solr indexing has suddenly stop working.
Here is all the detail which i got from system admin
while running cron we are getting message during run cron.php through command
PHP Notice: Undefined index: REMOTE_ADDR in /var/www/XXXXXXX/includes/bootstrap.inc on line 1670 PHP Fatal error: Exception thrown without a stack frame in Unknown on line 0
where should i look first and what are the possibility for apache solr indexing to stop suddenly.