MySQL server has gone away
If you while running spider getting this error too many times: MySQL server has gone away
login in PHPMyAdmin and run this query:
SHOW VARIABLES LIKE 'wait_timeout'
if this value is bellow 600 you need to contact your hosting support to change 'wait_timeout' in my.cnf file for mysql configuration to minimum 600
or you can login via SSH to "etc" folder and edit "my.cnf" file if you have VPS or Dedicated server.