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From André Warnier (tomcat)>
Subject Re: Strange URL rewrite when reverse proxy with Apache HTTP Server
Date Tue, 21 Feb 2017 23:39:34 GMT
On 21.02.2017 23:28, Aaron Gray wrote:
> Antonio:  The Tomcat server has no knowledge of the F5, or that it is being
> fronted by an Apache HTTP Server.  I do SSL termination in Apache HTTP
> Server, and clear-text from HTTP to Tomcat.
> My redirect port for the normal HTTP listen in Tomcat is commented out.
>      <Connector port="18080" protocol="HTTP/1.1"
>                 connectionTimeout="20000" />
>      <!-- A "Connector" using the shared thread pool-->
>      <!--
>      <Connector executor="tomcatThreadPool"
>                 port="8080" protocol="HTTP/1.1"
>                 connectionTimeout="20000"
>                 redirectPort="8443" />
>      -->
> Andre:
> The URL I am using is
> It is listening on port 80 and 443, if you hit 80, internally it redirects
> you to 443.  No SSL cert on the F5 load balancer.  It simply sends the
> traffic to one of the two HTTP servers (round-robin, also tried
> persistence, no difference).  The HTTP server is listening only for HTTPS
> on 23270/tcp.
> Hitting
> I see my "Hello world!" which is all that is in index.html.  This is the
> DocumentRoot of HTTP, and *not* proxied over at this time.

So in this case, there is no delay, and you get the Apache httpd-hosted "index.html" 
containing "Hello World. Right ?

> /SelfService and /static are proxied
> /static just being my test of static content, but still served up by Tomcat..
> It's exactly 30 seconds before the page cannot be loaded when trying
> anything proxied to Tomcat, but also accessed via the F5 load balancer.
> Not sure where the 30 seconds comes from; perhaps a load balancer time out,
> as I dont see a "30" in my httpd configurations or my tomcat server.xml

You can certainly look at the Apache httpd logs, and the tomcat logs, to see if you get a

request or not.
In Apache httpd, you can set the loglevel individually for mod_proxy (if you are running v

2.4), and it should show something if it gets this request and forwards it to tomcat.
In tomcat, you can either enable an access log (which will show if it receives this 
request), or you could temporarily remove/rename the /static webapp. This way, it should 
trigger an error "not found" which you would also see in the error log.

> There should be nothing between them to hinder it.  We have many load
> balancers and this one specifically you dont need to open any firewall
> requests for the specific networks the HTTP servers are on.  I did have to
> get the firewall opened up to allow me to hit
> because the VIP for ""
> is in the DMZ, and my Desktop & VPN networks cannot hit it on 80/443
> without opening holes.  But beyond that, any connection from the F5 to the
> HTTP Server should be 100% open bi-directional, since same subnet.

But something isn't working, otherwise you would not be asking.

a) hitting the tomcat webapps through httpd seems to be working fine
   (browser -> httpd:23270 -> tomcat:18080 -> webapp or static)

b) hitting a non-proxied-to-tomcat resource of httpd seems to work fine too, even through

the F5
   (browser -> F5:443 -> httpd:23270 -> html page)

c) it is only when you do :
   (browser -> F5:443 -> httpd:23270 -> tomcat:18080 -> webapp or static)
   that you see this issue

It would really help if you looked in the logs of both httpd and tomcat, and checked for 
differences betweens cases a, b and c above.

I believe that the F5 message with the port 23270 is a minor issue, of information 
disclosure by the F5, that it should not disclose.

But the reason why it returns this error is obviously that in that case, it does not get a

response from his request to httpd.
The reason for this response not coming back to the F5 (in case c only), can be due to 
either httpd or tomcat. But F5 doesn't know about tomcat. So for the F5, it is httpd which

is not responding. Thus,
- either httpd is never getting the request from the F5 (unlikely, because in b above it 
gets it and responds)
- or httpd is getting the request from the F5, but not forwarding it to tomcat, but also 
not returning an immediate error response to F5 (which seems also unlikely, because of a 
and b)
- or httpd is getting the request, forwarding it to tomcat, but not getting a response 
from tomcat. So
   - either tomcat is never getting the request from httpd (but in a, it gets it)
   - or tomcat is getting the request from httpd, but not responding (but in a, it does)
   - or tomcat is getting the request and responding, but the response never gets back to

httpd (but in a, it does)

So if a and b and c are all accurate, there is something apparently illogical happening.
This would lead to the conclusion that a and b and c cannot all be accurate.

The logs.. ?

> On Tue, Feb 21, 2017 at 2:05 PM, Antonio S. Cofino <>
> wrote:
>> Aaron, on tomcat instances change the redirectPort attributte on the http
>> conectó to the loabbalancer's port 443
>> My guess is that your webapp has restriction rule requesting SSL con
>> fidntial channel. Therefore the non-confidential to the 18080 port from the
>> balancer are redirected to the 23270 port, but it should be 443.
>> Antonio
>> El 21/2/2017 19:46, "Aaron Gray" <> escribió:
>> I have an application server from a vendor that comes bundled with an
>> additional Apache Tomcat server.  The webapp SelfService.war is vendor
>> supplied too.
>> Here's my problem (IP's replaced to protect the innocent):
>> networks:
>> DMZ=172.x.x.x
>> INTERNAL=10.x.x.x
>> server1 https listen =
>> server2 https listen =
>> F5 load balancer hostname =
>> backend tomcat server =
>> mod_proxy configuration:
>> ProxyPass /SelfService
>> ProxyPassReverse /SelfService
>> When I access these DMZ webservers which mod_proxy back to Apache Tomcat
>> as:
>> and
>> <>
>> They load properly. Perfectly, every time!
>> When I access these DMZ webservers via the F5 load balancer (to which I
>> dont have access to, but the network folks configure for me), it hangs.
>> Eventually returns:
>> cant load.
>> No idea why the URL is being re-written with the ":23270".
>> I added static content to the server.xml on (Tomcat) to test:
>> <Context docBase="/path/to/tomcat/static" path="/static" />
>> Then put a simple index.html in there.  Accessing via the Apache Web
>> Servers works fine, but if you hit it with the Load Balancer it once again
>> adds the
>> Do you have any thoughts?  Thanks so much, I have been working with this
>> for weeks now with no success

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