A couple of curly questions.

Thanks in advance to all those that will respond to these questions.

I will accept part answers, if you only know for certain one of these
scenarios, please tell me.

I am in the process of how best to design my proxy hierarchy, which will
effect a lot of users.

Thanks,

Dave.

QUESTIONS:
---------

1) I want a couple of proxies to sit in front of a real proxy that caches
the information. Like the following situation:

                        Proxy/Cache
                        / | \
                       / | \
                      / | \
                Proxy 1 Proxy 2 Proxy 3

  I do not want Proxy 1, PRoxy 2 or Proxy 3 to store anything in their
local cache. I want them to get all their information from the parent
Proxy/Cache.

Q: How would I implement this, should I just set the cache_swap to 0 or is
there a tricky way of doing this? first_level_swap_dir 0,
second_level_swap_dir 0???

2) Take the following scenario:

        Proxy 1 ---------------- Proxy 2
        / \
       / \
      / \
Proxy A Proxy B
  |
  |
Browser

If the Browser requests a page, it asks Proxy A for the page, Proxy A
does not have it. Proxy A then asks parent Proxy 1 for the page, Proxy 1
does not have the page, so then asks it's sibling Proxy 2. Proxy 2 has
the page.

Q: What is stored in Proxy A's access.log??

                TCP_MISS:FIRST_PARENT_MISS??

   I want to know whether the parent fetched it direct or from a sibling,
is that possible??

3) Take this scenario:

        Proxy_1 Proxy_2
     ----------- -------------
     | Page Z | | Page Y |
     | | | |
     ----------- -------------
              \ /
               \ /
                \ /
                 ---- Proxy A -----
                        |
                        |
                     Browser

  Proxy A has the following configuration:

            cache_host Proxy_1 parent 3128 3130
        cache_host Proxy_2 parent 3128 3130

  Proxy_1 and Proxy_2 are not siblings.

Q: If the browser requests page Y, which is cached at Proxy_2, how does it
get it??
Does Proxy A first query Proxy_1 about the page, and a false value get
returned. Then it queries Proxy_2 about the page, Proxy_2 has the page so
returns a true value. The page then gets delivered to Proxy A then to
Browser.

OR -> Does Proxy A send off concurrent requests to both Proxy_1 and
Proxy_2, then waits on a true signal from one, and if it gets a true value
returned, it gets the page from that proxy.

Another Q: What if Proxy A receives a false value from both Proxy_1 and
Proxy_2?? Who retrieves it for Proxy A??

4) Final Question:

        Take this scenario:

        Proxy_1 ---------------------- Proxy_2
     ----------- -------------
     | Page Z | | Page Y |
     | | | |
     ----------- -------------
              \ /
               \ /
                \ /
                 ---- Proxy A -----
                        |
                        |
                     Browser

 This time Proxy_1 and Proxy_2 are siblings. Proxy A's configuration is
the following:

        cache_host Proxy_1 parent 3128 3130
        cache_host Proxy_2 parent 3128 3130

Q: If Proxy A requests page Y which is at Proxy_2, will Proxy A firstly
query Proxy_1, who will then query it's sibling Proxy_2? Proxy_2 has the
page, Proxy_2 will deliver it to Proxy_1, then to Proxy_1 will deliver it
to Proxy_A...

OR ........

Thanks for this,

----------------------------------------------------------------------
David Richards Ph: +61 7 3864 4354
Computing Services e-mail: dj.richards@qut.edu.au
Queensland University of Technology
----------------------------------------------------------------------
Received on Wed May 14 1997 - 23:21:58 MDT