Product and version FileMaker Server 15.0.3 (2 machine deployment)
OS and version Windows Server 2012R2
Description
When FileMaker WPE is stopped from the Status page of the admin console on the master machine, it shows that it is stopped but keeps responding.
This is a problem as being able to enable/disable some services without having to take the whole server down is useful during maintenance work or data updates run on server but without access for other systems accessing FileMaker through XML while maintenance work is carried out.
No errors were shown attempting to stop the server and the status page in the admin console updates to show that the service has indeed stopped. Which doesn't seem to keep it from responding.
How to replicate
Master machine setup like this:
Run a query like this:
http://172.16.0.204/fmi/xml/fmresultset.xml?-dbnames
for the following response (trimmed at the end):
<fmresultset xmlns="http://www.filemaker.com/xml/fmresultset" version="1.0">
<product build="10/27/2016" name="FileMaker Web Publishing Engine" version="15.0.3.308"/>
<datasource database="DBNAMES" date-format="" layout="" table="" time-format="" timestamp-format="" total-count="5"/>
Workaround
Stopping the IIS process on the worker machine should ensure that no web pages are published as would probably a redeployment of the server. But that shouldn't be necessary and it would be helpful to disable/enable subsets of web services (PHP, XML, WebDirect) without a "all or nothing" approach.
I may not be understanding you correctly here, but you can disable PHP, XML and WebDirect though the 3 "Enable..." checkboxes in Admin Console > Web Publishing, tabs PHP, XML and FileMaker WebDirect. This still doesn't stop the engine running, it will just stop the publishing (e.g., no longer list any databases with the XML request).
Other than that, I can't seem to reproduce this issue in my 2-machine setup (same FileMaker Server and OS version as you). When I toggle WPE off, I no longer get a response via XML.