oracle gateway 报错

SQL>  select * from Z_WHS@gwmysql;
ERROR:
ORA-28511: lost RPC connection to heterogeneous remote agent using
SID=ORA-28511: lost RPC connection to heterogeneous remote agent using
SID=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.121.90)(PORT
=1521)))(CONNECT_DATA=(SID=rmt)))
ORA-02063: preceding line from GWMYSQL
Process ID: 20358
Session ID: 11 Serial number: 46988






no rows selected


SQL>