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  • Coldfusion on VPS, how much JVM heap memory?

    - by Steven Filipowicz
    Recently I got a VPS server and I'm running Coldfusion, the website was running fine until it got more and more traffic and I started to encounter 'OutOfMemory' exceptions. I thought simply to rise the memory of the VPS server, but this didn't help. After doing some Google searches I found a setting in de CF Admin settings to set the JVM Heap memory. It was on the standard: Max Heap size 512MB and Min Heap size was empty. After playing around a bit I have now set it to Min 50MB and Max 200MB, good things is that I'm not getting the 'OutOfMemory' exceptions anymore. So far so good! But with about 50 active visitors on the website, the website starts to get slow. The CPU usage is only about 8% (Windows Taskmanager), also the taskmanager show only about 30% of the 3GB RAM in use. So I'm thinking that my values could be tweaked to use more of the RAM. Honestly I don't understand these JVM Memory heap settings, so I have no clue what is a good setting for me. I found a CF script that displays the memory usage, the details are: Heap Memory Usage - Committed 194 MB Heap Memory Usage - Initial 50.0 MB Heap Memory Usage - Max 194 MB Heap Memory Usage - Used 163 MB JVM - Free Memory 31.2 MB JVM - Max Memory 194 MB JVM - Total Memory 194 MB JVM - Used Memory 163 MB Memory Pool - Code Cache - Used 13.0 MB Memory Pool - PS Eden Space - Used 6.75 MB Memory Pool - PS Old Gen - Used 155 MB Memory Pool - PS Perm Gen - Used 64.2 MB Memory Pool - PS Survivor Space - Used 1.07 MB Non-Heap Memory Usage - Committed 77.4 MB Non-Heap Memory Usage - Initial 18.3 MB Non-Heap Memory Usage - Max 240 MB Non-Heap Memory Usage - Used 77.2 MB Free Allocated Memory: 30mb Total Memory Allocated: 194mb Max Memory Available to JVM: 194mb % of Free Allocated Memory: 16% % of Available Memory Allocated: 100% My JVM arguments are: -server -Dsun.io.useCanonCaches=false -XX:MaxPermSize=192m -XX:+UseParallelGC - Dcoldfusion.rootDir={application.home}/../ -Dcoldfusion.libPath={application.home}/../lib Can I give the JVM more memory? If so, what settings should I use? Thanks very much!!

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  • iTunes Home Sharing only works one way between 2 WinXP PC's on the same LAN

    - by scunliffe
    Both PC's have the latest iTunes installed. PC (A) can "see" that there is a shared library "B library" but attempts to connect to it return this error message: The shared library "{Username}'s Library" is not responding (-3259) Check that any firewall software running on either the shared computer or this computer has been set to allow communication on port 3689. however the reverse works fine. e.g. PC (B) can "see" shared library "A library" and can access all content. Notes: Both PC's have Home Sharing enabled (turned off/on several times to verify). Both PC's have Windows Firewall turned on, but in the exceptions tab, iTunes is allowed, and Port 3689 is also added as a firewall exception (just in case) Both iTunes accounts have been "authorized" on both PC's Both PC's connect via LAN via D-Link DIR-615 router. In the advanced application rules, iTunes has also been added to allow traffic on port 3689 un-hindered. Is there any other magical setting/configuration option that I should be aware of and set in order to get this to work? I could care less about sharing apps etc. I just want the music sharing to work. Update: Solved! It turns out on PC (B) there were multiple accounts set up. 1 of the accounts had the checkbox checked under the windows firewall "On" option which states "No exceptions" thus even though it was added to the exception list on the main user account, this other account was blocking access.

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  • Gwibber on Ubuntu doesn't open

    - by Radian
    Gwibber Doesn't open . When I tried to Open it from Command Line I got this error ** (gwibber:3752): WARNING **: Trying to register gtype 'WnckWindowState' as enum when in fact it is of type 'GFlags' ** (gwibber:3752): WARNING **: Trying to register gtype 'WnckWindowActions' as enum when in fact it is of type 'GFlags' ** (gwibber:3752): WARNING **: Trying to register gtype 'WnckWindowMoveResizeMask' as enum when in fact it is of type 'GFlags' No dbus monitor yet Updating... ERROR:dbus.proxies:Introspect error on com.Gwibber.Service:/com/gwibber/Service: dbus.exceptions.DBusException: org.freedesktop.DBus.Error.NoReply: Message did not receive a reply (timeout by message bus) Traceback (most recent call last): File "/usr/bin/gwibber", line 67, in client.Client() File "/usr/lib/python2.6/dist-packages/gwibber/client.py", line 447, in init self.w = GwibberClient() File "/usr/lib/python2.6/dist-packages/gwibber/client.py", line 29, in init self.model = gwui.Model() File "/usr/lib/python2.6/dist-packages/gwibber/gwui.py", line 43, in init self.services = json.loads(self.daemon.GetServices()) File "/usr/lib/pymodules/python2.6/dbus/proxies.py", line 68, in call return self._proxy_method(*args, **keywords) File "/usr/lib/pymodules/python2.6/dbus/proxies.py", line 140, in call **keywords) File "/usr/lib/pymodules/python2.6/dbus/connection.py", line 620, in call_blocking message, timeout) dbus.exceptions.DBusException: org.freedesktop.DBus.Error.NoReply: Message did not receive a reply (timeout by message bus) I tried to remove it and to Install again but It has the same error It was Working probably , then suddenly it didn't

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  • How to set minimum SQL Server resource allocation for a database?

    - by Jeff Widmer
    Over the past Christmas holiday week, when the website I work on was experiencing very low traffic, we saw several Request timed out exceptions (one on each day 12/26, 12/28, 12/29, and 12/30) on several pages that require user authentication. We rarely saw Request timed out exceptions prior to this very low traffic week. We believe the timeouts were due to the database that it uses being "spun down" on the SQL Server and taking longer to spin up when a request came in. There are 2 databases on the SQL Server (SQL Server 2005), one which is specifically for this application and the other for the public facing website and for authentication; so in the case where users were not logged into the application (which definitely could have been for several hours at a time over Christmas week) the application database probably received no requests. We think at this point SQL Server reallocated resources to the other database and then when a request came in, extra time was needed to spin up the application database and the timeout occurred. Is there a way to tell SQL Server to give a minimum amount of resources to a database at all times?

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  • jdbc4 CommunicationsException

    - by letronje
    I have a machine running a java app talking to a mysql instance running on the same instance. the app uses jdbc4 drivers from mysql. I keep getting com.mysql.jdbc.exceptions.jdbc4.CommunicationsException at random times. Here is the whole message. Could not open JDBC Connection for transaction; nested exception is com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was25899 milliseconds ago.The last packet sent successfully to the server was 25899 milliseconds ago, which is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem. For mysql, the value of global 'wait_timeout' and 'interactive_timeout' is set to 3600 seconds and 'connect_timeout' is set to 60 secs. the wait timeout value is much higher than the 26 secs(25899 msecs). mentioned in the exception trace. I use dbcp for connection pooling and here is spring bean config for the datasource. <bean id="dataSource" destroy-method="close" class="org.apache.commons.dbcp.BasicDataSource" > <property name="driverClassName" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/db"/> <property name="username" value="xxx"/> <property name="password" value="xxx" /> <property name="poolPreparedStatements" value="false" /> <property name="maxActive" value="3" /> <property name="maxIdle" value="3" /> </bean> Any idea why this could be happening? Will using c3p0 solve the problem ?

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  • IIS 7.5 fails to open database after computer machine on that database server is working restarts.

