1ZMQ_SETSOCKOPT(3) 0MQ Manual ZMQ_SETSOCKOPT(3)
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3
4
6 zmq_setsockopt - set 0MQ socket options
7
9 int zmq_setsockopt (void *socket, int option_name, const void
10 *option_value, size_t option_len);
11
12 Caution: All options, with the exception of ZMQ_SUBSCRIBE,
13 ZMQ_UNSUBSCRIBE, ZMQ_LINGER, ZMQ_ROUTER_HANDOVER, ZMQ_ROUTER_MANDATORY,
14 ZMQ_PROBE_ROUTER, ZMQ_XPUB_VERBOSE, ZMQ_XPUB_VERBOSER,
15 ZMQ_REQ_CORRELATE, ZMQ_REQ_RELAXED, ZMQ_SNDHWM and ZMQ_RCVHWM, only
16 take effect for subsequent socket bind/connects.
17
18 Specifically, security options take effect for subsequent bind/connect
19 calls, and can be changed at any time to affect subsequent binds and/or
20 connects.
21
23 The zmq_setsockopt() function shall set the option specified by the
24 option_name argument to the value pointed to by the option_value
25 argument for the 0MQ socket pointed to by the socket argument. The
26 option_len argument is the size of the option value in bytes. For
27 options taking a value of type "character string", the provided byte
28 data should either contain no zero bytes, or end in a single zero byte
29 (terminating ASCII NUL character).
30
31 The following socket options can be set with the zmq_setsockopt()
32 function:
33
34 ZMQ_AFFINITY: Set I/O thread affinity
35 The ZMQ_AFFINITY option shall set the I/O thread affinity for newly
36 created connections on the specified socket.
37
38 Affinity determines which threads from the 0MQ I/O thread pool
39 associated with the socket’s context shall handle newly created
40 connections. A value of zero specifies no affinity, meaning that work
41 shall be distributed fairly among all 0MQ I/O threads in the thread
42 pool. For non-zero values, the lowest bit corresponds to thread 1,
43 second lowest bit to thread 2 and so on. For example, a value of 3
44 specifies that subsequent connections on socket shall be handled
45 exclusively by I/O threads 1 and 2.
46
47 See also zmq_init(3) for details on allocating the number of I/O
48 threads for a specific context.
49
50
51 Option value type uint64_t
52
53 Option value unit N/A (bitmap)
54
55 Default value 0
56
57 Applicable socket types N/A
58
59
60 ZMQ_BACKLOG: Set maximum length of the queue of outstanding connections
61 The ZMQ_BACKLOG option shall set the maximum length of the queue of
62 outstanding peer connections for the specified socket; this only
63 applies to connection-oriented transports. For details refer to your
64 operating system documentation for the listen function.
65
66
67
68 Option value type int
69
70 Option value unit connections
71
72 Default value 100
73
74 Applicable socket types all, only for
75 connection-oriented
76 transports.
77
78
79 ZMQ_BINDTODEVICE: Set name of device to bind the socket to
80 The ZMQ_BINDTODEVICE option binds this socket to a particular device,
81 eg. an interface or VRF. If a socket is bound to an interface, only
82 packets received from that particular interface are processed by the
83 socket. If device is a VRF device, then subsequent binds/connects to
84 that socket use addresses in the VRF routing table.
85
86 Note
87 requires setting CAP_NET_RAW on the compiled program.
88
89
90 Option value type character string
91
92 Option value unit N/A
93
94 Default value not set
95
96 Applicable socket types all, when using TCP or UDP
97 transports.
98
99
100 ZMQ_CONNECT_RID: Assign the next outbound connection id
101 This option name is now deprecated. Use ZMQ_CONNECT_ROUTING_ID instead.
102 ZMQ_CONNECT_RID remains as an alias for now.
103
104 ZMQ_CONNECT_ROUTING_ID: Assign the next outbound routing id
105 The ZMQ_CONNECT_ROUTING_ID option sets the peer id of the peer
106 connected via the next zmq_connect() call, such that that connection is
107 immediately ready for data transfer with the given routing id. This
108 option applies only to the first subsequent call to zmq_connect(),
109 zmq_connect() calls thereafter use the default connection behaviour.
110
111 Typical use is to set this socket option ahead of each zmq_connect()
112 call. Each connection MUST be assigned a unique routing id. Assigning a
113 routing id that is already in use is not allowed.
114
115 Useful when connecting ROUTER to ROUTER, or STREAM to STREAM, as it
116 allows for immediate sending to peers. Outbound routing id framing
117 requirements for ROUTER and STREAM sockets apply.
118
119 The routing id must be from 1 to 255 bytes long and MAY NOT start with
120 a zero byte (such routing ids are reserved for internal use by the 0MQ
121 infrastructure).
122
123
124 Option value type binary data
125
126 Option value unit N/A
127
128 Default value NULL
129
130 Applicable socket types ZMQ_ROUTER, ZMQ_STREAM
131
132
133 ZMQ_CONFLATE: Keep only last message
134 If set, a socket shall keep only one message in its inbound/outbound
135 queue, this message being the last message received/the last message to
136 be sent. Ignores ZMQ_RCVHWM and ZMQ_SNDHWM options. Does not support
137 multi-part messages, in particular, only one part of it is kept in the
138 socket internal queue.
139
140 Note
141 If recv is not called on the inbound socket, the queue and memory
142 will grow with each message received. Use zmq_getsockopt(3) with
143 ZMQ_EVENTS to trigger the conflation of the messages.
144
145
146 Option value type int
147
148 Option value unit boolean
149
150 Default value 0 (false)
151
152 Applicable socket types ZMQ_PULL, ZMQ_PUSH,
153 ZMQ_SUB, ZMQ_PUB,
154 ZMQ_DEALER
155
156
157 ZMQ_CONNECT_TIMEOUT: Set connect() timeout
158 Sets how long to wait before timing-out a connect() system call. The
159 connect() system call normally takes a long time before it returns a
160 time out error. Setting this option allows the library to time out the
161 call at an earlier interval.
162
163
164 Option value type int
165
166 Option value unit milliseconds
167
168 Default value 0 (disabled)
169
170 Applicable socket types all, when using TCP
171 transports.
172
173
174 ZMQ_CURVE_PUBLICKEY: Set CURVE public key
175 Sets the socket’s long term public key. You must set this on CURVE
176 client sockets, see zmq_curve(7). You can provide the key as 32 binary
177 bytes, or as a 40-character string encoded in the Z85 encoding format
178 and terminated in a null byte. The public key must always be used with
179 the matching secret key. To generate a public/secret key pair, use
180 zmq_curve_keypair(3). To derive the public key from a secret key, use
181 zmq_curve_public(3).
