----- Original Message -----
> Hi,
>
> There was an issue raised in the user mail thread about disabling
> dns. I have also been looking at this.
>
> I am using TS 3.0.1 on fedora 14 and ubuntu 10.04.
>
> When this flag is set the DNS lookup event before the
For context, quoting myself from users@
in forward proxy mode:
CONFIG proxy.config.http.no_dns_just_forward_to_parent INT 1
> HTTP_OS_DNS_HOOK does not appear to be called.
> However there is a DNS lookup performed after the cache lookup when
> it is a miss.
>
> Here is an extract from the logfile, with the DNS lookup:
> [Dec 6 10:16:01.619] Server {3066604400} DEBUG: (http) [0]
> [&HttpSM::state_api_callout, HTTP_API_CONTINUE]
> [Dec 6 10:16:01.619] Server {3066604400} DEBUG: (http_trans)
> [HttpTransact::HandleCacheOpenRead]
> [Dec 6 10:16:01.619] Server {3066604400} DEBUG: (http_trans)
> CacheOpenRead -- miss
> [Dec 6 10:16:01.619] Server {3066604400} DEBUG: (http_trans) Next
> action DNS_LOOKUP; OSDNSLookup
> [Dec 6 10:16:01.619] Server {3066604400} DEBUG: (http) [0] State
> Transition: CACHE_LOOKUP -> DNS_LOOKUP
> [Dec 6 10:16:01.619] Server {3066604400} DEBUG: (http_seq)
> [HttpStateMachineGet::do_hostdb_lookup] Doing DNS Lookup
> [Dec 6 10:16:01.639] Server {3066604400} DEBUG: (dns) received
> query trafficserver.apache.org type = 1, timeout = 0
> [Dec 6 10:16:01.640] Server {3086886720} DEBUG: (dns) enqueing
> query trafficserver.apache.org
> [Dec 6 10:16:01.640] Server {3086886720} DEBUG: (dns) adding first
> to collapsing queue
> [Dec 6 10:16:01.640] Server {3086886720} DEBUG: (dns) send query
> for trafficserver.apache.org to fd 38
> [Dec 6 10:16:01.640] Server {3086886720} DEBUG: (dns) sent qname =
> trafficserver.apache.org, id = 4377, nameserver = 0
> [Dec 6 10:16:01.640] Server {3086886720} DEBUG: (dns) sent_one:
> failover_number for resolver 0 is 1
> [Dec 6 10:16:02.082] Server {3086886720} DEBUG: (dns) received
> packet size = 274
> [Dec 6 10:16:02.082] Server {3086886720} DEBUG: (dns) primary DNS
> response code = 0
> [Dec 6 10:16:02.082] Server {3086886720} DEBUG: (dns) received A
> name = trafficserver.apache.org
> [Dec 6 10:16:02.082] Server {3086886720} DEBUG: (dns) received A =
> 140.211.11.131
> [Dec 6 10:16:02.082] Server {3086886720} DEBUG: (dns) SUCCESS
> result for trafficserver.apache.org = 140.211.11.131 retry 0
> [Dec 6 10:16:02.082] Server {3066604400} DEBUG: (dns) called back
> continuation for trafficserver.apache.org
> [Dec 6 10:16:02.082] Server {3066604400} DEBUG: (http) [0]
> [HttpSM::main_handler, EVENT_HOST_DB_LOOKUP]
> [Dec 6 10:16:02.082] Server {3066604400} DEBUG: (http) [0]
> [&HttpSM::state_hostdb_lookup, EVENT_HOST_DB_LOOKUP]
> [Dec 6 10:16:02.082] Server {3066604400} DEBUG: (http_trans)
> [HttpTransact::OSDNSLookup] This was attempt 1
> [Dec 6 10:16:02.082] Server {3066604400} DEBUG: (http_seq)
> [HttpTransact::OSDNSLookup] DNS Lookup successful
> [Dec 6 10:16:02.082] Server {3066604400} DEBUG: (http_trans)
> [OSDNSLookup] DNS lookup for O.S. successful IP: 140.211.11.131
> [Dec 6 10:16:02.082] Server {3066604400} DEBUG: (http_trans) Next
> action HttpTransact::HTTP_API_OS_DNS; HandleCacheOpenReadMiss
> [Dec 6 10:16:02.082] Server {3066604400} DEBUG: (http) [0] State
> Transition: DNS_LOOKUP -> API_OS_DNS
> [Dec 6 10:16:02.082] Server {3066604400} DEBUG: (http_trans)
> [HandleCacheOpenReadMiss] --- MISS
> [Dec 6 10:16:02.082] Server {3066604400} DEBUG: (http_seq)
> [HttpTransact::HandleCacheOpenReadMiss] Miss in cache
> [Dec 6 10:16:02.082] Server {3066604400} DEBUG: (http_trans) Next
> action DNS_LOOKUP; HttpTransact::PPDNSLookup
> [Dec 6 10:16:02.082] Server {3066604400} DEBUG: (http) [0] State
> Transition: API_OS_DNS -> DNS_LOOKUP
> [Dec 6 10:16:02.082] Server {3066604400} DEBUG: (dns)
> [HttpTransact::HandleRequest] Skipping DNS lookup, provided by
> plugin
> [Dec 6 10:16:02.082] Server {3066604400} DEBUG: (http_trans)
> [HttpTransact::PPDNSLookup] This was attempt 1
>
> It maybe related to the following issues:
> https://issues.apache.org/jira/browse/TS-859
> https://issues.apache.org/jira/browse/TS-905
>
> I have applied the fix for 859 to my copy.
>
> I have also made the following change and it appears to fix the
> problem with the DNS lookup, the code was added to line 6413 in
> HttpSM.cc. I probably should
> added something to check that a parent has been specified also, if
Hah, yeah :)
> somebody could review and comment I would be really grateful.
>
> } else if (t_state.parent_result.r == PARENT_UNDEFINED &&
> t_state.dns_info.lookup_success) {
> Debug("dns", "[HttpTransact::HandleRequest] Skipping DNS
> lookup, provided by plugin");
> call_transact_and_set_next_state(NULL);
> break;
> /* change start */
> } else if (t_state.dns_info.looking_up ==
> HttpTransact::ORIGIN_SERVER &&
> t_state.http_config_param->no_dns_forward_to_parent){
> Debug("dns", "[HttpTransact::HandleRequest] Skipping DNS
> lookup, no_dns_forward_to_parent turned on");
> t_state.dns_info.lookup_success = true;
> call_transact_and_set_next_state(NULL);
> break;
> /* change end */
(I hope someone with some actual mad skillz can take care of this part :)
> Regards,
>
> Kevin.
So long,
i
--
Igor Galić
Tel: +43 (0) 664 886 22 883
Mail: i.ga...@brainsware.org
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