Splunk brings powerful indexing, search, alerting and reporting to the challenge of managing server virtualization. It's the only approach that easily crosses tiers - both inside and outside of the VM - for a complete picture. Splunk indexes all IT data across every tier - the physical servers, hypervisor, VMs, and deployed applications, capturing data in real-time so that the evidence not lost as VMs are created and destroyed. Powerful search and navigation lets you trace performance problems and errors across components. Visibility across VMs highlights resource competition issues. Flexible alerting and reporting give you continuous visibility and monitoring of changing virtual environments. Whether you're testing a new virtualization rollout or managing an existing infrastructure, Splunk puts you back in control.
See http://www.splunk.com/base/Documentation/latest/Admin/InstallSplunkApplications for generic instructions of how to install and configure applications..
To find your xen data, search for "source=xenapi"