1<?xml version="1.0" encoding="utf-8" ?>
2<!DOCTYPE erlref SYSTEM "erlref.dtd">
3
4<erlref>
5  <header>
6    <copyright>
7      <year>2002</year>
8      <year>2017</year>
9      <holder>Ericsson AB, All Rights Reserved</holder>
10    </copyright>
11    <legalnotice>
12  Licensed under the Apache License, Version 2.0 (the "License");
13  you may not use this file except in compliance with the License.
14  You may obtain a copy of the License at
15
16      http://www.apache.org/licenses/LICENSE-2.0
17
18  Unless required by applicable law or agreed to in writing, software
19  distributed under the License is distributed on an "AS IS" BASIS,
20  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
21  See the License for the specific language governing permissions and
22  limitations under the License.
23
24  The Initial Developer of the Original Code is Ericsson AB.
25    </legalnotice>
26
27    <title>etop</title>
28    <prepared>Siri Hansen</prepared>
29    <responsible></responsible>
30    <docno></docno>
31    <approved></approved>
32    <checked></checked>
33    <date></date>
34    <rev></rev>
35    <file></file>
36  </header>
37  <module since="">etop</module>
38  <modulesummary>Erlang Top is a tool for presenting information about Erlang
39  processes similar to the information presented by "top" in UNIX.</modulesummary>
40  <description>
41
42    <p>Start Erlang Top with the provided scripts
43      <c>etop</c>. This starts a hidden Erlang node
44      that connects to the node to be measured. The measured node is
45      specified with option <c>-node</c>. If the measured node has a
46      different cookie than the default cookie for the user who
47      invokes the script, the cookie must be explicitly specified with
48      option <c>-setcookie</c>.</p>
49
50    <p>Under Windows, batch file <c>etop.bat</c> can be used.</p>
51
52    <p>When executing the <c>etop</c> script, configuration
53    parameters can be specified as command-line options,
54    for example, <c>etop -node testnode@myhost -setcookie MyCookie</c>.
55    The following configuration parameters exist for the
56    tool:</p>
57    <taglist>
58      <tag><c>node</c></tag>
59      <item><p>The measured node.</p>
60	    <p>Value: <c>atom()</c></p>
61	    <p>Mandatory</p></item>
62      <tag><c>setcookie</c></tag>
63      <item><p>Cookie to use for the <c>etop</c> node. Must be same as the
64      cookie on the measured node.</p>
65            <p>Value: <c>atom()</c></p></item>
66      <tag><c>lines</c></tag>
67      <item><p>Number of lines (processes) to display.</p>
68            <p>Value: <c>integer()</c></p>
69	    <p>Default: <c>10</c></p></item>
70      <tag><c>interval</c></tag>
71      <item><p>Time interval (in seconds) between each update of
72       the display.</p>
73            <p>Value: <c>integer()</c></p>
74	    <p>Default: <c>5</c></p></item>
75      <tag><c>accumulate</c></tag>
76      <item><p>If <c>true</c>, the execution time and reductions are
77       accumulated.</p>
78            <p>Value: <c>boolean()</c></p>
79	    <p>Default: <c>false</c></p></item>
80      <tag><c>sort</c></tag>
81      <item><p>Identifies what information to sort by.</p>
82      <p>Value: <c>runtime | reductions | memory | msg_q</c></p>
83      <p>Default: <c>runtime</c> (<c>reductions</c> if <c>tracing=off</c>)</p></item>
84      <tag><c>tracing</c></tag>
85      <item><p><c>etop</c> uses the Erlang trace facility, and thus no
86       other tracing is possible on the measured node while
87      <c>etop</c> is running, unless this option is set to
88      <c>off</c>. Also helpful if the <c>etop</c> tracing causes too
89       high load on the measured node. With tracing off, runtime is
90       not measured.</p>
91            <p>Value: <c>on | off</c></p>
92	    <p>Default: <c>on</c></p></item>
93    </taglist>
94
95    <p>For details about Erlang Top, see the
96    <seeguide marker="etop_ug">User's Guide</seeguide>.</p>
97
98  </description>
99  <funcs>
100    <func>
101      <name since="OTP R15B01">start() -> ok</name>
102      <fsummary>Start etop.</fsummary>
103      <desc>
104        <p>Starts <c>etop</c>.
105        Notice that <c>etop</c> is preferably started with the <c>etop</c> script.</p>
106      </desc>
107    </func>
108    <func>
109      <name since="OTP R15B01">start(Options) -> ok</name>
110      <fsummary>Start etop.</fsummary>
111      <type>
112        <v>Options = [Option]</v>
113        <v>Option = {Key, Value}</v>
114        <v>Key = atom()</v>
115        <v>Value = term()</v>
116      </type>
117      <desc>
118        <p>Starts <c>etop</c>. To view the possible options, use
119          <seemfa marker="#help/0"><c>help/0</c></seemfa>.</p>
120      </desc>
121    </func>
122    <func>
123      <name since="OTP R15B01">help() -> ok</name>
124      <fsummary>Display the etop help.</fsummary>
125      <desc>
126        <p>Displays the help of <c>etop</c> and
127          its options.</p>
128      </desc>
129    </func>
130    <func>
131      <name since="">config(Key,Value) -> Result</name>
132      <fsummary>Change the configuration of the tool.</fsummary>
133      <type>
134        <v>Result = ok | {error,Reason}</v>
135        <v>Key = lines | interval | accumulate | sort</v>
136        <v>Value = term()</v>
137      </type>
138      <desc>
139        <p>Changes the configuration parameters of the tool during runtime.
140	Allowed parameters are <c>lines</c>, <c>interval</c>, <c>accumulate</c>,
141	and <c>sort</c>.</p>
142      </desc>
143    </func>
144    <func>
145      <name since="">dump(File) -> Result</name>
146      <fsummary>Dump the current display to a file.</fsummary>
147      <type>
148        <v>Result = ok | {error,Reason}</v>
149        <v>File = string()</v>
150      </type>
151      <desc>
152        <p>Dumps the current display to a text file.</p>
153      </desc>
154    </func>
155    <func>
156      <name since="">stop() -> stop</name>
157      <fsummary>Terminate etop.</fsummary>
158      <desc>
159        <p>Terminates <c>etop</c>.</p>
160      </desc>
161    </func>
162  </funcs>
163</erlref>
164
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