182
183 Note
184 an option value size of 40 is supported for backwards
185 compatibility, though is deprecated.
186
187
188 Option value type binary data or Z85 text
189 string
190
191 Option value size 32 or 41
192
193 Default value NULL
194
195 Applicable socket types all, when using TCP
196 transport
197
198
199 ZMQ_CURVE_SECRETKEY: Set CURVE secret key
200 Sets the socket’s long term secret key. You must set this on both CURVE
201 client and server sockets, see zmq_curve(7). You can provide the key as
202 32 binary bytes, or as a 40-character string encoded in the Z85
203 encoding format and terminated in a null byte. To generate a
204 public/secret key pair, use zmq_curve_keypair(3). To derive the public
205 key from a secret key, use zmq_curve_public(3).
206
207 Note
208 an option value size of 40 is supported for backwards
209 compatibility, though is deprecated.
210
211
212 Option value type binary data or Z85 text
213 string
214
215 Option value size 32 or 41
216
217 Default value NULL
218
219 Applicable socket types all, when using TCP
220 transport
221
222
223 ZMQ_CURVE_SERVER: Set CURVE server role
224 Defines whether the socket will act as server for CURVE security, see
225 zmq_curve(7). A value of 1 means the socket will act as CURVE server. A
226 value of 0 means the socket will not act as CURVE server, and its
227 security role then depends on other option settings. Setting this to 0
228 shall reset the socket security to NULL. When you set this you must
229 also set the server’s secret key using the ZMQ_CURVE_SECRETKEY option.
230 A server socket does not need to know its own public key.
231
232
233 Option value type int
234
235 Option value unit 0, 1
236
237 Default value 0
238
239 Applicable socket types all, when using TCP
240 transport
241
242
243 ZMQ_CURVE_SERVERKEY: Set CURVE server key
244 Sets the socket’s long term server key. You must set this on CURVE
245 client sockets, see zmq_curve(7). You can provide the key as 32 binary
246 bytes, or as a 40-character string encoded in the Z85 encoding format
247 and terminated in a null byte. This key must have been generated
248 together with the server’s secret key. To generate a public/secret key
249 pair, use zmq_curve_keypair(3).
250
251 Note
252 an option value size of 40 is supported for backwards
253 compatibility, though is deprecated.
254
255
256 Option value type binary data or Z85 text
257 string
258
259 Option value size 32 or 41
260
261 Default value NULL
262
263
264
265
266 Applicable socket types all, when using TCP
267 transport
268
269
270 ZMQ_DISCONNECT_MSG: set a disconnect message that the socket will generate
271 when accepted peer disconnect
272 When set, the socket will generate a disconnect message when accepted
273 peer has been disconnected. You may set this on ROUTER, SERVER and PEER
274 sockets. The combination with ZMQ_HEARTBEAT_IVL is powerful and
275 simplify protocols, when heartbeat recognize a connection drop it will
276 generate a disconnect message that can match the protocol of the
277 application.
278
279
280 Option value type binary data
281
282 Option value unit N/A
283
284 Default value NULL
285
286 Applicable socket types ZMQ_ROUTER, ZMQ_SERVER and
287 ZMQ_PEER
288
289
290 ZMQ_GSSAPI_PLAINTEXT: Disable GSSAPI encryption
291 Defines whether communications on the socket will be encrypted, see
292 zmq_gssapi(7). A value of 1 means that communications will be
293 plaintext. A value of 0 means communications will be encrypted.
294
295
296 Option value type int
297
298 Option value unit 0, 1
299
300 Default value 0 (false)
301
302 Applicable socket types all, when using TCP
303 transport
304
305
306 ZMQ_GSSAPI_PRINCIPAL: Set name of GSSAPI principal
307 Sets the name of the principal for whom GSSAPI credentials should be
308 acquired.
309
310
311 Option value type character string
312
313 Option value unit N/A
314
315 Default value not set
316
317 Applicable socket types all, when using TCP
318 transport
319
320
321 ZMQ_GSSAPI_SERVER: Set GSSAPI server role
322 Defines whether the socket will act as server for GSSAPI security, see
323 zmq_gssapi(7). A value of 1 means the socket will act as GSSAPI server.
324 A value of 0 means the socket will act as GSSAPI client.
325
326
327 Option value type int
328
329 Option value unit 0, 1
330
331
332 Default value 0 (false)
333
334 Applicable socket types all, when using TCP
335 transport
336
337
338 ZMQ_GSSAPI_SERVICE_PRINCIPAL: Set name of GSSAPI service principal
339 Sets the name of the principal of the GSSAPI server to which a GSSAPI
340 client intends to connect.
341
342
343 Option value type character string
344
345 Option value unit N/A
346
347 Default value not set
348
349 Applicable socket types all, when using TCP
350 transport
351
352
353 ZMQ_GSSAPI_SERVICE_PRINCIPAL_NAMETYPE: Set name type of service principal
354 Sets the name type of the GSSAPI service principal. A value of
355 ZMQ_GSSAPI_NT_HOSTBASED (0) means the name specified with
356 ZMQ_GSSAPI_SERVICE_PRINCIPAL is interpreted as a host based name. A
357 value of ZMQ_GSSAPI_NT_USER_NAME (1) means it is interpreted as a local
358 user name. A value of ZMQ_GSSAPI_NT_KRB5_PRINCIPAL (2) means it is
359 interpreted as an unparsed principal name string (valid only with the
360 krb5 GSSAPI mechanism).
361
362
363 Option value type int
364
365 Option value unit 0, 1, 2
366
367 Default value 0
368 (ZMQ_GSSAPI_NT_HOSTBASED)
369
370 Applicable socket types all, when using TCP or IPC
371 transport
372
373
374 ZMQ_GSSAPI_PRINCIPAL_NAMETYPE: Set name type of principal
375 Sets the name type of the GSSAPI principal. A value of
376 ZMQ_GSSAPI_NT_HOSTBASED (0) means the name specified with
377 ZMQ_GSSAPI_PRINCIPAL is interpreted as a host based name. A value of
378 ZMQ_GSSAPI_NT_USER_NAME (1) means it is interpreted as a local user
379 name. A value of ZMQ_GSSAPI_NT_KRB5_PRINCIPAL (2) means it is
380 interpreted as an unparsed principal name string (valid only with the
381 krb5 GSSAPI mechanism).
