$ cat test.log
GET /DATA_String/{send_num = 1}HTTP/1.1
GET /DATA_String/{send_num = 2}HTTP/1.1
GET /DATA_String/{send_num = 3}HTTP/1.1
GET /DATA_String/{send_num = 4}HTTP/1.1
GET /DATA_String/{send_num = 5}HTTP/1.1