MEDIUM: resolvers: add a ref on server to the used A/AAAA answer item
This patch adds a head list into answer items on servers which use
this record to set their IPs. It makes lookup on duplicated ip faster and
allow to check immediatly if an item is still valid renewing the IP.
This results in better performances on A/AAAA resolutions.
This is an optimization but it could avoid to trigger the haproxy's
internal wathdog in some circumstances. And for this reason
it should be backported as far we can (2.0 ?)
(cherry picked from commit bd78c912fd73b8506a39c53b6f0b00330f998aca)
Signed-off-by: Willy Tarreau <w@1wt.eu>
diff --git a/include/haproxy/resolvers-t.h b/include/haproxy/resolvers-t.h
index 96874aa..57d85f6 100644
--- a/include/haproxy/resolvers-t.h
+++ b/include/haproxy/resolvers-t.h
@@ -115,6 +115,7 @@
char target[DNS_MAX_NAME_SIZE+1]; /* Response data: SRV or CNAME type target */
unsigned int last_seen; /* When was the answer was last seen */
struct resolv_answer_item *ar_item; /* pointer to a RRset from the additional section, if exists */
+ struct list attached_servers; /* attached server head */
struct list list;
};
diff --git a/include/haproxy/resolvers.h b/include/haproxy/resolvers.h
index baf43d5..ba426fa 100644
--- a/include/haproxy/resolvers.h
+++ b/include/haproxy/resolvers.h
@@ -41,7 +41,7 @@
struct resolv_options *resolv_opts, void *currentip,
short currentip_sin_family,
void **newip, short *newip_sin_family,
- void *owner);
+ struct server *owner);
void resolv_purge_resolution_answer_records(struct resolv_resolution *resolution);
int resolv_link_resolution(void *requester, int requester_type, int requester_locked);
diff --git a/include/haproxy/server-t.h b/include/haproxy/server-t.h
index 714e248..1d2a449 100644
--- a/include/haproxy/server-t.h
+++ b/include/haproxy/server-t.h
@@ -365,6 +365,7 @@
#endif
#endif
struct resolv_srvrq *srvrq; /* Pointer representing the DNS SRV requeest, if any */
+ struct list ip_rec_item; /* to attach server to a A or AAAA record item */
struct {
const char *file; /* file where the section appears */
struct eb32_node id; /* place in the tree of used IDs */
diff --git a/src/resolvers.c b/src/resolvers.c
index fd887ec..02f0b68 100644
--- a/src/resolvers.c
+++ b/src/resolvers.c
@@ -575,7 +575,7 @@
struct resolvers *resolvers = res->resolvers;
struct resolv_requester *req;
struct resolv_answer_item *item, *itemback;
- struct server *srv;
+ struct server *srv, *srvback;
struct resolv_srvrq *srvrq;
list_for_each_entry_safe(item, itemback, &res->response.answer_list, list) {
@@ -592,32 +592,36 @@
/* Remove obsolete items */
if (tick_is_lt(tick_add(item->last_seen, resolvers->hold.obsolete), now_ms)) {
- if (item->type != DNS_RTYPE_SRV)
- goto rm_obselete_item;
-
- list_for_each_entry(req, &res->requesters, list) {
- if ((srvrq = objt_resolv_srvrq(req->owner)) == NULL)
- continue;
-
+ if (item->type == DNS_RTYPE_A || item->type == DNS_RTYPE_AAAA) {
/* Remove any associated server */
- for (srv = srvrq->proxy->srv; srv != NULL; srv = srv->next) {
- HA_SPIN_LOCK(SERVER_LOCK, &srv->lock);
- if (srv->srvrq == srvrq && srv->svc_port == item->port &&
- item->data_len == srv->hostname_dn_len &&
- !resolv_hostname_cmp(srv->hostname_dn, item->target, item->data_len)) {
- resolv_unlink_resolution(srv->resolv_requester, 0);
- srvrq_update_srv_status(srv, 1);
- ha_free(&srv->hostname);
- ha_free(&srv->hostname_dn);
- srv->hostname_dn_len = 0;
- memset(&srv->addr, 0, sizeof(srv->addr));
- srv->svc_port = 0;
+ list_for_each_entry_safe(srv, srvback, &item->attached_servers, ip_rec_item) {
+ LIST_DEL_INIT(&srv->ip_rec_item);
+ }
+ }
+ else if (item->type == DNS_RTYPE_SRV) {
+ list_for_each_entry(req, &res->requesters, list) {
+ if ((srvrq = objt_resolv_srvrq(req->owner)) == NULL)
+ continue;
+
+ /* Remove any associated server */
+ for (srv = srvrq->proxy->srv; srv != NULL; srv = srv->next) {
+ HA_SPIN_LOCK(SERVER_LOCK, &srv->lock);
+ if (srv->srvrq == srvrq && srv->svc_port == item->port &&
+ item->data_len == srv->hostname_dn_len &&
+ !resolv_hostname_cmp(srv->hostname_dn, item->target, item->data_len)) {
+ resolv_unlink_resolution(srv->resolv_requester, 0);
+ srvrq_update_srv_status(srv, 1);