382
383
384 Option value type int
385
386 Option value unit 0, 1, 2
387
388 Default value 0
389 (ZMQ_GSSAPI_NT_HOSTBASED)
390
391 Applicable socket types all, when using TCP or IPC
392 transport
393
394
395 ZMQ_HANDSHAKE_IVL: Set maximum handshake interval
396 The ZMQ_HANDSHAKE_IVL option shall set the maximum handshake interval
397 for the specified socket. Handshaking is the exchange of socket
398 configuration information (socket type, routing id, security) that
399 occurs when a connection is first opened, only for connection-oriented
400 transports. If handshaking does not complete within the configured
401 time, the connection shall be closed. The value 0 means no handshake
402 time limit.
403
404
405 Option value type int
406
407 Option value unit milliseconds
408
409 Default value 30000
410
411 Applicable socket types all but ZMQ_STREAM, only
412 for connection-oriented
413 transports
414
415
416 ZMQ_HELLO_MSG: set an hello message that will be sent when a new peer
417 connect
418 When set, the socket will automatically send an hello message when a
419 new connection is made or accepted. You may set this on DEALER, ROUTER,
420 CLIENT, SERVER and PEER sockets. The combination with ZMQ_HEARTBEAT_IVL
421 is powerful and simplify protocols, as now heartbeat and sending the
422 hello message can be left out of protocols and be handled by zeromq.
423
424
425 Option value type binary data
426
427 Option value unit N/A
428
429 Default value NULL
430
431 Applicable socket types ZMQ_ROUTER, ZMQ_DEALER,
432 ZMQ_CLIENT, ZMQ_SERVER and
433 ZMQ_PEER
434
435
436 ZMQ_HEARTBEAT_IVL: Set interval between sending ZMTP heartbeats
437 The ZMQ_HEARTBEAT_IVL option shall set the interval between sending
438 ZMTP heartbeats for the specified socket. If this option is set and is
439 greater than 0, then a PING ZMTP command will be sent every
440 ZMQ_HEARTBEAT_IVL milliseconds.
441
442
443 Option value type int
444
445 Option value unit milliseconds
446
447 Default value 0
448
449 Applicable socket types all, when using
450 connection-oriented
451 transports
452
453
454 ZMQ_HEARTBEAT_TIMEOUT: Set timeout for ZMTP heartbeats
455 The ZMQ_HEARTBEAT_TIMEOUT option shall set how long to wait before
456 timing-out a connection after sending a PING ZMTP command and not
457 receiving any traffic. This option is only valid if ZMQ_HEARTBEAT_IVL
458 is also set, and is greater than 0. The connection will time out if
459 there is no traffic received after sending the PING command, but the
460 received traffic does not have to be a PONG command - any received
461 traffic will cancel the timeout.
462
463
464
465
466 Option value type int
467
468 Option value unit milliseconds
469
470 Default value 0 normally,
471 ZMQ_HEARTBEAT_IVL if it is
472 set
473
474 Applicable socket types all, when using
475 connection-oriented
476 transports
477
478
479 ZMQ_HEARTBEAT_TTL: Set the TTL value for ZMTP heartbeats
480 The ZMQ_HEARTBEAT_TTL option shall set the timeout on the remote peer
481 for ZMTP heartbeats. If this option is greater than 0, the remote side
482 shall time out the connection if it does not receive any more traffic
483 within the TTL period. This option does not have any effect if
484 ZMQ_HEARTBEAT_IVL is not set or is 0. Internally, this value is rounded
485 down to the nearest decisecond, any value less than 100 will have no
486 effect.
487
488
489 Option value type int
490
491 Option value unit milliseconds
492
493 Default value 0
494
495 Maximum value 6553599 (which is 2^16-1
496 deciseconds)
497
498 Applicable socket types all, when using
499 connection-oriented
500 transports
501
502
503 ZMQ_IDENTITY: Set socket identity
504 This option name is now deprecated. Use ZMQ_ROUTING_ID instead.
505 ZMQ_IDENTITY remains as an alias for now.
506
507 ZMQ_IMMEDIATE: Queue messages only to completed connections
508 By default queues will fill on outgoing connections even if the
509 connection has not completed. This can lead to "lost" messages on
510 sockets with round-robin routing (REQ, PUSH, DEALER). If this option is
511 set to 1, messages shall be queued only to completed connections. This
512 will cause the socket to block if there are no other connections, but
513 will prevent queues from filling on pipes awaiting connection.
514
515
516 Option value type int
517
518 Option value unit boolean
519
520 Default value 0 (false)
521
522 Applicable socket types all, only for
523 connection-oriented
524 transports.
525
526
527 ZMQ_INVERT_MATCHING: Invert message filtering
528 Reverses the filtering behavior of PUB-SUB sockets, when set to 1.
529
530 On PUB and XPUB sockets, this causes messages to be sent to all
531 connected sockets except those subscribed to a prefix that matches the
532 message. On SUB sockets, this causes only incoming messages that do not
533 match any of the socket’s subscriptions to be received by the user.
534
535 Whenever ZMQ_INVERT_MATCHING is set to 1 on a PUB socket, all SUB
536 sockets connecting to it must also have the option set to 1. Failure to
537 do so will have the SUB sockets reject everything the PUB socket sends
538 them. XSUB sockets do not need to do this because they do not filter
539 incoming messages.
540
541
542 Option value type int
543
544 Option value unit 0,1
545
546 Default value 0
547
548 Applicable socket types ZMQ_PUB, ZMQ_XPUB, ZMQ_SUB
549
550
551 ZMQ_IPV6: Enable IPv6 on socket
552 Set the IPv6 option for the socket. A value of 1 means IPv6 is enabled
553 on the socket, while 0 means the socket will use only IPv4. When IPv6
554 is enabled the socket will connect to, or accept connections from, both
555 IPv4 and IPv6 hosts.
556
557
558 Option value type int
559
560 Option value unit boolean
561
562 Default value 0 (false)
563
564 Applicable socket types all, when using TCP
565 transports.
566
567
568 ZMQ_LINGER: Set linger period for socket shutdown
569 The ZMQ_LINGER option shall set the linger period for the specified
570 socket. The linger period determines how long pending messages which
571 have yet to be sent to a peer shall linger in memory after a socket is
572 disconnected with zmq_disconnect(3) or closed with zmq_close(3), and
573 further affects the termination of the socket’s context with
574 zmq_ctx_term(3). The following outlines the different behaviours:
575
576 • A value of -1 specifies an infinite linger period. Pending messages
577 shall not be discarded after a call to zmq_disconnect() or
578 zmq_close(); attempting to terminate the socket’s context with
579 zmq_ctx_term() shall block until all pending messages have been
580 sent to a peer.
