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I am working on a ASP.net MVC4 project where a same project needs to be deployed to many clients on daily basis, each client will have its own domain / sub domain and a separate app pool and db (MSSSQL).
Doing each deployment manually could take at least 1-2 hours if everything goes well. Is there anyway using which I can do this in some automated way?
Moreover, we also need to update all of the apps when a new version is released.. may be one by one or all of them at same time. However, doing this manually could take weeks and once we have more clients then it will not possible doing this update manually.
The update involves, suspending app for some time, taking a full backup of files and db, update application code/ files in app folder, upgrade db with a script and then start app, doing some diagnosis script to check if update was successful or not, if not we need to check what went wrong?
How can we automate this updates? Any idea would be great on how to approach this issue.
As a developer for BuildMaster, I can say that this scenario, known as the "Core Version" pattern, is a common one. If you're OK with a paid solution, you can setup your deployment plans within the tool that do exactly what you described.
As a more concrete example, we experience this exact situation in a slightly different way. BuildMaster has a set of 60+ extensions that rely on a specific SDK version. In our recent 4.0 release, we had to re-deploy every extension because of breaking API changes within the SDK. This is essentially equivalent to having a bunch of customers and deploying to them all at once. We have set up our deployment plans such that any time we create a new release of the SDK application, we have the option to set a variable that says to build every extension that relies on the SDK:
In BuildMaster, the idea is to promote a build (i.e. an immutable object that travels through various environments like Dev, Test, Staging, Prod) to its final environment (where it becomes the deployed build for the release). In your case, this would be pushing your MVC application to its final environment, and that would then trigger the deployments of all dependent applications (i.e. your customers' instances of your application). For our SDK, the plan looks like this:
For your scenario, you would only need the single action, "Promote Build". As I mentioned before, any dependents would then be promoted to their final environments, so all your customer deployments would kick off once that action is run during deployment. As an example, our Azure extension's deployment plan for its final environment looks like this (internal URLs redacted):
You may have noticed that these plans are marked "Shared", which means every extension we have has the exact same deployment plan, but utilizes different variables to handle the minor differences like names, paths, etc.
Since this is such an enormous topic I could go on for ages, but I think that should be sufficient for your use-case if you wanted to try it out.
There are others but you could setup Team Server Foundation to deploy automated builds.
http://msdn.microsoft.com/en-us/library/ff650529.aspx
I find the easiest way to do this from an MVC project is to create a publish profile.
This is done by right-clicking your project selecting publish and then configuring it to your needs.
Then from TFS you create a new build definition, this kicks of a wizard which takes you through it.
There are quite a few options which would be too long to go into for every scenario.
The main change I usually find the most important is to set an MSBuild Argument to deploy with the publish profile.
This can be found at Process > Advanced > MSBuild Arguments.
Once this is configured correctly it's a simple case of right-clicking and queue new build to build and deploy.
You wil need different PublishProfile/Build configuration per deployment environment.
For backups I use a powershell script which can be called manually or from TFS.
You also have a drop folder in TFS which keeps a backup of x many releases.
The datbases are automatically configured via Sql server to backup, TBH I didn't set that up it was a DB admin guy who is also involved with releases.
From a dev testing side I use jMeter (http://jmeter.apache.org/) to run some automated scripts that check that users can login and view certain screens, just to confirm nothing major has gone wrong. However there is usually a testing team to run more detailed tests, again not setup by me.
All of the above will probably take you sometime to setup but in the long run it will literally save you weeks of time over a year.
A free alternative to TFS is http://www.cruisecontrolnet.org/, I have used this in the past too and is pretty good.
You can automate your .Net deployments with Beanstalk, which will give you a way to trigger deployments with a single click, watch progress, manage permissions and see history of deployments. Check out this guide on the topic:
http://guides.beanstalkapp.com/deployments/deploy-dotnet.html
I hope you will find it useful.
P.S. - I work at Beanstalk.
I am new to web development and am unfamiliar with some of the methods for best testing the web end information. On my current project I am using Weblogic to deploy my JSP project through Eclipse.
The webpages build fine and everything works, but currently I am restarting my localhost server every time I make a change to the css or the jsp, which a single round trip can be up to 3-5 min. is there a more efficient way of testing the css other than restarting my server every time? What about jsp?