    - by Jenea
    Hi. I decided to post this question also here in case the issues we have is related to sql server. There is a problem that bother me for some time. I have an asp.net mvc that uses NHibernate for modeling the database. The infrastructure is the following: Windows 2008 R2 for all virtual machines. IIS 7.5 is working on one virtual machine. Sql Server 2008 is working on another virtual machine. We have couple of databases, two that stores application data and one that registers all unhandled exceptions. Sometimes virtual machine that hosts database server restarts (in the middle of the night, not quite sure about the reason) after that connection to the databases that stores application data is not working and as result there are thousands of unhandled exceptions that get registered in the third database. Important to mention that databases are accessible from Management Studio. The problem is solved by resetting IIS. Connetion are handled via NHibernateUtil class which opens and closes session at each request.

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  • jdbc4 CommunicationsException

    - by letronje
    I have a machine running a java app talking to a mysql instance running on the same instance. the app uses jdbc4 drivers from mysql. I keep getting com.mysql.jdbc.exceptions.jdbc4.CommunicationsException at random times. Here is the whole message. Could not open JDBC Connection for transaction; nested exception is com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was25899 milliseconds ago.The last packet sent successfully to the server was 25899 milliseconds ago, which is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem. For mysql, the value of global 'wait_timeout' and 'interactive_timeout' is set to 3600 seconds and 'connect_timeout' is set to 60 secs. the wait timeout value is much higher than the 26 secs(25899 msecs). mentioned in the exception trace. I use dbcp for connection pooling and here is spring bean config for the datasource. <bean id="dataSource" destroy-method="close" class="org.apache.commons.dbcp.BasicDataSource" > <property name="driverClassName" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/db"/> <property name="username" value="xxx"/> <property name="password" value="xxx" /> <property name="poolPreparedStatements" value="false" /> <property name="maxActive" value="3" /> <property name="maxIdle" value="3" /> </bean> Any idea why this could be happening? Will using c3p0 solve the problem ?

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  • iTunes Home Sharing only works one way between 2 Windows XP PC's on the same LAN

    - by scunliffe
    Both PC's have the latest iTunes installed. PC (A) can "see" that there is a shared library "B library" but attempts to connect to it return this error message: The shared library "{Username}'s Library" is not responding (-3259) Check that any firewall software running on either the shared computer or this computer has been set to allow communication on port 3689. however the reverse works fine. e.g. PC (B) can "see" shared library "A library" and can access all content. Notes: Both PC's have Home Sharing enabled (turned off/on several times to verify). Both PC's have Windows Firewall turned on, but in the exceptions tab, iTunes is allowed, and Port 3689 is also added as a firewall exception (just in case) Both iTunes accounts have been "authorized" on both PC's Both PC's connect via LAN via D-Link DIR-615 router. In the advanced application rules, iTunes has also been added to allow traffic on port 3689 un-hindered. Is there any other magical setting/configuration option that I should be aware of and set in order to get this to work? I could care less about sharing apps etc. I just want the music sharing to work. Update: Solved! It turns out on PC (B) there were multiple accounts set up. 1 of the accounts had the checkbox checked under the Windows firewall "On" option which states "No exceptions" thus even though it was added to the exception list on the main user account, this other account was blocking access.

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  • How do you permanently disable the 'This Connection is Untrusted' page on Firefox

    - by TheIronChef9
    I'm going insane. Can someone please help me to COMPLETELY DISABLE the 'This Connection is Untrusted' page on Firefox. Facts: I am running Firefox 23.0 on an Ubuntu machine (downloaded and installed ubuntu today) It is a work computer and I have to use my employer's proxy While visiting Webpages/webapps like Gmail or Google brings up the 'This Connection is Untrusted' page and I have to go through the whole tedious task of selecting 'I understand the Risks' and add Exceptions, etc. etc. The fact is, I don't care about the risks. I would rather this computer melt into the ground than have to see that page ever again. I want to dance naked in untrusted pages and not give a damn about the consequences. I just never want to see that page again. Ever. For some sites (eg. wikipedia), the css doesn't load and I end up seeing them in plain text. As a result these sites are completely useless. Wasted hours trying to solve this for stackoverflow.com. These issues happen on the Firefox on my Windows XP machine as well (also using the same proxy). I don't want to export/import certificates or create exceptions for every site that shows this bloody page. I just want this page gone. I don't want Firefox to tell me what's safe and what's not. Also, my system time and date are correct. I've also tried the lies on this page too with no good results. Edit: I've also tried the whole going into the Advance-Certificates-validation setup page and unchecked 'Use the Online Certificate Status Protocol (OCSP) to confirm the current validity of certificates' checkbox. Nothing happened even after restarting firefox or rebooting. I need help. Thanks.

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  • Throwing a new exception while throwing an old exception

    - by FredOverflow
    If a destructor throws in C++ during stack unwinding caused by an exception, the program terminates. (That's why destructors should never throw in C++.) If a finally block is entered in Java because of an exception in the corresponding try block and that finally block throws another exception, the first exception is silently swallowed. This question crossed my mind: Could a programming language handle multiple exceptions being thrown at the same time? Would that be useful? Have you ever missed that ability? Is there a language that already supports this? Is there any experience with such an approach? Any thoughts?

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  • How to get default Ctrl+Tab functionality in WinForms MDI app when hosting WPF UserControls

    - by jpierson
    I have a WinForms based app with traditional MDI implementation within it except that I'm hosting WPF based UserControls via the ElementHost control as the main content for each of my MDI children. This is the solution recommended by Microsoft for achieving MDI with WPF although there are various side effects unfortunately. One of which is that my Ctrl+Tab functionality for tab switching between each MDI child is gone because the tab key seems to be swallowed up by the WPF controls. Is there a simple solution to this that will let the Ctrl+tab key sequences reach my WinForms MDI parent so that I can get the built-in tab switching functionality?

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  • Throwing an exception while handling an exception

    - by FredOverflow
    If a destructor throws in C++ during stack unwinding caused by an exception, the program terminates. (That's why destructors should never throw in C++.) If a finally block is entered in Java because of an exception in the corresponding try block and that finally block throws another exception, the first exception is silently swallowed. This question crossed my mind: Could a programming language handle multiple exceptions being thrown at the same time? Would that be useful? Have you ever missed that ability? Is there a language that already supports this? Is there any experience with such an approach? Any thoughts?

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  • SetSel on EN_SETFOCUS or WM_SETFOCUS doesn't work

    - by Coder
    I've ran into next mystic thing in Winapi/MFC, I have an edit box, contents of which I have to select on Tab, Lclick, Rclick, Mclick and so on. The sort of obvious path is to handle the SETFOCUS message and call SetSel(0, -1), which should select all text. But it doesn't work! What's wrong? I tried googling, everyone seems to override Lclilks or handle SetSel in parent windows, but this is wrong from encapsulation point of view, also multiple clicks (user wants to insert something in the middle of the text) will break, and so on. Why isn't my approach working, I tried like 10 different ways, tried to trap all possible focus messages, looked up info on MSDN, but nothing works as expected. Also, I need to recreate the carret on focus, which also doesn't seem to work. SETFOCUS message gets trapped alright. If I add __asm int 3, it breaks every time. It's the create carret and setsel that gets swallowed it seems.

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  • PostSharp OnExceptionAspect not working as expected

    - by Rune Sundling
    Created a simple class to test out the OnExceptionAspect in PostSharp. [Serializable] [AttributeUsage(AttributeTargets.Method | AttributeTargets.Class)] public class ExceptionSwallower : OnExceptionAspect { public override void OnException(MethodExecutionEventArgs eventArgs) { eventArgs.FlowBehavior = FlowBehavior.Return; base.OnException(eventArgs); } } Added the attribute to a method [ExceptionSwallower] public void SomeMethod() { throw new Exception(); } and invoked it. However, the exception is not actually swallowed, which seems odd. I haven't been able to find any similar problems, so I expect there is some minor thing I haven't gotten right. Anyone?