581
582 • The value of 0 specifies no linger period. Pending messages shall
583 be discarded immediately after a call to zmq_disconnect() or
584 zmq_close().
585
586 • Positive values specify an upper bound for the linger period in
587 milliseconds. Pending messages shall not be discarded after a call
588 to zmq_disconnect() or zmq_close(); attempting to terminate the
589 socket’s context with zmq_ctx_term() shall block until either all
590 pending messages have been sent to a peer, or the linger period
591 expires, after which any pending messages shall be discarded.
592
593 Option value type int
594 Option value unit milliseconds
595 Default value -1 (infinite)
596 Applicable socket types all
597
598
599 ZMQ_MAXMSGSIZE: Maximum acceptable inbound message size
600 Limits the size of the inbound message. If a peer sends a message
601 larger than ZMQ_MAXMSGSIZE it is disconnected. Value of -1 means no
602 limit.
603
604
605 Option value type int64_t
606
607 Option value unit bytes
608
609 Default value -1
610
611 Applicable socket types all
612
613
614 ZMQ_METADATA: Add application metadata properties to a socket
615 The ZMQ_METADATA option shall add application metadata to the specified
616 socket, the metadata is exchanged with peers during connection setup. A
617 metadata property is specfied as a string, delimited by a colon,
618 starting with the metadata property followed by the metadata value, for
619 example "X-key:value". Property names are restrited to maximum 255
620 characters and must be prefixed by "X-". Multiple application metadata
621 properties can be added to a socket by executing zmq_setsockopt()
622 multiple times. As the argument is a null-terminated string, binary
623 data must be encoded before it is added e.g. using Z85
624 (zmq_z85_encode(3)).
625
626 Note
627 in DRAFT state, not yet available in stable releases.
628
629
630 Option value type character string
631
632 Option value unit N/A
633
634 Default value not set
635
636 Applicable socket types all
637
638
639 ZMQ_MULTICAST_HOPS: Maximum network hops for multicast packets
640 Sets the time-to-live field in every multicast packet sent from this
641 socket. The default is 1 which means that the multicast packets don’t
642 leave the local network.
643
644
645 Option value type int
646
647 Option value unit network hops
648
649 Default value 1
650
651 Applicable socket types all, when using multicast
652 transports
653
654
655 ZMQ_MULTICAST_MAXTPDU: Maximum transport data unit size for multicast
656 packets
657 Sets the maximum transport data unit size used for outbound multicast
658 packets.
659
660 This must be set at or below the minimum Maximum Transmission Unit
661 (MTU) for all network paths over which multicast reception is required.
662
663
664 Option value type int
665
666
667 Option value unit bytes
668
669 Default value 1500
670
671 Applicable socket types all, when using multicast
672 transports
673
674
675 ZMQ_PLAIN_PASSWORD: Set PLAIN security password
676 Sets the password for outgoing connections over TCP or IPC. If you set
677 this to a non-null value, the security mechanism used for connections
678 shall be PLAIN, see zmq_plain(7). If you set this to a null value, the
679 security mechanism used for connections shall be NULL, see zmq_null(3).
680
681
682 Option value type character string
683
684 Option value unit N/A
685
686 Default value not set
687
688 Applicable socket types all, when using TCP
689 transport
690
691
692 ZMQ_PLAIN_SERVER: Set PLAIN server role
693 Defines whether the socket will act as server for PLAIN security, see
694 zmq_plain(7). A value of 1 means the socket will act as PLAIN server. A
695 value of 0 means the socket will not act as PLAIN server, and its
696 security role then depends on other option settings. Setting this to 0
697 shall reset the socket security to NULL.
698
699
700 Option value type int
701
702 Option value unit 0, 1
703
704 Default value 0
705
706 Applicable socket types all, when using TCP
707 transport
708
709
710 ZMQ_PLAIN_USERNAME: Set PLAIN security username
711 Sets the username for outgoing connections over TCP or IPC. If you set
712 this to a non-null value, the security mechanism used for connections
713 shall be PLAIN, see zmq_plain(7). If you set this to a null value, the
714 security mechanism used for connections shall be NULL, see zmq_null(3).
715
716
717 Option value type character string
718
719 Option value unit N/A
720
721 Default value not set
722
723 Applicable socket types all, when using TCP
724 transport
725
726
727 ZMQ_USE_FD: Set the pre-allocated socket file descriptor
728 When set to a positive integer value before zmq_bind is called on the
729 socket, the socket shall use the corresponding file descriptor for
730 connections over TCP or IPC instead of allocating a new file
731 descriptor. Useful for writing systemd socket activated services. If
732 set to -1 (default), a new file descriptor will be allocated instead
733 (default behaviour).
734
735 Note
736 if set after calling zmq_bind, this option shall have no effect.
737 NOTE: the file descriptor passed through MUST have been ran through
738 the "bind" and "listen" system calls beforehand. Also, socket
739 option that would normally be passed through zmq_setsockopt like
740 TCP buffers length, IP_TOS or SO_REUSEADDR MUST be set beforehand
741 by the caller, as they must be set before the socket is bound.
742
743
744 Option value type int
745
746 Option value unit file descriptor
747
748 Default value -1
749
750 Applicable socket types all bound sockets, when
751 using IPC or TCP transport
752
753
754 ZMQ_PRIORITY: Set the Priority on socket
755 Sets the protocol-defined priority for all packets to be sent on this
756 socket, where supported by the OS. In Linux, values greater than 6
757 require admin capability (CAP_NET_ADMIN)
758
759
760 Option value type int
761
762 Option value unit >0
763
764 Default value 0
765
766 Applicable socket types all, only for
767 connection-oriented
768 transports
769
770
771 ZMQ_PROBE_ROUTER: bootstrap connections to ROUTER sockets
772 When set to 1, the socket will automatically send an empty message when
773 a new connection is made or accepted. You may set this on REQ, DEALER,
774 or ROUTER sockets connected to a ROUTER socket. The application must
775 filter such empty messages. The ZMQ_PROBE_ROUTER option in effect
776 provides the ROUTER application with an event signaling the arrival of
777 a new peer.
