-essential', 'vim', 'curl', 'git-core', 'nano', 'freetds-bin' ]: ensure => 'installed', } None of the packages are installed.

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• How to know the source of certain TCP traffic on AIX

  - by A.Rashad

  We have two AIX boxes, one for production system and another for testing. both systems are running ATM machine switches, where the ATM device is connected via TCP socket. we had an issue on production system where the machine would power off or get disconnected but the netstat -na | grep <IP of machine > would still mention that the socket is up when simulated that case on the UAT environment, the problem did not happen, where the socket would terminate in 3 to 5 minutes. when sniffed on the traffic between the machine and ATM we found that no traffic takes place on production while there is some sort of heartbeat on UAT. but it is not initiated by the application. $>tcpdump | grep -v "10.2.2.71" | grep -v "HSRP" | grep "10.3.1.30" tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on en6, link-type 1, capture size 96 bytes 09:08:13.323421 IP server073.afs3-callback > 10.3.1.30.impera: . 278204201:278204202(1) ack 3307884029 win 164 09:08:13.335334 IP 10.3.1.30.impera > server073.afs3-callback: . ack 1 win 64180 09:08:23.425771 IP 10.3.1.30.impera > server073.afs3-callback: . 1:2(1) ack 1 win 64180 09:08:23.425789 IP server073.afs3-callback > 10.3.1.30.impera: . ack 2 win 65535 09:09:13.628985 IP server073.afs3-callback > 10.3.1.30.impera: . 0:1(1) ack 1 win 164 09:09:13.633900 IP 10.3.1.30.impera > server073.afs3-callback: . ack 1 win 64180 09:09:23.373634 IP 10.3.1.30.impera > server073.afs3-callback: . 1:2(1) ack 1 win 64180 09:09:23.373647 IP server073.afs3-callback > 10.3.1.30.impera: . ack 2 win 65535 while on production, that traffic is not there. we want to know where this traffic is initiated from to implement on production to sense disconnection our comms parameters are: tcp_keepcnt = 2 tcp_keepidle = 100 tcp_keepinit = 150 tcp_keepintvl = 150 tcp_finwait2 = 1200 can anyone help?

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• opening adobe reader results in infinite explorer.exe process creation loop

  - by irrational John

  First, apologies if the answer to this is only a Google away. I tried, honest I did. But I wasn't able to find anything about this problem posted elsewhere. I'm using Adobe Reader v9.3.2 in Windows 7 Home Premium 64-bit. If you want more system details, then just request them. What happens is that when I attempt to open a PDF by clicking "Open" on it then (1) adobe reader never opens and (2) the explorer.exe program is (apparently) recursively opened. I base this on opening the Task Manager and seeing a long list of explorer.exe processes under the "Processes" tab. Usually there is only one. When I recreate this problem, the list of explorer.exe processes are at least a page or two long. (Too many to bother counting). I "correct" this problem by logging off and then logging back on. This kills all the explorer.exe tasks. Unfortunately I don't know another way to terminate them all. Now here's the curious part. This only happens when I attempt to "Open" a PDF file. If instead I use the context menu (right mouse click on the PDF) and select "Open with" and "Adobe Reader 9.3" then Adobe Reader opens the file with no problem. It seems that there is something wrong with the setting for the default open action for PDF files. However, I have been unable to fix this by changing the Windows setting. Here is what I have tried. When I open Control Panel > All Control Panel Items > Default Programs > Set Associations I do not find an entry for file type .pdf. There are only entries for .pdfxml and .pdx. When use "Open with" on a PDF file and select "Choose default program", the check box for "Always use the selected program to open this kind of file" is disabled (greyed out). I have uninstalled and reinstalled Adobe Reader but the problem persists. While obviously no lives are at stake here, this problem is annoying the frickin' heck out of me. If I forget and recreate this bug then I have to stop everything I'm doing to stop it. Any suggestions on how I might go about fixing this?

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• Postfix flow/hook reference, or high-level overview?

  - by threecheeseopera

  The Postfix MTA consists of several components/services that work together to perform the different stages of delivery and receipt of mail; these include the smtp daemon, the pickup and cleanup processes, the queue manager, the smtp service, pipe/spawn/virtual/rewrite ... and others (including the possibility of custom components). Postfix also provides several types of hooks that allow it to integrate with external software, such as policy servers, filters, bounce handlers, loggers, and authentication mechanisms; these hooks can be connected to different components/stages of the delivery process, and can communicate via (at least) IPC, network, database, several types of flat files, or a predefined protocol (e.g. milter). An old and very limited example of this is shown at this page. My question: Does anyone have access to a resource that describes these hooks, the components/delivery stages that the hook can interact with, and the supported communication methods? Or, more likely, documentation of the various Postfix components and the hooks/methods that they support? For example: Given the requirement "if the recipient primary MX server matches 'shadysmtpd', check the recipient address against a list; if there is a match, terminate the SMTP connection without notice". My software would need to 1) integrate into the proper part of the SMTP process, 2) use some method to perform the address check (TCP map server? regular expressions? mysql?), and 3) implement the required action (connection termination). Additionally, there will probably be several methods to accomplish this, and another requirement would be to find that which best fits (ex: a network server might be faster than a flat-file lookup; or, if a large volume of mail might be affected by this check, it should be performed as early in the mail process as possible). Real-world example: The apolicy policy server (performs checks on addresses according to user-defined rules) is designed as a standalone TCP server that hooks into Postfix inside the smtpd component via the directive 'check_policy_service inet:127.0.0.1:10001' in the 'smtpd_client_restrictions' configuration option. This means that, when Postfix first receives an item of mail to be delivered, it will create a TCP connection to the policy server address:port for the purpose of determining if the client is allowed to send mail from this server (in addition to whatever other restrictions / restriction lookup methods are defined in that option); the proper action will be taken based on the server's response. Notes: 1)The Postfix architecture page describes some of this information in ascii art; what I am hoping for is distilled, condensed, reference material. 2) Please correct me if I am wrong on any level; there is a mountain of material, and I am just one man ;) Thanks!