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  • Regex to split a string (in Java) so that spaces are preserved?

    - by david
    I need to split a string (in Java) into individual words ... but I need to preserve spaces. An example of the text I need to split is something like this: ABC . . . . DEF . . . . GHI I need to see "ABC", " . . . .", "DEF", ". . . .", and "GHI". Obviously splitting on the space character \s isn't going to work, as all the spaces get swallowed up as one space. Any suggestions? Thanks

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  • The Stub Proto: Not Just For Stub Objects Anymore

    - by user9154181
    One of the great pleasures of programming is to invent something for a narrow purpose, and then to realize that it is a general solution to a broader problem. In hindsight, these things seem perfectly natural and obvious. The stub proto area used to build the core Solaris consolidation has turned out to be one of those things. As discussed in an earlier article, the stub proto area was invented as part of the effort to use stub objects to build the core ON consolidation. Its purpose was merely as a place to hold stub objects. However, we keep finding other uses for it. It turns out that the stub proto should be more properly thought of as an auxiliary place to put things that we would like to put into the proto to help us build the product, but which we do not wish to package or deliver to the end user. Stub objects are one example, but private lint libraries, header files, archives, and relocatable objects, are all examples of things that might profitably go into the stub proto. Without a stub proto, these items were handled in a variety of ad hoc ways: If one part of the workspace needed private header files, libraries, or other such items, it might modify its Makefile to reach up and over to the place in the workspace where those things live and use them from there. There are several problems with this: Each component invents its own approach, meaning that programmers maintaining the system have to invest extra effort to understand what things mean. In the past, this has created makefile ghettos in which only the person who wrote the makefiles feels confident to modify them, while everyone else ignores them. This causes many difficulties and benefits no one. These interdependencies are not obvious to the make, utility, and can lead to races. They are not obvious to the human reader, who may therefore not realize that they exist, and break them. Our policy in ON is not to deliver files into the proto unless those files are intended to be packaged and delivered to the end user. However, sometimes non-shipping files were copied into the proto anyway, causing a different set of problems: It requires a long list of exceptions to silence our normal unused proto item error checking. In the past, we have accidentally shipped files that we did not intend to deliver to the end user. Mixing cruft with valuable items makes it hard to discern which is which. The stub proto area offers a convenient and robust solution. Files needed to build the workspace that are not delivered to the end user can instead be installed into the stub proto. No special exceptions or custom make rules are needed, and the intent is always clear. We are already accessing some private lint libraries and compilation symlinks in this manner. Ultimately, I'd like to see all of the files in the proto that have a packaging exception delivered to the stub proto instead, and for the elimination of all existing special case makefile rules. This would include shared objects, header files, and lint libraries. I don't expect this to happen overnight — it will be a long term case by case project, but the overall trend is clear. The Stub Proto, -z assert_deflib, And The End Of Accidental System Object Linking We recently used the stub proto to solve an annoying build issue that goes back to the earliest days of Solaris: How to ensure that we're linking to the OS bits we're building instead of to those from the running system. The Solaris product is made up of objects and files from a number of different consolidations, each of which is built separately from the others from an independent code base called a gate. The core Solaris OS consolidation is ON, which stands for "Operating System and Networking". You will frequently also see ON called the OSnet. There are consolidations for X11 graphics, the desktop environment, open source utilities, compilers and development tools, and many others. The collection of consolidations that make up Solaris is known as the "Wad Of Stuff", usually referred to simply as the WOS. None of these consolidations is self contained. Even the core ON consolidation has some dependencies on libraries that come from other consolidations. The build server used to build the OSnet must be running a relatively recent version of Solaris, which means that its objects will be very similar to the new ones being built. However, it is necessarily true that the build system objects will always be a little behind, and that incompatible differences may exist. The objects built by the OSnet link to other objects. Some of these dependencies come from the OSnet, while others come from other consolidations. The objects from other consolidations are provided by the standard library directories on the build system (/lib, /usr/lib). The objects from the OSnet itself are supposed to come from the proto areas in the workspace, and not from the build server. In order to achieve this, we make use of the -L command line option to the link-editor. The link-editor finds dependencies by looking in the directories specified by the caller using the -L command line option. If the desired dependency is not found in one of these locations, ld will then fall back to looking at the default locations (/lib, /usr/lib). In order to use OSnet objects from the workspace instead of the system, while still accessing non-OSnet objects from the system, our Makefiles set -L link-editor options that point at the workspace proto areas. In general, this works well and dependencies are found in the right places. However, there have always been failures: Building objects in the wrong order might mean that an OSnet dependency hasn't been built before an object that needs it. If so, the dependency will not be seen in the proto, and the link-editor will silently fall back to the one on the build server. Errors in the makefiles can wipe out the -L options that our top level makefiles establish to cause ld to look at the workspace proto first. In this case, all objects will be found on the build server. These failures were rarely if ever caught. As I mentioned earlier, the objects on the build server are generally quite close to the objects built in the workspace. If they offer compatible linking interfaces, then the objects that link to them will behave properly, and no issue will ever be seen. However, if they do not offer compatible linking interfaces, the failure modes can be puzzling and hard to pin down. Either way, there won't be a compile-time warning or error. The advent of the stub proto eliminated the first type of failure. With stub objects, there is no dependency ordering, and the necessary stub object dependency will always be in place for any OSnet object that needs it. However, makefile errors do still occur, and so, the second form of error was still possible. While working on the stub object project, we realized that the stub proto was also the key to solving the second form of failure caused by makefile errors: Due to the way we set the -L options to point at our workspace proto areas, any valid object from the OSnet should be found via a path specified by -L, and not from the default locations (/lib, /usr/lib). Any OSnet object found via the default locations means that we've linked to the build server, which is an error we'd like to catch. Non-OSnet objects don't exist in the proto areas, and so are found via the default paths. However, if we were to create a symlink in the stub proto pointing at each non-OSnet dependency that we require, then the non-OSnet objects would also be found via the paths specified by -L, and not from the link-editor defaults. Given the above, we should not find any dependency objects from the link-editor defaults. Any dependency found via the link-editor defaults means that we have a Makefile error, and that we are linking to the build server inappropriately. All we need to make use of this fact is a linker option to produce a warning when it happens. Although warnings are nice, we in the OSnet have a zero tolerance policy for build noise. The -z fatal-warnings option that was recently introduced with -z guidance can be used to turn the warnings into fatal build errors, forcing the programmer to fix them. This was too easy to resist. I integrated 7021198 ld option to warn when link accesses a library via default path PSARC/2011/068 ld -z assert-deflib option into snv_161 (February 2011), shortly after the stub proto was introduced into ON. This putback introduced the -z assert-deflib option to the link-editor: -z assert-deflib=[libname] Enables warning messages for libraries specified with the -l command line option that are found by examining the default search paths provided by the link-editor. If a libname value is provided, the default library warning feature is enabled, and the specified library is added to a list of libraries for which no warnings will be issued. Multiple -z assert-deflib options can be specified in order to specify multiple libraries for which warnings should not be issued. The libname value should be the name of the library file, as found by the link-editor, without any path components. For example, the following enables default library warnings, and excludes the standard C library. ld ... -z assert-deflib=libc.so ... -z assert-deflib is a specialized option, primarily of interest in build environments where multiple objects with the same name exist and tight control over the library used is required. If is not intended for general use. Note that the definition of -z assert-deflib allows for exceptions to be specified as arguments to the option. In general, the idea of using a symlink from the stub proto is superior because it does not clutter up the link command with a long list of objects. When building the OSnet, we usually use the plain from of -z deflib, and make symlinks for the non-OSnet dependencies. The exception to this are dependencies supplied by the compiler itself, which are usually found at whatever arbitrary location the compiler happens to be installed at. To handle these special cases, the command line version works better. Following the integration of the link-editor change, I made use of -z assert-deflib in OSnet builds with 7021896 Prevent OSnet from accidentally linking to build system which integrated into snv_162 (March 2011). Turning on -z assert-deflib exposed between 10 and 20 existing errors in our Makefiles, which were all fixed in the same putback. The errors we found in our Makefiles underscore how difficult they can be prevent without an automatic system in place to catch them. Conclusions The stub proto is proving to be a generally useful construct for ON builds that goes beyond serving as a place to hold stub objects. Although invented to hold stub objects, it has already allowed us to simplify a number of previously difficult situations in our makefiles and builds. I expect that we'll find uses for it beyond those described here as we go forward.

