summaryrefslogtreecommitdiff
path: root/ovsdb/ovsdb-server.1.in
blob: a55af399a4a16441b8a89dd97190cd10da2153fe (plain)
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
.\" -*- nroff -*-
.de IQ
.  br
.  ns
.  IP "\\$1"
..
.TH ovsdb\-server 1 "@VERSION@" "Open vSwitch" "Open vSwitch Manual"
.\" This program's name:
.ds PN ovsdb\-server
.
.SH NAME
ovsdb\-server \- Open vSwitch database server
.
.SH SYNOPSIS
\fBovsdb\-server\fR
[\fIdatabase\fR]\&...
[\fB\-\-remote=\fIremote\fR]\&...
[\fB\-\-run=\fIcommand\fR]
.so lib/daemon-syn.man
.so lib/service-syn.man
.so lib/vlog-syn.man
.so ovsdb/replication-syn.man
.so lib/ssl-syn.man
.so lib/ssl-bootstrap-syn.man
.so lib/ssl-peer-ca-cert-syn.man
.so lib/ssl-connect-syn.man
.so lib/unixctl-syn.man
.so lib/common-syn.man
.
.SH DESCRIPTION
The \fBovsdb\-server\fR program provides RPC interfaces to one or more
Open vSwitch databases (OVSDBs).  It supports JSON-RPC client
connections over active or passive TCP/IP or Unix domain sockets.
.PP
Each OVSDB file may be specified on the command line as \fIdatabase\fR.
If none is specified, the default is \fB@DBDIR@/conf.db\fR.  The database
files must already have been created and initialized using, for
example, \fBovsdb\-tool create\fR.
.
.SH "ACTIVE and BACKUP"
\fBovsdb\-server\fR runs either as a backup server, or as an active server.
When  \fBovsdb\-server\fR is running as a backup server, all transactions that
can modify the database content, including the lock commands are rejected.
Active server, on the other hand, accepts all ovsdb server transactions.
When \fBovsdb\-server\fR role changes, all existing client connection are
reset, requiring clients to reconnect to the server.
.PP
By default, \fBovsdb\-server\fR runs as an active server, except when the
\fB\-\-sync\-from=\fIserver\fR command line option is specified and without
the \fB\-\-no\-sync option\fR.  During runtime, \fBovsdb\-server\fR role can be switch by using appctl commands.
.PP
\fBovsdb-server/connect\-active\-ovsdb\-server\fR switches
\fBovsdb\-server\fR into a backup server, Conversely,
\fBovsdb-server/disconnect\-active\-ovsdb\-server\fR switches server into
an active one.
.
.SH OPTIONS
.
.IP "\fB\-\-remote=\fIremote\fR"
Adds \fIremote\fR as a connection method used by \fBovsdb\-server\fR.
\fIremote\fR must take one of the following forms:
.
.RS
.so ovsdb/remote-passive.man
.so ovsdb/remote-active.man
.
.IP "\fBdb:\fIdb\fB,\fItable\fB,\fIcolumn\fR"
Reads additional connection methods from \fIcolumn\fR in all of the
rows in \fItable\fR within \fIdb\fR.  As the contents of \fIcolumn\fR changes,
\fBovsdb\-server\fR also adds and drops connection methods accordingly.
.IP
If \fIcolumn\fR's type is string or set of strings, then the
connection methods are taken directly from the column.  The connection
methods in the column must have one of the forms described above.
.IP
If \fIcolumn\fR's type is UUID or set of UUIDs and references a table,
then each UUID is looked up in the referenced table to obtain a row.
The following columns in the row, if present and of the correct type,
configure a connection method.  Any additional columns are ignored.
.RS
.IP "\fBtarget\fR (string)"
Connection method, in one of the forms described above.  This column
is mandatory: if it is missing or empty then no connection method can
be configured.
.IP "\fBmax_backoff\fR (integer)"
Maximum number of milliseconds to wait between connection attempts.
