1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
|
<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE erlref SYSTEM "erlref.dtd">
<erlref>
<header>
<copyright>
<year>2002</year><year>2016</year>
<holder>Ericsson AB, All Rights Reserved</holder>
</copyright>
<legalnotice>
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
The Initial Developer of the Original Code is Ericsson AB.
</legalnotice>
<title>ttb</title>
<prepared>Siri Hansen, Bartlomiej Puzon</prepared>
<responsible></responsible>
<docno>1</docno>
<approved></approved>
<checked></checked>
<date>2010-08-13</date>
<rev>PA1</rev>
<file>ttb.xml</file>
</header>
<module since="">ttb</module>
<modulesummary>A base for building trace tools for distributed systems.</modulesummary>
<description>
<p>The Trace Tool Builder, <c>ttb</c>, is a base for building trace
tools for distributed systems.
</p>
<p>When using <c>ttb</c>, do not use module <c>dbg</c> in application
Runtime_Tools in parallel.</p>
</description>
<funcs>
<func>
<name since="OTP R15B">start_trace(Nodes, Patterns, FlagSpec, Opts) -> Result</name>
<fsummary>Start a trace port on each specified node.</fsummary>
<type>
<v>Result = see p/2</v>
<v>Nodes = see tracer/2</v>
<v>Patterns = [tuple()]</v>
<v>FlagSpec = {Procs, Flags}</v>
<v>Proc = see p/2</v>
<v>Flags = see p/2</v>
<v>Opts = see tracer/2</v>
</type>
<desc>
<p>This function is a shortcut allowing to start a trace with one command. Each
tuple in <c>Patterns</c> is converted to a list, which in turn is passed to
<c>ttb:tpl/2,3,4</c>.</p>
<p>The call:</p>
<pre>
> <input>ttb:start_trace([Node, OtherNode],
[{mod, foo, []}, {mod, bar, 2}],
{all, call},
[{file, File}, {handler,{fun myhandler/4, S}}]).</input></pre>
<p> is equivalent to:</p>
<pre>
> <input>ttb:start_trace([Node, OtherNode],
[{file, File}, {handler,{fun myhandler/4, S}}]),
ttb:tpl(mod, foo, []),
ttb:tpl(mod, bar, 2, []),
ttb:p(all, call).</input></pre>
</desc>
</func>
<func>
<name since="">tracer() -> Result</name>
<fsummary>Equivalent to tracer(node()).</fsummary>
<desc>
<p>Equivalent to <c>tracer(node())</c>.</p>
</desc>
</func>
<func>
<name since="">tracer(Shortcut) -> Result</name>
<fsummary>Handy shortcuts for common tracing settings.</fsummary>
<type>
<v>Shortcut = shell | dbg</v>
</type>
<desc>
<p>Handy shortcuts for common tracing settings.</p>
<p><c>shell</c> is equivalent to <c>tracer(node(),[{file, {local, "ttb"}}, shell])</c>.</p>
<p><c>dbg</c> is equivalent to <c>tracer(node(),[{shell, only}])</c>.</p>
</desc>
</func>
<func>
<name since="">tracer(Nodes) -> Result</name>
<fsummary>Equivalent to tracer(Nodes,[]).</fsummary>
<desc>
<p>Equivalent to <c>tracer(Nodes,[])</c>.</p>
</desc>
</func>
<func>
<name since="">tracer(Nodes,Opts) -> Result</name>
<fsummary>Start a trace port on each specified node.</fsummary>
<type>
<v>Result = {ok, ActivatedNodes} | {error,Reason}</v>
<v>Nodes = atom() | [atom()] | all | existing | new</v>
<v>Opts = Opt | [Opt]</v>
<v>Opt = {file,Client} | {handler, FormatHandler} | {process_info,PI} |
shell | {shell, ShellSpec} | {timer, TimerSpec} |
{overload_check, {MSec, Module, Function}} |
{flush, MSec} | resume | {resume, FetchTimeout} |
{queue_size, QueueSize}</v>
<v>TimerSpec = MSec | {MSec, StopOpts}</v>
<v>MSec = FetchTimeout = integer()</v>
<v>Module = Function = atom() </v>
<v>StopOpts = see stop/2</v>
<v>Client = File | {local, File}</v>
<v>File = Filename | Wrap</v>
<v>Filename = string()</v>
<v>Wrap = {wrap,Filename} | {wrap,Filename,Size,Count}</v>
<v>FormatHandler = See format/2</v>
<v>PI = true | false </v>
<v>ShellSpec = true | false | only</v>
<v>QueueSize = non_neg_integer()</v>
</type>
<desc>
<p>Starts a file trace port on all specified nodes
and points the system tracer for sequential tracing to
the same port.