Edit: Followup:
For any that stumble past this: After reading up on different staging methods as #better_use_mkstemp suggested, I couldn't figure out how to explicitly set eclipse up to stage or nostage deploy, however I did find some nifty things.
You can do an Incremental push (expand drop down in the servers view in eclipse, right click project that is deployed on a running server > click "Incremental Publish". This only pushes what has changed since last push) which helps a bit.
The other thing I found was an automatic deploy when a file changes, but that had it pushing while I was still editing the file which was a bit annoying. Using this feature you can also have it auto deploy each time there is a new version, but I didn't play around with that since we're not changing the version number yet.
Check how you are deploying your application. If you deploy using nostage mode, the server(s) will keep looking in the original deployment directory and will automatically detect jsp changes for refreshes.
This is as opposed to stage mode, where the original war/ear deployment is actually copied to each individual server.
Read more here: http://docs.oracle.com/cd/E11035_01/wls100/deployment/deploy.html#wp1027044
Sounds like if you keeps dropping your updated deployment files in the same directory with nostage you won't need a restart.
For our company websites we develop in a style that would be most accurately called Continuous Deployment (http://toni.org/2010/05/19/in-praise-of-continuous-deployment-the-wordpress-com-story/)
We have a web farm and every site is located on two servers for fail over purposes. We wish to automate the process of deploying to our dev server, test server, and prod servers. Out websites are ASP.Net websites (not web applications) so we don’t do builds, we just push the pages. We generally change our main site anywhere from 2-20 times a day depending on many variables. These changes can be simple text/html changes to adding new pages/functionality.
Currently we use TFS for our source control, and each site is its own repository. We don’t have branches, you manually push your changes to dev (we develop on local machines) when it needs to be reviewed, then after sign off you check in your changes and push them to prod manually (this ensures that the source files are what is actually on prod and merges happen right then). Obviously there is a lot of room for error in here and it happens, infrequently, where a dev forgets a critical file and brings down the entire site.
It seems that most deployment tools are built upon a build process, which isn’t something we are likely to move to since we need to be extremely agile in meeting our business needs. What we’d really like, we think, is something like the following:
Dev gets latest version of website from source control, which is essentially a copy of production
Dev does work on his own box.
When it is ready to be reviewed by task owner he creates some form of changeset (either checking in the change or something else) and a tool would then push that change to dev
After review (and further possible changes) dev then is able to have the tool push all the changes for this task to test (UAT)
After this sign off the changes are automatically pushed to prod and checked into the prod branch, or whatever, for anyone else to get
We’ve toyed around with the idea of having three branches of the code in TFS, but we aren’t sure how you would pull from one branch (prod) but check in to a dev branch (none of us are TFS gurus).
So, how have other people handled this scenario? We are not wedded to TFS as a source control provider if there is something out there that would do what we wanted, nor do we require a vertical solution, we are more than happy to plug in different components as long as they can be plugged in, or even develop our own if we have to.
Thanks in advance.
I'm sure you can do this with TFS, but I've successfully done what you're describing with Mercurial, and it works pretty well.
With Mercurial (I'd assume Git is the same way), you can pull from one repo, and push to another. So you'd pull from Prod, do your change, commit locally, push to Dev, and then whenever you're happy, push the changesets into Prod (either from Dev or from Local, doesn't matter).
To get started, you'd have a Prod repo, then clone it into a Dev repo - both of these are on your server. At this point they're identical.
TortoiseHG on Windows gives you the ability to easily choose which repository you're synchronizing with. You can keep both the Prod and Dev repos in your list, and decide which one to use when it's time to pull or push.
At work we currently use the following deployment strategy:
Run a batch script to clear out all Temporary ASP.NET files
Run a batch script that compiles every ASPX file into its own DLL (ASP.NET Web Site, not Web Application)
Copy each individually changed file (ASPX and DLL) to the appropriate folder on the live server.
Open up the Deployment Scripts folder, run each SQL script (table modifications, stored procs, etc.) manually on the production database.
Say a prayer before going to sleep (joking on this one, maybe)
Test first thing the next morning and hope for the best - fix bugs as they come up.
We have been bitten a few times in the past because someone will forget to run a script, or think they ran something but didn't, or overwrote a sproc related to some module because there are two files (one in a Sprocs folder and one in a [ModuleName]Related folder) or copied the wrong DLL (since they can have the same names with like a random alphanumeric number generated by .NET).