.IP "\fBinactivity_probe\fR (integer)"
Maximum number of milliseconds of idle time on connection to
client before sending an inactivity probe message.
.IP "\fBread_only\fR (boolean)"
If true, only read-only transactions are allowed on this connection.
.RE
.IP
It is an error for \fIcolumn\fR to have another type.
.RE
.
.IP
To connect or listen on multiple connection methods, use multiple
\fB\-\-remote\fR options.
.
.IP "\fB\-\-run=\fIcommand\fR]"
Ordinarily \fBovsdb\-server\fR runs forever, or until it is told to
exit (see \fBRUNTIME MANAGEMENT COMMANDS\fR below).  With this option,
\fBovsdb\-server\fR instead starts a shell subprocess running
\fIcommand\fR.  When the subprocess terminates, \fBovsdb\-server\fR
also exits gracefully.  If the subprocess exits normally with exit
code 0, then \fBovsdb\-server\fR exits with exit code 0 also;
otherwise, it exits with exit code 1.
.IP
This option can be useful where a database server is needed only to
run a single command, e.g.:
.B "ovsdb\-server \-\-remote=punix:socket \-\-run='ovsdb\-client dump unix:socket Open_vSwitch'"
.IP
This option is not supported on Windows platform.
.SS "Daemon Options"
.ds DD \
\fBovsdb\-server\fR detaches only after it starts listening on all \
configured remotes.
.so lib/daemon.man
.SS "Service Options"
.so lib/service.man
.SS "Logging Options"
.so lib/vlog.man
.SS "Syncing Options"
.so ovsdb/replication.man
.SS "Public Key Infrastructure Options"
The options described below for configuring the SSL public key
infrastructure accept a special syntax for obtaining their
configuration from the database.  If any of these options is given
\fBdb:\fIdb\fB,\fItable\fB,\fIcolumn\fR as its argument, then the
actual file name is read from the specified \fIcolumn\fR in \fItable\fR
within the \fIdb\fR database.  The \fIcolumn\fR must have type
string or set of strings.  The first nonempty string in the table is taken
as the file name.  (This means that ordinarily there should be at most
one row in \fItable\fR.)
.so lib/ssl.man
.so lib/ssl-bootstrap.man
.so lib/ssl-peer-ca-cert.man
.SS "SSL Connection Options"
.so lib/ssl-connect.man
.SS "Other Options"
.so lib/unixctl.man
.so lib/common.man
.SH "RUNTIME MANAGEMENT COMMANDS"
\fBovs\-appctl\fR(8) can send commands to a running
\fBovsdb\-server\fR process.  The currently supported commands are
described below.
.SS "OVSDB\-SERVER COMMANDS"
These commands are specific to \fBovsdb\-server\fR.
.IP "\fBexit\fR"
Causes \fBovsdb\-server\fR to gracefully terminate.
.IP "\fBovsdb\-server/compact\fR [\fIdb\fR]\&..."
Compacts each database \fIdb\fR in-place.  If no \fIdb\fR is
specified, compacts every database in-place.  A database is also
compacted automatically when a transaction is logged if it is over 4
times as large as its previous compacted size (and at least 10 MB),
but not before 100 commits have been added or 10 minutes have elapsed
since the last compaction.
.
.IP "\fBovsdb\-server/reconnect\fR"
Makes \fBovsdb\-server\fR drop all of the JSON\-RPC
connections to database clients and reconnect.
.IP
This command might be useful for debugging issues with database
clients.
.
.IP "\fBovsdb\-server/add\-remote \fIremote\fR"
Adds a remote, as if \fB\-\-remote=\fIremote\fR had been specified on
the \fBovsdb\-server\fR command line.  (If \fIremote\fR is already a
remote, this command succeeds without changing the configuration.)
.
.IP "\fBovsdb\-server/remove\-remote \fIremote\fR"
Removes the specified \fIremote\fR from the configuration, failing
with an error if \fIremote\fR is not configured as a remote.  This
command only works with remotes that were named on \fB\-\-remote\fR or
\fBovsdb\-server/add\-remote\fR, that is, it will not remove remotes
added indirectly because they were read from the database by
configuring a \fBdb:\fIdb\fB,\fItable\fB,\fIcolumn\fR remote.
