httpd-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jai <>
Subject Re: [users@httpd] Re: Apache workers DNS change question?
Date Mon, 06 Jul 2009 21:00:40 GMT
We are not going to change it dynamically. We are going to bring down jboss
servers when we change IP address. But we will not be able to bring apache
since it has JK Mount configured for applications other than the application
we bring down. Sure. I will search it in tomcat forums and will go ahead
with this exercise. Thanks a lot for your help.

On Mon, Jul 6, 2009 at 3:49 PM, André Warnier <> wrote:

> Jai wrote:
>> Apache is acting as a front end webserver and it sends requests to Jboss
>> application server. We have configured Jboss servers as a workers in
>> apache
>> file. We have specified Jboss host name in
>> Very good, so now we know something more : that you are using mod_jk as
> the Apache-to-JBoss Connector.
> (Why is this kind of information always so hard to pry out of posters ?)
> I believe that there was a thread on the Tomcat users forum, not so long
> ago (less than 6 months), which touched on this issue.
> (The Tomcat users support list has a lot of messages about mod_jk).
> The point is : if in your "" file, you have something
> like this :
> then it means that in order to pass the request to the correct host, mod_jk
> has to do at least one DNS lookup, to get the IP address of this host.
> Of course, it would be very inefficient to re-do this DNS lookup at each
> request, so it is done once, and the result is cached.
> Of course if you change the IP address of Tomcat without letting mod_jk
> know, it is going to get confused.  So you need a way to force mod_jk to
> re-do this DNS lookup.
> I believe that doing an Apache httpd "graceful restart" would do it.
> But do not take my word for it, and do a search on the Apache and Tomcat
> forums, using the words above.
> Some of the mailing list archives mentioned on their respective website
> homepages are searchable.
> Now, I do have a question however :
> You cannot just "change the IP address" of a Tomcat's host dynamically, can
> you ?  So what's exactly the point of this whole exercise ?
> ---------------------------------------------------------------------
> The official User-To-User support forum of the Apache HTTP Server Project.
> See <URL:> for more info.
> To unsubscribe, e-mail:
>  "   from the digest:
> For additional commands, e-mail:

View raw message