diff --git a/src/entry/Maat_rule.cpp b/src/entry/Maat_rule.cpp
index 290d9da..4ac7936 100644
--- a/src/entry/Maat_rule.cpp
+++ b/src/entry/Maat_rule.cpp
@@ -26,7 +26,7 @@
 #include "mesa_fuzzy.h"
 #include "great_index_engine.h"
 
-int MAAT_FRAME_VERSION_1_8_20160624_PERF_TEST=1;
+int MAAT_FRAME_VERSION_1_8_20160627_PERF_TEST=1;
 const char *maat_module="MAAT Frame";
 
 const char* CHARSET_STRING[]={"NONE","gbk","big5","unicode","utf8","bin",
@@ -989,6 +989,8 @@ void destroy_maat_scanner(struct _Maat_scanner_t*scanner)
 	MESA_htable_destroy(scanner->group_hash, NULL);
 	MESA_htable_destroy(scanner->region_hash, NULL);
 	map_destroy(scanner->district_map);
+	scanner->district_map=NULL;
+	assert(scanner->tmp_district_map==NULL);
 	destroy_bool_matcher((void*)scanner->expr_compiler);
 	q_cnt=MESA_lqueue_get_count(scanner->region_update_q);
 	for(i=0;i<q_cnt;i++)
@@ -1337,8 +1339,12 @@ int get_district_id(_Maat_scanner_t *scanner,const char* district_str)
 	map_ret=map_str2int(scanner->district_map, district_str,&district_id);
 	if(map_ret<0)
 	{
+		if(scanner->tmp_district_map==NULL)
+		{
+			scanner->tmp_district_map=map_duplicate(scanner->district_map);
+		}
 		district_id= scanner->district_num;
-		map_register(scanner->district_map,district_str, district_id);
+		map_register(scanner->tmp_district_map,district_str, district_id);
 		scanner->district_num++;
 	}
 	return district_id;
@@ -2427,6 +2433,9 @@ void garbage_bury(MESA_lqueue_head garbage_q,void *logger)
 			case GARBAGE_BOOL_MATCHER:
 				destroy_bool_matcher(bag->bool_matcher);
 				break;
+			case GARBAGE_MAP_STR2INT:
+				map_destroy(bag->str2int_map);
+				break;
 			default:
 				assert(0);
 		}
@@ -2468,6 +2477,7 @@ void plugin_table_callback(struct _Maat_table_info_t* table,const char* table_li
 void do_scanner_update(struct _Maat_scanner_t* scanner,MESA_lqueue_head garbage_q,int scan_thread_num,void* logger)
 {
 	void *tmp1=NULL,*tmp2=NULL;
+	MESA_htable_handle tmp_map=NULL;
 	int i=0;
 	long q_cnt;
 	GIE_create_para_t para;
@@ -2506,6 +2516,13 @@ void do_scanner_update(struct _Maat_scanner_t* scanner,MESA_lqueue_head garbage_
 		digest_batch_update(scanner->digest_handle[i], scanner->digest_update_q[i],logger);
 		pthread_rwlock_unlock(&(scanner->digest_rwlock[i]));
 	}
+	if(scanner->tmp_district_map!=NULL)
+	{
+		tmp_map=scanner->district_map;
+		scanner->district_map=scanner->tmp_district_map;
+		scanner->tmp_district_map=NULL;
+		garbage_bagging(GARBAGE_MAP_STR2INT, tmp_map, garbage_q);
+	}
 	scanner->last_update_time=time(NULL);
 
 	return;
diff --git a/src/entry/Maat_rule_internal.h b/src/entry/Maat_rule_internal.h
index b8ad00d..2038ad8 100644
--- a/src/entry/Maat_rule_internal.h
+++ b/src/entry/Maat_rule_internal.h
@@ -271,7 +271,8 @@ enum maat_garbage_type
 	GARBAGE_SCANNER=0,
 	GARBAGE_GROUP_RULE,
 	GARBAGE_COMPILE_RULE,
-	GARBAGE_BOOL_MATCHER
+	GARBAGE_BOOL_MATCHER,
+	GARBAGE_MAP_STR2INT
 };
 struct iconv_handle_t
 {
@@ -310,6 +311,7 @@ struct _Maat_scanner_t
 	MESA_htable_handle group_hash;
 	MESA_htable_handle compile_hash;
 	MESA_htable_handle district_map;
+	MESA_htable_handle tmp_district_map;
 	unsigned int district_num;
 	unsigned int cfg_num;
 	unsigned int exprid_generator;
@@ -366,6 +368,7 @@ struct _maat_garbage_t
 		struct _Maat_compile_rule_t* compile_rule;
 		void* bool_matcher;
 		void * raw;
+		MESA_htable_handle str2int_map;
 	};
 };
 void garbage_bagging(enum maat_garbage_type type,void *p,MESA_lqueue_head garbage_q);
diff --git a/src/entry/map_str2int.cpp b/src/entry/map_str2int.cpp
index 2e8752e..6e5c8e4 100644
--- a/src/entry/map_str2int.cpp
+++ b/src/entry/map_str2int.cpp
@@ -22,7 +22,7 @@ MESA_htable_handle map_create(void)
 	MESA_htable_handle string2int_map;
 	MESA_htable_create_args_t hargs;
 	memset(&hargs,0,sizeof(hargs));
-	hargs.thread_safe=8;
+	hargs.thread_safe=0;
 	hargs.hash_slot_size = 4*1024;
 	hargs.max_elem_num = 0;
 	hargs.eliminate_type = HASH_ELIMINATE_ALGO_FIFO;
@@ -74,4 +74,23 @@ int map_str2int(MESA_htable_handle handle,const char* string,int* value)
 		return -1;
 	}	
 }
+void duplicate_func(const uchar * key, uint size, void * data, void * user)
+{
+	MESA_htable_handle target=(MESA_htable_handle)user;
+	int value=*(int*)data;
+	int ret=0;
+	char* string=(char*)calloc(sizeof(char),(size+1));
+	memcpy(string,key,size);
+	ret=map_register(target,key,value);
+	assert(ret>0);
+}
+MESA_htable_handle map_duplicate(MESA_htable_handle origin_map)
+{
+	int ret=0;
+	MESA_htable_handle target=NULL;
+	target=map_create();
+	ret=MESA_htable_iterate(origin_map, duplicate_func, target);
+	assert(ret==0);
+	return target;
+}
 
diff --git a/src/entry/map_str2int.h b/src/entry/map_str2int.h
index 4652ee9..132a1e0 100644
--- a/src/entry/map_str2int.h
+++ b/src/entry/map_str2int.h
@@ -4,5 +4,6 @@ MESA_htable_handle map_create(void);
 void map_destroy(MESA_htable_handle p);
 int map_register(MESA_htable_handle handle,const char* string,int value);
 int map_str2int(MESA_htable_handle handle,const char* string,int* value);
+MESA_htable_handle map_duplicate(MESA_htable_handle origin_map);
 #endif