We have a current setup like the following:
- HTTPServer - IBM HTTPD Server v?
- WASServer6.1 - WebSphere Application Server v6.1 (Running App "A")
The basic communication is as follows on the listed ports. [All port numbers listed are the listening ports.] The
plugin-cfg.xml is appropriately configured, and this same topology has been operating in a Production environment for 6+ years.
HTTPServer:8080 --> WASServer6.1:9081
We now need to adapt in these new things, changing the topology somewhat:
- IHSServer - IBM HTTPD Server v? (newer than above)
- WASServer8.5 - WebSphere Application Server v8.5.5 (Running App "B")
AuthService - Stand-alone Java service (not running in app container)
HTTPServer:8080 ---> AuthService:9090 ---> IHSServer:8081 ---> WASServer8.5:9081 \ \ WASServer6.1:9081
httpd.conf configured with
ProxyPass directives that proxy certain requests to AuthService:9090. AuthService does some work, and then copies the headers of the request into a new [POST] request that is sent to IHSServer:8081, where the
plugin-cfg.xml is mapped with the App B information to forward requests on to App B running on WASServer8.5. The ultimate goal is to take advantage of the plugin's state-awareness of the WAS JVMs. In our Production-level environment, there would be multiple JVMs to which IHS could forward requests.
NOTE: The AuthService is stateless, and so there is no need for any affinity to a particular JVM on WAS.
The problem is that this doesn't work for some reason. Requests sent through this path return with a
HTTP 404 from IHSServer.
Troubleshooting with verbose logging for IHSServer has revealed that for some reason IHSServer is seeing the port number of the original forwarding proxy (HTTPServer:8080) and comparing it to the
VirtualHostGroup virtualhosts listing in the
plugin-cfg.xml (Why?). Finding no suitable match for port 8080, it gives up and spits out a 404.
If we replace things, as below, by first hitting some other Apache server listening on Port 80:
SomeOtherHTTPServer:80 ---> AuthService:9090 ---> IHSServer:8081 ---> WASServer8.5:9081 \ \ WASServer:9081
...the request is accepted by IHSServer and things work properly. Similarly, if an appropriately-formed request payload is sent directly to AuthService:9090, the request is accepted and everything works.
We attempted to add
<VirtualHost Name="*:8080"/> to the
plugin-cfg.xml on IHSServer, but that doesn't seem to make a difference.
EDIT: We've taken some
tcpdump captures at every node along this pathway, and it's clear that IHSServer immediately rejects requests with a 404 when they've come through the HTTPServer:8080. IHSServer doesn't even attempt to do anything with the request.
What other things could we do to troubleshoot/correct this? Why does the plugin on IHSServer care about the listening port of an upstream web server?