Reasons for IIS to fail gzip open: wildcard application mapping

I summarized the reason for a GZIP failure: PHP's extension and iis conflict, and today I encountered a new situation, confirming that there is no conflict, the permissions are set properly, the configuration is correct, but GZIP is failed to open, confirm After a few times there is no problem, you can only find the reason from other aspects.

Because it is IIS, it is necessary to consider the reasons for affecting the opening of GZIP from IIS. In addition to IIS itself, IIS also maps the wildcard application in the ISAPI filter and the home directory. Two places can hook up external dll files to extend the functionality of IIS.

First look at the ISAPI filter, the server has a lot of ISAPI filters installed, the components for URL rewriting ISAPI_Rewrite, .Net, PHP and some other filters. First remove the filter other than the above three ISAPI filters, restart IIS, detect GZIP, there is still no output.

Then look inside the wildcard application mapping in the main directory, for some reason, add a wildcard application mapping, delete it, restart IIS, and then detect GZIP, the HTTP header has already output GZIP, Use the gzip detection tool on the network again to detect and support GZIP.

I was troubled by the problem of GZIP failure for a week. The following work is to contact the developer of the wildcard application to feedback this problem and let them solve it.