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• installed mongo using brew but stuck at prompt

  - by user50946

  I have installed mongo using brew on my mac. When I give mongo command I see this MongoDB shell version: 2.4.6 connecting to: test but it stays there and never give me command prompt back anyone else noticed something like this I have reinstalled with no luck. The issue is persistent thanks Logs ***** SERVER RESTARTED ***** Fri Oct 18 08:11:48.360 [initandlisten] MongoDB starting : pid=2081 port=27017 dbpath=/usr/local/var/mongodb 64-bit host=Asims-MacBook-Air.local Fri Oct 18 08:11:48.360 [initandlisten] db version v2.4.6 Fri Oct 18 08:11:48.360 [initandlisten] git version: nogitversion Fri Oct 18 08:11:48.360 [initandlisten] build info: Darwin minimountain.local 12.5.0 Darwin Kernel Version 12.5.0: Sun Sep 29 13:33:47 PDT 2013; root:xnu-2050.48.12~1/RELEASE_X86_64 x86_64 BOOST_LIB_VERSION=1_49 Fri Oct 18 08:11:48.360 [initandlisten] allocator: tcmalloc Fri Oct 18 08:11:48.360 [initandlisten] options: { bind_ip: "127.0.0.1", config: "/usr/local/etc/mongod.conf", dbpath: "/usr/local/var/mongodb", logappend: "true", logpath: "/usr/local/var/log/mongodb/mongo.log" } Fri Oct 18 08:11:48.361 [initandlisten] journal dir=/usr/local/var/mongodb/journal Fri Oct 18 08:11:48.361 [initandlisten] recover : no journal files present, no recovery needed Fri Oct 18 08:11:48.398 [websvr] admin web console waiting for connections on port 28017 Fri Oct 18 08:11:48.398 [initandlisten] waiting for connections on port 27017 Fri Oct 18 08:12:03.279 [signalProcessingThread] got signal 1 (Hangup: 1), will terminate after current cmd ends Fri Oct 18 08:12:03.279 [signalProcessingThread] now exiting Fri Oct 18 08:12:03.279 dbexit: Fri Oct 18 08:12:03.279 [signalProcessingThread] shutdown: going to close listening sockets... Fri Oct 18 08:12:03.279 [signalProcessingThread] closing listening socket: 9 Fri Oct 18 08:12:03.279 [signalProcessingThread] closing listening socket: 10 Fri Oct 18 08:12:03.280 [signalProcessingThread] closing listening socket: 11 Fri Oct 18 08:12:03.280 [signalProcessingThread] removing socket file: /tmp/mongodb-27017.sock Fri Oct 18 08:12:03.280 [signalProcessingThread] shutdown: going to flush diaglog... Fri Oct 18 08:12:03.280 [signalProcessingThread] shutdown: going to close sockets... Fri Oct 18 08:12:03.280 [signalProcessingThread] shutdown: waiting for fs preallocator... Fri Oct 18 08:12:03.280 [signalProcessingThread] shutdown: lock for final commit... Fri Oct 18 08:12:03.280 [signalProcessingThread] shutdown: final commit... Fri Oct 18 08:12:03.282 [signalProcessingThread] shutdown: closing all files... Fri Oct 18 08:12:03.282 [signalProcessingThread] closeAllFiles() finished

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• SIGINT and SIGTSTP ignored by most common applications

  - by Vašek Potocek

  After the last upgrade to my Fedora, a strange behaviour started occurring in X terminal applications. I can't seem to stop any process using Ctrl+C, it just results in printing ^C to the console. Similarly, Ctrl+Z prints ^Z and the process goes on. Both work well in non-graphical virtual consoles. I checked stty -a and it seems perfectly normal: speed 38400 baud; rows 24; columns 80; line = 0; intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = M-^?; eol2 = M-^?; swtch = M-^?; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0; -parenb -parodd cs8 hupcl -cstopb cread -clocal -crtscts -ignbrk brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff -iuclc ixany imaxbel iutf8 opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0 isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke This is independent of the terminal (gnome-terminal, XFCE4 terminal, xterm). I later noticed that it may not be caused by the terminal at all: INT or TSTP sent directly to the respective process are ignored, too. This comprises various applications I used to terminate using Ctrl+C on a regular basis (and which often don't have any better means of exiting): cat, find, tail -f, java, ping, mplayer when stuck on a broken file... Even bash ignores Ctrl+C when I want to break a command line I have been entering and then changed my mind (no ^C is printed in this case). I need to delete it character by character (of which there may be hundreds if filename completion has been used) or intentionally run the unwanted command. Strangely enough, vim does recognize Ctrl+C—just to say its "use :quit", of course. This is extremely annoying and prevents me from working efficiently. Everything had been working until lately, maybe a week ago or so. I can not find any possible causes in Google, perhaps I'm trying wrong search terms or misidentifying the main problem. What could be it and how could I revert the standard behaviour, please? Update Ctrl+Z works sometimes. It seems that in the very first terminal I launch after logging in it stops the running command but stops working after that.

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• System locking up with suspicious messages about hard disk

