diff --git a/HISTORY b/HISTORY
index 9c2489e..2192ec8 100644
--- a/HISTORY
+++ b/HISTORY
@@ -1,11 +1,12 @@
 
-Version 1.40  2018-08-27
+Version 1.40  2018-09-27
   * add function conn_pool_parse_server_info and conn_pool_load_server_info
   * support directive: #@add_annotation, for example:
     #@add_annotation CONFIG_GET /usr/lib/libshmcache.so /etc/libshmcache.conf
   * add function fc_split_string and fc_match_delim
   * add json_parser.[hc] for parse json array and map
   * add function fc_strdup
+  * add function fc_memmem
 
 Version 1.39  2018-07-31
   * add #@function REPLACE_VARS
diff --git a/src/common_define.h b/src/common_define.h
index e825bdd..cf11583 100644
--- a/src/common_define.h
+++ b/src/common_define.h
@@ -81,15 +81,15 @@ extern int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int kind);
 #define USE_SENDFILE
 #endif
 
-#define MAX_PATH_SIZE				256
+#define MAX_PATH_SIZE                  256
 #define LOG_FILE_DIR				"logs"
 #define CONF_FILE_DIR				"conf"
 #define DEFAULT_CONNECT_TIMEOUT			30
 #define DEFAULT_NETWORK_TIMEOUT			30
-#define DEFAULT_MAX_CONNECTONS			256
-#define DEFAULT_WORK_THREADS			4
-#define SYNC_LOG_BUFF_DEF_INTERVAL              10
-#define TIME_NONE                               -1
+#define DEFAULT_MAX_CONNECTONS        1024
+#define DEFAULT_WORK_THREADS             4
+#define SYNC_LOG_BUFF_DEF_INTERVAL      10
+#define TIME_NONE                       -1
 
 #define IP_ADDRESS_SIZE	16
 #define INFINITE_FILE_SIZE (256 * 1024LL * 1024 * 1024 * 1024 * 1024LL)
@@ -232,6 +232,12 @@ typedef void* (*MallocFunc)(size_t size);
         (dest).len = strlen(src); \
     } while (0)
 
+#define FC_SET_STRING_EX(dest, src, len)  \
+    do {  \
+        (dest).str = src;  \
+        (dest).len = len;  \
+    } while (0)
+
 #define FC_SET_STRING_NULL(dest)  \
     do {  \
         (dest).str = NULL;   \
diff --git a/src/shared_func.c b/src/shared_func.c
index 10e7eb5..4defaee 100644
--- a/src/shared_func.c
+++ b/src/shared_func.c
@@ -2781,3 +2781,33 @@ char *fc_strdup(const char *str, const int len)
     *(output + len) = '\0';
     return output;
 }
+
+const char *fc_memmem(const string_t *str, const string_t *needle)
+{
+    const char *ps;
+    const char *last;
+    const char *pn;
+    const char *nend;
+    int loop;
+    int i;
+
+    loop = str->len - needle->len;
+    if (loop < 0) {
+        return NULL;
+    }
+
+    last = str->str + loop;
+    nend = needle->str + needle->len;
+    for (ps=str->str; ps<=last; ps++) {
+        for (pn=needle->str,i=0; pn<nend; pn++,i++) {
+            if (*pn != *(ps + i)) {
+                break;
+            }
+        }
+        if (pn == nend) {
+            return ps;
+        }
+    }
+
+    return NULL;
+}
diff --git a/src/shared_func.h b/src/shared_func.h
index f73e4a2..d1cb224 100644
--- a/src/shared_func.h
+++ b/src/shared_func.h
@@ -824,6 +824,14 @@ bool ends_with(const char *str, const char *needle);
 */
 char *fc_strdup(const char *str, const int len);
 
+/** memmem
+ *  parameters:
+ *  	str: the string to match
+ *      needle: the needle string
+ *  return: the matched string, NULL for fail
+*/
+const char *fc_memmem(const string_t *str, const string_t *needle);
+
 #ifdef __cplusplus
 }
 #endif