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  • JSF: Cannot catch ViewExpiredException

    - by ifischer
    I'm developing a JSF 2.0 application on Glassfish v3 and i'm trying to handle the ViewExpiredException. But whatever i do, i always get a Glassfish error report instead of my own error page. To simulate the occurrence of the VEE, i inserted the following function into my backing bean, which fires the VEE. I'm triggering this function from my JSF page through a commandLink. The Code: @Named public class PersonHome { (...) public void throwVEE() { throw new ViewExpiredException(); } } At first i tried it by simply adding an error-page to my web.xml: <error-page> <exception-type>javax.faces.application.ViewExpiredException</exception-type> <location>/error.xhtml</location> </error-page> But this doesn't work, i'm not redirected to error but i'm shown the Glassfish errorpage, which shows a HTTP Status 500 page with the following content: description:The server encountered an internal error () that prevented it from fulfilling this request. exception: javax.servlet.ServletException: javax.faces.application.ViewExpiredException root cause: javax.faces.el.EvaluationException:javax.faces.application.ViewExpiredException root cause:javax.faces.application.ViewExpiredException Next thing i tried was to write ExceptionHandlerFactory and a CustomExceptionHandler, as described in JavaServerFaces 2.0 - The Complete Reference. So i inserted the following tag into faces-config.xml: <factory> <exception-handler-factory> exceptions.ExceptionHandlerFactory </exception-handler-factory> </factory> And added these classes: The factory: package exceptions; import javax.faces.context.ExceptionHandler; public class ExceptionHandlerFactory extends javax.faces.context.ExceptionHandlerFactory { private javax.faces.context.ExceptionHandlerFactory parent; public ExceptionHandlerFactory(javax.faces.context.ExceptionHandlerFactory parent) { this.parent = parent; } @Override public ExceptionHandler getExceptionHandler() { ExceptionHandler result = parent.getExceptionHandler(); result = new CustomExceptionHandler(result); return result; } } The custom exception handler: package exceptions; import java.util.Iterator; import javax.faces.FacesException; import javax.faces.application.NavigationHandler; import javax.faces.application.ViewExpiredException; import javax.faces.context.ExceptionHandler; import javax.faces.context.ExceptionHandlerWrapper; import javax.faces.context.FacesContext; import javax.faces.event.ExceptionQueuedEvent; import javax.faces.event.ExceptionQueuedEventContext; class CustomExceptionHandler extends ExceptionHandlerWrapper { private ExceptionHandler parent; public CustomExceptionHandler(ExceptionHandler parent) { this.parent = parent; } @Override public ExceptionHandler getWrapped() { return this.parent; } @Override public void handle() throws FacesException { for (Iterator<ExceptionQueuedEvent> i = getUnhandledExceptionQueuedEvents().iterator(); i.hasNext();) { ExceptionQueuedEvent event = i.next(); System.out.println("Iterating over ExceptionQueuedEvents. Current:" + event.toString()); ExceptionQueuedEventContext context = (ExceptionQueuedEventContext) event.getSource(); Throwable t = context.getException(); if (t instanceof ViewExpiredException) { ViewExpiredException vee = (ViewExpiredException) t; FacesContext fc = FacesContext.getCurrentInstance(); NavigationHandler nav = fc.getApplication().getNavigationHandler(); try { // Push some useful stuff to the flash scope for // use in the page fc.getExternalContext().getFlash().put("expiredViewId", vee.getViewId()); nav.handleNavigation(fc, null, "/login?faces-redirect=true"); fc.renderResponse(); } finally { i.remove(); } } } // At this point, the queue will not contain any ViewExpiredEvents. // Therefore, let the parent handle them. getWrapped().handle(); } } But STILL i'm NOT redirected to my error page - i'm getting the same HTTP 500 error like above. What am i doing wrong, what could be missing in my implementation so that the exception is handled correctly?

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  • Dynamically sized UIWebView in a UITableViewCell with auto layout - constraint violation

    - by Orion Edwards
    I've got a UITableViewCell which contains a UIWebView. The table view cell adjusts it's height depending on the web view contents. I've got it all working fine, however when the view loads, I get a constraint violation exception in the debugger (the app continues running and functionally works fine, but I'd like to resolve this exception if possible). How I've got it set up: The TableView sets the cell height like this: -(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath { if(indexPath.section == 0) { [_topCell layoutIfNeeded]; CGFloat finalHeight = [_topCell.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize].height; return finalHeight + 1; } The cell constraints are as follows: Arbitrary 7px offset from the cell's contentView (top) to the webView Web view has arbitrary fixed height constraint of 62px (will expand later once content loads) Arbitrary 8px offset from the webView to the cell's contentView (bottom) in my viewDidLoad, I tell the webView to go and load a URL, and in the webViewDidFinishLoad, I update the web view height constraint, like this -(void)webViewDidFinishLoad:(UIWebView *)webView { CGSize fittingSize = [webView sizeThatFits:CGSizeZero]; // fittingSize is approx 500 [self.tableView beginUpdates]; // Exceptions happen on the following line setting the constant _topCell.webViewHeightConstraint.constant = fittingSize.height; [_topCell layoutSubviews]; [self.tableView endUpdates]; } The exception looks like this: Unable to simultaneously satisfy constraints. Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) ( "<NSLayoutConstraint:0x10964b250 V:[webView(62)] (Names: webView:0x109664a00 )>", "<NSLayoutConstraint:0x109243d30 V:|-(7)-[webView] (Names: webView:0x109664a00, cellContent:0x1092436f0, '|':cellContent:0x1092436f0 )>", "<NSLayoutConstraint:0x109243f80 V:[webView]-(8)-| (Names: cellContent:0x1092436f0, webView:0x109664a00, '|':cellContent:0x1092436f0 )>", "<NSAutoresizingMaskLayoutConstraint:0x10967c210 h=--& v=--& V:[cellContent(78)] (Names: cellContent:0x1092436f0 )>" ) Will attempt to recover by breaking constraint <NSLayoutConstraint:0x10964b250 V:[webView(62)] (Names: webView:0x109664a00 )> This seems a bit weird. It's implied that the constraint which sets the height of the web view is going to be broken, however the web view does get it's height correctly set, and the tableview renders perfectly well. From my guesses, it looks like the newly increased web view height constraint (it's about 500px after the web view loads) is going to conflict with the <NSAutoresizingMaskLayoutConstraint:0x10967c210 h=--& v=--& V:[cellContent(78)] setting the cell height to 78 (put there by interface builder). This makes sense, however I don't want that cell content to have a fixed height of 78px, I want it to increase it's height, and functionally, it actually does this, just with these exceptions. I've tried setting _topCell.contentView.translatesAutoresizingMaskIntoConstraints = NO; to attempt to remove the NSAutoresizingMaskLayoutConstraint - this stops the exceptions, but then all the other layout is screwed up and the web view is about 10px high in the middle of the table view for no reason. I've also tried setting _topCell.contentView.autoresizingMask |= UIViewAutoresizingFlexibleHeight; in the viewDidLoad to hopefully affect the contentView 78px height constraint, but this has no effect Any help would be much appreciated

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  • Isn't it better to use a single try catch instead of tons of TryParsing and other error handling sometimes?