</p>
<p><em>Options:</em></p>
<taglist>
<tag><c>Filename</c></tag>
<item><p>The specified <c>Filename</c> is prefixed with the node name.
Default <c>Filename</c> is <c>ttb</c>.</p></item>
<tag><c>File={wrap,Filename,Size,Count}</c></tag>
<item><p>Can be used if the size of the trace logs must be limited.
Default values are
<c>Size=128*1024</c> and <c>Count=8</c>.</p></item>
<tag><c>Client</c></tag>
<item><p>When tracing diskless nodes, <c>ttb</c> must be started
from an external "trace control node" with disk access, and
<c>Client</c> must be <c>{local, File}</c>. All
trace information is then sent to the trace control node where
it is written to file.</p></item>
<tag><c>queue_size</c></tag>
<item><p>When tracing to shell or <c>{local,File}</c>, an ip
trace driver is used internally. The ip trace driver has a
queue of maximum <c>QueueSize</c> messages waiting to be
delivered. If the driver cannot deliver messages as fast as
they are produced, the queue size might be exceeded and
messages are dropped. This parameter is optional, and is
only useful if many <c>{drop,N}</c> trace messages are
received by the trace handler. It has no meaning if shell
or <c>{local,File}</c> is not used. See
<seealso marker="runtime_tools:dbg#trace_port/2">dbg:trace_port/2</seealso>
for more information about the ip trace driver.</p></item>
<tag><c>process_info</c></tag>
<item><p>Indicates if process
information is to be collected. If <c>PI = true</c> (which is
default), each process identifier <c>Pid</c> is replaced by a
tuple <c>{Pid,ProcessInfo,Node}</c>, where <c>ProcessInfo</c>
is the registered process name, its globally registered name,
or its initial function. To turn off this functionality,
set <c>PI = false</c>.</p></item>
<tag><c>{shell, ShellSpec}</c></tag>
<item><p>Indicates that trace messages are to be printed on the
console as they are received by the tracing process. This implies
trace client <c>{local, File}</c>. If <c>ShellSpec</c>
is <c>only</c> (instead of <c>true</c>), no trace logs are stored.</p></item>
<tag><c>shell</c></tag>
<item><p>Shortcut for <c>{shell, true}</c>.</p></item>
<tag><c>timer</c></tag>
<item><p>Indicates that the trace is to be
automatically stopped after <c>MSec</c> milliseconds. <c>StopOpts</c>
are passed to command <c>ttb:stop/2</c> if specified (default is <c>[]</c>).
Notice that the timing is approximate, as delays related to
network communication are always present. The timer starts after
<c>ttb:p/2</c> is issued, so you can set up your trace patterns before.</p></item>
<tag><c>overload_check</c></tag>
<item><p>Allows to enable overload
checking on the nodes under trace. <c>Module:Function(check)</c>
is performed each <c>MSec</c> millisecond. If the check returns
<c>true</c>, the tracing is disabled on a specified node.</p>
<p><c>Module:Function</c> must be able to handle at least three
atoms: <c>init</c>, <c>check</c>, and <c>stop</c>. <c>init</c> and
<c>stop</c> allows you to initialize and clean
up the check environment.</p>
<p>When a node gets overloaded, it is not possible to issue <c>ttb:p/2</c>
or any command from the <c>ttb:tp/2,3,4</c> family, as it would lead to
inconsistent tracing state (different trace specifications on
different nodes).</p></item>
<tag><c>flush</c></tag>
<item><p>Periodically flushes all file trace
port clients (see
<seealso marker="runtime_tools:dbg#flush_trace_port/1">
<c>dbg:flush_trace_port/1</c></seealso>). When enabled,
the buffers are freed each <c>MSec</c> millisecond. This option is
not allowed with <c>{file, {local, File}}</c> tracing.</p></item>
<tag><c>{resume, FetchTimeout}</c></tag>
<item><p>Enables the autoresume feature.
