When loading isapi_redirect.dll as an extension, not a filter, restarting of the app pool hangs. You will see logs in the system log like the following: A process serving application pool 'DefaultAppPool' exceeded time limits during shut down. The process id was '1676'. A process serving application pool 'DefaultAppPool' failed to respond to a ping. The process id was '5516'. A process serving application pool 'DefaultAppPool' suffered a fatal communication error with the World Wide Web Publishing Service. The process id was '6200'. The data field contains the error number. Attached is a Crash/Hang Analysis of a dump using Debug Diagnostics Tools from the IIS Debug Kit.
Moving to connectors. Some version information would be helpful.
isapi_redirect 1.2.28, Windows Server 2003 R2 SP 2, IIS 6 Did the attachment go through, it also has version info? I can't see it.
Created attachment 24100 [details] Patch to fix deadlock when using isapi_redirect as an extension
Created attachment 24127 [details] Slightly better code to fix deadlock
Good catch! Applied a slightly different patch https://svn.apache.org/viewvc/tomcat/jk/trunk/native/iis/jk_isapi_plugin.c?r1=802231&r2=803365&diff_format=h
Will be part of 1.2.29.