remove 'nalives' check and update strategy.

src/nameservice/UpstreamPolicies.cc

@@ -167,11 +167,6 @@ bool UPSGroupPolicy::select(const ParsedURI& uri, WFNSTracing *tracing,
 	}
 
 	this->check_breaker();
-	if (this->nalives == 0)
-	{
-		pthread_rwlock_unlock(&this->rwlock);
-		return false;
-	}
 
 	// select_addr == NULL will only happened in consistent_hash
 	EndpointAddress *select_addr = this->first_strategy(uri, tracing);
@@ -510,9 +505,10 @@ EndpointAddress *UPSWeightedRandomPolicy::first_strategy(const ParsedURI& uri,
 EndpointAddress *UPSWeightedRandomPolicy::another_strategy(const ParsedURI& uri,
 														   WFNSTracing *tracing)
 {
-	/* When all servers down, recover all. */
+	/* When all servers are down, recover all servers if any server
+	 * reaches fusing timeout. */
 	if (this->available_weight == 0)
-		this->clear_breaker();
+		this->try_clear_breaker();
 
 	int temp_weight = this->available_weight;
 	if (temp_weight == 0)

src/nameservice/WFServiceGovernance.cc

@@ -274,6 +274,8 @@ void WFServiceGovernance::check_breaker_locked(int64_t cur_time)
 			list_del(pos);
 			pos->next = NULL;
 		}
+		else
+			break;
 	}
 }
 
@@ -285,10 +287,17 @@ void WFServiceGovernance::check_breaker()
 	pthread_mutex_unlock(&this->breaker_lock);
 }
 
-void WFServiceGovernance::clear_breaker()
+void WFServiceGovernance::try_clear_breaker()
 {
 	pthread_mutex_lock(&this->breaker_lock);
-	this->check_breaker_locked(INT64_MAX);
+	if (!list_empty(&this->breaker_list))
+	{
+		struct list_head *pos = this->breaker_list.next;
+		struct EndpointAddress::address_entry *entry;
+		entry = list_entry(pos, struct EndpointAddress::address_entry, list);
+		if (GET_CURRENT_SECOND >= entry->ptr->broken_timeout)
+			this->check_breaker_locked(INT64_MAX);
+	}
 	pthread_mutex_unlock(&this->breaker_lock);
 }
 

src/nameservice/WFServiceGovernance.h

@@ -175,8 +175,8 @@ protected:
 											WFNSTracing *tracing);
 	virtual EndpointAddress *another_strategy(const ParsedURI& uri,
 											  WFNSTracing *tracing);
-	void clear_breaker();
 	void check_breaker();
+	void try_clear_breaker();
 	void pre_delete_server(EndpointAddress *addr);
 
 	struct TracingData