When enabled, remote nodes try to reconnect to the controlling node
if they are restarted. The feature requires application Runtime_Tools
to be started (so it has to be present in the <c>.boot</c>
scripts if the traced nodes run with embedded Erlang). If this is
not possible, resume can be performed manually by starting
<c>Runtime_Tools</c> remotely using
<seealso marker="kernel:rpc#call/4"><c>rpc:call/4</c></seealso>.</p>
<p><c>ttb</c> tries to fetch all logs from a reconnecting node before
reinitializing the trace. This must finish within <c>FetchTimeout</c>
milliseconds or is aborted.</p>
<p>By default, autostart information is stored in a file named
<c>ttb_autostart.bin</c> on each node. If this is not desired
(for example, on diskless nodes), a custom module handling autostart
information storage and retrieval can be provided by specifying
environment variable <c>ttb_autostart_module</c> for the application
Runtime_Tools. The module must respond to the following API:</p>
<taglist>
<tag><c>write_config(Data) -> ok</c></tag>
<item><p>Stores the provided data for further retrieval. It is
important to realize that the data storage used must not
be affected by the node crash.</p></item>
<tag><c>read_config() -> {ok, Data} | {error, Error}</c></tag>
<item><p>Retrieves configuration stored with <c>write_config(Data)</c>.</p></item>
<tag><c>delete_config() -> ok</c></tag>
<item><p>Deletes configuration stored with <c>write_config(Data)</c>.
Notice that after this call any subsequent calls to <c>read_config</c>
must return <c>{error, Error}</c>.</p>
</item>
</taglist>
<p><c>resume</c> implies the default <c>FetchTimeout</c>, which is
10 seconds</p>
</item>
</taglist>
</desc>
</func>
<func>
<name since="">p(Item,Flags) -> Return</name>
<fsummary>Set the specified trace flags on the specified processes or ports.</fsummary>
<type>
<v>Return = {ok,[{Item,MatchDesc}]}</v>
<v>Items = Item | [Item]</v>
<v>Item = pid() | port() | RegName | {global,GlobalRegName} |
all | processes | ports |
existing | existing_processes | existing_ports |
new | new_processes | new_ports</v>
<v>RegName = atom()</v>
<v>GlobalRegName = term()</v>
<v>Flags = Flag | [Flag]</v>
</type>
<desc>
<p>Sets the specified trace flags on the specified processes
or ports. Flag <c>timestamp</c> is always turned on.
</p>
<p>See the Reference Manual for module
<seealso marker="runtime_tools:dbg"><c>dbg</c></seealso>
for the possible trace flags. Parameter
<c>MatchDesc</c> is the same as returned from
<c>dbg:p/2</c>.</p>
<p>Processes can be specified as registered names, globally
registered names, or process identifiers. Ports can be
specified as registered names or port identifiers. If a
registered name is specified, the flags are set on
processes/ports with this name on all active nodes.</p>
<p>Issuing this command starts the timer for this trace if option
<c>timer</c> is specified with <c>tracer/2</c>.
</p>
</desc>
</func>
<func>
<name>tp, tpl, tpe, ctp, ctpl, ctpg, ctpe</name>
<fsummary>Set and clear trace patterns.</fsummary>
<desc>
<p>These functions are to be used with trace
flag <c>call</c>, <c>send</c>, and <c>'receive'</c> for
setting and clearing trace patterns.</p>
<p>When trace flag <c>call</c> is set on a process,
function calls are traced on that process if a trace
pattern is set for the called function.</p>
<p>The <c>send</c> and <c>'receive'</c> flags enable tracing
of all messages sent and received by the process/port. Trace
patterns set with <c>tpe</c> may limit traced messages based
on the message content, the sender, and/or the receiver.</p>
<p>Trace patterns specify how to trace a function or a message
by using match specifications. Match specifications are
described in the
<seealso marker="erts:match_spec"><c>ERTS User's Guide</c></seealso>.
</p>
<p>These functions are equivalent to the corresponding
functions in module
<seealso marker="runtime_tools:dbg">dbg</seealso>,
but all calls are stored in the
history. The history buffer makes it easy to create configuration
files; the same trace environment can be set up many
times, for example, to compare two test runs. It also
reduces the amount of typing when using <c>ttb</c> from the
Erlang shell.
