IQ15.4 muliplex server环境，发现有警告：
1>sp_iqmpxvalidate
2>go
------------------------------------
WARNING: Event ev_iqmpxstatus is disbaled
(1 row affected)
(return status = 2 )
1>
修复方法：
1.在协调节点上执行下列语句：
1>ALTER EVENT ev_iqmpxstatus ENABLE
2>go
1>
2. stop,synchronized and restart the secondary nodes.