(You can remove a database source with \fBovsdb\-server/remove\-remote
\fBdb:\fIdb\fB,\fItable\fB,\fIcolumn\fR, but not individual
remotes found indirectly through the database.)
.
.IP "\fBovsdb\-server/list\-remotes"
Outputs a list of the currently configured remotes named on
\fB\-\-remote\fR or \fBovsdb\-server/add\-remote\fR, that is, it does
not list remotes added indirectly because they were read from the
database by configuring a
\fBdb:\fIdb\fB,\fItable\fB,\fIcolumn\fR remote.
.
.IP "\fBovsdb\-server/add\-db \fIdatabase\fR"
Adds the \fIdatabase\fR to the running \fBovsdb\-server\fR.  The database
file must already have been created and initialized using, for example,
\fBovsdb\-tool create\fR.
.
.IP "\fBovsdb\-server/remove\-db \fIdatabase\fR"
Removes \fIdatabase\fR from the running \fBovsdb\-server\fR.  \fIdatabase\fR
must be a database name as listed by \fBovsdb-server/list\-dbs\fR.
.IP
If a remote has been configured that points to the specified
\fIdatabase\fR (e.g. \fB\-\-remote=db:\fIdatabase\fB,\fR... on the
command line), then it will be disabled until another database with
the same name is added again (with \fBovsdb\-server/add\-db\fR).
.IP
Any public key infrastructure options specified through this database
(e.g. \fB\-\-private\-key=db:\fIdatabase,\fR... on the command line)
will be disabled until another database with the same name is added
again (with \fBovsdb\-server/add\-db\fR).
.
.IP "\fBovsdb\-server/list\-dbs"
Outputs a list of the currently configured databases added either through
the command line or through the \fBovsdb\-server/add\-db\fR command.
.
.IP "\fBovsdb\-server/set\-active\-ovsdb\-server \fIserver"
Sets  the active \fIserver\fR from which \fBovsdb\-server\fR connects through
\fBovsdb\-server/connect\-active\-ovsdb\-server\fR.
.
.IP "\fBovsdb\-server/get\-active\-ovsdb\-server"
Gets the active server from which \fBovsdb\-server\fR is currently synchronizing
its databases.
.
.IP "\fBovsdb\-server/connect\-active\-ovsdb\-server"
Causes \fBovsdb\-server\fR to synchronize its databases with the server
specified by \fBovsdb\-server/set\-active\-ovsdb\-server\fR.
.
.IP "\fBovsdb\-server/disconnect\-active\-ovsdb\-server"
Causes \fBovsdb\-server\fR to  stop  synchronizing  its  databases with a active server.
.
.IP "\fBovsdb\-server/set\-sync\-exclude\-tables \fIdb\fB:\fItable\fR[\fB,\fIdb\fB:\fItable\fR]..."
Sets the \fItable\fR whitin \fIdb\fR that will be excluded from synchronization.
.
.IP "\fBovsdb\-server/get\-sync\-exclude\-tables"
Gets  the  tables  that are currently excluded from synchronization.
.
.IP "\fBovsdb\-server/sync\-status"
Prints a summary of replication run time information. The \fBstate\fR
information is always provided, indicating whether the server is running
in the \fIactive\fR or the \fIbackup\fR mode.
When running in backup mode, replication connection status, which
can be either \fIconnecting\fR, \fIreplicating\fR or \fIerror\fR, are shown.
When the connection is in \fIreplicating\fR state, further output shows
the list of databases currently replicating, and the tables that are
excluded.
.
.so lib/vlog-unixctl.man
.so lib/memory-unixctl.man
.so lib/coverage-unixctl.man
.SH "SPECIFICATIONS"
.
