Log Viewer 
The Log Viewer tool allows you to view all log and trace messages that are generated in the whole SAP NetWeaver system landscape. These log records assist you to monitor and diagnose problems.
You can access the Log Viewer tool by choosing 
SAP NetWeaver Administrator 
Problem
management Logs and Traces
Log Viewer 
.
You can also use the quick link: http://<host>:<port>/nwa/logs.
Integration
In SAP NetWeaver Administrator you can configure the Log Viewer from the Log Configuration tool.
More information: Log Configuration with SAP NetWeaver Administrator
Features
The Log Viewer tool allows you to:
View list and text formatted logs and traces on selected systems in a set of predefined views.
More information: Predefined Views
View application and system logs. The messages in log files provide hints to the cause of problematic behavior.
Know the certain system problem via the trace messages.
View logs and traces from an AS Java that is not running.
More information: Using Standalone Log Viewer
View ABAP log messages.
Control the amount of displayed log data.
Filter and view logs and traces.
More information: Filtering Logs and Traces
Search for particular logs and traces.
More information: Searching for Logs and Traces
Merge list formatted logs and traces.
View archives of logs and traces.
Create your own custom views.
Download log content.
More information: Downloading Log and Trace Records
Import and export custom views.
More information: Creating, Exporting and Importing Custom Views