.TH etop 3erl "observer 2.15.1" "Ericsson AB" "Erlang Module Definition"
.SH NAME
etop \- Erlang Top is a tool for presenting information about Erlang
  processes similar to the information presented by "top" in UNIX.
.SH DESCRIPTION
.LP
Start Erlang Top with the provided scripts \fIetop\fR\&\&. This starts a hidden Erlang node that connects to the node to be measured\&. The measured node is specified with option \fI-node\fR\&\&. 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 \fI-setcookie\fR\&\&.
.LP
Under Windows, batch file \fIetop\&.bat\fR\& can be used\&.
.LP
When executing the \fIetop\fR\& script, configuration parameters can be specified as command-line options, for example, \fIetop -node testnode@myhost -setcookie MyCookie\fR\&\&. The following configuration parameters exist for the tool:
.RS 2
.TP 2
.B
\fInode\fR\&:
The measured node\&.
.RS 2
.LP
Value: \fIatom()\fR\&
.RE

.RS 2
.LP
Mandatory
.RE

.TP 2
.B
\fIsetcookie\fR\&:
Cookie to use for the \fIetop\fR\& node\&. Must be same as the cookie on the measured node\&.
.RS 2
.LP
Value: \fIatom()\fR\&
.RE

.TP 2
.B
\fIlines\fR\&:
Number of lines (processes) to display\&.
.RS 2
.LP
Value: \fIinteger()\fR\&
.RE

.RS 2
.LP
Default: \fI10\fR\&
.RE

.TP 2
.B
\fIinterval\fR\&:
Time interval (in seconds) between each update of the display\&.
.RS 2
.LP
Value: \fIinteger()\fR\&
.RE

.RS 2
.LP
Default: \fI5\fR\&
.RE

.TP 2
.B
\fIaccumulate\fR\&:
If \fItrue\fR\&, the execution time and reductions are accumulated\&.
.RS 2
.LP
Value: \fIboolean()\fR\&
.RE

.RS 2
.LP
Default: \fIfalse\fR\&
.RE

.TP 2
.B
\fIsort\fR\&:
Identifies what information to sort by\&.
.RS 2
.LP
Value: \fIruntime | reductions | memory | msg_q\fR\&
.RE

.RS 2
.LP
Default: \fIruntime\fR\& (\fIreductions\fR\& if \fItracing=off\fR\&)
.RE

.TP 2
.B
\fItracing\fR\&:
\fIetop\fR\& uses the Erlang trace facility, and thus no other tracing is possible on the measured node while \fIetop\fR\& is running, unless this option is set to \fIoff\fR\&\&. Also helpful if the \fIetop\fR\& tracing causes too high load on the measured node\&. With tracing off, runtime is not measured\&.
.RS 2
.LP
Value: \fIon | off\fR\&
.RE

.RS 2
.LP
Default: \fIon\fR\&
.RE

.RE
.LP
For details about Erlang Top, see the User\&'s Guide\&.
.SH EXPORTS
.LP
.B
start() -> ok
.br
.RS
.LP
Starts \fIetop\fR\&\&. Notice that \fIetop\fR\& is preferably started with the \fIetop\fR\& script\&.
.RE

.LP
.B
start(Options) -> ok
.br
.RS
.LP
Types:

.RS 3
Options = [Option]
.br
Option = {Key, Value}
.br
Key = atom()
.br
Value = term()
.br
.RE
.RE
.RS
.LP
Starts \fIetop\fR\&\&. To view the possible options, use \fIhelp/0\fR\&\&.
.RE

.LP
.B
help() -> ok
.br
.RS
.LP
Displays the help of \fIetop\fR\& and its options\&.
.RE

.LP
.B
config(Key,Value) -> Result
.br
.RS
.LP
Types:

.RS 3
Result = ok | {error,Reason}
.br
Key = lines | interval | accumulate | sort
.br
Value = term()
.br
.RE
.RE
.RS
.LP
Changes the configuration parameters of the tool during runtime\&. Allowed parameters are \fIlines\fR\&, \fIinterval\fR\&, \fIaccumulate\fR\&, and \fIsort\fR\&\&.
.RE

.LP
.B
dump(File) -> Result
.br
.RS
.LP
Types:

.RS 3
Result = ok | {error,Reason}
.br
File = string()
.br
.RE
.RE
.RS
.LP
Dumps the current display to a text file\&.
.RE

.LP
.B
stop() -> stop
.br
.RS
.LP
Terminates \fIetop\fR\&\&.
.RE