.PP
\fBovsdb\-server\fR implements the Open vSwitch Database (OVSDB)
protocol specified in RFC 7047, with the following clarifications:
.
.IP "3.1. JSON Usage"
RFC 4627 says that names within a JSON object should be unique.
The Open vSwitch JSON parser discards all but the last value
for a name that is specified more than once.
.
.IP
The definition of <error> allows for implementation extensions.
Currently \fBovsdb\-server\fR uses the following additional "error"
strings which might change in later releases):
.
.RS
.IP "\fBsyntax error\fR or \fBunknown column\fR"
The request could not be parsed as an OVSDB request.  An additional
"syntax" member, whose value is a string that contains JSON, may
narrow down the particular syntax that could not be parsed.
.IP "\fBinternal error\fR"
The request triggered a bug in \fBovsdb\-server\fR.
.IP "\fBovsdb error\fR"
A map or set contains a duplicate key.
.RE
.
.IP "3.2. Schema Format"
RFC 7047 requires the "version" field in <database-schema>.  Current
versions of \fBovsdb\-server\fR allow it to be omitted (future
versions are likely to require it).
.IP
RFC 7047 allows columns that contain weak references to be immutable.
This raises the issue of the behavior of the weak reference when the
rows that it references are deleted.  Since version 2.6,
\fBovsdb\-server\fR forces columns that contain weak references to be
mutable.
.
.IP "4. Wire Protocol"
The original OVSDB specifications included the following reason,
omitted from RFC 7047, to operate JSON-RPC directly over a stream
instead of over HTTP:
.
.RS
.IP \(bu
JSON-RPC is a peer-to-peer protocol, but HTTP is a client-server
protocol, which is a poor match.  Thus, JSON-RPC over HTTP requires
the client to periodically poll the server to receive server requests.
.IP \(bu
HTTP is more complicated than stream connections and doesn't provide
any corresponding advantage.
.IP \(bu
The JSON-RPC specification for HTTP transport is incomplete.
.RE
.
.IP "4.1.5. Monitor"
For backward compatibility, \fBovsdb\-server\fR currently permits a
single <monitor-request> to be used instead of an array; it is treated
as a single-element array.  Future versions of \fBovsdb\-server\fR
might remove this compatibility feature.
.IP
Because the <json-value> parameter is used to match subsequent update
notifications (see below) to the request, it must be unique among all
active monitors.  \fBovsdb\-server\fR rejects attempt to create two
monitors with the same identifier.
.
.IP "4.1.12. Monitor_cond"
A new monitor method added in Open vSwitch version 2.6. The monitor_cond
request enables a client to replicate subsets of tables within an OVSDB
database by requesting notifications of changes to rows matching one of
the conditions specified in "where" by receiving the specified contents
of these rows when table updates occur. Monitor_cond also allows a more
efficient update notifications by receiving table-updates2 notifications
(described below).
.
.IP
The monitor method described in Section 4.1.5 also applies to monitor_cond,
with the following exceptions:
.
.RS
.IP \(bu
RPC request method becomes "monitor_cond".
.IP \(bu
Reply result follows <table-updates2>, described in Section 4.1.14.
.IP \(bu
Subsequent changes are sent to the client using the "update2" monitor
notification, described in Section 4.1.14
.IP \(bu
Update notifications are being sent only for rows matching [<condition>*].
.RE
.
.IP
The request object has the following members:
.
.PP
.RS
.nf
"method": "monitor_cond"
"params": [<db-name>, <json-value>, <monitor-cond-requests>]
"id": <nonnull-json-value>
.fi
.RE
.
.IP
The <json-value> parameter is used to match subsequent update notifications
(see below) to this request. The <monitor-cond-requests> object maps the name
of the table to an array of <monitor-cond-request>.
.
.IP
Each <monitor-cond-request> is an object with the following members:
.
.PP
.RS
.nf
"columns": [<column>*]            optional
"where": [<condition>*]           optional
"select": <monitor-select>        optional
.fi
.RE
.
