diff --git a/docs/about-timer.md b/docs/about-timer.md
index ffa99a93..bea28129 100644
--- a/docs/about-timer.md
+++ b/docs/about-timer.md
@@ -10,10 +10,10 @@ using timer_callback_t = std::function<void (WFTimerTask *)>;
 
 class WFTaskFactory
 {
-...
+    ...
     static WFTimerTask *create_timer_task(unsigned int microseconds,
                                           timer_callback_t callback);
-	static WFTimerTask *create_timer_task(time_t seconds, long nanoseconds,
+    static WFTimerTask *create_timer_task(time_t seconds, long nanoseconds,
                                           timer_callback_t callback);
 };
 ~~~
diff --git a/docs/en/about-timer.md b/docs/en/about-timer.md
index b6a705bb..4e4c4a1c 100644
--- a/docs/en/about-timer.md
+++ b/docs/en/about-timer.md
@@ -11,7 +11,7 @@ using timer_callback_t = std::function<void (WFTimerTask *)>;
 
 class WFTaskFactory
 {
-...
+    ...
     static WFTimerTask *create_timer_task(unsigned int microseconds,
                                           timer_callback_t callback);
     static WFTimerTask *create_timer_task(time_t seconds, long nanoseconds,
diff --git a/src/manager/UpstreamManager.h b/src/manager/UpstreamManager.h
index d1e4290a..aef93df2 100644
--- a/src/manager/UpstreamManager.h
+++ b/src/manager/UpstreamManager.h
@@ -44,7 +44,7 @@
  * - Additional, we support Main-backup & Group for server and working well in any mode.
  *
  * @code{.cc}
-	upstream_create_weighted_random("abc.sogou", true);           //UPSTREAM_WIGHTED_RANDOM
+	upstream_create_weighted_random("abc.sogou", true);           //UPSTREAM_WEIGHTED_RANDOM
 	upstream_add_server("abc.sogou", "192.168.2.100:8081");       //weight=1, max_fails=200
 	upstream_add_server("abc.sogou", "192.168.2.100:9090");       //weight=1, max_fails=200
 	AddressParams params = ADDRESS_PARAMS_DEFAULT;
diff --git a/src/nameservice/UpstreamPolicies.cc b/src/nameservice/UpstreamPolicies.cc
index 0d3959f3..55de99f2 100644
--- a/src/nameservice/UpstreamPolicies.cc
+++ b/src/nameservice/UpstreamPolicies.cc
@@ -194,17 +194,17 @@ bool UPSGroupPolicy::select(const ParsedURI& uri, WFNSTracing *tracing,
 }
 
 /*
- * flag true : return an available one. If not exists, return NULL.
- *      false: means addr maybe group-alive.
- *      	   If addr is not available, get one from addr->group.
+ * addr_failed true: return an available one. If not exists, return NULL.
+ * 			  false: means addr maybe group-alive.
+ * 					 If addr is not available, get one from addr->group.
  */
 EndpointAddress *UPSGroupPolicy::check_and_get(EndpointAddress *addr,
-											   bool flag,
+											   bool addr_failed,
 											   WFNSTracing *tracing)
 {
 	UPSAddrParams *params = static_cast<UPSAddrParams *>(addr->params);
 
-	if (flag == true) // && addr->fail_count >= addr->params->max_fails
+	if (addr_failed == true) // means fail_count >= max_fails
 	{
 		if (params->group_id == -1)
 			return NULL;
@@ -397,7 +397,8 @@ int UPSGroupPolicy::remove_server_locked(const std::string& address)
 	return ret;
 }
 
-EndpointAddress *UPSGroupPolicy::consistent_hash_with_group(unsigned int hash)
+EndpointAddress *UPSGroupPolicy::consistent_hash_with_group(unsigned int hash,
+															WFNSTracing *tracing)
 {
 	const UPSAddrParams *params;
 	EndpointAddress *addr = NULL;
@@ -427,7 +428,7 @@ EndpointAddress *UPSGroupPolicy::consistent_hash_with_group(unsigned int hash)
 	if (!addr)
 		return NULL;
 
-	return this->check_and_get(addr, false, NULL);
+	return this->check_and_get(addr, false, tracing);
 }
 
 void UPSWeightedRandomPolicy::add_server_locked(EndpointAddress *addr)
@@ -636,7 +637,7 @@ EndpointAddress *UPSConsistentHashPolicy::first_strategy(const ParsedURI& uri,
 										uri.path ? uri.path : "",
 										uri.query ? uri.query : "",
 										uri.fragment ? uri.fragment : "");
-	return this->consistent_hash_with_group(hash_value);
+	return this->consistent_hash_with_group(hash_value, tracing);
 }
 
 EndpointAddress *UPSManualPolicy::first_strategy(const ParsedURI& uri,
@@ -659,6 +660,6 @@ EndpointAddress *UPSManualPolicy::another_strategy(const ParsedURI& uri,
 										uri.path ? uri.path : "",
 										uri.query ? uri.query : "",
 										uri.fragment ? uri.fragment : "");
-	return this->consistent_hash_with_group(hash_value);
+	return this->consistent_hash_with_group(hash_value, tracing);
 }
 
diff --git a/src/nameservice/UpstreamPolicies.h b/src/nameservice/UpstreamPolicies.h
index ab7b2bf5..75a4df2c 100644
--- a/src/nameservice/UpstreamPolicies.h
+++ b/src/nameservice/UpstreamPolicies.h
@@ -71,9 +71,10 @@ protected:
 	virtual void add_server_locked(EndpointAddress *addr);
 	virtual int remove_server_locked(const std::string& address);
 
-	EndpointAddress *consistent_hash_with_group(unsigned int hash);
+	EndpointAddress *consistent_hash_with_group(unsigned int hash,
+												WFNSTracing *tracing);
 	EndpointAddress *check_and_get(EndpointAddress *addr,
-								   bool flag, WFNSTracing *tracing);
+								   bool addr_failed, WFNSTracing *tracing);
 
 	bool is_alive(const EndpointAddress *addr) const;
 };