mod_jk2, load balancing and TC:TDC

[Timothy Stone <ci...@petmystone.com>]

List,

O'Reilly's new /Tomcat:The Definitive Guide/ is worth the purchase. But 
something seems a miss in the chapter on load balancing Tomcats with 
mod_jk2.

I want to provide load balancing and failover as illustrated in the book 
(pg. 237, fig. 10-2).

For those without the book, here's the ASCII:

       ----          +           +------+----+      +------+
      /    \--       +     +---->|      |    |----->|      |
    --        \      +     |     +------+----+      +------+
   / Internet /----->+-----+      httpd0 mjk2 .   .^  tc0
   \__      --       +     |                   . .
      \----/         +     |                    .
                     +     |                   . .
                     +     |                  .   .
                     +     |     +------+----+     >+------+
                     +     +---->|      |    |----->|      |
                     +           +------+----+      +------+
                                  httpd1 mjk2           tc1


What's not clear in the book, or the documentation, is if mod_jk2 on a 
given httpd instance "autodiscovers" other tomcat? The 
workers2.properties file given is not clear either. I think it's 
implied, but poorly. Is this a black mark on an otherwise great book? 
Possibly.

I think what is being unsaid, is that both HTTPD's workers2.properties 
files provide tomcatIds that point to the "jvmRoutes" of the respective 
tomcat. Can anyone clarify? The book otherwise teases me as I have a 
production environment that could greatly benefit from upgrading to 
mod_jk2 v. mod_jk and the topology outlined in the book /TC:TDC/.

Thanks in advance to all!
Tim