Iis asp. NET 1.1 and 2.0 coexist

Be careful when installing and running. NET 1.1 and. NET 2.0 on the same computer!

Does your project occasionally encounter server application unavailable errors? Or this error is reported continuously!

Today, I helped a teacher upgrade a web psychological evaluation system. the system was originally ASP. NET 1.1, the new version is ASP. NET 2.0 .. (PS: other ASP files are installed on the server. netProgram, Using ASP. net1.1 .)

1. Create a directory on the server and copy the files of all published web programs to the new directory.
2. Create a new virtual directory on the server's IIS and configure it as an application that can execute scripts (the process is the same as that of creating a. NET Framework 1.1 program .) Then, configure the. NET Framework of this virtual directory to 2.0.
After success, the following error occurs when you access the configured program:

Server application unavailable
The Web application you are attempting to access on this web server is currently unavailable. Please hit the "refresh" button in your web browser to retry your request.

Administrator Note: an error message detailing the cause of this specific request failure can be found in the application event log of the Web server. please review this log entry to discover what caused this error to occur.

After carefully reading the IIS Help documentation, I found that this error was caused by the IIS6 application isolation mechanism. The default application isolation mechanism of IIS is called "Working Process Isolation Mode". In this mode, an application is divided into multiple groups, each of which is an "Application pool ", each application pool is isolated from each other. The benefits of isolation are security, stability, and so on. Each application pool in IIS is managed by a "worker process", that is, "w3wp.exe ". If you run multiple applications in the application pool, we can see multiple w3wp.exe. The created virtual directories are directed to the "ultultapppool" in iis6.

The cause of the above error is :.. NET Framework 2.0 program and. net framework1.1 (or 1.0) programs are put into the same application pool (ultapppool pool by default), that is, managed by the same worker process: w3wp.exe, however, a single working process cannot manage different programs (or different versions of programs) at the same time. If you first access. net Framework 1.1 page, the worker first loads and manages the assembly of Version 1.1. net Framework 2.0 web application page, the server application unavailable error is returned. In contrast, if w3wp.exe in the development application pool has accessed the 2.0 web application before it is started (the application assembly has been loaded at this time. net Framework 1.1 web assembly). When you access the Web application page of 1.0 or, a Chinese prompt such as "server application unavailable" will also appear. (You can use w3wp.exe to test .)

Solution: Create an application pool named "ASP. net2.0 ", select the virtual directory of the system, click" properties "-", select the application pool you just created in "application pool", and click "OK ".

 

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