How to read the trace

The trace consists of trace lines and event symbols. The colors referred to below are the OLT's default colors. You can change these by selecting File > Preferences > OLT > Display > Colors. (If you do not see Display, click on the button beside OLT.)

Trace lines
A trace line is a horizontal line connecting a sequence of events (object method calls), which run under a single thread of execution. Each trace line represents an object, servlet, JSP, or EJB residing on an application server, or the client application or servlet that initiated a method call to the server. The name of each trace is shown to the left of the line:

trace lines

Each trace line name consists of four parts, representing the following information:

1 host name
2 process ID
job name
ngjava.gif (312 bytes) object hash code
3 on a client trace: client ID1
on an object trace: object ID
ngjava.gif (312 bytes) trace ID
4 on a client trace: client
on an object trace: object name

1For C++ clients, the client ID is the thread ID for the client.

To help you navigate on the trace, every fourth line is colored blue.

Events
An event is a call to a method, the receiving of the method call, the reply to the method call and the receipt of the reply, or the start or end of a process. Object method calls are shown on the trace as circles. Start and exit events are shown as squares. An arrow connects paired events, with the arrowhead representing the direction of data flow.

Identifying predecessor and successor events
Predecessor and successor events are those events that follow or precede a particular event in its own thread, and related events in other threads. To identify all predecessors and successors to a particular event, position the mouse pointer over an event and hold down Ctrl, while clicking on the event. All predecessor events are colored red, and all successor events are colored green.

Status lines
The status lines at the bottom of the window provide information identifying the location of the selected event and the current event. The selected event (highlighted green by default) is the last event you clicked with the left mouse button. The current event is the event that your mouse pointer is currently positioned over. As you move your pointer, the current event changes.

status lines

This textual representation of each event consists of seven parts, representing the following information:

1 event type
2 method name
3 host name
4 process ID
job name
ngjava.gif (312 bytes) object hash code
5 on a client trace: client ID1
on an object trace: object ID
ngjava.gif (312 bytes) trace ID
6 on a client trace: client
on an object trace: object name
7 position on the trace

1For C++ clients, the client ID is the thread ID for the client.

ngrelc.gif (533 bytes)
Object Level Trace
Trace symbols
Selected event
Partial-order display
Real-time display
Performance analysis
Circular log support

ngrelt.gif (466 bytes)
Navigating the trace
Finding an event