.IP
The "columns", if present, define the columns within the table to be monitored
that match conditions. If not present all columns are being monitored.
.
.IP
The "where" if present is a JSON array of <condition> and boolean values. If not
present or condition is an empty array, implicit True will be considered and
updates on all rows will be sent.
.
.IP
<monitor-select> is an object with the following members:
.
.PP
.RS
.nf
"initial": <boolean>              optional
"insert": <boolean>               optional
"delete": <boolean>               optional
"modify": <boolean>               optional
.fi
.RE
.
.IP
The contents of this object specify how the columns or table are to be
monitored as explained in more detail below.
.
.IP
The response object has the following members:
.
.PP
.RS
.nf
"result": <table-updates2>
"error": null
"id": same "id" as request
.fi
.RE
.
.IP
The <table-updates2> object is described in detail in Section 4.1.14. It
contains the contents of the tables for which "initial" rows are selected.
If no tables initial contents are requested, then "result" is an empty object.
.
.IP
Subsequently, when changes to a specified table that match one of the conditions
in monitor-cond-request are committed, the changes are automatically sent to the
client using the "update2" monitor notification (see Section 4.1.14). This
monitoring persists until the JSON-RPC session terminates or until the client
sends a "monitor_cancel" JSON-RPC request.
.
.IP
Each <monitor-cond-request> specifies one or more conditions and the manner in
which the rows that match the conditions are to be monitored. The circumstances in
which an "update" notification is sent for a row within the table are determined by
<monitor-select>:
.
.RS
.IP \(bu
If "initial" is omitted or true, every row in the original table that matches one of
the conditions is sent as part of the response to the "monitor_cond" request.
.IP \(bu
If "insert" is omitted or true, "update" notifications are sent for rows newly
inserted into the table that match conditions or for rows modified in the table
so that their old version does not match the condition and new version does.
.IP \(bu
If "delete" is omitted or true, "update" notifications are sent for rows deleted
from the table that match conditions or for rows modified in the table so that
their old version does match the conditions and new version does not.
.IP \(bu
If "modify" is omitted or true, "update" notifications are sent whenever a row in
the table that matches conditions in both old and new version is modified.
.RE
.
.IP
Both monitor and monitor_cond sessions can exist concurrently. However,
monitor and monitor_cond shares the same <json-value> parameter space; it
must be unique among all monitor and monitor_cond sessions.
.
.IP "4.1.13. Monitor_cond_change"
The "monitor_cond_change" request enables a client to change an existing
"monitor_cond" replication of the database by specifying a new condition
and columns for each replicated table. Currently changing the columns set
is not supported.
.
.IP
The request object has the following members:
.
.IP
.RS
.nf
"method": "monitor_cond_change"
"params": [<json-value>, <json-value>, <monitor-cond-update-requests>]
"id": <nonnull-json-value>
.fi
.RE
.
.IP
The <json-value> parameter should have a value of an existing conditional
monitoring session from this client. The second <json-value> in params array
is the requested value for this session. This value is valid only after
"monitor_cond_change" is committed. A user can use these values to distinguish
between update messages before conditions update and after. The
<monitor-cond-update-requests> object maps the name of the table to an array of
<monitor-cond-update-request>.
.
.IP
Each <monitor-cond-update-request> is an object with the following members:
.
.IP
.RS
.nf
"columns": [<column>*]         optional
"where": [<condition>*]        optional
.fi
.RE
.
.IP
The "columns" specify a new array of columns to be monitored
(Currently unsupported).
.
.IP
The "where" specify a new array of conditions to be applied to this monitoring
session.
.
.IP
The response object has the following members:
.
.IP
.RS
.nf
"result": null
"error": null
"id": same "id" as request
.fi
.RE
.IP
Subsequent <table-updates2> notifications are described in detail in Section
4.1.14 in the RFC. If insert contents are requested by original monitor_cond
request, <table-updates2> will contain rows that match the new condition and
do not match the old condition.
If deleted contents are requested by origin monitor request, <table-updates2>
will contain any matched rows by old condition and not matched by the new
condition.
