SQL Server Agent crashes when scheduled procedures make select in DBLink on an offline Oracle database

I have SQL Server 2014 and I'm using SQL Server Agent to start some scheduled procedures during the day. These procedures make some selects (in DBlink) on an Oracle database that is handled by another company. Sometimes the Oracle database is offline and my procedures seem to be stucked and I should restart the entire server the make the SQL Server Agent work again. What am I doing wrong? I suppose there is a sort of timeout to end the procedure and release the SQL Agent. Example of select: SELECT * from openquery(positions, 'SELECT * from oracleTableDbLink.POSITION' )