Philip Hazel wrote:
>
> On Thu, 10 Jun 1999, Tony Abbott wrote:
>
> > sorry, guess I wasn't too clear there. I did mean if the query defers,
> > if by that you mean 'server unreachable' or some similar temporary
> > failure. You could then specify a second query that is identical except
> > for the server name. I just think it would be better than creating
> > extensions to an established URL syntax.
>
> Michael is right in finding a problem here. A lookup such as
>
> ${lookup ldap {<url>}{true-string}{false-string}}
>
> has no provision for handling defers. Inside drivers, action is usually
> taken at a higher level. "Some lookup we are doing couldn't be
> completed: better defer delivery" is what usually happens.
I agree that there is a problem here. It's pointless having replicated
LDAP servers and not making good use of them! What I'm suggesting is
that instead of changing the syntax of the query URL, which (correct me
if I'm wrong) is defined in some RFC, rather allow fallback query URL's
to be specified, say something along the lines of:
${lookup ldap {{<url1>}{<url2>}{<urln>}}{true-string}{false-string}}
If the first query defers, the second is tried, and so on. All that will
change between the query URLs is the hostname, but you do also have the
option of changing the rest too (although I can't fathom why one would
want to do this.)
Personally I just don't like the idea of modifying a well established
query syntax in a nonstandard way...
-t
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Tony Abbott tabbott@???
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http://www.intekom.co.za Fax: +27-11-315-0707
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