</p>
<taglist>
<tag><c>tp</c></tag>
<item><p>Sets trace patterns on global function calls.</p></item>
<tag><c>tpl</c></tag>
<item><p>Sets trace patterns on local and global function calls.</p></item>
<tag><c>tpe</c></tag>
<item><p>Sets trace patterns on messages.</p></item>
<tag><c>ctp</c></tag>
<item><p>Clears trace patterns on local and global function
calls.</p></item>
<tag><c>ctpl</c></tag>
<item><p>Clears trace patterns on local function calls.</p></item>
<tag><c>ctpg</c></tag>
<item><p>Clears trace patterns on global function calls.</p></item>
<tag><c>ctpe</c></tag>
<item><p>Clears trace patterns on messages.</p></item>
</taglist>
<p>With <c>tp</c> and <c>tpl</c>, one of the match specification shortcuts
can be used (for example, <c>ttb:tp(foo_module, caller)</c>).</p>
<p>The shortcuts are as follows:</p>
<list type="bulleted">
<item><c>return</c> - for <c>[{'_',[],[{return_trace}]}]</c>
(report the return value from a traced function)</item>
<item><c>caller</c> - for <c>[{'_',[],[{message,{caller}}]}]</c>
(report the calling function)</item>
<item><c>{codestr, Str}</c> - for <c>dbg:fun2ms/1</c> arguments
passed as strings (example: <c>"fun(_) -> return_trace() end"</c>)
</item>
</list>
</desc>
</func>
<func>
<name since="">list_history() -> History</name>
<fsummary>Return all calls stored in history.</fsummary>
<type>
<v>History = [{N,Func,Args}]</v>
</type>
<desc>
<p>All calls to <c>ttb</c> is stored in the history. This
function returns the current content of the history. Any entry
can be reexecuted with <c>run_history/1</c> or stored in a
configuration file with <c>write_config/2,3</c>.</p>
</desc>
</func>
<func>
<name since="">run_history(N) -> ok | {error, Reason}</name>
<fsummary>Execute one entry of the history.</fsummary>
<type>
<v>N = integer() | [integer()]</v>
</type>
<desc>
<p>Executes the specified entry or entries from the history
list. To list history, use <c>list_history/0</c>.</p>
</desc>
</func>
<func>
<name since="">write_config(ConfigFile,Config)</name>
<fsummary>Equivalent to write_config(ConfigFile,Config,[]).</fsummary>
<desc>
<p>Equivalent to <c>write_config(ConfigFile,Config,[])</c>.</p>
</desc>
</func>
<func>
<name since="">write_config(ConfigFile,Config,Opts) -> ok | {error,Reason}</name>
<fsummary>Create a configuration file.</fsummary>
<type>
<v>ConfigFile = string()</v>
<v>Config = all | [integer()] | [{Mod,Func,Args}]</v>
<v>Mod = atom()</v>
<v>Func = atom()</v>
<v>Args = [term()]</v>
<v>Opts = Opt | [Opt]</v>
<v>Opt = append</v>
</type>
<desc>
<p>Creates or extends a configuration file, which can be
used for restoring a specific configuration later.
</p>
<p>The contents of the configuration file can either be fetched from
the history or specified directly as a list of
<c>{Mod,Func,Args}</c>.
</p>
<p>If the complete history is to be stored in the configuration file,
<c>Config</c> must be <c>all</c>. If only a selected number
of entries from the history are to be stored, <c>Config</c>
must be a list of integers pointing out the entries to be
stored.
</p>
<p>If <c>Opts</c> is not specified or if it is <c>[]</c>,
<c>ConfigFile</c> is deleted and a new file is created. If
<c>Opts = [append]</c>, <c>ConfigFile</c> is not deleted.
The new information is appended at the end of the file.</p>
</desc>
</func>
<func>
<name since="">run_config(ConfigFile) -> ok | {error,Reason}</name>
<fsummary>Execute all entries in a configuration file.</fsummary>
<type>
<v>ConfigFile = string()</v>
</type>
<desc>
<p>Executes all entries in the specified configuration file.
Notice that the history of the last trace is always available
in file <c>ttb_last_config</c>.</p>
</desc>
</func>
<func>
<name since="">run_config(ConfigFile,NumList) -> ok | {error,Reason}</name>
<fsummary>Execute selected entries from a configuration file.</fsummary>
<type>
<v>ConfigFile = string()</v>
<v>NumList = [integer()]</v>
</type>
<desc>
<p>Executes selected entries from the specified configuration
file. <c>NumList</c> is a list of integers pointing out the
entries to be executed.