778
779 Note
780 do not set this option on a socket that talks to any other socket
781 types: the results are undefined.
782
783
784 Option value type int
785
786 Option value unit 0, 1
787
788 Default value 0
789
790 Applicable socket types ZMQ_ROUTER, ZMQ_DEALER,
791 ZMQ_REQ
792
793
794 ZMQ_RATE: Set multicast data rate
795 The ZMQ_RATE option shall set the maximum send or receive data rate for
796 multicast transports such as zmq_pgm(7) using the specified socket.
797
798
799
800
801 Option value type int
802
803 Option value unit kilobits per second
804
805 Default value 100
806
807 Applicable socket types all, when using multicast
808 transports
809
810
811 ZMQ_RCVBUF: Set kernel receive buffer size
812 The ZMQ_RCVBUF option shall set the underlying kernel receive buffer
813 size for the socket to the specified size in bytes. A value of -1 means
814 leave the OS default unchanged. For details refer to your operating
815 system documentation for the SO_RCVBUF socket option.
816
817
818 Option value type int
819
820 Option value unit bytes
821
822 Default value -1
823
824 Applicable socket types all
825
826
827 ZMQ_RCVHWM: Set high water mark for inbound messages
828 The ZMQ_RCVHWM option shall set the high water mark for inbound
829 messages on the specified socket. The high water mark is a hard limit
830 on the maximum number of outstanding messages 0MQ shall queue in memory
831 for any single peer that the specified socket is communicating with. A
832 value of zero means no limit.
833
834 If this limit has been reached the socket shall enter an exceptional
835 state and depending on the socket type, 0MQ shall take appropriate
836 action such as blocking or dropping sent messages. Refer to the
837 individual socket descriptions in zmq_socket(3) for details on the
838 exact action taken for each socket type.
839
840 Note
841 0MQ does not guarantee that the socket will be able to queue as
842 many as ZMQ_RCVHWM messages, and the actual limit may be lower or
843 higher, depending on socket transport. A notable example is for
844 sockets using TCP transport; see zmq_tcp(7).
845
846
847 Option value type int
848
849 Option value unit messages
850
851 Default value 1000
852
853 Applicable socket types all
854
855
856 ZMQ_RCVTIMEO: Maximum time before a recv operation returns with EAGAIN
857 Sets the timeout for receive operation on the socket. If the value is
858 0, zmq_recv(3) will return immediately, with a EAGAIN error if there is
859 no message to receive. If the value is -1, it will block until a
860 message is available. For all other values, it will wait for a message
861 for that amount of time before returning with an EAGAIN error.
862
863
864 Option value type int
865
866
867
868 Option value unit milliseconds
869
870 Default value -1 (infinite)
871
872 Applicable socket types all
873
874
875 ZMQ_RECONNECT_IVL: Set reconnection interval
876 The ZMQ_RECONNECT_IVL option shall set the initial reconnection
877 interval for the specified socket. The reconnection interval is the
878 period 0MQ shall wait between attempts to reconnect disconnected peers
879 when using connection-oriented transports. The value -1 means no
880 reconnection.
881
882 Note
883 The reconnection interval may be randomized by 0MQ to prevent
884 reconnection storms in topologies with a large number of peers per
885 socket.
886
887
888 Option value type int
889
890 Option value unit milliseconds
891
892 Default value 100
893
894 Applicable socket types all, only for
895 connection-oriented
896 transports
897
898
899 ZMQ_RECONNECT_IVL_MAX: Set maximum reconnection interval
900 The ZMQ_RECONNECT_IVL_MAX option shall set the maximum reconnection
901 interval for the specified socket. This is the maximum period 0MQ shall
902 wait between attempts to reconnect. On each reconnect attempt, the
903 previous interval shall be doubled untill ZMQ_RECONNECT_IVL_MAX is
904 reached. This allows for exponential backoff strategy. Default value
905 means no exponential backoff is performed and reconnect interval
906 calculations are only based on ZMQ_RECONNECT_IVL.
907
908 Note
909 Values less than ZMQ_RECONNECT_IVL will be ignored.
910
911
912 Option value type int
913
914 Option value unit milliseconds
915
916 Default value 0 (only use
917 ZMQ_RECONNECT_IVL)
918
919 Applicable socket types all, only for
920 connection-oriented
921 transports
922
923
924 ZMQ_RECONNECT_STOP: Set condition where reconnection will stop
925 The ZMQ_RECONNECT_STOP option shall set the conditions under which
926 automatic reconnection will stop. This can be useful when a process
927 binds to a wild-card port, where the OS supplies an ephemeral port.
928
929 The ZMQ_RECONNECT_STOP_CONN_REFUSED option will stop reconnection when
930 0MQ receives the ECONNREFUSED return code from the connect. This
931 indicates that there is no code bound to the specified endpoint.
932
933 The ZMQ_RECONNECT_STOP_HANDSHAKE_FAILED option will stop reconnection
934 if the 0MQ handshake fails. This can be used to detect and/or prevent
935 errant connection attempts to non-0MQ sockets. Note that when
936 specifying this option you may also want to set ZMQ_HANDSHAKE_IVL — the
937 default handshake interval is 30000 (30 seconds), which is typically
938 too large.
939
940 The ZMQ_RECONNECT_STOP_AFTER_DISCONNECT option will stop reconnection
941 when zmq_disconnect() has been called. This can be useful when the
942 user’s request failed (server not ready), as the socket does not need
943 to continue to reconnect after user disconnect actively.
944
945 Note
946 in DRAFT state, not yet available in stable releases.
947
948
949 Option value type int
950
951 Option value unit 0,
952 ZMQ_RECONNECT_STOP_CONN_REFUSED,
953 ZMQ_RECONNECT_STOP_HANDSHAKE_FAILED,
954 ZMQ_RECONNECT_STOP_CONN_REFUSED
955 |
956 ZMQ_RECONNECT_STOP_HANDSHAKE_FAILED
957
958 Default value 0
959
960 Applicable socket types all, only for connection-oriented
961 transports (ZMQ_HANDSHAKE_IVL is not
962 applicable for ZMQ_STREAM sockets)
963
964
965 ZMQ_RECOVERY_IVL: Set multicast recovery interval
966 The ZMQ_RECOVERY_IVL option shall set the recovery interval for
967 multicast transports using the specified socket. The recovery interval
968 determines the maximum time in milliseconds that a receiver can be
969 absent from a multicast group before unrecoverable data loss will
970 occur.
