Infrastructure issues can be related to problems starting up the server. Or the server being unavailable or unresponsive. Or transactions failing. It might even be due to errors in backbone resources that your infrastructure is dependent on, such as data sources and persistent stores. These are all examples of infrastructure problems, and in most of these cases it's the logs that will guide you to what the real issue is. In other cases, however, the log information may not be sufficient, at which point you may have to consider increasing the logger levels to obtain more information.
Chapter 3, Monitoring Oracle SOA Suite 11g includes a section titled Identifying and viewing log file entries, wherein we describe how to configure logger levels. For example, you can easily increase a logger from
NOTIFICATION:1 (INFO) to
TRACE:32 (FINEST) to dump more information into the logs. Regardless of the type of problem (including composite issues...