</p>
<p>To list the contents of a configuration file, use
<c>list_config/1</c>.</p>
<p>Notice that the history of the last trace is always available
in file <c>ttb_last_config</c>.</p>
</desc>
</func>
<func>
<name since="">list_config(ConfigFile) -> Config | {error,Reason}</name>
<fsummary>List all entries in a configuration file.</fsummary>
<type>
<v>ConfigFile = string()</v>
<v>Config = [{N,Func,Args}]</v>
</type>
<desc>
<p>Lists all entries in the specified configuration file.</p>
</desc>
</func>
<func>
<name since="">write_trace_info(Key,Info) -> ok</name>
<fsummary>Write any information to file <c>.ti</c>.</fsummary>
<type>
<v>Key = term()</v>
<v>Info = Data | fun() -> Data</v>
<v>Data = term()</v>
</type>
<desc>
<p>File <c>.ti</c> contains <c>{Key,ValueList}</c>
tuples. This function adds <c>Data</c> to the <c>ValueList</c>
associated with <c>Key</c>. All information written with this
function is included in the call to the format handler.</p>
</desc>
</func>
<func>
<name since="">seq_trigger_ms() -> MatchSpec</name>
<fsummary>Equivalent to seq_trigger_ms(all).</fsummary>
<desc>
<p>Equivalent to <c>seq_trigger_ms(all)</c>.</p>
</desc>
</func>
<func>
<name since="">seq_trigger_ms(Flags) -> MatchSpec</name>
<fsummary>Return a match_spec() which starts sequential tracing.</fsummary>
<type>
<v>MatchSpec = match_spec()</v>
<v>Flags = all | SeqTraceFlag | [SeqTraceFlag]</v>
<v>SeqTraceFlag = atom()</v>
</type>
<desc>
<p>A match specification can turn on or off sequential
tracing. This function returns a match specification, which
turns on sequential tracing with the specified <c>Flags</c>.
</p>
<p>This match specification can be specified as the last argument
to <c>tp</c> or <c>tpl</c>. The activated <c>Item</c>
then becomes a <em>trigger</em> for sequential tracing. This
means that if the item is called on a process with trace flag
<c>call</c> set, the process is "contaminated"
with token <c>seq_trace</c>.
</p>
<p>If <c>Flags = all</c>, all possible flags are set.
</p>
<p>The possible values for <c>SeqTraceFlag</c> are available in
<seealso marker="kernel:seq_trace"><c>seq_trace</c></seealso>.</p>
<p>For a description of the <c>match_spec()</c> syntax,
see section
<seealso marker="erts:match_spec"><c>Match Specifications in Erlang</c></seealso>
in ERTS, which explains the general match specification "language".
</p>
<note>
<p>The <em>system tracer</em> for sequential tracing is
automatically initiated by <c>ttb</c> when a trace port is
started with <c>ttb:tracer/0,1,2</c>.</p>
</note>
<p>An example of how to use function <c>seq_trigger_ms/0,1</c> follows:</p>
<pre>
(tiger@durin)5> <input>ttb:tracer().</input>
{ok,[tiger@durin]}
(tiger@durin)6> <input>ttb:p(all,call).</input>
{ok,{[all],[call]}}
(tiger@durin)7> <input>ttb:tp(mod,func,ttb:seq_trigger_ms()).</input>
{ok,[{matched,1},{saved,1}]}
(tiger@durin)8></pre>
<p>Whenever <c>mod:func(...)</c> is called after this,
token <c>seq_trace</c> is set on the executing process.</p>
</desc>
</func>
<func>
<name since="">stop()</name>
<fsummary>Equivalent to stop([]).</fsummary>
<desc>
<p>Equivalent to <c>stop([])</c>.</p>
</desc>
</func>
<func>
<name since="">stop(Opts) -> stopped | {stopped, Dir}</name>
<fsummary>Stop tracing and fetch/format logs from all nodes.</fsummary>
<type>
<v>Opts = Opt | [Opt]</v>
<v>Opt = nofetch | {fetch_dir, Dir} | format | {format, FormatOpts} | return_fetch_dir</v>
<v>Dir = string()</v>
<v>FormatOpts = see format/2</v>
</type>
<desc>
<p>Stops tracing on all nodes. Logs and
trace information files are sent to the trace control
node and stored in a directory named
<c>ttb_upload_FileName-Timestamp</c>, where <c>Filename</c> is
the one provided with <c>{file, File}</c> during trace setup
and <c>Timestamp</c> is of the
form <c>yyyymmdd-hhmmss</c>. Even logs from nodes on the same
machine as the trace control node are moved to this directory.