.
.IP
Changes according to the new conditions are automatically sent to the client
using the "update2" monitor notification. An update, if any, as a result of a
condition change, will be sent to the client before the reply to the
"monitor_cond_change" request.
.
.IP "4.1.14. Update2 notification"
The "update2" notification is sent by the server to the client to report
changes in tables that are being monitored following a "monitor_cond" request
as described above. The notification has the following members:
.
.RS
.nf
"method": "update2"
"params": [<json-value>, <table-updates2>]
"id": null
.fi
.RE
.
.IP
The <json-value> in "params" is the same as the value passed as the
<json-value>  in "params" for the corresponding "monitor" request.
<table-updates2> is an object that maps from a table name to a <table-update2>.
A <table-update2> is an object that maps from row's UUID to a <row-update2>
object. A <row-update2> is an object with one of the following members:
.
.RS
.IP "\(dqinitial\(dq: <row>"
present for "initial" updates
.IP "\(dqinsert\(dq: <row>"
present for "insert" updates
.IP "\(dqdelete\(dq: <row>"
present for "delete" updates
.IP "\(dqmodify\(dq: <row>"
present for "modify" updates
.RE
.
.IP
The format of <row> is described in Section 5.1.
.
.IP
<row> is always a null object for a "delete" update. In "initial" and
"insert" updates, <row> omits columns whose values equal the default
value of the column type.
.
.IP
For a "modify" update, <row> contains only the columns that are modified.
<row> stores the difference between the old and new value for those columns,
as described below.
.
.IP
For columns with single value, the difference is the value of the new
column.
.
.IP
The difference between two sets are all elements that only belong
to one of the sets.
.
.IP
The difference between two maps are all key-value pairs whose keys
appears in only one of the maps, plus the key-value pairs whose keys
appear in both maps but with different values.  For the latter
elements, <row> includes the value from the new column.
.
.IP
Initial views of rows are not presented in update2 notifications,
but in the response object to the monitor_cond request. The formatting
of the <table-updates2> object, however, is the same in either case.
.
.IP "5.1. Notation"
For <condition>, RFC 7047 only allows the use of \fB!=\fR, \fB==\fR,
\fBincludes\fR, and \fBexcludes\fR operators with set types.  Open
vSwitch 2.4 and later extend <condition> to allow the use of \fB<\fR,
\fB<=\fR, \fB>=\fR, and \fB>\fR operators with columns with type ``set
of 0 or 1 integer'' and ``set of 0 or 1 real''.  These conditions
evaluate to false when the column is empty, and otherwise as described
in RFC 7047 for integer and real types.
.
.IP
<condition> is specified in Section 5.1 in the RFC with the following change:
A condition can be either a 3-element JSON array as described in the RFC or a
boolean value. In case of an empty array an implicit true boolean value will be
considered.
.
.SH "BUGS"
.
In Open vSwitch before version 2.4, when \fBovsdb\-server\fR sent
JSON-RPC error responses to some requests, it incorrectly formulated
them with the \fBresult\fR and \fBerror\fR swapped, so that the
response appeared to indicate success (with a nonsensical result)
rather than an error.  The requests that suffered from this problem
were:
.
.IP \fBtransact\fR
.IQ \fBget_schema\fR
Only if the request names a nonexistent database.
.IP \fBmonitor\fR
.IQ \fBlock\fR
.IQ \fBunlock\fR
In all error cases.
.
.PP
Of these cases, the only error that a well-written application is
likely to encounter in practice is \fBmonitor\fR of tables or columns
that do not exist, in an situation where the application has been
upgraded but the old database schema is still temporarily in use.  To
handle this situation gracefully, we recommend that clients should
treat a \fBmonitor\fR response with a \fBresult\fR that contains an
\fBerror\fR key-value pair as an error (assuming that the database
being monitored does not contain a table named \fBerror\fR).
.
.SH "SEE ALSO"
.
.BR ovsdb\-tool (1).