- From: Klaus Weide <kweide@tezcat.com>
- Date: Wed, 3 Feb 1999 10:44:13 -0600 (CST)
- To: www-lib@w3.org
Trying to understand the logic of the DNS cache, I found several things
that look wrong. First, the comparison logic in HTGetHostByName makes
it obvious that "small number" is "good". (The comment
double best_weight = 1e30; /* Pretty good */
is misleading.) But HTDoConnect passes a negative value to
HTDNS_updateWeigths as deltatime after a successful connect.
Fix: replace the two occurrences in HTTCP.c of
me->connecttime -= HTGetTimeInMillis();
with
me->connecttime = HTGetTimeInMillis() - me->connecttime;
Second, the values in HTTCP.c's #defines for TCP_PENALTY and TCP_DELAY
seem to be meant as seconds, but are added to me->connecttime
directly - there's a facor of 1000 missing somewhere.
Questions: HTDoConnect has
if (HT_HOSTUNREACHABLE(socerrno))
me->connecttime += TCP_DELAY;
else
me->connecttime += TCP_PENALTY;
Shouldn't that be the other way?
What are the other errors, anticipated to not be covered by
HT_HOSTUNREACHABLE? The comment for TCP_DELAY says:
/* x seconds penalty on a multi-homed host if IP-address is timed out */
Is the code using TCP_DELAY actually reached if a conect timeout occurs?
Nit: the spelling of "Weight" in HTDNS_updateWeigths (and some trace
messages in that function) is wrong. I only noticed when searching
for "weight" didn't find anything. :)
Klaus
Received on Wednesday, 3 February 1999 11:44:21 UTC