    - by Ryan Peschel
    I know people say it's bad to use exceptions for flow control and to only use exceptions for exceptional situations, but sometimes isn't it just cleaner and more elegant to wrap the entire block in a try-catch? For example, let's say I have a dialog window with a TextBox where the user can type input in to be parsed in a key-value sort of manner. This situation is not as contrived as you might think because I've inherited code that has to handle this exact situation (albeit not with farm animals). Consider this wall of code: class Animals { public int catA, catB; public float dogA, dogB; public int mouseA, mouseB, mouseC; public double cow; } class Program { static void Main(string[] args) { string input = "Sets all the farm animals CAT 3 5 DOG 21.3 5.23 MOUSE 1 0 1 COW 12.25"; string[] splitInput = input.Split(' '); string[] animals = { "CAT", "DOG", "MOUSE", "COW", "CHICKEN", "GOOSE", "HEN", "BUNNY" }; Animals animal = new Animals(); for (int i = 0; i < splitInput.Length; i++) { string token = splitInput[i]; if (animals.Contains(token)) { switch (token) { case "CAT": animal.catA = int.Parse(splitInput[i + 1]); animal.catB = int.Parse(splitInput[i + 2]); break; case "DOG": animal.dogA = float.Parse(splitInput[i + 1]); animal.dogB = float.Parse(splitInput[i + 2]); break; case "MOUSE": animal.mouseA = int.Parse(splitInput[i + 1]); animal.mouseB = int.Parse(splitInput[i + 2]); animal.mouseC = int.Parse(splitInput[i + 3]); break; case "COW": animal.cow = double.Parse(splitInput[i + 1]); break; } } } } } In actuality there are a lot more farm animals and more handling than that. A lot of things can go wrong though. The user could enter in the wrong number of parameters. The user can enter the input in an incorrect format. The user could specify numbers too large or too small for the data type to handle. All these different errors could be handled without exceptions through the use of TryParse, checking how many parameters the user tried to use for a specific animal, checking if the parameter is too large or too small for the data type (because TryParse just returns 0), but every one should result in the same thing: A MessageBox appearing telling the user that the inputted data is invalid and to fix it. My boss doesn't want different message boxes for different errors. So instead of doing all that, why not just wrap the block in a try-catch and in the catch statement just display that error message box and let the user try again? Maybe this isn't the best example but think of any other scenario where there would otherwise be tons of error handling that could be substituted for a single try-catch. Is that not the better solution?

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  • Parallelism in .NET – Part 19, TaskContinuationOptions

    - by Reed
    My introduction to Task continuations demonstrates continuations on the Task class.  In addition, I’ve shown how continuations allow handling of multiple tasks in a clean, concise manner.  Continuations can also be used to handle exceptional situations using a clean, simple syntax. In addition to standard Task continuations , the Task class provides some options for filtering continuations automatically.  This is handled via the TaskContinationOptions enumeration, which provides hints to the TaskScheduler that it should only continue based on the operation of the antecedent task. This is especially useful when dealing with exceptions.  For example, we can extend the sample from our earlier continuation discussion to include support for handling exceptions thrown by the Factorize method: // Get a copy of the UI-thread task scheduler up front to use later var uiScheduler = TaskScheduler.FromCurrentSynchronizationContext(); // Start our task var factorize = Task.Factory.StartNew( () => { int primeFactor1 = 0; int primeFactor2 = 0; bool result = Factorize(10298312, ref primeFactor1, ref primeFactor2); return new { Result = result, Factor1 = primeFactor1, Factor2 = primeFactor2 }; }); // When we succeed, report the results to the UI factorize.ContinueWith(task => textBox1.Text = string.Format("{0}/{1} [Succeeded {2}]", task.Result.Factor1, task.Result.Factor2, task.Result.Result), CancellationToken.None, TaskContinuationOptions.NotOnFaulted, uiScheduler); // When we have an exception, report it factorize.ContinueWith(task => textBox1.Text = string.Format("Error: {0}", task.Exception.Message), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, uiScheduler); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The above code works by using a combination of features.  First, we schedule our task, the same way as in the previous example.  However, in this case, we use a different overload of Task.ContinueWith which allows us to specify both a specific TaskScheduler (in order to have your continuation run on the UI’s synchronization context) as well as a TaskContinuationOption.  In the first continuation, we tell the continuation that we only want it to run when there was not an exception by specifying TaskContinuationOptions.NotOnFaulted.  When our factorize task completes successfully, this continuation will automatically run on the UI thread, and provide the appropriate feedback. However, if the factorize task has an exception – for example, if the Factorize method throws an exception due to an improper input value, the second continuation will run.  This occurs due to the specification of TaskContinuationOptions.OnlyOnFaulted in the options.  In this case, we’ll report the error received to the user. We can use TaskContinuationOptions to filter our continuations by whether or not an exception occurred and whether or not a task was cancelled.  This allows us to handle many situations, and is especially useful when trying to maintain a valid application state without ever blocking the user interface.  The same concepts can be extended even further, and allow you to chain together many tasks based on the success of the previous ones.  Continuations can even be used to create a state machine with full error handling, all without blocking the user interface thread.

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  • Error Handling Examples(C#)

    “The purpose of reviewing the Error Handling code is to assure that the application fails safely under all possible error conditions, expected and unexpected. No sensitive information is presented to the user when an error occurs.” (OWASP, 2011) No Error Handling The absence of error handling is still a form of error handling. Based on the code in Figure 1, if an error occurred and was not handled within either the ReadXml or BuildRequest methods the error would bubble up to the Search method. Since this method does not handle any acceptations the error will then bubble up the stack trace. If this continues and the error is not handled within the application then the environment in which the application is running will notify the user running the application that an error occurred based on what type of application. Figure 1: No Error Handling public DataSet Search(string searchTerm, int resultCount) { DataSet dt = new DataSet(); dt.ReadXml(BuildRequest(searchTerm, resultCount)); return dt; } Generic Error Handling One simple way to add error handling is to catch all errors by default. If you examine the code in Figure 2, you will see a try-catch block. On April 6th 2010 Louis Lazaris clearly describes a Try Catch statement by defining both the Try and Catch aspects of the statement. “The try portion is where you would put any code that might throw an error. In other words, all significant code should go in the try section. The catch section will also hold code, but that section is not vital to the running of the application. So, if you removed the try-catch statement altogether, the section of code inside the try part would still be the same, but all the code inside the catch would be removed.” (Lazaris, 2010) He also states that all errors that occur in the try section cause it to stops the execution of the try section and redirects all execution to the catch section. The catch section receives an object containing information about the error that occurred so that they system can gracefully handle the error properly. When errors occur they commonly log them in some form. This form could be an email, database entry, web service call, log file, or just an error massage displayed to the user.  Depending on the error sometimes applications can recover, while others force an application to close. Figure 2: Generic Error Handling public DataSet Search(string searchTerm, int resultCount) { DataSet dt = new DataSet(); try { dt.ReadXml(BuildRequest(searchTerm, resultCount)); } catch (Exception ex) { // Handle all Exceptions } return dt; } Error Specific Error Handling Like the Generic Error Handling, Error Specific error handling allows for the catching of specific known errors that may occur. For example wrapping a try catch statement around a soap web service call would allow the application to handle any error that was generated by the soap web service. Now, if the systems wanted to send a message to the web service provider every time a soap error occurred but did not want to notify them if any other type of error occurred like a network time out issue. This would be varying tedious to accomplish using the General Error Handling methodology. This brings us to the use case for using the Error Specific error handling methodology.  The Error Specific Error handling methodology allows for the TryCatch statement to catch various types of errors depending on the type of error that occurred. In Figure 3, the code attempts to handle DataException differently compared to how it potentially handles all other errors. This allows for specific error handling for each type of known error, and still allows for error handling of any unknown error that my occur during the execution of the TryCatch statement. Figure 5: Error Specific Error Handling public DataSet Search(string searchTerm, int resultCount) { DataSet dt = new DataSet(); try { dt.ReadXml(BuildRequest(searchTerm, resultCount)); } catch (TimeoutException ex) { // Handle Timeout TimeoutException Only } catch (Exception) { // Handle all Exceptions } return dt; }

