Comment 5 for bug 1245934

mysql> select * from heartbeat;
+----------------------------+-----------+--------------------+----------+-----------------------+---------------------+
| ts | server_id | file | position | relay_master_log_file | exec_master_log_pos |
+----------------------------+-----------+--------------------+----------+-----------------------+---------------------+
| 2013-05-03 17:23:15 | 1 | NULL | NULL | NULL | NULL |
| 2013-11-26T14:39:51.001960 | 101 | centos6-bin.000019 | 4711312 | NULL | NULL |
+----------------------------+-----------+--------------------+----------+-----------------------+---------------------+
2 rows in set (0.00 sec)

Related http://www.mysqlperformanceblog.com/2013/07/29/pt-heartbeat-2-1-your-troubles-are-over/

Unfortunately, I am still not able to reproduce the problem.