Skip to content

delay DNS for origin server until it is required #1756

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
vmamidi merged 1 commit into from
May 7, 2017
Merged

delay DNS for origin server until it is required #1756

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
38 changes: 23 additions & 15 deletions proxy/http/HttpTransact.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1494,6 +1494,9 @@ HttpTransact::PPDNSLookup(State *s)
if (!s->current.server->dst_addr.isValid()) {
if (s->current.request_to == PARENT_PROXY) {
TRANSACT_RETURN(SM_ACTION_DNS_LOOKUP, PPDNSLookup);
} else if (s->parent_result.result == PARENT_DIRECT && s->http_config_param->no_dns_forward_to_parent != 1) {
// We ran out of parents but parent configuration allows us to go to Origin Server directly
TRANSACT_RETURN(SM_ACTION_DNS_LOOKUP, OSDNSLookup);
} else {
// We could be out of parents here if all the parents failed DNS lookup
ink_assert(s->current.request_to == HOST_NONE);
Expand Down Expand Up @@ -1978,6 +1981,9 @@ HttpTransact::LookupSkipOpenServer(State *s)

if (s->current.request_to == PARENT_PROXY) {
TRANSACT_RETURN(SM_ACTION_DNS_LOOKUP, PPDNSLookup);
} else if (s->parent_result.result == PARENT_FAIL) {
handle_parent_died(s);
return;
}

ink_assert(s->current.request_to == ORIGIN_SERVER);
Expand Down Expand Up @@ -2176,13 +2182,10 @@ HttpTransact::HandleCacheOpenRead(State *s)
// cache miss
DebugTxn("http_trans", "CacheOpenRead -- miss");
SET_VIA_STRING(VIA_DETAIL_CACHE_LOOKUP, VIA_DETAIL_MISS_NOT_CACHED);
// StartAccessControl(s);
if (s->force_dns) {
HandleCacheOpenReadMiss(s);
} else {
// Cache Lookup Unsuccessful ..calling dns lookup
TRANSACT_RETURN(SM_ACTION_DNS_LOOKUP, OSDNSLookup);
}
// Perform DNS for the origin when it is required.
// 1. If parent configuration does not allow to go to origin there is no need of performing DNS
// 2. If parent satisfies the request there is no need to go to origin to perfrom DNS
HandleCacheOpenReadMiss(s);
} else {
// cache hit
DebugTxn("http_trans", "CacheOpenRead -- hit");
Expand Down Expand Up @@ -3129,7 +3132,12 @@ HttpTransact::HandleCacheOpenReadMiss(State *s)
return;
}
if (!s->current.server->dst_addr.isValid()) {
ink_release_assert(s->current.request_to == PARENT_PROXY || s->http_config_param->no_dns_forward_to_parent != 0);
ink_release_assert(s->parent_result.result == PARENT_DIRECT || s->current.request_to == PARENT_PROXY ||
s->http_config_param->no_dns_forward_to_parent != 0);
if (s->parent_result.result == PARENT_DIRECT && s->http_config_param->no_dns_forward_to_parent != 1) {
TRANSACT_RETURN(SM_ACTION_DNS_LOOKUP, OSDNSLookup);
return;
}
if (s->current.request_to == PARENT_PROXY) {
TRANSACT_RETURN(SM_ACTION_DNS_LOOKUP, HttpTransact::PPDNSLookup);
} else {
Expand All @@ -3138,8 +3146,11 @@ HttpTransact::HandleCacheOpenReadMiss(State *s)
}
}
build_request(s, &s->hdr_info.client_request, &s->hdr_info.server_request, s->current.server->http_version);

s->next_action = how_to_open_connection(s);
s->current.attempts = 0;
s->next_action = how_to_open_connection(s);
if (s->current.server == &s->server_info && s->next_hop_scheme == URL_WKSIDX_HTTP) {
HttpTransactHeaders::remove_host_name_from_url(&s->hdr_info.server_request);
}
} else { // miss, but only-if-cached is set
build_error_response(s, HTTP_STATUS_GATEWAY_TIMEOUT, "Not Cached", "cache#not_in_cache");
s->next_action = SM_ACTION_SEND_ERROR_CACHE_NOOP;
Expand Down Expand Up @@ -3639,11 +3650,8 @@ HttpTransact::handle_response_from_parent(State *s)
TRANSACT_RETURN(SM_ACTION_DNS_LOOKUP, PPDNSLookup);
break;
case ORIGIN_SERVER:
s->current.attempts = 0;
s->next_action = how_to_open_connection(s);
if (s->current.server == &s->server_info && s->next_hop_scheme == URL_WKSIDX_HTTP) {
HttpTransactHeaders::remove_host_name_from_url(&s->hdr_info.server_request);
}
// Next lookup is Origin Server, try DNS for Origin Server
TRANSACT_RETURN(SM_ACTION_DNS_LOOKUP, OSDNSLookup);
break;
case HOST_NONE:
handle_parent_died(s);
Expand Down