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  • career in Mobile sw/Application Development [closed]

    - by pramod
    i m planning to do a course on Wireless & mobile computing.The syllabus are given below.Please check & let me know whether its worth to do.How is the job prospects after that.I m a fresher & from electronic Engg.The modules are- *Wireless and Mobile Computing (WiMC) – Modules* C, C++ Programming and Data Structures 100 Hours C Revision C, C++ programming tools on linux(Vi editor, gdb etc.) OOP concepts Programming constructs Functions Access Specifiers Classes and Objects Overloading Inheritance Polymorphism Templates Data Structures in C++ Arrays, stacks, Queues, Linked Lists( Singly, Doubly, Circular) Trees, Threaded trees, AVL Trees Graphs, Sorting (bubble, Quick, Heap , Merge) System Development Methodology 18 Hours Software life cycle and various life cycle models Project Management Software: A Process Various Phases in s/w Development Risk Analysis and Management Software Quality Assurance Introduction to Coding Standards Software Project Management Testing Strategies and Tactics Project Management and Introduction to Risk Management Java Programming 110 Hours Data Types, Operators and Language Constructs Classes and Objects, Inner Classes and Inheritance Inheritance Interface and Package Exceptions Threads Java.lang Java.util Java.awt Java.io Java.applet Java.swing XML, XSL, DTD Java n/w programming Introduction to servlet Mobile and Wireless Technologies 30 Hours Basics of Wireless Technologies Cellular Communication: Single cell systems, multi-cell systems, frequency reuse, analog cellular systems, digital cellular systems GSM standard: Mobile Station, BTS, BSC, MSC, SMS sever, call processing and protocols CDMA standard: spread spectrum technologies, 2.5G and 3G Systems: HSCSD, GPRS, W-CDMA/UMTS,3GPP and international roaming, Multimedia services CDMA based cellular mobile communication systems Wireless Personal Area Networks: Bluetooth, IEEE 802.11a/b/g standards Mobile Handset Device Interfacing: Data Cables, IrDA, Bluetooth, Touch- Screen Interfacing Wireless Security, Telemetry Java Wireless Programming and Applications Development(J2ME) 100 Hours J2ME Architecture The CLDC and the KVM Tools and Development Process Classification of CLDC Target Devices CLDC Collections API CLDC Streams Model MIDlets MIDlet Lifecycle MIDP Programming MIDP Event Architecture High-Level Event Handling Low-Level Event Handling The CLDC Streams Model The CLDC Networking Package The MIDP Implementation Introduction to WAP, WML Script and XHTML Introduction to Multimedia Messaging Services (MMS) Symbian Programming 60 Hours Symbian OS basics Symbian OS services Symbian OS organization GUI approaches ROM building Debugging Hardware abstraction Base porting Symbian OS reference design porting File systems Overview of Symbian OS Development – DevKits, CustKits and SDKs CodeWarrior Tool Application & UI Development Client Server Framework ECOM STDLIB in Symbian iPhone Programming 80 Hours Introducing iPhone core specifications Understanding iPhone input and output Designing web pages for the iPhone Capturing iPhone events Introducing the webkit CSS transforms transitions and animations Using iUI for web apps Using Canvas for web apps Building web apps with Dashcode Writing Dashcode programs Debugging iPhone web pages SDK programming for web developers An introduction to object-oriented programming Introducing the iPhone OS Using Xcode and Interface builder Programming with the SDK Toolkit OS Concepts & Linux Programming 60 Hours Operating System Concepts What is an OS? Processes Scheduling & Synchronization Memory management Virtual Memory and Paging Linux Architecture Programming in Linux Linux Shell Programming Writing Device Drivers Configuring and Building GNU Cross-tool chain Configuring and Compiling Linux Virtual File System Porting Linux on Target Hardware WinCE.NET and Database Technology 80 Hours Execution Process in .NET Environment Language Interoperability Assemblies Need of C# Operators Namespaces & Assemblies Arrays Preprocessors Delegates and Events Boxing and Unboxing Regular Expression Collections Multithreading Programming Memory Management Exceptions Handling Win Forms Working with database ASP .NET Server Controls and client-side scripts ASP .NET Web Server Controls Validation Controls Principles of database management Need of RDBMS etc Client/Server Computing RDBMS Technologies Codd’s Rules Data Models Normalization Techniques ER Diagrams Data Flow Diagrams Database recovery & backup SQL Android Application 80 Hours Introduction of android Why develop for android Android SDK features Creating android activities Fundamental android UI design Intents, adapters, dialogs Android Technique for saving data Data base in Androids Maps, Geocoding, Location based services Toast, using alarms, Instant messaging Using blue tooth Using Telephony Introducing sensor manager Managing network and wi-fi connection Advanced androids development Linux kernel security Implement AIDL Interface. Project 120 Hours

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  • How to Open Any Folder as a Project in the NetBeans Platform