  - by Chris Conway

  My system has started behaving strangely, intermittently locking up. I see messages like the following in syslog: Nov 18 22:22:00 claypool kernel: [ 3428.078156] ata3.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0 Nov 18 22:22:00 claypool kernel: [ 3428.078163] ata3.00: irq_stat 0x40000000 Nov 18 22:22:00 claypool kernel: [ 3428.078167] sr 2:0:0:0: CDB: Test Unit Ready: 00 00 00 00 00 00 Nov 18 22:22:00 claypool kernel: [ 3428.078182] ata3.00: cmd a0/00:00:00:00:00/00:00:00:00:00/a0 tag 0 Nov 18 22:22:00 claypool kernel: [ 3428.078184] res 50/00:03:00:00:00/00:00:00:00:00/a0 Emask 0x1 (device error) Nov 18 22:22:00 claypool kernel: [ 3428.078188] ata3.00: status: { DRDY } Nov 18 22:22:00 claypool kernel: [ 3428.080887] ata3.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0 Nov 18 22:22:00 claypool kernel: [ 3428.080890] ata3.00: irq_stat 0x40000000 Nov 18 22:22:00 claypool kernel: [ 3428.080893] sr 2:0:0:0: CDB: Test Unit Ready: 00 00 00 00 00 00 Nov 18 22:22:00 claypool kernel: [ 3428.080905] ata3.00: cmd a0/00:00:00:00:00/00:00:00:00:00/a0 tag 0 Nov 18 22:22:00 claypool kernel: [ 3428.080906] res 50/00:03:00:00:00/00:00:00:00:00/a0 Emask 0x1 (device error) Nov 18 22:22:00 claypool kernel: [ 3428.080910] ata3.00: status: { DRDY } And then this: Nov 18 23:13:56 claypool kernel: [ 6544.000798] ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen Nov 18 23:13:56 claypool kernel: [ 6544.000804] ata1.00: failed command: FLUSH CACHE EXT Nov 18 23:13:56 claypool kernel: [ 6544.000814] ata1.00: cmd ea/00:00:00:00:00/00:00:00:00:00/a0 tag 0 Nov 18 23:13:56 claypool kernel: [ 6544.000815] res 40/00:00:00:4f:c2/00:00:00:00:00/40 Emask 0x4 (timeout) Nov 18 23:13:56 claypool kernel: [ 6544.000819] ata1.00: status: { DRDY } Nov 18 23:13:56 claypool kernel: [ 6544.000825] ata1: hard resetting link Nov 18 23:14:01 claypool kernel: [ 6549.360324] ata1: link is slow to respond, please be patient (ready=0) Nov 18 23:14:06 claypool kernel: [ 6554.008091] ata1: COMRESET failed (errno=-16) Nov 18 23:14:06 claypool kernel: [ 6554.008103] ata1: hard resetting link Nov 18 23:14:11 claypool kernel: [ 6559.372246] ata1: link is slow to respond, please be patient (ready=0) Nov 18 23:14:16 claypool kernel: [ 6564.020228] ata1: COMRESET failed (errno=-16) Nov 18 23:14:16 claypool kernel: [ 6564.020235] ata1: hard resetting link Nov 18 23:14:21 claypool kernel: [ 6569.380109] ata1: link is slow to respond, please be patient (ready=0) Nov 18 23:14:31 claypool kernel: [ 6579.460243] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300) Nov 18 23:14:31 claypool kernel: [ 6579.486595] ata1.00: configured for UDMA/133 Nov 18 23:14:31 claypool kernel: [ 6579.486601] ata1.00: retrying FLUSH 0xea Emask 0x4 Nov 18 23:14:31 claypool kernel: [ 6579.486939] ata1.00: device reported invalid CHS sector 0 Nov 18 23:14:31 claypool kernel: [ 6579.486952] ata1: EH complete Nov 18 23:17:01 claypool CRON[3910]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly) Nov 18 23:17:01 claypool CRON[3908]: (CRON) error (grandchild #3910 failed with exit status 1) Nov 18 23:17:01 claypool postfix/sendmail[3925]: fatal: open /etc/postfix/main.cf: No such file or directory Nov 18 23:17:01 claypool CRON[3908]: (root) MAIL (mailed 1 byte of output; but got status 0x004b, #012) Nov 18 23:39:01 claypool CRON[4200]: (root) CMD ( [ -x /usr/lib/php5/maxlifetime ] && [ -d /var/lib/php5 ] && find /var/lib/php5/ -type f -cmin +$(/usr/lib/php5/maxlifetime) -print0 | xargs -n 200 -r -0 rm) There are no messages marked after 23:39. When I next tried to use the machine, it would not return from the screensaver (blank screen), nor switch to another terminal, and I had to hard reboot it. [UPDATE] The output of smartctl is here. I had trouble getting this, because / is being mounted read-only (?!), which prevents most applications from running. Also, it may not be related, but I have the following worrying messages in dmesg: [ 10.084596] k8temp 0000:00:18.3: Temperature readouts might be wrong - check erratum #141 [ 10.098477] i2c i2c-0: nForce2 SMBus adapter at 0x600 [ 10.098483] ACPI: resource nForce2_smbus [io 0x0700-0x073f] conflicts with ACPI region SM00 [??? 0x00000700-0x0000073f flags 0x30] [ 10.098486] ACPI: This conflict may cause random problems and system instability [ 10.098487] ACPI: If an ACPI driver is available for this device, you should use it instead of the native driver [ 10.098509] i2c i2c-1: nForce2 SMBus adapter at 0x700 [ 10.112570] Linux agpgart interface v0.103 [ 10.155329] atk: Resources not safely usable due to acpi_enforce_resources kernel parameter [ 10.161506] it87: Found IT8712F chip at 0x290, revision 8 [ 10.161517] it87: VID is disabled (pins used for GPIO) [ 10.161527] it87: in3 is VCC (+5V) [ 10.161528] it87: in7 is VCCH (+5V Stand-By) [ 10.161560] ACPI: resource it87 [io 0x0295-0x0296] conflicts with ACPI region ECRE [??? 0x00000290-0x000002af flags 0x45] [ 10.161562] ACPI: This conflict may cause random problems and system instability [ 10.161564] ACPI: If an ACPI driver is available for this device, you should use it instead of the native driver [UPDATE 2] I swapped in a new SATA cable, per Phil's suggestion. The current output of smartctl is here, if it helps. [UPDATE 3] I don't think the cable fixed it. The system hasn't locked up yet, but my media player crashed a few minutes ago and I have the following in the syslog: Nov 20 16:07:17 claypool kernel: [ 2294.400033] ata1: link is slow to respond, please be patient (ready=0) Nov 20 16:07:47 claypool kernel: [ 2324.084581] ata1: COMRESET failed (errno=-16) Nov 20 16:07:47 claypool kernel: [ 2324.084588] ata1: limiting SATA link speed to 1.5 Gbps Nov 20 16:07:47 claypool kernel: [ 2324.084592] ata1: hard resetting link I get the following response from smartctl: $ sudo smartctl -a /dev/sda [sudo] password for chris: sudo: Can't open /var/lib/sudo/chris/0: Read-only file system smartctl 5.40 2010-03-16 r3077 [i686-pc-linux-gnu] (local build) Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net Device: /0:0:0:0 Version: scsiModePageOffset: response length too short, resp_len=47 offset=50 bd_len=46 >> Terminate command early due to bad response to IEC mode page A mandatory SMART command failed: exiting. To continue, add one or more '-T permissive' options.

