External processor is not available

[hd-sam]

I'm not sure why this keeps happening. The site randomly will go down and will be back up immediately as soon as I restart LSWS.

This is a single site running LSWS on a cPanel server, the MySQL database is on a secondary server.

As soon as the site goes down, the logs constantly state 'External processor not available' :

2012-10-28 13:40:17.589 [NOTICE] [IPREDACTED:64149-0#APVH_domainREDACTED.com:lsapi] Redirect: #8, URL: /500/index.php
2012-10-28 13:40:17.589 [INFO] [IPREDACTED:64149-0#APVH_domainREDACTED.com:lsapi] HttpExtConnector state: 0, request body sent: 0, response body size: 0, response body sent:0, left in buffer: 0, attempts: 0.
2012-10-28 13:40:17.589 [INFO] [IPREDACTED:64149-0#APVH_domainREDACTED.com:lsapi] External processor is not available.
2012-10-28 13:40:17.891 [INFO] [IP2REDACTED:43818-0#APVH_domainREDACTED.com:lsapi] Connection idle time: 125 while in state: 5 watching for event: 25,close!
2012-10-28 13:40:17.891 [NOTICE] [IP2REDACTED:43818-0#APVH_domainREDACTED.com:lsapi] Content len: 0, Request line: 'GET /forum/attachments/football/randomimage.jpg HTTP/1.1'
2012-10-28 13:40:17.891 [NOTICE] [IP2REDACTED:43818-0#APVH_domainREDACTED.com:lsapi] Redirect: #5, URL: /500/index.php
2012-10-28 13:40:17.891 [INFO] [IP2REDACTED:43818-0#APVH_domainREDACTED.com:lsapi] HttpExtConnector state: 0, request body sent: 0, response body size: 0, response body sent:0, left in buffer: 0, attempts: 0.
2012-10-28 13:40:17.891 [INFO] [IP2REDACTED:43818-0#APVH_domainREDACTED.com:lsapi] External processor is not available.