Blacklist when 16 queries fail in a row.

git-svn-id: file:///svn/unbound/trunk@1764 be551aaa-1e26-0410-a405-d3ace91eadb9

daemon/cachedump.c

@@ -786,7 +786,7 @@ print_dp_details(SSL* ssl, struct worker* worker, struct delegpt* dp)
 {
 	char buf[257];
 	struct delegpt_addr* a;
-	int lame, dlame, rlame, rtt, edns_vs, to;
+	int lame, dlame, rlame, rtt, edns_vs, to, lost;
 	uint8_t edns_lame_known;
 	for(a = dp->target_list; a; a = a->next_target) {
 		addr_to_str(&a->addr, a->addrlen, buf, sizeof(buf));
@@ -801,15 +801,15 @@ print_dp_details(SSL* ssl, struct worker* worker, struct delegpt* dp)
 		 * lameness won't be reported then */
 		if(!infra_get_lame_rtt(worker->env.infra_cache, 
 			&a->addr, a->addrlen, dp->name, dp->namelen,
-			LDNS_RR_TYPE_A, &lame, &dlame, &rlame, &rtt, 
+			LDNS_RR_TYPE_A, &lame, &dlame, &rlame, &rtt, &lost,
 			*worker->env.now)) {
 			if(!ssl_printf(ssl, "not in infra cache.\n"))
 				return;
 			continue; /* skip stuff not in infra cache */
 		}
-		if(!ssl_printf(ssl, "%s%s%srtt %d msec. ",
+		if(!ssl_printf(ssl, "%s%s%srtt %d msec, %d lost. ",
 			lame?"LAME ":"", dlame?"NoDNSSEC ":"",
-			rlame?"NoAuthButRecursive ":"", rtt))
+			rlame?"NoAuthButRecursive ":"", rtt, lost))
 			return;
 		if(infra_host(worker->env.infra_cache, &a->addr, a->addrlen,
 			*worker->env.now, &edns_vs, &edns_lame_known, &to)) {

doc/Changelog

@@ -1,3 +1,7 @@
+17 August 2009: Wouter
+	- Fix so that servers are only blacklisted if they fail to reply 
+	  to 16 queries in a row and the timeout gets above 2 minutes.
+
 14 August 2009: Wouter
 	- unbound-control lookup prints out infra cache information, like RTT.
 	- Fix bug in DLV lookup reported by Amanda from Secure64.

iterator/iter_utils.c

@@ -151,6 +151,8 @@ iter_apply_cfg(struct iter_env* iter_env, struct config_file* cfg)
  *		values 0 .. 49 are not used, unless that is changed.
  *	USEFUL_SERVER_TOP_TIMEOUT
  *		This value exactly is given for unresponsive blacklisted.
+ *	USEFUL_SERVER_TOP_TIMEOUT+1
+ *		For non-blacklisted servers: huge timeout, but has traffic.
  *	USEFUL_SERVER_TOP_TIMEOUT ..
  *		dnsseclame servers get penalty
  *	USEFUL_SERVER_TOP_TIMEOUT*2 ..
@@ -170,7 +172,7 @@ iter_filter_unsuitable(struct iter_env* iter_env, struct module_env* env,
 	uint8_t* name, size_t namelen, uint16_t qtype, uint32_t now, 
 	struct delegpt_addr* a)
 {
-	int rtt, lame, reclame, dnsseclame;
+	int rtt, lame, reclame, dnsseclame, lost;
 	if(a->bogus)
 		return -1; /* address of server is bogus */
 	if(donotq_lookup(iter_env->donotq, &a->addr, a->addrlen)) {
@@ -182,7 +184,7 @@ iter_filter_unsuitable(struct iter_env* iter_env, struct module_env* env,
 	/* check lameness - need zone , class info */
 	if(infra_get_lame_rtt(env->infra_cache, &a->addr, a->addrlen, 
 		name, namelen, qtype, &lame, &dnsseclame, &reclame, 
-		&rtt, now)) {
+		&rtt, &lost, now)) {
 		log_addr(VERB_ALGO, "servselect", &a->addr, a->addrlen);
 		verbose(VERB_ALGO, "   rtt=%d%s%s%s", rtt,
 			lame?" LAME":"",
@@ -190,9 +192,12 @@ iter_filter_unsuitable(struct iter_env* iter_env, struct module_env* env,
 			reclame?" REC_LAME":"");
 		if(lame)
 			return -1; /* server is lame */
-		else if(rtt >= USEFUL_SERVER_TOP_TIMEOUT)
+		else if(rtt >= USEFUL_SERVER_TOP_TIMEOUT && 
+			lost >= USEFUL_SERVER_MAX_LOST)
 				/* server is unresponsive */
 			return USEFUL_SERVER_TOP_TIMEOUT; 
+		else if(rtt >= USEFUL_SERVER_TOP_TIMEOUT) /* not blacklisted*/
+			return USEFUL_SERVER_TOP_TIMEOUT+1; 
 		else if(reclame)
 			return rtt+USEFUL_SERVER_TOP_TIMEOUT*2; /* nonpref */
 		else if(dnsseclame )

