How to test linkedserver's connectivity in TSQL

Question

I need to write a procedure to collect data from several remote servers,

I use linkedservers and OPENQUERY to gather data from servers, but sometimes I lose connection

Answer 1

USE master;  
GO  
sp_testlinkedserver [LINKED_SERVER_NAME];  
GO 

or

SELECT * FROM OPENQUERY(LINKED_SERVER_NAME , 'select name DATABASE_NAME ,SYS_CONTEXT (''USERENV'', ''SESSION_USER'') USERNAME, host_name from v$database, dual, v$instance') ;