This seems highly inefficient to me - a lot of manual things and very error prone. It can sometimes take 2-3 or more hours for a developer to perform a deployment (we do them late at night, like around midnight) due to all the manual steps and remembering what files need to be copied, where they need to be copied, what scripts need to be run, making sure scripts are run in the right order, etc.
There has got to be an easier way than taking two hours to copy and paste individual ASPX pages, DLLs, images, stylesheets and the like and run some 30+ SQL scripts manually. We use SVN as our source control system (mainly just for update/commit though, we don't do branching) but have no unit tests or testing strategy. Is there some kind of tool that I can look into to help us make our deployments smoother?
I did not go through all of it, but the You're deploying it wrong series from Troy Hunt might be a good place to look at.
Points discussed in the series :
Config transforms
Build Automation
Continuous Integration
We have four stages before it can be deployed.
Development
QA
UAT
Production
We have build scripts (inside bamboo build server) running against QA and against UAT. Our DBA is the only person who can run create scripts against QA, UAT, and PROD. Anything that goes from QA -> UAT is like a test run deployment. UAT gets reverted by copying the production systems down again.
When we release into Production we just create a whole new site and point it at the UAT database and test that environmentally it is working fine. Then when this is working good we flick the 'switch' and point the production IIS record at the next site, and change the DB connection to point at Prod DB.
Because we are using a completely diff folder structure all of our files get copied up so there is no chance of missing one. Because we have had test runs of deployment into UAT we know we haven't missed a DB script (DB Scripts are combined into one generally). Because we have tested a shadow copy of the IIS website we know that environmentally it should work. We can then do all this set up during the day - and then do the final switch flicking at midnight or whenever - reducing the impact on devs.
tl;dr; Automated build and deploy; UAT system for test running deployment; Deployment during work hours; Flick switch/run DB update at midnight.
I am a developer for BuildMaster, a tool which can very easily automate the steps you have outlined above, and we have a limited version free for a team of 5 developers.
Most of your pain points will disappear the moment you set up the deployment automation - mainly the batch script execution and the file-by-file copying. Once you're fully automated, you can even schedule the deployment for night time and only have to worry about it if there's an error in the process (you can set up a notifier for a failed build).
On the database side, you can integrate your database with BuildMaster as well and if you upload the scripts into the tool it will keep track of which ones were run against which database.
To see how to set up a simple web application deployment plan, you can run one of the example applications included. You can also check out: http://inedo.com/support/tutorials/lunchmaster/part-1 to see how to create one yourself - it's slightly outdated since we've made it even easier to get started out-of-the-box but the main concepts are the same.
Please see this blog post and associated talk by Scott Hanselman titled "Web Deployment Made Awesome"
Blog
Video
As for SQL Deployment, you might want to consider one of the following:
RikMigrations
Migrator.NET
FluentMigrator
Mantee Introduction & Source
Have a User Acceptance Testing (UAT) environment which is completely isolated from your development environment, and only accessible to the UAT manager.
Setup a UAT build which you can manually trigger upon each release, when triggered this should send all your deployment files as well as a deployment checklist to the UAT manager, who will redeploy all files to the UAT environment, and run any database upgrade scripts.
Once the applications users and testers have signed off the UAT release, the UAT manager can be authorised to deploy to the PRODUCTION environment using the exact same procedure and checklists as the UAT release. This will guarantee that you never miss any deployment steps, and test the deployment process prior to moving it into production.
Caveats- I'm in an environment where we can't use MSI, batch, etc for the final deployment
Things that helped:
A build server that does the full compilation on a build server and runs all unit tests and integration tests. Why find out you have something in an aspx page that doesn't compile on deployment night? (I admit your Q doesn't make it clear if compilation is happening on deployment night)
I have a page that administrators can reach that exercises environment and deployment failure points, e.g. connect to db, connect to reporting services, send an email, read and write to the temp folder.
Also, put all the things that the administrator needs to change into a file external from web.config. The connection string and app settings sections natively support a way to do this (i.e. don't reinvent the web.config system just to create a separate file)
Here is an article on how to do better integration tests: http://suburbandestiny.com/Tech/?p=601 There is a ton of good literature how to do unit tests, but often if you app already exists, you will have to refactor until unit testing becomes possible. If that isn't an option, then don't be a purist and put together some integration tests that are fast and repeatable as possible.