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• Class Loading Deadlocks

  - by tomas.nilsson

  Mattis follows up on his previous post with one more expose on Class Loading Deadlocks As I wrote in a previous post, the class loading mechanism in Java is very powerful. There are many advanced techniques you can use, and when used wrongly you can get into all sorts of trouble. But one of the sneakiest deadlocks you can run into when it comes to class loading doesn't require any home made class loaders or anything. All you need is classes depending on each other, and some bad luck. First of all, here are some basic facts about class loading: 1) If a thread needs to use a class that is not yet loaded, it will try to load that class 2) If another thread is already loading the class, the first thread will wait for the other thread to finish the loading 3) During the loading of a class, one thing that happens is that the <clinit method of a class is being run 4) The <clinit method initializes all static fields, and runs any static blocks in the class. Take the following class for example: class Foo { static Bar bar = new Bar(); static { System.out.println("Loading Foo"); } } The first time a thread needs to use the Foo class, the class will be initialized. The <clinit method will run, creating a new Bar object and printing "Loading Foo" But what happens if the Bar object has never been used before either? Well, then we will need to load that class as well, calling the Bar <clinit method as we go. Can you start to see the potential problem here? A hint is in fact #2 above. What if another thread is currently loading class Bar? The thread loading class Foo will have to wait for that thread to finish loading. But what happens if the <clinit method of class Bar tries to initialize a Foo object? That thread will have to wait for the first thread, and there we have the deadlock. Thread one is waiting for thread two to initialize class Bar, thread two is waiting for thread one to initialize class Foo. All that is needed for a class loading deadlock is static cross dependencies between two classes (and a multi threaded environment): class Foo { static Bar b = new Bar(); } class Bar { static Foo f = new Foo(); } If two threads cause these classes to be loaded at exactly the same time, we will have a deadlock. So, how do you avoid this? Well, one way is of course to not have these circular (static) dependencies. On the other hand, it can be very hard to detect these, and sometimes your design may depend on it. What you can do in that case is to make sure that the classes are first loaded single threadedly, for example during an initialization phase of your application. The following program shows this kind of deadlock. To help bad luck on the way, I added a one second sleep in the static block of the classes to trigger the unlucky timing. Notice that if you uncomment the "//Foo f = new Foo();" line in the main method, the class will be loaded single threadedly, and the program will terminate as it should. public class ClassLoadingDeadlock { // Start two threads. The first will instansiate a Foo object, // the second one will instansiate a Bar object. public static void main(String[] arg) { // Uncomment next line to stop the deadlock // Foo f = new Foo(); new Thread(new FooUser()).start(); new Thread(new BarUser()).start(); } } class FooUser implements Runnable { public void run() { System.out.println("FooUser causing class Foo to be loaded"); Foo f = new Foo(); System.out.println("FooUser done"); } } class BarUser implements Runnable { public void run() { System.out.println("BarUser causing class Bar to be loaded"); Bar b = new Bar(); System.out.println("BarUser done"); } } class Foo { static { // We are deadlock prone even without this sleep... // The sleep just makes us more deterministic try { Thread.sleep(1000); } catch(InterruptedException e) {} } static Bar b = new Bar(); } class Bar { static { try { Thread.sleep(1000); } catch(InterruptedException e) {} } static Foo f = new Foo(); }

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• Trash Destination Adapter

  The Trash Destination and this article came from early experiences of using SSIS and community feedback at the time. When developing a package it is very useful to have a destination adapter that does nothing but consume rows with no setup requirement. You often want run a package part way through development, or just add a path so you can set a Data Viewer. There are stock tasks that can be used, but with the Trash Destination all columns are treated as selected automatically (usage type of read-only), so the pipeline knows they are required. It is also obvious that this is for development or diagnostic purposes, and is clearly not a part of the functional design of the package. It is also ideal for just playing around and exploring concepts in SSIS, and is often used in conjunction with the Data Generator Source. Using these two components it is easy to setup a test of an expression in the Derived Column Transformation for example. The Data Generator Source provides some dummy data, and the Trash Destination allows you to anchor the output path and set a Data Viewer to examine the results. It can also be used when performance tuning packages. It is a consistent and known quantity that has no external influences, so it is ideal as a destination when breaking the data flow into sections to isolate a bottleneck. The adapter is really simple to use and requires no setup. Simply drop it onto the pipeline designer and use it to terminate your data flow path. Installation The component is provided as an MSI file which you can download and run to install it. This simply places the files on disk in the correct locations and also installs the assemblies in the Global Assembly Cache as per Microsoft’s recommendations. You may need to restart the SQL Server Integration Services service, as this caches information about what components are installed, as well as restarting any open instances of Business Intelligence Development Studio (BIDS) / Visual Studio that you may be using to build your SSIS packages. Finally, for 2005/2008, you will have to add the transformation to the Visual Studio toolbox manually. Right-click the toolbox, and select Choose Items.... Select the SSIS Data Flow Items tab, and then check the Trash Destination transformation in the Choose Toolbox Items window. This process has been described in detail in the related FAQ entry for How do I install a task or transform component? We recommend you follow best practice and apply the current Microsoft SQL Server Service pack to your SQL Server servers and workstations. Downloads The Trash Destination is available for SQL Server 2005, SQL Server 2008 (includes R2) and SQL Server 2012. Please choose the version to match your SQL Server version, or you can install multiple versions and use them side by side if you have more than one version of SQL Server installed. Trash Destination for SQL Server 2005 Trash Destination for SQL Server 2008 Trash Destination for SQL Server 2012 Version History SQL Server 2012 Version 3.0.0.34 - SQL Server 2012 release. Includes upgrade support for both 2005 and 2008 packages to 2012. (5 Jun 2012) SQL Server 2008 Version 2.0.0.33 - SQL Server 2008 release. Includes support for upgrade of 2005 packages. RTM compatible, previously February 2008 CTP. (4 Mar 2008) Version 2.0.0.31 - SQL Server 2008 November 2007 CTP. (14 Feb 2008) SQL Server 2005 Version 1.0.2.18 - SQL Server 2005 RTM Refresh. SP1 Compatibility Testing. (12 Jun 2006) Version 1.0.1.1 - SQL Server 2005 IDW 15 June CTP. Minor enhancements over v1.0.1.0. (11 Jun 2005) Version 1.0.1.0 - SQL Server 2005 IDW 14 April CTP. First Public Release. (30 May 2005) Troubleshooting Make sure you have downloaded the version that matches your version of SQL Server. We offer separate downloads for SQL Server 2005, SQL Server 2008 and SQL Server 2012. If you an error when you try and use the component along the lines of The component could not be added to the Data Flow task. Please verify that this component is properly installed.  ... The data flow object "Konesans ..." is not installed correctly on this computer, this usually indicates that the internal cache of SSIS components needs to be updated. This is held by the SSIS service, so you need restart the the SQL Server Integration Services service. You can do this from the Services applet in Control Panel or Administrative Tools in Windows. You can also restart the computer if you prefer. You may also need to restart any current instances of Business Intelligence Development Studio (BIDS) / Visual Studio that you may be using to build your SSIS packages. The full error message is shown below for reference: TITLE: Microsoft Visual Studio ------------------------------ The component could not be added to the Data Flow task. Please verify that this component is properly installed. ------------------------------ ADDITIONAL INFORMATION: The data flow object "Konesans.Dts.Pipeline.TrashDestination.Trash, Konesans.Dts.Pipeline.TrashDestination, Version=1.0.1.0, Culture=neutral, PublicKeyToken=b8351fe7752642cc" is not installed correctly on this computer. (Microsoft.DataTransformationServices.Design) For 2005/2008, once installation is complete you need to manually add the task to the toolbox before you will see it and to be able add it to packages - How do I install a task or transform component? This is not necessary for SQL Server 2012 as the new SSIS toolbox automatically detects components. If you are still having issues then contact us, but please provide as much detail as possible about error, as well as which version of the the task you are using and details of the SSIS tools installed.

