Module Summary

Erlang Top is a tool for presenting information about Erlang processes similar to the information presented by "top" in UNIX.


Start Erlang Top with the provided scripts etop. This starts a hidden Erlang node that connects to the node to be measured. The measured node is specified with option -node. If the measured node has a different cookie than the default cookie for the user who invokes the script, the cookie must be explicitly specified with option -setcookie.

Under Windows, batch file etop.bat can be used.

When executing the etop script, configuration parameters can be specified as command-line options, for example, etop -node testnode@myhost -setcookie MyCookie. The following configuration parameters exist for the tool:


The measured node.

Value: atom()



Cookie to use for the etop node. Must be same as the cookie on the measured node.

Value: atom()


Number of lines (processes) to display.

Value: integer()

Default: 10


Time interval (in seconds) between each update of the display.

Value: integer()

Default: 5


If true, the execution time and reductions are accumulated.

Value: boolean()

Default: false


Identifies what information to sort by.

Value: runtime | reductions | memory | msg_q

Default: runtime (reductions if tracing=off)


etop uses the Erlang trace facility, and thus no other tracing is possible on the measured node while etop is running, unless this option is set to off. Also helpful if the etop tracing causes too high load on the measured node. With tracing off, runtime is not measured.

Value: on | off

Default: on

For details about Erlang Top, see the User's Guide.


start() -> ok

Starts etop. Notice that etop is preferably started with the etop script.

start(Options) -> ok


Options = [Option]
Option = {Key, Value}
Key = atom()
Value = term()

Starts etop. To view the possible options, use help/0.

help() -> ok

Displays the help of etop and its options.

config(Key,Value) -> Result


Result = ok | {error,Reason}
Key = lines | interval | accumulate | sort
Value = term()

Changes the configuration parameters of the tool during runtime. Allowed parameters are lines, interval, accumulate, and sort.

dump(File) -> Result


Result = ok | {error,Reason}
File = string()

Dumps the current display to a text file.

stop() -> stop

Terminates etop.