Keep your dependencies in bin instead of GAC, since it's easier to tell an administrator to copy files than it is to teach them to administer the GAC.
I am looking for different techniques/tools you use to deploy an ASP.NET web application project (NOT ASP.NET web site) to production?
I am particularly interested of the workflow happening between the time your Continuous Integration Build server drops the binaries at some location and the time the first user request hits these binaries.
Are you using some specific tools or just XCOPY? How is the application packaged (ZIP, MSI, ...)?
When an application is deployed for the first time how do you setup the App Pool and Virtual Directory (do you create them manually or with some tool)?
When a static resource changes (CSS, JS or image file) do you redeploy the whole application or only the modified resource? How about when an assembly/ASPX page changes?
Do you keep track of all deployed versions for a given application and in case something goes wrong do you have procedures of restoring the application to a previous known working state?
Feel free to complete the previous list.
And here's what we use to deploy our ASP.NET applications:
We add a Web Deployment Project to the solution and set it up to build the ASP.NET web application
We add a Setup Project (NOT Web Setup Project) to the solution and set it to take the output of the Web Deployment Project
We add a custom install action and in the OnInstall event we run a custom build .NET assembly that creates an App Pool and a Virtual Directory in IIS using System.DirectoryServices.DirectoryEntry (This task is performed only the first time an application is deployed). We support multiple Web Sites in IIS, Authentication for Virtual Directories and setting identities for App Pools.
We add a custom task in TFS to build the Setup Project (TFS does not support Setup Projects so we had to use devenv.exe to build the MSI)
The MSI is installed on the live server (if there's a previous version of the MSI it is first uninstalled)
We have all of our code deployed in MSIs using Setup Factory. If something has to change we redeploy the entire solution. This sounds like overkill for a css file, but it absolutely keeps all environments in sync, and we know exactly what is in production (we deploy to all test and uat environments the same way).
We do rolling deployment to the live servers, so we don't use installer projects; we have something more like CI:
"live" build-server builds from the approved source (not the "HEAD" of the repo)
(after it has taken a backup ;-p)
robocopy publishes to a staging server ("live", but not in the F5 cluster)
final validation done on the staging server, often with "hosts" hacks to emulate the entire thing as closely as possible
robocopy /L is used automatically to distribute a list of the changes in the next "push", to alert of any goofs
as part of a scheduled process, the cluster is cycled, deploying to the nodes in the cluster via robocopy (while they are out of the cluster)
robocopy automatically ensures that only changes are deployed.
Re the App Pool etc; I would love this to be automated (see this question), but at the moment it is manual. I really want to change that, though.
(it probably helps that we have our own data-centre and server-farm "on-site", so we don't have to cross many hurdles)
Website
Deployer:
http://www.codeproject.com/KB/install/deployer.aspx
I publish website to a local folder, zip it, then upload it over FTP. Deployer on server then extracts zip, replaces config values (in Web.Config and other files), and that's it.
Of course for first run you need to connect to the server and setup IIS WebSite, database, but after that publishing updates is piece of cake.
Database
For keeping databases in sync I use http://www.red-gate.com/products/sql-development/sql-compare/
If server is behind bunch of routers and you can't directly connect (which is requirement of SQL Compare), use https://secure.logmein.com/products/hamachi2/ to create VPN.
I deploy mostly ASP.NET apps to Linux servers and redeploy everything for even the smallest change. Here is my standard workflow:
I use a source code repository (like Subversion)
On the server, I have a bash script that does the following:
Checks out the latest code
Does a build (creates the DLLs)
Filters the files down to the essentials (removes code files for example)
Backs up the database
Deploys the files to the web server in a directory named with the current date
Updates the database if a new schema is included in the deployment
Makes the new installation the default one so it will be served with the next hit
Checkout is done with the command-line version of Subversion and building is done with xbuild (msbuild work-alike from the Mono project). Most of the magic is done in ReleaseIt.
On my dev server I essentially have continuous integration but on the production side I actually SSH into the server and initiate the deployment manually by running the script. My script is cleverly called 'deploy' so that is what I type at the bash prompt. I am very creative. Not.