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• Killing Stuck Child JVM's

  - by ACShorten

  Note: This facility only applies to Oracle Utilities Application Framework products using COBOL. In some situations, the Child JVM's may spin. This causes multiple startup/shutdown Child JVM messages to be displayed and recursive child JVM's to be initiated and shunned. If the following: Unable to establish connection on port …. after waiting .. seconds.The issue can be caused intermittently by CPU spins in connection to the creation of new processes, specifically Child JVMs. Recursive (or double) invocation of the System.exit call in the remote JVM may be caused by a Process.destroy call that the parent JVM always issues when shunning a JVM. The issue may happen when the thread in the parent JVM that is responsible for the recycling gets stuck and it affects all child JVMs. If this issue occurs at your site then there are a number of options to address the issue: Configure an Operating System level kill command to force the Child JVM to be shunned when it becomes stuck. Configure a Process.destroy command to be used if the kill command is not configured or desired. Specify a time tolerance to detect stuck threads before issuing the Process.destroy or kill commands. Note: This facility is also used when the Parent JVM is also shutdown to ensure no zombie Child JVM's exit. The following additional settings must be added to the spl.properties for the Business Application Server to use this facility: spl.runtime.cobol.remote.kill.command – Specify the command to kill the Child JVM process. This can be a command or specify a script to execute to provide additional information. The kill.command property can accept two arguments, {pid} and {jvmNumber}, in the specified string. The arguments must be enclosed in curly braces as shown here. Note: The PID will be appended to the killcmd string, unless the {pid} and {jvmNumber} arguments are specified. The jvmNumber can be useful if passed to a script for logging purposes. Note: If a script is used it must be in the path and be executable by the OS user running the system. spl.runtime.cobol.remote.destroy.enabled – Specify whether to use the Process.destroy command instead of the kill command. Specify true or false. Default value is false. Note: Unless otherwise required, it is recommended to use the kill command option if shunning JVM's is an issue. There this value can remain its default value, false, unless otherwise required. spl.runtime.cobol.remote.kill.delaysecs – Specify the number of seconds to wait for the Child JVM to terminate naturally before issuing the Process.destroy or kill commands. Default is 10 seconds. For example: spl.runtime.cobol.remote.kill.command=kill -9 {pid} {jvmNumber}spl.runtime.cobol.remote.destroy.enabled=falsespl.runtime.cobol.remote.kill.delaysecs=10 When a Child JVM is to be recycled, these properties are inspected and the spl.runtime.cobol.remote.kill.command, executed if provided. This is done after waiting for spl.runtime.cobol.remote.kill.delaysecs seconds to give the JVM time to shut itself down. The spl.runtime.cobol.remote.destroy.enabled property must be set to true AND the spl.runtime.cobol.remote.kill.command omitted for the original Process.destroy command to be used on the process. Note: By default the spl.runtime.cobol.remote.destroy enabled is set to false and is therefore disabled. If neither spl.runtime.cobol.remote.kill.command nor spl.runtime.cobol.remote.destroy.enabled is specified, child JVMs will not beforcibly killed. They will be left to shut themselves down (which may lead to orphan JVMs). If both are specified, the spl.runtime.cobol.remote.kill.command is preferred and spl.runtime.cobol.remote.destroy.enabled defaulted to false.It is recommended to invoke a script to issue the direct kill command instead of directly using the kill -9 commands.For example, the following sample script ensures that the process Id is an active cobjrun process before issuing the kill command: forcequit.sh #!/bin/shTHETIME=`date +"%Y-%m-%d %H:%M:%S"`if [ "$1" = "" ]then  echo "$THETIME: Process Id is required" >>$SPLSYSTEMLOGS/forcequit.log  exit 1fijavaexec=cobjrunps e $1 | grep -c $javaexecif [ $? = 0 ]then  echo "$THETIME: Process $1 is an active $javaexec process -- issuing kill-9 $1" >>$SPLSYSTEMLOGS/forcequit.log  kill -9 $1exit 0else  echo "$THETIME: Process id $1 is not a $javaexec process or not active --  kill will not be issued" >>$SPLSYSTEMLOGS/forcequit.logexit 1fi This script's name would then be specified as the value for the spl.runtime.cobol.remote.kill.command property, for example: spl.runtime.cobol.remote.kill.command=forcequit.sh The forcequit script does not have any explicit parameters but pid is passed automatically. To use the jvmNumber parameter it must explicitly specified in the command. For example, to call script forcequit.sh and pass it the pid and the child JVM number, specify it as follows: spl.runtime.cobol.remote.kill.command=forcequit.sh {pid} {jvmNumber} The script can then use the JVM number for logging purposes or to further ensure that the correct pid is being killed.If the arguments are omitted, the pid is automatically appended to the spl.runtime.cobol.remote.kill.command string. To use this facility the following patches must be installed: Patch 13719584 for Oracle Utilities Application Framework V2.1, Patches 13684595 and 13634933 for Oracle Utilities Application Framework V2.2 Group Fix 4 (as Patch 13640668) for Oracle Utilities Application Framework V4.1.

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• BizTalk &ndash; Routing failure on Delivery Notifications (BizTalk 2006 R2 to 2013)

  - by S.E.R.