    - by Geertjan
    Typically, as described in the NetBeans Project Type Tutorial, you'll define a project type based on the presence of a file (e.g., "project.xml" or "customer.txt" or something like that) in a folder. I.e., if the file is there, then its parent, i.e., the folder that contains the file, is a project and should be opened in your application. However, in some scenarios (as with the HTML5 project type introduced in NetBeans IDE 7.3), the user should be able to open absolutely any folder at all into the application. How to create a project type that is that liberal? Here you go, the only condition that needs to be true is that the selected item in the "Open Project" dialog is a folder, as defined in the "isProject" method below. Nothing else. That's it. If you select a folder, it will be opened in your application, displaying absolutely everything as-is (since below there's no ProjectLogicalView defined): import java.beans.PropertyChangeListener; import java.io.IOException; import javax.swing.Icon; import org.netbeans.api.project.Project; import org.netbeans.api.project.ProjectInformation; import org.netbeans.spi.project.ProjectFactory; import org.netbeans.spi.project.ProjectState; import org.openide.filesystems.FileObject; import org.openide.loaders.DataFolder; import org.openide.loaders.DataObjectNotFoundException; import org.openide.nodes.FilterNode; import org.openide.util.Exceptions; import org.openide.util.ImageUtilities; import org.openide.util.Lookup; import org.openide.util.lookup.Lookups; import org.openide.util.lookup.ServiceProvider; @ServiceProvider(service = ProjectFactory.class) public class FolderProjectFactory implements ProjectFactory { @Override public boolean isProject(FileObject projectDirectory) { return DataFolder.findFolder(projectDirectory) != null; } @Override public Project loadProject(FileObject dir, ProjectState state) throws IOException { return isProject(dir) ? new FolderProject(dir) : null; } @Override public void saveProject(Project prjct) throws IOException, ClassCastException { // leave unimplemented for the moment } private class FolderProject implements Project { private final FileObject projectDir; private Lookup lkp; private FolderProject(FileObject dir) { this.projectDir = dir; } @Override public FileObject getProjectDirectory() { return projectDir; } @Override public Lookup getLookup() { if (lkp == null) { lkp = Lookups.fixed(new Object[]{ new Info(), }); } return lkp; } private final class Info implements ProjectInformation { @Override public Icon getIcon() { Icon icon = null; try { icon = ImageUtilities.image2Icon( new FilterNode(DataFolder.find( getProjectDirectory()).getNodeDelegate()).getIcon(1)); } catch (DataObjectNotFoundException ex) { Exceptions.printStackTrace(ex); } return icon; } @Override public String getName() { return getProjectDirectory().getName(); } @Override public String getDisplayName() { return getName(); } @Override public void addPropertyChangeListener(PropertyChangeListener pcl) { //do nothing, won't change } @Override public void removePropertyChangeListener(PropertyChangeListener pcl) { //do nothing, won't change } @Override public Project getProject() { return FolderProject.this; } } } } Even the ProjectInformation implementation really isn't needed at all, since it provides nothing more than the icon in the "Open Project" dialog, the rest (i.e., the display name in the "Open Project" dialog) is provided by default regardless of whether you have a ProjectInformation implementation or not.

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  • Oracle GoldenGate Active-Active Part 1

    - by Nick_W
    My name is Nick Wagner, and I'm a recent addition to the Oracle Maximum Availability Architecture (MAA) product management team.  I've spent the last 15+ years working on database replication products, and I've spent the last 10 years working on the Oracle GoldenGate product.  So most of my posting will probably be focused on OGG.  One question that comes up all the time is around active-active replication with Oracle GoldenGate.  How do I know if my application is a good fit for active-active replication with GoldenGate?   To answer that, it really comes down to how you plan on handling conflict resolution.  I will delve into topology and deployment in a later blog, but here is a simple architecture: The two most common resolution routines are host based resolution and timestamp based resolution. Host based resolution is used less often, but works with the fewest application changes.  Think of it like this: any transactions from SystemA always take precedence over any transactions from SystemB.  If there is a conflict on SystemB, then the record from SystemA will overwrite it.  If there is a conflict on SystemA, then it will be ignored.  It is quite a bit less restrictive, and in most cases, as long as all the tables have primary keys, host based resolution will work just fine.  Timestamp based resolution, on the other hand, is a little trickier. In this case, you can decide which record is overwritten based on timestamps. For example, does the older record get overwritten with the newer record?  Or vice-versa?  This method not only requires primary keys on every table, but it also requires every table to have a timestamp/date column that is updated each time a record is inserted or updated on the table.  Most homegrown applications can always be customized to include these requirements, but it's a little more difficult with 3rd party applications, and might even be impossible for large ERP type applications.  If your database has these features - whether it’s primary keys for host based resolution, or primary keys and timestamp columns for timestamp based resolution - then your application could be a great candidate for active-active replication.  But table structure is not the only requirement.  The other consideration applies when there is a conflict; i.e., do I need to perform any notification or track down the user that had their data overwritten?  In most cases, I don't think it's necessary, but if it is required, OGG can always create an exceptions table that contains all of the overwritten transactions so that people can be notified. It's a bit of extra work to implement this type of option, but if the business requires it, then it can be done. Unless someone is constantly monitoring this exception table or has an automated process in dealing with exceptions, there will be a delay in getting a response back to the end user. Ideally, when setting up active-active resolution we can include some simple procedural steps or configuration options that can reduce, or in some cases eliminate the potential for conflicts.  This makes the whole implementation that much easier and foolproof.  And I'll cover these in my next blog. 

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  • Activation Error while testing Exception Handling Application Block