971
972 Caution
973 Exercise care when setting large recovery intervals as the data
974 needed for recovery will be held in memory. For example, a 1 minute
975 recovery interval at a data rate of 1Gbps requires a 7GB in-memory
976 buffer.
977
978
979 Option value type int
980
981 Option value unit milliseconds
982
983 Default value 10000
984
985 Applicable socket types all, when using multicast
986 transports
987
988
989 ZMQ_REQ_CORRELATE: match replies with requests
990 The default behaviour of REQ sockets is to rely on the ordering of
991 messages to match requests and responses and that is usually
992 sufficient. When this option is set to 1, the REQ socket will prefix
993 outgoing messages with an extra frame containing a request id. That
994 means the full message is (request id, 0, user frames...). The REQ
995 socket will discard all incoming messages that don’t begin with these
996 two frames.
997
998
999 Option value type int
1000
1001
1002 Option value unit 0, 1
1003
1004 Default value 0
1005
1006 Applicable socket types ZMQ_REQ
1007
1008
1009 ZMQ_REQ_RELAXED: relax strict alternation between request and reply
1010 By default, a REQ socket does not allow initiating a new request with
1011 zmq_send(3) until the reply to the previous one has been received. When
1012 set to 1, sending another message is allowed and previous replies will
1013 be discarded if any. The request-reply state machine is reset and a new
1014 request is sent to the next available peer.
1015
1016 If set to 1, also enable ZMQ_REQ_CORRELATE to ensure correct matching
1017 of requests and replies. Otherwise a late reply to an aborted request
1018 can be reported as the reply to the superseding request.
1019
1020
1021 Option value type int
1022
1023 Option value unit 0, 1
1024
1025 Default value 0
1026
1027 Applicable socket types ZMQ_REQ
1028
1029
1030 ZMQ_ROUTER_HANDOVER: handle duplicate client routing ids on ROUTER sockets
1031 If two clients use the same routing id when connecting to a ROUTER, the
1032 results shall depend on the ZMQ_ROUTER_HANDOVER option setting. If that
1033 is not set (or set to the default of zero), the ROUTER socket shall
1034 reject clients trying to connect with an already-used routing id. If
1035 that option is set to 1, the ROUTER socket shall hand-over the
1036 connection to the new client and disconnect the existing one.
1037
1038
1039 Option value type int
1040
1041 Option value unit 0, 1
1042
1043 Default value 0
1044
1045 Applicable socket types ZMQ_ROUTER
1046
1047
1048 ZMQ_ROUTER_MANDATORY: accept only routable messages on ROUTER sockets
1049 Sets the ROUTER socket behaviour when an unroutable message is
1050 encountered. A value of 0 is the default and discards the message
1051 silently when it cannot be routed or the peers SNDHWM is reached. A
1052 value of 1 returns an EHOSTUNREACH error code if the message cannot be
1053 routed or EAGAIN error code if the SNDHWM is reached and ZMQ_DONTWAIT
1054 was used. Without ZMQ_DONTWAIT it will block until the SNDTIMEO is
1055 reached or a spot in the send queue opens up.
1056
1057 When ZMQ_ROUTER_MANDATORY is set to 1, ZMQ_POLLOUT events will be
1058 generated if one or more messages can be sent to at least one of the
1059 peers. If ZMQ_ROUTER_MANDATORY is set to 0, the socket will generate a
1060 ZMQ_POLLOUT event on every call to zmq_poll resp. zmq_poller_wait_all.
1061
1062
1063 Option value type int
1064
1065 Option value unit 0, 1
1066
1067
1068
1069 Default value 0
1070
1071 Applicable socket types ZMQ_ROUTER
1072
1073
1074 ZMQ_ROUTER_RAW: switch ROUTER socket to raw mode
1075 Sets the raw mode on the ROUTER, when set to 1. When the ROUTER socket
1076 is in raw mode, and when using the tcp:// transport, it will read and
1077 write TCP data without 0MQ framing. This lets 0MQ applications talk to
1078 non-0MQ applications. When using raw mode, you cannot set explicit
1079 identities, and the ZMQ_SNDMORE flag is ignored when sending data
1080 messages. In raw mode you can close a specific connection by sending it
1081 a zero-length message (following the routing id frame).
1082
1083 Note
1084 This option is deprecated, please use ZMQ_STREAM sockets instead.
1085
1086
1087 Option value type int
1088
1089 Option value unit 0, 1
1090
1091 Default value 0
1092
1093 Applicable socket types ZMQ_ROUTER
1094
1095
1096 ZMQ_ROUTING_ID: Set socket routing id
1097 The ZMQ_ROUTING_ID option shall set the routing id of the specified
1098 socket when connecting to a ROUTER socket.
1099
1100 A routing id must be at least one byte and at most 255 bytes long.
1101 Identities starting with a zero byte are reserved for use by the 0MQ
1102 infrastructure.
1103
1104 If two clients use the same routing id when connecting to a ROUTER, the
1105 results shall depend on the ZMQ_ROUTER_HANDOVER option setting. If that
1106 is not set (or set to the default of zero), the ROUTER socket shall
1107 reject clients trying to connect with an already-used routing id. If
1108 that option is set to 1, the ROUTER socket shall hand-over the
1109 connection to the new client and disconnect the existing one.
1110
1111
1112 Option value type binary data
1113
1114 Option value unit N/A
1115
1116 Default value NULL
1117
1118 Applicable socket types ZMQ_REQ, ZMQ_REP,
1119 ZMQ_ROUTER, ZMQ_DEALER.
1120
1121
1122 ZMQ_SNDBUF: Set kernel transmit buffer size
1123 The ZMQ_SNDBUF option shall set the underlying kernel transmit buffer
1124 size for the socket to the specified size in bytes. A value of -1 means
1125 leave the OS default unchanged. For details please refer to your
1126 operating system documentation for the SO_SNDBUF socket option.
1127
1128
1129 Option value type int
1130
1131 Option value unit bytes
1132
1133 Default value -1
1134
1135
1136 Applicable socket types all
1137
1138
1139 ZMQ_SNDHWM: Set high water mark for outbound messages
1140 The ZMQ_SNDHWM option shall set the high water mark for outbound
1141 messages on the specified socket. The high water mark is a hard limit
1142 on the maximum number of outstanding messages 0MQ shall queue in memory
1143 for any single peer that the specified socket is communicating with. A
1144 value of zero means no limit.