  Originally posted on: http://geekswithblogs.net/SERivas/archive/2013/11/11/biztalk-routing-failure-on-delivery-notifications.aspxThis is a detailed explanation of a something I posted a few month ago on stackoverflow, concerning a weird behavior (a bug, really…) of the delivery notifications in BizTalk. Reminder: what are delivery notifications Mechanism BizTalk has the ability to automatically publish positive acknowledgments (ACK) when it has succeeded transmitting a message or negative acknowledgments (NACK) in case of a transmission failure. Orchestrations can use delivery notifications to subscribe to those ACKs and NACKs in order to know if a message sent on a one-way send port has been successfully transmitted. Delivery Notifications can be “activated” in two ways: The most common and easy way is to set the Delivery Notification property of a logical send port (in the orchestration designer) to Transmitted: Another way is to set the BTS.AckRequired context property of the message to be sent to true: NOTE: fundamentally, those methods are strictly equivalent since the fact of setting the Delivery Notification to Transmitted on the send port only tells BizTalk the BTS.AckRequired context property has to be set to true on the outgoing message. Related context properties ACKs and NACKs have a common set of propoted context properties, which are : Propriété Description AckType Equals ACK when successful or NACK otherwise AckID MessageID of the message concerned by the acknowledgment AckOwnerID InstanceID of the instance associated with the acknowledgment AckSendPortID ID of the send port AckSendPortName Name of the send port AckOutboundTransportLocation URI of the send port AckReceivePortID ID of the port the message came from AckReceivePortName Name of the port the message came from AckInboundTransportLocation URI of the port the message came from Detailed behavior The way Delivery Notifications are handled by BizTalk is peculiar compared to the standard behavior of the Message Box: if no active subscription exists for the acknowledgment, it is simply discarded. The direct consequence of this is that there can be no routing failure for an acknowledgment, and an acknowledgment cannot be suspended. Moreover, when a message is sent to a send port where Delivery Notification = Transmitted, a correlation set is initialized and a correlation token is attached to the message (Context property: CorrelationToken). This correlation token will also be attached to the acknowledgment. So when the acknowledgment is issued, it is automatically routed to the source orchestration. Finally, when a NACK is received by the source orchestration, a DeliveryFailureException is thrown, which can be caught in Catch section. Context of the problem Consider this scenario: In an orchestration, Delivery Notifications are activated on a One-Way send port In case of a transmission failure, the messaging instance is suspended and the orchestration catches an exception (DeliveryFailureException). When the exception is caught, the orchestration does some logging and then terminates (thanks to a Terminate shape). So that leaves only the suspended messaging instance, waiting to be resumed. Symptoms Once the problem that caused the transmission failure is solved, the messaging instance is resumed. Considering what was said in the reminder, we would expect the instance to complete, leaving no active or suspended instance. Nevertheless, the result is that the messaging instance is once more suspended, this time because of a routing failure: The routing failure report shows that the suspended message has the following attached properties: Explanation Those properties clearly indicate that the message being suspended is an acknowledgment (ACK in this case), which was published in the message box and was supended because no subscribers were found. This makes sense, since the source orchestration was terminated before we resumed the messaging instance. So its subscription to the acknowledgments was no longer active when the ACK was published, which explains the routing failure. But this behavior is in direct contradiction with what was said earlier: an acknowledgment must be discarded when no subscriber is found and therefore should not be suspended. Cause It is indeed an outright bug, which appeared with the SP1 of BizTalk 2006 R2 and was never corrected since then: not in the next 4 CUs, not in BizTalk 2009, not in 2010 and not event in 2013 – though I haven’t tested CU1 and CU2 for this last edition, but I bet there is nothing to be expected from those CUs (on this particular point). Side effects This bug can have pretty nasty side effects: this behavior can be propagated to other ports, due to routing mechanisms. For instance: you have configured the ESB Toolkit and have activated the “Enable routing failure for failed messages”. The result will be that the ESB Exception SQL send port will also try and publish ACKs or NACKs concerning its own messaging instances. In itself, this is already messy, but remember that those acknowledgments will also have the source correlation token attached to them… See how far it goes? Well, actually there is more: in SQL send ports, transactions will be rolled back because of the routing failure (I guess it also happens with other adapters - like Oracle, but I haven’t tested them). Again, think of what happens when the send port is the ESB Exception send port: your BizTalk box is going mad, but you have no idea since no exception can be written in the exception database! All of this can be tricky to diagnose, I can tell you that… Solution There is no real solution, only a work-around, but it won’t solve all of the problems and side effects. The idea is to create an orchestration which subscribes to all acknowledgments. That is to say: The message type of the incoming message will be XmlDocument The BTS.AckType property exists The logical receive port will use direct binding By doing so, all acknowledgments will be consumed by an instance of this orchestration, thus avoiding the routing failure. Here is an example of what this orchestration could look like: In order not to pollute the HAT and the DTA Db (after all, this orchestration is only meant to be a palliative to some faulty internal BizTalk mechanism, so there should be no trace of its execution), all tracking must be deactivated:

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• creating a pre-menu level select screen

  - by Ephiras

  Hi I am working on creating a tower Defence java applet game and have come to a road block about implementing a title screen that i can select the level and difficulty of the rest of the game. my title screen class is called Menu. from this menu class i need to pass in many different variables into my Main class. i have used different classes before and know how to run them and such. but if both classes extend applet and each has its individual graphics method how can i run things from Main even though it was created in Menu. what i essentially want to do is run the Menu class withits action listeners and graphics until a Difficulty button has been selected, run the main class (which 100% works without having to have the Menu class) and pretty much terminate Menu so that i cannot go back to it, do not see its buttons or graphics menus. can i run one applet annd when i choose a button close that one and launch the other one? IF you would like to download the full project you can find it here, i had to comment out all the code that wasn't working my Menu class import java.awt.*; import java.awt.event.*; import java.applet.*; public class Menu extends Applet implements ActionListener{ Button bEasy,bMed,bHard; Main m; public void init(){ bEasy= new Button("Easy"); bEasy.setBounds(140,200,100,50); add(bEasy); bMed = new Button("Medium");bMed.setBounds(280,200,100,50); add(bMed); bHard= new Button("Hard");bHard.setBounds(420,200,100,50); add(bHard); setLayout(null); } public void actionPerformed(ActionEvent e){ Main m = new Main(20,10,3000,mapMed);//break; switch (e.getSource()){ case bEasy: Main m = new Main(6000,20,"levels/levelEasy.png");break;//enimies tower money world case bMed: Main m = new Main(4000,15,"levels/levelMed.png");break; case bHard: Main m = new Main(2000,10,"levels/levelEasy.png");break; default: break; } } public void paint(){ //m.draw(g) } } and here is my main class initialising code. import java.awt.*; import java.awt.event.*; import java.applet.*; import java.io.IOException; public class Main extends Applet implements Runnable, MouseListener, MouseMotionListener, ActionListener{ Button startButton, UpgRange, UpgDamage; //set up the buttons Color roadCol,startCol,finCol,selGrass,selRoad; //set up the colors Enemy e[][]; Tower t[]; Image towerpic,backpic,roadpic,levelPic; private Image i; private Graphics doubleG; //here is the world 0=grass 1=road 2=start 3=end int world[][],eStartX,eStartY; boolean drawMouse,gameEnd; static boolean start=false; static int gridLength=15; static int round=0; int Mx,My,timer=1500; static int sqrSize=31; int towers=0,towerSelected=-10; static int castleHealth=2000; String levelPath; //choose the level Easy Med or Hard int maxEnemy[] = {5,7,12,20,30,15,50,30,40,60};//number of enimies per round int maxTowers=15;//maximum number of towers allowed static int money =2000,damPrice=600,ranPrice=350,towerPrice=700; //money = the intial ammount of money you start of with //damPrice is the price to increase the damage of a tower //ranPrice is the price to increase the range of a tower public void main(int cH,int mT,int mo,int dP,int rP,int tP,String path,int[] mE)//constructor 1 castleHealth=cH; maxTowers=mT; money=mo; damPrice=dP; ranPrice=rP; towerPrice=tP; String levelPath=path; maxEnemy = mE; buildLevel(); } public void main(int cH,int mT,String path)//basic constructor castleHealth=cH; maxTowers=mT; String levelPath=path; maxEnemy = mE; buildLevel(); } public void init(){ setSize(sqrSize*15+200,sqrSize*15);//set the size of the screen roadCol = new Color(255,216,0);//set the colors for the different objects startCol = new Color(0,38,255); finCol = new Color(255,0,0); selRoad = new Color(242,204,155);//selColor is the color of something when your mouse hovers over it selGrass = new Color(0,190,0); roadpic = getImage(getDocumentBase(),"images/road.jpg"); towerpic = getImage(getDocumentBase(),"images/tower.png"); backpic = getImage(getDocumentBase(),"images/grass.jpg"); levelPic = getImage(getDocumentBase(),"images/level.jpg"); e= new Enemy[maxEnemy.length][];//activates all of the enimies for (int r=0;r<e.length;r++) e[r] = new Enemy[maxEnemy[r]]; t= new Tower[maxTowers]; for (int i=0;i<t.length;i++) t[i]= new Tower();//activates all the towers for (int i=0;i<e.length; i++)//sets all of the enimies starting co ordinates for (int j=0;j<e[i].length;j++) e[i][j] = new Enemy(eStartX,eStartY,world); initButtons();//initialise all the buttons addMouseMotionListener(this); addMouseListener(this); }