In production, I have to type 'deploy' twice: once to check-out, build, and deploy to a dated directory and once to make that directory the default instance. Since the directories are dated, I can revert to any previous deployment simply by typing 'deploy' from within the relevant directory.
Initial deployment takes a couple of minutes and reversion to a prior version takes a few seconds.
It has been a nice solution for me and relies only on the three command-line utilities (svn, xbuild, and releaseit), the DB client, SSH, and Bash.
I really need to update the copy of ReleaseIt on CodePlex sometime:
http://releaseit.codeplex.com/
Simple XCopy for ASP.NET. Zip it up, sftp to the server, extract into the right location. For the first deployment, manual set up of IIS
Answering your questions:
XCopy
Manually
For static resources, we only deploy the changed resource.
For DLL's we deploy the changed DLL and ASPX pages.
Yes, and yes.
Keeping it nice and simple has saved us alot of headaches so far.
Are you using some specific tools or just XCOPY? How is the application packaged (ZIP, MSI, ...)?
As a developer for BuildMaster, this is naturally what I use. All applications are built and packaged within the tool as artifacts, which are stored internally as ZIP files.
When an application is deployed for the first time how do you setup the App Pool and Virtual Directory (do you create them manually or with some tool)?
Manually - we create a change control within the tool that reminds us the exact steps to perform in future environments as the application moves through its testing environments. This could also be automated with a simple PowerShell script, but we do not add new applications very often so it's just as easy to spend the 1 minute it takes to create the site manually.
When a static resource changes (CSS, JS or image file) do you redeploy the whole application or only the modified resource? How about when an assembly/ASPX page changes?
By default, the process of deploying artifacts is set-up such that only files that are modified are transferred to the target server - this includes everything from CSS files, JavaScript files, ASPX pages, and linked assemblies.
Do you keep track of all deployed versions for a given application and in case something goes wrong do you have procedures of restoring the application to a previous known working state?
Yes, BuildMaster handles all of this for us. Restoring is mostly as simple as re-executing an old build promotion, but sometimes database changes need to be manually restored, and data loss can occur. The basic rollback process is detailed here: http://inedo.com/support/tutorials/performing-a-deployment-rollback-with-buildmaster
web setup/install projects - so you can easily uninstall it if something goes wrong
Unfold is a capistrano-like deployment solution I wrote for .net applications. It is what we use on all of our projects and it's a very flexible solution. It solves most of the typical problems for .net applications as explained in this blog post by Rob Conery.
it comes with a good "default" behavior, in the sense that it does a lot of standard stuff for you: getting the code from source control, building, creating the application pool, setting up IIS, etc
releases based on what's in source control
it has task hooks, so the default behaviour can be easily extended or altered
it has rollback
it's all powershell, so there aren't any external dependencies
it uses powershell remoting to access remote machines
Here's an introduction and some other blog posts.
So to answer the questions above:
How is the application packaged (ZIP, MSI, ...)?
Git (or another scm) is the default way to get the application on the target machine. Alternatively you can perform a local build and copy the result over the Powereshell remoting connection
When an application is deployed for the first time how do you setup the App Pool and Virtual Directory (do you create them manually or with some tool)?
Unfold configures the application pool and website application using Powershell's WebAdministration Module. It allows us (and you) to modify any aspect of the application pool or website
When a static resource changes (CSS, JS or image file) do you redeploy the whole application or only the modified resource? How about when an assembly/ASPX page changes?
Yes unfold does this, any deploy is installed next to the others. That way we can easily rollback
when somehting goes wrong. It also allows us to easily trace back a deployed version to
a source control revision.
Do you keep track of all deployed versions for a given application?
Yes, unfold keeps old versions around. Not all versions, but a number of versions. It makes rolling back almost trivial.
We've been improving our release process for the past year and now we've got it down pat. I'm using Jenkins to manage all of our automated builds and releases, but I'm sure you could use TeamCity or CruiseControl.
