Search notes:

ORA-17008: Closed connection

As per MOS note 2873922.1, the ORA-17008 error typically happens in conjunction with failover activity against a RAC database, especially on a RAC node is brought down from a JAVA application configured to use failover (FCF/Fast Connection Failover).
I was experiencing this error when travelling in a train, using a Hot-Spot connection with SQL Developer (likely as a result of the Hot-Spot loosing its connection to the telcom provider).
Hm‥ 
set serveroutput on
begin
   dbms_output.put_line(sqlerrm(-17008));
end;
/
ORA-17008: Message 17008 not found;  product=RDBMS; facility=ORA

See also

Other Oracle error messages such as ORA-17002: I/O Error
MOS Note 2873922.1

Index

Fatal error: Uncaught PDOException: SQLSTATE[HY000]: General error: 8 attempt to write a readonly database in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php:51 Stack trace: #0 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(51): PDOStatement->execute(Array) #1 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(66): id_of(Object(PDO), 'uri', '/notes/developm...') #2 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(30): insert_webrequest_('/notes/developm...', 1758206669, '216.73.216.150', 'Mozilla/5.0 App...', NULL) #3 /home/httpd/vhosts/renenyffenegger.ch/httpsdocs/notes/development/databases/Oracle/errors/ORA-17008_Closed-connection(51): insert_webrequest() #4 {main} thrown in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php on line 51