+ ha_free(&srv->hostname);
+ ha_free(&srv->hostname_dn);
+ srv->hostname_dn_len = 0;
+ memset(&srv->addr, 0, sizeof(srv->addr));
+ srv->svc_port = 0;
+ }
+ HA_SPIN_UNLOCK(SERVER_LOCK, &srv->lock);
}
- HA_SPIN_UNLOCK(SERVER_LOCK, &srv->lock);
}
}
- rm_obselete_item:
LIST_DELETE(&item->list);
if (item->ar_item) {
pool_free(resolv_answer_item_pool, item->ar_item);
@@ -902,6 +906,7 @@
/* initialization */
answer_record->ar_item = NULL;
answer_record->last_seen = TICK_ETERNITY;
+ LIST_INIT(&answer_record->attached_servers);
offset = 0;
len = resolv_read_name(resp, bufend, reader, tmpname, DNS_MAX_NAME_SIZE, &offset, 0);
@@ -1153,6 +1158,7 @@
if (answer_record == NULL)
goto invalid_resp;
answer_record->last_seen = TICK_ETERNITY;
+ LIST_INIT(&answer_record->attached_servers);
offset = 0;
len = resolv_read_name(resp, bufend, reader, tmpname, DNS_MAX_NAME_SIZE, &offset, 0);
@@ -1311,7 +1317,6 @@
/* Save the number of records we really own */
r_res->header.arcount = nb_saved_records;
-
resolv_check_response(resolution);
return RSLV_RESP_VALID;
@@ -1335,9 +1340,9 @@
struct resolv_options *resolv_opts, void *currentip,
short currentip_sin_family,
void **newip, short *newip_sin_family,
- void *owner)
+ struct server *owner)
{
- struct resolv_answer_item *record;
+ struct resolv_answer_item *record, *found_record = NULL;
int family_priority;
int currentip_found;
unsigned char *newip4, *newip6;
@@ -1346,6 +1351,10 @@
int score, max_score;
int allowed_duplicated_ip;
+ /* srv is linked to an alive ip record */
+ if (owner && LIST_INLIST(&owner->ip_rec_item))
+ return RSLV_UPD_NO;
+
family_priority = resolv_opts->family_prio;
allowed_duplicated_ip = resolv_opts->accept_duplicate_ip;
*newip = newip4 = newip6 = NULL;
@@ -1410,9 +1419,25 @@
/* Check if the IP found in the record is already affected to a
* member of a group. If not, the score should be incremented
* by 2. */
- if (owner && snr_check_ip_callback(owner, ip, &ip_type)) {
- if (!allowed_duplicated_ip) {
- continue;
+ if (owner) {
+ struct server *srv;
+ int already_used = 0;
+
+ list_for_each_entry(srv, &record->attached_servers, ip_rec_item) {
+ if (srv == owner)
+ continue;
+ if (srv->proxy == owner->proxy) {
+ already_used = 1;
+ break;
+ }
+ }
+ if (already_used) {
+ if (!allowed_duplicated_ip) {
+ continue;
+ }
+ }
+ else {
+ score += 2;
}
} else {
score += 2;
@@ -1439,9 +1464,15 @@
newip4 = ip;
else
newip6 = ip;
+ found_record = record;
currentip_found = currentip_sel;
- if (score == 15)
+ if (score == 15) {
+ /* this was not registered on the current record but it matches
+ * let's fix it (it may comes from state file */
+ if (owner)
+ LIST_APPEND(&found_record->attached_servers, &owner->ip_rec_item);
return RSLV_UPD_NO;
+ }
max_score = score;
}
} /* list for each record entries */
@@ -1494,6 +1525,12 @@
return RSLV_UPD_NO;
not_found:
+
+ /* the ip of this record was chosen for the server */
+ if (owner && found_record) {
+ LIST_APPEND(&found_record->attached_servers, &owner->ip_rec_item);
+ }
+
list_for_each_entry(record, &r_res->answer_list, list) {
/* Move the first record to the end of the list, for internal
* round robin */
@@ -1832,12 +1869,18 @@
{
struct resolv_resolution *res;
struct resolv_requester *req;
+ struct server *srv;
/* Nothing to do */
if (!requester || !requester->resolution)
return;
res = requester->resolution;
+ /* remove ref from the resolution answer item list to the requester */
+ if ((srv = objt_server(requester->owner)) != NULL) {
+ LIST_DEL_INIT(&srv->ip_rec_item);
+ }
+
/* Clean up the requester */
LIST_DELETE(&requester->list);
requester->resolution = NULL;
diff --git a/src/server.c b/src/server.c
index 7f4e34f..a7a3812 100644
--- a/src/server.c
+++ b/src/server.c
@@ -2164,6 +2164,7 @@
srv->proxy = proxy;
srv->pendconns = EB_ROOT;
LIST_APPEND(&servers_list, &srv->global_list);
+ LIST_INIT(&srv->ip_rec_item);
srv->next_state = SRV_ST_RUNNING; /* early server setup */
srv->last_change = now.tv_sec;
@@ -3530,6 +3531,7 @@
if (!snr_update_srv_status(s, 1)) {
memset(&s->addr, 0, sizeof(s->addr));
HA_SPIN_UNLOCK(SERVER_LOCK, &s->lock);
+ LIST_DEL_INIT(&s->ip_rec_item);
return 0;
}
HA_SPIN_UNLOCK(SERVER_LOCK, &s->lock);