|
| Product |
| FileUp |
| Version |
| 4.x or 5.x |
| Title |
| How do I know if I should be using FileUp's ISAPI filter? |
| Problem |
| The FileUp ISAPI filter was installed by default in versions 4.0.0 through 4.0.11 of FileUp. It can be installed manually in version 4.0.12 and above. ISAPI filters intercept the HTTP request at a very low level, and sometimes there can be conflicts between different ISAPI filters. Often, the fastest solution to FileUp ISAPI filter-related problems is to simply remove the filter from IIS. If you are unfamiliar with the purpose and function of the FileUp ISAPI filter, this article will walk you through the implications of removing it. |
| Solution |
The ISAPI filter was designed to circumvent ASP.NET's behavior of forcing uploads to be cached to memory. Caching an upload to memory can cause symptoms ranging from inefficient use of server memory to upload failure or even server crashes, especially as traffic or file sizes increase. The ISAPI filter allows FileUp to cache the upload to disk, as was traditionally supported in ASP.
- If your application is an ASP application, you do not need to use the ISAPI filter.
- If you are running a .NET application on IIS 5 with version 4 of FileUp, then the ISAPI filter is the best solution for improving memory resource utilization.
- If you are running a .NET application on IIS 5 with version 5 of FileUp, then either the ISAPI filter or the HttpModule can be used to improve memory resource utilization. If you are likely to upgrade your webserver to IIS 6 (see below), or experience conflicts with other ISAPI level filters, use the HttpModule instead of the ISAPI filter.
- If you are running a .NET application on IIS 6 with version 5 of FileUp, then use the HttpModule instead of the ISAPI filter. The ISAPI filter is not appropriate for the IIS 6 native processing model.
- If you are running your .NET application on IIS 6 with version 4 of FileUp and consequently, are dependent on using the ISAPI filter, you will need to run your web server in IIS 5 Isolation mode in order to use the filter. The ISAPI filter was designed for the IIS 5 processing model, and is not appropriate for IIS 6's native processing model, which does not support this type of "Read Raw Data" ISAPI-level filter.
- If you are running your .NET application on IIS 6 with version 4 of FileUp and would like to have the functionality of ISAPI filter, but cannot run your server in IIS 5 Isolation Mode, then you will need to upgrade to version 5 of FileUp and use the HttpModule instead. FileUp version 5's HttpModule is designed to replace the ISAPI filter and it is designed for IIS 6's native processing model.
- If you are moving your application from IIS 5 to IIS 6, you will want to check to see if you are already using the FileUp ISAPI filter. This can be done in two steps. First, check your scripts to see if they are marked to be processed by the filter, and then confirm that the filter is installed. Scripts are marked to be processed by the filter by changing the filename extension to ".upl" or ".uplx". Look for the ISAPI filter to be installed in IIS at the machine level. For step by step instructions on how this is done, please see our online documentation regarding both of these topics at: http://support.softartisans.com/docs/FileUpV4/prog_g_dotnet_largeuploads.htm#isapi
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| Created : 3/11/2004 12:32:47 PM (last modified : 3/11/2004 12:32:47 PM) |
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