1145
1146 If this limit has been reached the socket shall enter an exceptional
1147 state and depending on the socket type, 0MQ shall take appropriate
1148 action such as blocking or dropping sent messages. Refer to the
1149 individual socket descriptions in zmq_socket(3) for details on the
1150 exact action taken for each socket type.
1151
1152 Note
1153 0MQ does not guarantee that the socket will accept as many as
1154 ZMQ_SNDHWM messages, and the actual limit may be as much as 90%
1155 lower depending on the flow of messages on the socket. The socket
1156 may even be able to accept more messages than the ZMQ_SNDHWM
1157 threshold; a notable example is for sockets using TCP transport;
1158 see zmq_tcp(7).
1159
1160
1161 Option value type int
1162
1163 Option value unit messages
1164
1165 Default value 1000
1166
1167 Applicable socket types all
1168
1169
1170 ZMQ_SNDTIMEO: Maximum time before a send operation returns with EAGAIN
1171 Sets the timeout for send operation on the socket. If the value is 0,
1172 zmq_send(3) will return immediately, with a EAGAIN error if the message
1173 cannot be sent. If the value is -1, it will block until the message is
1174 sent. For all other values, it will try to send the message for that
1175 amount of time before returning with an EAGAIN error.
1176
1177
1178 Option value type int
1179
1180 Option value unit milliseconds
1181
1182 Default value -1 (infinite)
1183
1184 Applicable socket types all
1185
1186
1187 ZMQ_SOCKS_PROXY: Set SOCKS5 proxy address
1188 Sets the SOCKS5 proxy address that shall be used by the socket for the
1189 TCP connection(s). Supported authentication methods are: no
1190 authentication or basic authentication when setup with
1191 ZMQ_SOCKS_USERNAME. If the endpoints are domain names instead of
1192 addresses they shall not be resolved and they shall be forwarded
1193 unchanged to the SOCKS proxy service in the client connection request
1194 message (address type 0x03 domain name).
1195
1196
1197 Option value type character string
1198
1199 Option value unit N/A
1200
1201
1202
1203 Default value not set
1204
1205 Applicable socket types all, when using TCP
1206 transport
1207
1208
1209 ZMQ_SOCKS_USERNAME: Set SOCKS username and select basic authentication
1210 Sets the username for authenticated connection to the SOCKS5 proxy. If
1211 you set this to a non-null and non-empty value, the authentication
1212 method used for the SOCKS5 connection shall be basic authentication. In
1213 this case, use ZMQ_SOCKS_PASSWORD option in order to set the password.
1214 If you set this to a null value or empty value, the authentication
1215 method shall be no authentication, the default.
1216
1217
1218 Option value type character string
1219
1220 Option value unit N/A
1221
1222 Default value not set
1223
1224 Applicable socket types all, when using TCP
1225 transport
1226
1227
1228 ZMQ_SOCKS_PASSWORD: Set SOCKS basic authentication password
1229 Sets the password for authenticating to the SOCKS5 proxy server. This
1230 is used only when the SOCKS5 authentication method has been set to
1231 basic authentication through the ZMQ_SOCKS_USERNAME option. Setting
1232 this to a null value (the default) is equivalent to an empty password
1233 string.
1234
1235
1236 Option value type character string
1237
1238 Option value unit N/A
1239
1240 Default value not set
1241
1242 Applicable socket types all, when using TCP
1243 transport
1244
1245
1246 ZMQ_STREAM_NOTIFY: send connect and disconnect notifications
1247 Enables connect and disconnect notifications on a STREAM socket, when
1248 set to 1. When notifications are enabled, the socket delivers a
1249 zero-length message when a peer connects or disconnects.
1250
1251
1252 Option value type int
1253
1254 Option value unit 0, 1
1255
1256 Default value 1
1257
1258 Applicable socket types ZMQ_STREAM
1259
1260
1261 ZMQ_SUBSCRIBE: Establish message filter
1262 The ZMQ_SUBSCRIBE option shall establish a new message filter on a
1263 ZMQ_SUB socket. Newly created ZMQ_SUB sockets shall filter out all
1264 incoming messages, therefore you should call this option to establish
1265 an initial message filter.
1266
1267 An empty option_value of length zero shall subscribe to all incoming
1268 messages. A non-empty option_value shall subscribe to all messages
1269 beginning with the specified prefix. Multiple filters may be attached
1270 to a single ZMQ_SUB socket, in which case a message shall be accepted
1271 if it matches at least one filter.
1272
1273
1274 Option value type binary data
1275
1276 Option value unit N/A
1277
1278 Default value N/A
1279
1280 Applicable socket types ZMQ_SUB
1281
1282
1283 ZMQ_TCP_KEEPALIVE: Override SO_KEEPALIVE socket option
1284 Override SO_KEEPALIVE socket option (where supported by OS). The
1285 default value of -1 means to skip any overrides and leave it to OS
1286 default.
1287
1288
1289 Option value type int
1290
1291 Option value unit -1,0,1
1292
1293 Default value -1 (leave to OS default)
1294
1295 Applicable socket types all, when using TCP
1296 transports.
1297
1298
1299 ZMQ_TCP_KEEPALIVE_CNT: Override TCP_KEEPCNT socket option
1300 Override TCP_KEEPCNT socket option (where supported by OS). The default
1301 value of -1 means to skip any overrides and leave it to OS default.
1302
1303
1304 Option value type int
1305
1306 Option value unit -1,>0
1307
1308 Default value -1 (leave to OS default)
1309
1310 Applicable socket types all, when using TCP
1311 transports.
1312
1313
1314 ZMQ_TCP_KEEPALIVE_IDLE: Override TCP_KEEPIDLE (or TCP_KEEPALIVE on some OS)
1315 Override TCP_KEEPIDLE (or TCP_KEEPALIVE on some OS) socket option
1316 (where supported by OS). The default value of -1 means to skip any
1317 overrides and leave it to OS default.
1318
1319
1320 Option value type int
1321
1322 Option value unit -1,>0
1323
1324 Default value -1 (leave to OS default)
1325
1326 Applicable socket types all, when using TCP
1327 transports.
1328
1329
1330 ZMQ_TCP_KEEPALIVE_INTVL: Override TCP_KEEPINTVL socket option
1331 Override TCP_KEEPINTVL socket option(where supported by OS). The
1332 default value of -1 means to skip any overrides and leave it to OS
1333 default.
1334
1335
1336
1337 Option value type int
1338
1339 Option value unit -1,>0
1340
1341 Default value -1 (leave to OS default)
1342
1343 Applicable socket types all, when using TCP
1344 transports.
