Mod Cluster Manager returns 503 and 404 errors

Issue

• Receiving 503 and 404 errors from mod cluster when an application is deployed.
• access_log:

"GET /<context>/ HTTP/1.1" 503 435 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0; .NET CLR 1.0.3705; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.04506.648; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; InfoPath.3; MS-RTC LM 8; AskTbORJ/5.15.15.36191)"
"GET /<context>/ HTTP/1.1" 404 321 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0; .NET CLR 1.0.3705; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 

• error_log:

[error] ap_proxy_connect_backend disabling worker for (1.2.3.4)
[error] proxy: CLUSTER: (balancer://mycluster). All workers are in error state
[error] (70007)The timeout specified has expired: proxy: ajp: attempt to connect to 1.2.3.4:8009 (1.2.3.4) failed
[error] ap_proxy_connect_backend disabling worker for (1.2.3.4)