So upon checkin, our "normal" build does the following:
Jenkins does a SVN update to fetch the latest version of the code
A NuGet package restore is done running against our own local NuGet repository
The application is compiled using MsBuild. Setting this up is an adventure, because you need to install the correct MsBuild and then the ASP.NET and MVC dll's on your build box. (As a side note, when I had <MvcBuildViews>true</MvcBuildViews> entered in my .csproj files to compile the views, msbuild was randomly crashing, so I had to disable it)
Once the code is compiled the unit tests are run (I'm using nunit for this, but you can use anything you want)
If all the unit tests pass, I stop the IIS app pool, deploy the app locally (just a few basic XCOPY commands to copy over the necessary files) and then restart IIS (I've had problems with IIS locking files, and this solved it)
I have separate web.config files for each environment; dev, uat, prod. (I tried using the web transformation stuff with little success). So the right web.config file is also copied across
I then use PhantomJS to execute a bunch of UI tests. It also takes a bunch of screenshots at different resolutions (mobile, desktop) and stamps each screenshot with some information (page title, resolution). Jenkins has great support for handling these screenshots and they are saved as part of the build
Once the integration UI tests pass the build is successful
If someone clicks "Deploy to UAT":
If the last build was successful, Jenkins does another SVN update
The application is compiled using a RELEASE configuration
A "www" directory is created and the application is copied into it
I then use winscp to synchronise the filesystem between the build box and UAT
I send a HTTP request to the UAT server and make sure I get back a 200
This revision is tagged in SVN as UAT-datetime
If we've got this far, build is successful!
When we click "Deploy to Prod":
The user selects a UAT Tag that was previously created
The tag is "switched" to
Code is compiled and synced with Prod server
Http request to Prod server
This revision is tagged in SVN as Prod-datetime
The release is zipped and stored
All up a full build to production takes about 30 secs which I'm very, very happy with.
Upsides to this solution:
It's fast
Unit tests should catch logic errors
When a UI bug gets into production, the screenshots will hopefully show what revision # caused the it
UAT and Prod are kept in sync
Jenkins shows you a great release history to UAT and Prod with all of the commit messages
UAT and Prod releases are all tagged automatically
You can see when releases happen and who did them
The main downsides to this solution are:
Whenever you do a release to Prod you need to do a release to UAT. This was a conscious decision we made because we wanted to always ensure that UAT is always up to date with Prod. Still, it's a pain.
There's quite a few configuration files floating around. I've attempted to have it all in Jenkins, but there's a few support batch files needed as part of the process. (These are also checked in).
DB upgrade and downgrade scripts are part of the app and run at app startup. It works (mostly), but it's a pain.
I'd love to hear any other possible improvements!
Back in 2009, where this answer hails from, we used CruiseControl.net for our Continuous Integration builds, which also outputted Release Media.
From there we used Smart Sync software to compare against a production server that was out of the load balanced pool, and moved the changes up.
Finally, after validating the release, we ran a DOS script that primarily used RoboCopy to sync the code over to the live servers, stopping/starting IIS as it went.
At the last company I worked for we used to deploy using an rSync batch file to upload only the changes since the last upload. The beauty of rSync is that you can add exclude lists to exclude specific files or filename patterns. So excluding all of our .cs files, solution and project files is really easy, for instance.
We were using TortoiseSVN for version control, and so it was nice to be able to write in several SVN commands to accomplish the following:
First off, check the user has the latest revision. If not, either prompt them to update or run the update right there and then.
Download a text file from the server called "synclog.txt" that details who the SVN user is, what revision number they are uploading and the date and time of the upload. Append a new line for the current upload and then send it back to the server along with the changed files. This makes it extremely easy to find out what version of the site to roll back to on the off chance that an upload causes problems.
In addition to this there is a second batch file that just checks for file differences on the live server. This can highlight the common problem where someone would upload but not commit their changes to SVN. Combined with the sync log mentioned above we could find out who the likely culprit was and ask them to commit their work.
And lastly, rSync allows you to take a backup of the files that were replaced during the upload. We had it move them into a backup folder So if you suddenly realised that some of the files should not have been overwritten, you can find the last backup up version of every file in that folder.
While the solution felt a little clunky at the time I have since come to appreciate it a whole lot more when working in environments where the upload method is a lot less elegant or easy (remote desktop, copy and paste the entire site, for instance).
I'd recommend NOT just overwriting existing application files but instead create a directory per version and repointing the IIS application to the new path.
This has several benefits:
Quick to revert if needed
No need to stop IIS or the app pool to avoid locking issues
No risk of old files causing problems
More or less zero downtime (usually just a pause at the new appdomain initialises)
The only issue we've had is resources being cached if you don't restart the app pool and rely on the automatic appdomain switch.