iterator/iterator.h

@@ -65,6 +65,10 @@ struct iter_priv;
  * Equals RTT_MAX_TIMEOUT
  */
 #define USEFUL_SERVER_TOP_TIMEOUT	120000
+/** Number of lost messages in a row that get a host blacklisted.
+ * With 16, a couple different queries have to time out and no working
+ * queries are happening */
+#define USEFUL_SERVER_MAX_LOST	16
 /** number of retries on outgoing queries */
 #define OUTBOUND_MSG_RETRY 5
 /** RTT band, within this amount from the best, servers are chosen randomly.

services/cache/infra.c

@@ -219,6 +219,7 @@ new_host_entry(struct infra_cache* infra, struct sockaddr_storage* addr,
 	data->lameness = NULL;
 	data->edns_version = 0;
 	data->edns_lame_known = 0;
+	data->num_timeouts = 0;
 	rtt_init(&data->rtt);
 	return &key->entry;
 }
@@ -471,9 +472,14 @@ infra_rtt_update(struct infra_cache* infra,
 	/* have an entry, update the rtt, and the ttl */
 	data = (struct infra_host_data*)e->data;
 	data->ttl = timenow + infra->host_ttl;
-	if(roundtrip == -1)
+	if(roundtrip == -1) {
 		rtt_lost(&data->rtt, orig_rtt);
-	else	rtt_update(&data->rtt, roundtrip);
+		if(data->num_timeouts<255)
+			data->num_timeouts++; 
+	} else {
+		rtt_update(&data->rtt, roundtrip);
+		data->num_timeouts = 0;
+	}
 	if(data->rtt.rto > 0)
 		rto = data->rtt.rto;
 
@@ -513,7 +519,8 @@ int
 infra_get_lame_rtt(struct infra_cache* infra,
         struct sockaddr_storage* addr, socklen_t addrlen,
         uint8_t* name, size_t namelen, uint16_t qtype, 
-	int* lame, int* dnsseclame, int* reclame, int* rtt, uint32_t timenow)
+	int* lame, int* dnsseclame, int* reclame, int* rtt, int* lost,
+	uint32_t timenow)
 {
 	struct infra_host_data* host;
 	struct lruhash_entry* e = infra_lookup_host_nottl(infra, addr, 
@@ -523,6 +530,7 @@ infra_get_lame_rtt(struct infra_cache* infra,
 		return 0;
 	host = (struct infra_host_data*)e->data;
 	*rtt = rtt_unclamped(&host->rtt);
+	*lost = (int)host->num_timeouts;
 	/* check lameness first, if so, ttl on host does not matter anymore */
 	if(infra_lookup_lame(host, name, namelen, timenow, 
 		&dlm, &rlm, &alm, &olm)) {

services/cache/infra.h

@@ -74,6 +74,8 @@ struct infra_host_data {
 	 * EDNS lame is when EDNS queries or replies are dropped, 
 	 * and cause a timeout */
 	uint8_t edns_lame_known;
+	/** Number of consequtive timeouts; reset when reply arrives OK. */
+	uint8_t num_timeouts;
 };
 
 /**
@@ -270,13 +272,16 @@ int infra_edns_update(struct infra_cache* infra,
  * @param reclame: if function returns true, this is if it is recursion lame.
  * @param rtt: if function returns true, this returns avg rtt of the server.
  * 	The rtt value is unclamped and reflects recent timeouts.
+ * @param lost: number of queries lost in a row.  Reset to 0 when an answer
+ * 	gets back.  Gives a connectivity number.
  * @param timenow: what time it is now.
  * @return if found in cache, or false if not (or TTL bad).
  */
 int infra_get_lame_rtt(struct infra_cache* infra,
         struct sockaddr_storage* addr, socklen_t addrlen, 
 	uint8_t* name, size_t namelen, uint16_t qtype, 
-	int* lame, int* dnsseclame, int* reclame, int* rtt, uint32_t timenow);
+	int* lame, int* dnsseclame, int* reclame, int* rtt, int* lost,
+	uint32_t timenow);
 
 /**
  * Get memory used by the infra cache.