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What is DTrace Percept?

A back-end for Percept that is based on DTrace rather than on the built-in tracing machanisms of Erlang for the collection of trace information.

How can I use DTrace Percept?

Run the DTrace/SystemTap script and redirect its output into a file.

stap path/to/percept/lib/priv/dtrace/dtrace-percept.stap > trace.dat

dtrace path/to/percept/lib/priv/dtrace/dtrace-percept.d > trace.dat

Perform the action you want to trace.

erl -noshell - eval "bang:bang(2,30)." -s init stop

Stop the execution of the DTrace/SystemTap script (by pressing Ctrl+C).

Analyze the produced trace file.

1> percept:d_analyze("trace.dat").

Start the web server (as usual) and inspect the collected information using your favorite browser (as usual).

1> percept:start_webserver().

What is the current status of DTrace Percept?

Currently, the DTrace back-end of Percept traces specific events (spawn, link, getting unlinked, exit, active/inactive).

The back-end does not expose any flags that can be set, so that the user can specify the pieces of trace information that should be collected.

DTrace back-end can collect information only from Erlang VM's that are started after the execution of the DTrace/SystemTap script, and not from already running Erlang VM's.