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• Mark Hurd on the Customer Revolution: Oracle's Top 10 Insights

  - by Richard Lefebvre

  Reprint of an article from Forbes Businesses that fail to focus on customer experience will hear a giant sucking sound from their vanishing profitability. Because in today’s dynamic global marketplace, consumers now hold the power in the buyer-seller equation, and sellers need to revamp their strategy for this new world order. The ability to relentlessly deliver connected, personalized and rewarding customer experiences is rapidly becoming one of the primary sources of competitive advantage in today’s dynamic global marketplace. And the inability or unwillingness to realize that the customer is a company’s most important asset will lead, inevitably, to decline and failure. Welcome to the lifecycle of customer experience, in which consumers explore, engage, shop, buy, ask, compare, complain, socialize, exchange, and more across multiple channels with the unconditional expectation that each of those interactions will be completed in an efficient and personalized manner however, wherever, and whenever the customer wants. While many niche companies are offering point solutions within that sprawling and complex spectrum of needs and requirements, businesses looking to deliver superb customer experiences are still left having to do multiple product evaluations, multiple contract negotiations, multiple test projects, multiple deployments, and–perhaps most annoying of all–multiple and never-ending integration projects to string together all those niche products from all those niche vendors. With its new suite of customer-experience solutions, Oracle believes it can help companies unravel these challenges and move at the speed of their customers, anticipating their needs and desires and creating enduring and profitable relationships. Those solutions span the full range of marketing, selling, commerce, service, listening/insights, and social and collaboration tools for employees. When Oracle launched its suite of Customer Experience solutions at a recent event in New York City, president Mark Hurd analyzed the customer experience revolution taking place and presented Oracle’s strategy for empowering companies to capitalize on this important market shift. From Hurd’s presentation and related materials, I’ve extracted a list of Hurd’s Top 10 Insights into the Customer Revolution. 1. Please Don’t Feed the Competitor’s Pipeline!After enduring a poor experience, 89% of consumers say they would immediately take their business to your competitor. (Except where noted, the source for these findings is the 2011 Customer Experience Impact (CEI) Report including a survey commissioned by RightNow (acquired by Oracle in March 2012) and conducted by Harris Interactive.) 2. The Addressable Market Is Massive. Only 1% of consumers say their expectations were always met by their actual experiences. 3. They’re Willing to Pay More! In return for a great experience, 86% of consumers say they’ll pay up to 25% more. 4. The Social Media Microphone Is Always Live. After suffering through a poor experience, more than 25% of consumers said they posted a negative comment on Twitter or Facebook or other social media sites. Conversely, of those consumers who got a response after complaining, 22% posted positive comments about the company. 5.  The New Deal Is Never Done: Embrace the Entire Customer Lifecycle. An appropriately active and engaged relationship, says Hurd, extends across every step of the entire processs: need, research, select, purchase, receive, use, maintain, and recommend. 6. The 360-Degree Commitment. Customers want to do business with companies that actively and openly demonstrate the desire to establish strong and seamless connections across employees, the company, and the customer, says research firm Temkin Group in its report called “The CX Competencies.” 7. Understand the Emotional Drivers Behind Brand Love. What makes consumers fall in love with a brand? Among the top factors are friendly employees and customer reps (73%), easy access to information and support (55%), and personalized experiences, such as when companies know precisely what products or services customers have purchased in the past and what issues those customers have raised (36%). 8.  The Importance of Immediate Action. You’ve got one week to respond–and then the opportunity’s lost. If your company needs more than a week to answer a prospect’s question or request, most of those prospects will terminate the relationship. 9.  Want More Revenue, Less Churn, and More Referrals? Then improve the overall customer experience: Forrester’s research says that approach put an extra $900 million in the pockets of wireless service providers, $800 million for hotels, and $400 million for airlines. 10. The Formula for CX Success.  Hurd says it includes three elegantly interlaced factors: Connected Engagement, to personalize the experience; Actionable Insight, to maximize the engagement; and Optimized Execution, to deliver on the promise of value. RECOMMENDED READING: The Top 10 Strategic CIO Issues For 2013 Wal-Mart, Amazon, eBay: Who’s the Speed King of Retail? Career Suicide and the CIO: 4 Deadly New Threats Memo to Marc Benioff: Social Is a Tool, Not an App