    - by CletusLoomis
    I'm getting the following error while testing my EHAB implementation: {"Activation error occured while trying to get instance of type ExceptionPolicyImpl, key "LogPolicy""} System.Exception Stack Trace: StackTrace " at Microsoft.Practices.ServiceLocation.ServiceLocatorImplBase.GetInstance(Type serviceType, String key) in c:\Home\Chris\Projects\CommonServiceLocator\main\Microsoft.Practices.ServiceLocation\ServiceLocatorImplBase.cs:line 53 at Microsoft.Practices.ServiceLocation.ServiceLocatorImplBase.GetInstance[TService](String key) in c:\Home\Chris\Projects\CommonServiceLocator\main\Microsoft.Practices.ServiceLocation\ServiceLocatorImplBase.cs:line 103 at Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicy.GetExceptionPolicy(Exception exception, String policyName) in e:\Builds\EntLib\Latest\Source\Blocks\ExceptionHandling\Src\ExceptionHandling\ExceptionPolicy.cs:line 131 at Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicy.HandleException(Exception exceptionToHandle, String policyName) in e:\Builds\EntLib\Latest\Source\Blocks\ExceptionHandling\Src\ExceptionHandling\ExceptionPolicy.cs:line 55 at Blackbox.Exception.ExceptionMain.LogException(Exception pException) in C:_Work_Black Box\Blackbox.Exception\ExceptionMain.vb:line 14 at BlackBox.Business.BusinessMain.TestExceptionHandling() in C:_Work_Black Box\BlackBox.Business\BusinessMain.vb:line 16 at Blackbox.Service.Service1.TestExceptionHandling() in C:_Work_Black Box\Blackbox.Service\Service.svc.vb:line 43" String Inner Exception: InnerException {"Resolution of the dependency failed, type = "Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyImpl", name = "LogPolicy". Exception occurred while: Calling constructor Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.FormattedEventLogTraceListener(System.String source, System.String log, System.String machineName, Microsoft.Practices.EnterpriseLibrary.Logging.Formatters.ILogFormatter formatter). Exception is: ArgumentException - Event log names must consist of printable characters and cannot contain \, *, ?, or spaces At the time of the exception, the container was: Resolving Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyImpl,LogPolicy Resolving parameter "policyEntries" of constructor Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyImpl(System.String policyName, System.Collections.Generic.IEnumerable1[[Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyEntry, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]] policyEntries) Resolving Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyEntry,LogPolicy.All Exceptions Resolving parameter "handlers" of constructor Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyEntry(System.Type exceptionType, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.PostHandlingAction postHandlingAction, System.Collections.Generic.IEnumerable1[[Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.IExceptionHandler, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]] handlers, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Instrumentation.IExceptionHandlingInstrumentationProvider instrumentationProvider) Resolving Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Logging.LoggingExceptionHandler,LogPolicy.All Exceptions.Logging Exception Handler (mapped from Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.IExceptionHandler, LogPolicy.All Exceptions.Logging Exception Handler) Resolving parameter "writer" of constructor Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Logging.LoggingExceptionHandler(System.String logCategory, System.Int32 eventId, System.Diagnostics.TraceEventType severity, System.String title, System.Int32 priority, System.Type formatterType, Microsoft.Practices.EnterpriseLibrary.Logging.LogWriter writer) Resolving Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterImpl,LogWriter.default (mapped from Microsoft.Practices.EnterpriseLibrary.Logging.LogWriter, (none)) Resolving parameter "structureHolder" of constructor Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterImpl(Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterStructureHolder structureHolder, Microsoft.Practices.EnterpriseLibrary.Logging.Instrumentation.ILoggingInstrumentationProvider instrumentationProvider, Microsoft.Practices.EnterpriseLibrary.Logging.ILoggingUpdateCoordinator updateCoordinator) Resolving Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterStructureHolder,LogWriterStructureHolder.default (mapped from Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterStructureHolder, (none)) Resolving parameter "traceSources" of constructor Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterStructureHolder(System.Collections.Generic.IEnumerable1[[Microsoft.Practices.EnterpriseLibrary.Logging.Filters.ILogFilter, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]] filters, System.Collections.Generic.IEnumerable1[[System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]] traceSourceNames, System.Collections.Generic.IEnumerable1[[Microsoft.Practices.EnterpriseLibrary.Logging.LogSource, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]] traceSources, Microsoft.Practices.EnterpriseLibrary.Logging.LogSource allEventsTraceSource, Microsoft.Practices.EnterpriseLibrary.Logging.LogSource notProcessedTraceSource, Microsoft.Practices.EnterpriseLibrary.Logging.LogSource errorsTraceSource, System.String defaultCategory, System.Boolean tracingEnabled, System.Boolean logWarningsWhenNoCategoriesMatch, System.Boolean revertImpersonation) Resolving Microsoft.Practices.EnterpriseLibrary.Logging.LogSource,General Resolving parameter "traceListeners" of constructor Microsoft.Practices.EnterpriseLibrary.Logging.LogSource(System.String name, System.Collections.Generic.IEnumerable1[[System.Diagnostics.TraceListener, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]] traceListeners, System.Diagnostics.SourceLevels level, System.Boolean autoFlush, Microsoft.Practices.EnterpriseLibrary.Logging.Instrumentation.ILoggingInstrumentationProvider instrumentationProvider) Resolving Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.ReconfigurableTraceListenerWrapper,Event Log Listener (mapped from System.Diagnostics.TraceListener, Event Log Listener) Resolving parameter "wrappedTraceListener" of constructor Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.ReconfigurableTraceListenerWrapper(System.Diagnostics.TraceListener wrappedTraceListener, Microsoft.Practices.EnterpriseLibrary.Logging.ILoggingUpdateCoordinator coordinator) Resolving Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.FormattedEventLogTraceListener,Event Log Listener?implementation (mapped from System.Diagnostics.TraceListener, Event Log Listener?implementation) Calling constructor Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.FormattedEventLogTraceListener(System.String source, System.String log, System.String machineName, Microsoft.Practices.EnterpriseLibrary.Logging.Formatters.ILogFormatter formatter) "} System.Exception My web.config is as follows: <?xml version="1.0"?> <configuration> <configSections> <section name="loggingConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Logging.Configuration.LoggingSettings, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="true" /> <section name="exceptionHandling" type="Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Configuration.ExceptionHandlingSettings, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="true" /> </configSections> <loggingConfiguration name="" tracingEnabled="true" defaultCategory="General"> <listeners> <add name="Event Log Listener" type="Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.FormattedEventLogTraceListener, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" listenerDataType="Microsoft.Practices.EnterpriseLibrary.Logging.Configuration.FormattedEventLogTraceListenerData, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" source="Enterprise Library Logging" formatter="Text Formatter" log="C:\Blackbox.log" machineName="." traceOutputOptions="LogicalOperationStack, DateTime, Timestamp, Callstack" /> </listeners> <formatters> <add type="Microsoft.Practices.EnterpriseLibrary.Logging.Formatters.TextFormatter, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" template="Timestamp: {timestamp}{newline}&#xA;Message: {message}{newline}&#xA;Category: {category}{newline}&#xA;Priority: {priority}{newline}&#xA;EventId: {eventid}{newline}&#xA;Severity: {severity}{newline}&#xA;Title:{title}{newline}&#xA;Machine: {localMachine}{newline}&#xA;App Domain: {localAppDomain}{newline}&#xA;ProcessId: {localProcessId}{newline}&#xA;Process Name: {localProcessName}{newline}&#xA;Thread Name: {threadName}{newline}&#xA;Win32 ThreadId:{win32ThreadId}{newline}&#xA;Extended Properties: {dictionary({key} - {value}{newline})}" name="Text Formatter" /> </formatters> <categorySources> <add switchValue="All" name="General"> <listeners> <add name="Event Log Listener" /> </listeners> </add> </categorySources> <specialSources> <allEvents switchValue="All" name="All Events" /> <notProcessed switchValue="All" name="Unprocessed Category" /> <errors switchValue="All" name="Logging Errors &amp; Warnings"> <listeners> <add name="Event Log Listener" /> </listeners> </errors> </specialSources> </loggingConfiguration> <exceptionHandling> <exceptionPolicies> <add name="LogPolicy"> <exceptionTypes> <add name="All Exceptions" type="System.Exception, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" postHandlingAction="NotifyRethrow"> <exceptionHandlers> <add name="Logging Exception Handler" type="Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Logging.LoggingExceptionHandler, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" logCategory="General" eventId="100" severity="Error" title="Enterprise Library Exception Handling" formatterType="Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.TextExceptionFormatter, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling" priority="0" /> </exceptionHandlers> </add> </exceptionTypes> </add> <add name="WcfExceptionShielding"> <exceptionTypes> <add name="InvalidOperationException" type="System.InvalidOperationException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" postHandlingAction="ThrowNewException"> <exceptionHandlers> <add type="Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.WCF.FaultContractExceptionHandler, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.WCF, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" exceptionMessageResourceType="" exceptionMessageResourceName="This is the message" exceptionMessage="This is the exception" faultContractType="Blackbox.Service.WCFFault, Blackbox.Service, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Fault Contract Exception Handler"> <mappings> <add source="{Guid}" name="Id" /> <add source="{Message}" name="MessageText" /> </mappings> </add> </exceptionHandlers> </add> </exceptionTypes> </add> </exceptionPolicies> </exceptionHandling> <connectionStrings> <add name="CompassEntities" connectionString="metadata=~\bin\CompassModel.csdl|~\bin\CompassModel.ssdl|~\bin\CompassModel.msl;provider=Devart.Data.Oracle;provider connection string=&quot;User Id=foo;Password=foo;Server=foo64mo;Home=OraClient11g_home1;Persist Security Info=True&quot;" providerName="System.Data.EntityClient" /> <add name="BlackboxEntities" connectionString="metadata=~\bin\BlackboxModel.csdl|~\bin\BlackboxModel.ssdl|~\bin\BlackboxModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=sqldev1\cps;Initial Catalog=FundServ;Integrated Security=True;MultipleActiveResultSets=True&quot;" providerName="System.Data.EntityClient" /> </connectionStrings> <system.web> <compilation debug="true" strict="false" explicit="true" targetFramework="4.0" /> </system.web> <system.serviceModel> <behaviors> <serviceBehaviors> <behavior> <!-- To avoid disclosing metadata information, set the value below to false and remove the metadata endpoint above before deployment --> <serviceMetadata httpGetEnabled="true"/> <!-- To receive exception details in faults for debugging purposes, set the value below to true. Set to false before deployment to avoid disclosing exception information --> <serviceDebug includeExceptionDetailInFaults="false"/> </behavior> </serviceBehaviors> </behaviors> <serviceHostingEnvironment multipleSiteBindingsEnabled="true" /> </system.serviceModel> <system.webServer> <modules runAllManagedModulesForAllRequests="true"/> </system.webServer> </configuration> My code is as follows: Public Shared Function LogException(ByVal pException As System.Exception) As Boolean Return ExceptionPolicy.HandleException(pException, "LogPolicy") End Function Any assistance is appreciated.

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