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Observer
Reference Manual
Version 2.1.1

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Table of Contents

- observer (App)
- observer
  - Top of manual page
  - start/0
- ttb
  - Top of manual page
  - start_trace/4
  - tracer/0
  - tracer/1
  - tracer/1
  - tracer/2
  - p/2
  - /0
  - list_history/0
  - run_history/1
  - write_config/2
  - write_config/3
  - run_config/1
  - run_config/2
  - list_config/1
  - write_trace_info/2
  - seq_trigger_ms/0
  - seq_trigger_ms/1
  - stop/0
  - stop/1
  - get_et_handler/0
  - format/1
  - format/2
- etop
  - Top of manual page
  - start/0
  - start/1
  - help/0
  - config/2
  - dump/1
  - stop/0
- crashdump_viewer
  - Top of manual page
  - start/0
  - start/1
  - stop/0
- cdv

# etop

### MODULE

etop

### MODULE SUMMARY

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

### DESCRIPTION

etop should be started with the provided scripts etop. This will start a hidden erlang node which connects to the node to be measured. The measured node is given with the -node option. If the measured node has a different cookie than the default cookie for the user who invokes the script, the cookie must be explicitly given witht the -setcookie option.

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

The following configuration parameters exist for the etop tool. When executing the etop script, these parameters can be given as command line options, e.g. etop -node testnode@myhost -setcookie MyCookie.

node
  The measured node.
  Value: atom()
  Mandatory
setcookie
  Cookie to use for the etop node - must be the same as the cookie on the measured node.
  Value: atom()
lines
  Number of lines (processes) to display.
  Value: integer()
  Default: 10
interval
  The time interval (in seconds) between each update of the display.
  Value: integer()
  Default: 5
accumulate
  If true the execution time and reductions are accumulated.
  Value: boolean()
  Default: false
sort
  Identifies what information to sort by.
  Value: runtime | reductions | memory | msg_q
  Default: runtime (reductions if tracing=off)
tracing
  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

See the user's guide for more information about the etop tool.

### EXPORTS

start() -> ok

This function starts etop. Note that etop is preferably started with the etop script.

start(Options) -> ok

Types:

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

This function starts etop. Use help/0 to see a description of the possible options.

help() -> ok

This function prints the help of etop and its options.

config(Key,Value) -> Result

Types:

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

This function is used to change the tool's configuration parameters during runtime. The table above indicates the allowed values for each parameter.

dump(File) -> Result

Types:

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

This function dumps the current display to a text file.

stop() -> stop

This function terminates etop.