Trace symbols

The OLT viewer presents a visualization of the flow of events in the communication between objects in a distributed program. Each trace symbol appears on a line representing a separate process, as shown in the figure below, and also as text in the status bar. Parentheses enclose a complete call-reply sequence.

decorated small trace

The table below presents each trace symbol, its corresponding status line text, and a description of the type of event that it represents.

Symbol Status line text Type of event
start process start object created or retrieved
call circle call method call from client
debuggable circle receive call entry point to debuggable method of an object
reply circle reply method call completed from an object
receive reply circle receive reply method call completed from client
debuggable circle receive call call from a debuggable object to itself (nested)
reply circle reply call from an object to itself (nested)
one-way call circle one-way call method call from client, no reply expected
one-way receive circle receive one-way call entry point to an object method
untraceable circle untraceable call call from client, recipient is untraceable
stop process exit stop, or object destroyed or released
exception circle receive call application exception
exception circle call or reply event waiting for partner to arrive
call-reply sequence Parentheses denote the limits of a call-reply sequence


Selected event
Partial-order display
Real-time display
How to read the trace

ngrelt.gif (466 bytes)
Preparing for an OLT and IBM Distributed Debugger session
Navigating the trace