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• Thread.Interrupt Is Evil

  - by Alois Kraus

  Recently I have found an interesting issue with Thread.Interrupt during application shutdown. Some application was crashing once a week and we had not really a clue what was the issue. Since it happened not very often it was left as is until we have got some memory dumps during the crash. A memory dump usually means WindDbg which I really like to use (I know I am one of the very few fans of it).  After a quick analysis I did find that the main thread already had exited and the thread with the crash was stuck in a Monitor.Wait. Strange Indeed. Running the application a few thousand times under the debugger would potentially not have shown me what the reason was so I decided to what I call constructive debugging. I did create a simple Console application project and try to simulate the exact circumstances when the crash did happen from the information I have via memory dump and source code reading. The thread that was  crashing was actually MS code from an old version of the Microsoft Caching Application Block. From reading the code I could conclude that the main thread did call the Dispose method on the CacheManger class which did call Thread.Interrupt on the cache scavenger thread which was just waiting for work to do. My first version of the repro looked like this   static void Main(string[] args) { Thread t = new Thread(ThreadFunc) { IsBackground = true, Name = "Test Thread" }; t.Start(); Console.WriteLine("Interrupt Thread"); t.Interrupt(); } static void ThreadFunc() { while (true) { object value = Dequeue(); // block until unblocked or awaken via ThreadInterruptedException } } static object WaitObject = new object(); static object Dequeue() { object lret = "got value"; try { lock (WaitObject) { } } catch (ThreadInterruptedException) { Console.WriteLine("Got ThreadInterruptException"); lret = null; } return lret; } I do start a background thread and call Thread.Interrupt on it and then directly let the application terminate. The thread in the meantime does plenty of Monitor.Enter/Leave calls to simulate work on it. This first version did not crash. So I need to dig deeper. From the memory dump I did know that the finalizer thread was doing just some critical finalizers which were closing file handles. Ok lets add some long running finalizers to the sample. class FinalizableObject : CriticalFinalizerObject { ~FinalizableObject() { Console.WriteLine("Hi we are waiting to finalize now and block the finalizer thread for 5s."); Thread.Sleep(5000); } } class Program { static void Main(string[] args) { FinalizableObject fin = new FinalizableObject(); Thread t = new Thread(ThreadFunc) { IsBackground = true, Name = "Test Thread" }; t.Start(); Console.WriteLine("Interrupt Thread"); t.Interrupt(); GC.KeepAlive(fin); // prevent finalizing it too early // After leaving main the other thread is woken up via Thread.Abort // while we are finalizing. This causes a stackoverflow in the CLR ThreadAbortException handling at this time. } With this changed Main method and a blocking critical finalizer I did get my crash just like the real application. The funny thing is that this is actually a CLR bug. When the main method is left the CLR does suspend all threads except the finalizer thread and declares all objects as garbage. After the normal finalizers were called the critical finalizers are executed to e.g. free OS handles (usually). Remember that I did call Thread.Interrupt as one of the last methods in the Main method. The Interrupt method is actually asynchronous and does wake a thread up and throws a ThreadInterruptedException only once unlike Thread.Abort which does rethrow the exception when an exception handling clause is left. It seems that the CLR does not expect that a frozen thread does wake up again while the critical finalizers are executed. While trying to raise a ThreadInterrupedException the CLR goes down with an stack overflow. Ups not so nice. Why has this nobody noticed for years is my next question. As it turned out this error does only happen on the CLR for .NET 4.0 (x86 and x64). It does not show up in earlier or later versions of the CLR. I have reported this issue on connect here but so far it was not confirmed as a CLR bug. But I would be surprised if my console application was to blame for a stack overflow in my test thread in a Monitor.Wait call. What is the moral of this story? Thread.Abort is evil but Thread.Interrupt is too. It is so evil that even the CLR of .NET 4.0 contains a race condition during the CLR shutdown. When the CLR gurus can get it wrong the chances are high that you get it wrong too when you use this constructs. If you do not believe me see what Patrick Smacchia does blog about Thread.Abort and List.Sort. Not only the CLR creators can get it wrong. The BCL writers do sometimes have a hard time with correct exception handling as well. If you do tell me that you use Thread.Abort frequently and never had problems with it I do suspect that you do not have looked deep enough into your application to find such sporadic errors.

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• To refund or not to refund this client?

  - by Mahalia Samuels

  I'd really appreciate your advice on an ongoing project. I presented my client with a proposal and design samples which he approved, and he paid in full instead of the 50% upfront deposit as I'd given him a generous discount. He was then slow in furnishing me with some of the content, but once we did, he expected the website to be finished immediately which was not possible. Because he needed it done urgently, we agreed to try to get it done about 10 working days after the content was provided, but the developer who was helping me let me down. The next week, I completed the website myself and uploaded it to the server on a Friday afternoon. He then calls and texts me on following Sunday while I'm at church to say it's not online (there was probably a problem with his browser). The next morning, I received an email from him demanding a full refund within two days because he couldn't see the website (even though it was live, and I tested it on multiple browsers, a different computer and my phone), and he called me shouting at me because he couldn't access it. Finally when he was able to access it, he was unhappy with a certain detail regarding the slideshow which I began fixing and which was done the next day. He then referred me to another website and said he wanted it to look similar but not identical to it in terms of the layout. He also now wanted to add more features which were not in the original design. I got a designer to work on a new design which I sent to him for review, which if approved would be completed by 15 October, and he approved it last Thursday. He then called me yesterday to say that he wanted to change the design - he only approved it out of impatience. He now wants the website to be more similar to the other website he referred me to and he wants it done before the 15th! Then, he says to me that other people have done websites for him in three days - website's he's complained to me about for lacking dimension because they were just premium themes, whereas we'd designed and coded from scratch. I'm thinking of finishing the website but refunding him in full (or at least the refundable 50%) less domain registration and other non-refundable amounts, just to avoid further escalation of this matter and having him call me next week and say he wants to change it again. These are the applicable terms and conditions as laid out in the agreement: Total amount due for this project is Amount A. Client shall pay Consultant a deposit of Amount B (50% of total amount due for project) in advance before any work commences on the Project. The balance is due within 7 working days of completion of project. Deposit is non-refundable. Should client opt to host elsewhere, applicable transferral fee of Amount C will apply. Estimated project completion time frame is 14 to 30 days from the date Client furnishes Consultant with Brief and all other required media and data, provided that Client has made payment to secure the project. Consultant will make every effort to meet agreed upon due dates. The Client should be aware that failure to submit required information or materials, or last minute changes and excessive changes may cause subsequent delays. Client delays could result in significant delays in delivery of finished work. Major changes in client input or direction or brief will be charged at normal rates. Any work the Client wishes Consultant to create, which is not specified in the attached Proposal will be considered an additional service. Client agrees to pay Consultant for any additional expenses or additional services not included in the attached quotation and proposal if requested by the Client. Web design credit in the name of the Consultant, and link to Consultant’s website shall be placed on the footer of the final Website. Either party may terminate this Agreement by giving 7 days written notice to the other of such termination. In the event that Work is postponed or terminated at the request of the Client, Consultant shall have the right to bill pro rata at full rates for work completed through the date of that request, while reserving all rights under this Agreement. If additional payment is due, this shall be payable within seven days of the Client's written notification to stop work. In the event of termination, the Client shall also pay any expenses incurred by Consultant and the Consultant shall own all rights to the Work. Advice please?

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