PHP Warning:  odbc_connect(): SQL error: [unixODBC][Cache ODBC][State : 08S01][Native Code 461]\n[libcacheodbcur6435.so]\nCommunication link failure, SQL state 08S01 in SQLConnect in /var/www/html/sample/index.php on line 43

i got this error .

The USER DATA SOURCES is not working but SYSTEM DSN is working.