The history list is saved to a file named <c>ttb_last_config</c>
for further reference (as it is no longer accessible
through history and configuration management functions, like
<c>ttb:list_history/0</c>).
</p>
<p><em>Options:</em></p>
<taglist>
<tag><c>nofetch</c></tag>
<item><p>Indicates that trace logs are not to be
collected after tracing is stopped.</p></item>
<tag><c>{fetch, Dir}</c></tag>
<item><p>Allows specification of the directory
to fetch the data to. If the directory already exists, an
error is thrown.</p></item>
<tag><c>format</c></tag>
<item><p>Indicates the trace logs to be formatted after tracing
is stopped. All logs in the fetch directory are merged.</p></item>
<tag><c>return_fetch_dir</c></tag>
<item><p>Indicates the return value
to be <c>{stopped, Dir}</c> and not just <c>stopped</c>.
This implies <c>fetch</c>.</p></item>
</taglist>
</desc>
</func>
<func>
<name since="OTP R15B">get_et_handler()</name>
<fsummary>Return the <c>et</c> handler.</fsummary>
<desc>
<p>Returns the <c>et</c> handler, which can be used with <c>format/2</c>
or <c>tracer/2</c>.</p>
<p>Example: <c>ttb:format(Dir, [{handler, ttb:get_et_handler()}])</c>.</p>
</desc>
</func>
<func>
<name since="">format(File)</name>
<fsummary>Equivalent to <c>format(File,[])</c>.</fsummary>
<desc>
<p>Equivalent to <c>format(File,[])</c>.</p>
</desc>
</func>
<func>
<name since="">format(File,Options) -> ok | {error, Reason}</name>
<fsummary>Format a binary trace log.</fsummary>
<type>
<v>File = string() | [string()]</v>
<d>This can be the name of a binary log, a list of such logs,
or the name of a directory containing one or more binary logs.</d>
<v>Options = Opt | [Opt]</v>
<v>Opt = {out,Out} | {handler,FormatHandler} | disable_sort</v>
<v>Out = standard_io | string()</v>
<v>FormatHandler = {Function, InitialState}</v>
<v>Function = fun(Fd,Trace,TraceInfo,State) -> State</v>
<v>Fd = standard_io | FileDescriptor</v>
<d>File descriptor of the destination file <c>Out</c>.</d>
<v>Trace = tuple()</v>
<d>The trace message. For details, see the Reference Manual for
module <c>erlang</c>.</d>
<v>TraceInfo = [{Key,ValueList}]</v>
<d>Includes the keys <c>flags</c>, <c>client</c>, and <c>node</c>.
If <c>handler</c> is specified as option to the tracer function, this
is also included. Also, all information written with function
<c>write_trace_info/2</c> is included.</d>
</type>
<desc>
<p>Reads the specified binary trace log(s). The logs are processed
in the order of their time stamps as long as option <c>disable_sort</c>
is not specified.
</p>
<p>If <c>FormatHandler = {Function,InitialState}</c>,
<c>Function</c> is called for each trace message.</p>
<p>If <c>FormatHandler = get_et_handler()</c>, <c>et_viewer</c> in
application ET is used for presenting
the trace log graphically. <c>ttb</c> provides a few different
filters that can be selected from menu <em>Filters and scaling</em>
in the <c>et_viewer</c>.</p>
<p>If <c>FormatHandler</c> is not specified, a
default handler is used presenting each trace message as a
text line.
</p>
<p>The state returned from each call of <c>Function</c> is passed to
the next call, even if the next call is to format a message from another
log file.
</p>
<p>If <c>Out</c> is specified, <c>FormatHandler</c> gets the
file descriptor to <c>Out</c> as the first parameter.
</p>
<p><c>Out</c> is ignored if the <c>et</c> format handler is used.
</p>
<p>Wrap logs can be formatted one by one or all at once. To
format one of the wrap logs in a set, specify the exact file name.
To format the whole set of wrap logs, specify the name
with <c>*</c> instead of the wrap count. For examples, see the
<seealso marker="ttb_ug#format"><c>User's Guide</c></seealso>.
</p>
</desc>
</func>
</funcs>
</erlref>
|