Troubleshoot intermittent issue

We are facing one intermittent issue while accessing an application in the environment. The issue is that sometimes getting Null pointer exception in application code due to invalid response. It is happening only in IE8 browser. We are not encountering any issues in IE9 and firefox browsers.

As confirmed by Siteminder, siteminder server receives the Host Name as empty from F5 server intermittently, so that getting null pointer exception in application.

Development User IDs - https://dev-appdirectadmin.zahsystems.com

Below is the log snippet from webagent for successful case

[12/09/2015][20][8307][69][0000000000000000000000000a2f2883-2073-5668dde6-0045-8df04943][ProcessRequest][Start new request.]
[12/09/2015][20][8307][69][0000000000000000000000000a2f2883-2073-5668dde6-0045-8df04943][CSmHttpPlugin][Resolved HTTP_HOST: 'dev-appdirectadmin.zahsystems.com'.]
[12/09/2015][20][8307][69][][Entered CSmHttpPlugin::ResolveFQServerName sHost: ][dev-appdirectadmin.zahsystems.com]
[12/09/2015][20][8307][69][0000000000000000000000000a2f2883-2073-5668dde6-0045-8df04943][CSmHttpPlugin][Resolved hostname: 'dev-appdirectadmin.zahsystems.com'.]
[12/09/2015][20][8307][69][0000000000000000000000000a2f2883-2073-5668dde6-0045-8df04943][CSmHttpPlugin][Resolved agentname: 'gmpp-agent'.]
[12/09/2015][20][8307][69][][CSmHttpPlugin][Resolved Client IP address '10.47.145.238'.]
[12/09/2015][20][8307][69][0000000000000000000000000a2f2883-2073-5668dde6-0045-8df04943][CSmHttpPlugin][Resolved URL: '/pmachine/search/'.]
[12/09/2015][20][8307][69][0000000000000000000000000a2f2883-2073-5668dde6-0045-8df04943][CSmHttpPlugin][Resolved METHOD: 'GET'.]
[12/09/2015][20][8307][69][0000000000000000000000000a2f2883-2073-5668dde6-0045-8df04943][CSmHttpPlugin][Resolved cookie domain: '.zahsystems.com'.]

Below is the log snippet from webagent for unsuccessful case

[12/10/2015][05][26163][71][0000000000000000000000000a2f2883-6633-56695e37-0047-2da64f9a][ProcessRequest][Start new request.]
[12/10/2015][05][26163][71][0000000000000000000000000a2f2883-6633-56695e37-0047-2da64f9a][CSmHttpPlugin][Resolved HTTP_HOST: '.'.]
[12/10/2015][05][26163][71][][Entered CSmHttpPlugin::ResolveFQServerName sHost: ][.]
[12/10/2015][05][26163][71][0000000000000000000000000a2f2883-6633-56695e37-0047-2da64f9a][CSmHttpPlugin][Resolved hostname: '.'.]
[12/10/2015][05][26163][71][][CSmHttpPlugin][Entered Function server: ., port: :80]
[12/10/2015][05][26163][71][][CSmHttpPlugin][addrinfo lookup failed node name or service name not known]
[12/10/2015][05][26163][71][][CSmHttpPlugin][Leaving Function]