In 8u20, we moved the jre payload to inside of the installer.exe as a resource. The installer.exe is now residing in the MSI binary table, which does not get MSZIP compressed.
As a workaround for 8u20, we temporarily turned on UPX compression for the 32-bit offline, so that file is compressed. Though UPX is not idea for large offline installers, because it does not show feedback/progress...and appears to hang on older/slower systems. Also, the current version of UPX that we use does not work for 64bit exe's.
The correct long term fix is to move installer.exe to the file table, where it will get automatic MSZIP compression. MSI compression is comparable to UPX when you are dealing with large 80MB files like the jre offline. One side effect is that we will need a way of deleting the installer.exe at the end of the install. Normally, we would just delete it using installer.exe, but installer.exe can't delete itself when it is running. We may need to create a helper dll to delete installer.exe as a custom action at the end of the install.