1345
1346
1347 ZMQ_TCP_MAXRT: Set TCP Maximum Retransmit Timeout
1348 On OSes where it is supported, sets how long before an unacknowledged
1349 TCP retransmit times out. The system normally attempts many TCP
1350 retransmits following an exponential backoff strategy. This means that
1351 after a network outage, it may take a long time before the session can
1352 be re-established. Setting this option allows the timeout to happen at
1353 a shorter interval.
1354
1355
1356 Option value type int
1357
1358 Option value unit milliseconds
1359
1360 Default value 0 (leave to OS default)
1361
1362 Applicable socket types all, when using TCP
1363 transports.
1364
1365
1366 ZMQ_TOS: Set the Type-of-Service on socket
1367 Sets the ToS fields (Differentiated services (DS) and Explicit
1368 Congestion Notification (ECN) field of the IP header. The ToS field is
1369 typically used to specify a packets priority. The availability of this
1370 option is dependent on intermediate network equipment that inspect the
1371 ToS field and provide a path for low-delay, high-throughput,
1372 highly-reliable service, etc.
1373
1374
1375 Option value type int
1376
1377 Option value unit >0
1378
1379 Default value 0
1380
1381 Applicable socket types all, only for
1382 connection-oriented
1383 transports
1384
1385
1386 ZMQ_UNSUBSCRIBE: Remove message filter
1387 The ZMQ_UNSUBSCRIBE option shall remove an existing message filter on a
1388 ZMQ_SUB socket. The filter specified must match an existing filter
1389 previously established with the ZMQ_SUBSCRIBE option. If the socket has
1390 several instances of the same filter attached the ZMQ_UNSUBSCRIBE
1391 option shall remove only one instance, leaving the rest in place and
1392 functional.
1393
1394
1395 Option value type binary data
1396
1397 Option value unit N/A
1398
1399 Default value N/A
1400
1401 Applicable socket types ZMQ_SUB
1402
1403
1404 ZMQ_XPUB_VERBOSE: pass duplicate subscribe messages on XPUB socket
1405 Sets the XPUB socket behaviour on new duplicated subscriptions. If
1406 enabled, the socket passes all subscribe messages to the caller. If
1407 disabled, only the first subscription to each filter will be passed.
1408 The default is 0 (disabled).
1409
1410
1411 Option value type int
1412
1413 Option value unit 0, 1
1414
1415 Default value 0
1416
1417 Applicable socket types ZMQ_XPUB
1418
1419
1420 ZMQ_XPUB_VERBOSER: pass duplicate subscribe and unsubscribe messages on
1421 XPUB socket
1422 Sets the XPUB socket behaviour on new duplicated subscriptions and
1423 unsubscriptions. If enabled, the socket passes all subscribe and
1424 unsubscribe messages to the caller. If disabled, only the first
1425 subscription to each filter and the last unsubscription from each
1426 filter will be passed. The default is 0 (disabled).
1427
1428
1429 Option value type int
1430
1431 Option value unit 0, 1
1432
1433 Default value 0
1434
1435 Applicable socket types ZMQ_XPUB
1436
1437
1438 ZMQ_XPUB_MANUAL: change the subscription handling to manual
1439 Sets the XPUB socket subscription handling mode manual/automatic. A
1440 value of 0 is the default and subscription requests will be handled
1441 automatically. A value of 1 will change the subscription requests
1442 handling to manual, with manual mode subscription requests are not
1443 added to the subscription list. To add subscription the user need to
1444 call setsockopt with ZMQ_SUBSCRIBE on XPUB socket.
1445
1446
1447 Option value type int
1448
1449 Option value unit 0, 1
1450
1451 Default value 0
1452
1453 Applicable socket types ZMQ_XPUB
1454
1455
1456 ZMQ_XPUB_MANUAL_LAST_VALUE: change the subscription handling to manual
1457 This option is similar to ZMQ_XPUB_MANUAL. The difference is that
1458 ZMQ_XPUB_MANUAL_LAST_VALUE changes the XPUB socket behaviour to send
1459 the first message to the last subscriber after the socket receives a
1460 subscription and call setsockopt with ZMQ_SUBSCRIBE on XPUB socket.
1461 This prevents duplicated messages when using last value caching(LVC).
1462
1463 Note
1464 in DRAFT state, not yet available in stable releases.
1465
1466
1467 Option value type int
1468
1469
1470
1471 Option value unit 0, 1
1472
1473 Default value 0
1474
1475 Applicable socket types ZMQ_XPUB
1476
1477
1478 ZMQ_XPUB_NODROP: do not silently drop messages if SENDHWM is reached
1479 Sets the XPUB socket behaviour to return error EAGAIN if SENDHWM is
1480 reached and the message could not be send.
1481
1482 A value of 0 is the default and drops the message silently when the
1483 peers SNDHWM is reached. A value of 1 returns an EAGAIN error code if
1484 the SNDHWM is reached and ZMQ_DONTWAIT was used.
1485
1486
1487 Option value type int
1488
1489 Option value unit 0, 1
1490
1491 Default value 0
1492
1493 Applicable socket types ZMQ_XPUB, ZMQ_PUB
1494
1495
1496 ZMQ_XPUB_WELCOME_MSG: set welcome message that will be received by
1497 subscriber when connecting
1498 Sets a welcome message the will be recieved by subscriber when
1499 connecting. Subscriber must subscribe to the Welcome message before
1500 connecting. Welcome message will also be sent on reconnecting. For
1501 welcome message to work well user must poll on incoming subscription
1502 messages on the XPUB socket and handle them.
1503
1504 Use NULL and length of zero to disable welcome message.
1505
1506
1507 Option value type binary data
1508
1509 Option value unit N/A
1510
1511 Default value NULL
1512
1513 Applicable socket types ZMQ_XPUB
1514
1515
1516 ZMQ_ONLY_FIRST_SUBSCRIBE: Process only first subscribe/unsubscribe in a
1517 multipart message
1518 If set, only the first part of the multipart message is processed as a
1519 subscribe/unsubscribe message. The rest are forwarded as user data
1520 regardless of message contents.
1521
1522 It not set (default), subscribe/unsubscribe messages in a multipart
1523 message are processed as such regardless of their number and order.
1524
1525
1526 Option value type int
1527
1528 Option value unit boolean
1529
1530 Default value 0 (false)
1531
1532 Applicable socket types ZMQ_XSUB, ZMQ_XPUB
1533
1534
1535 ZMQ_ZAP_DOMAIN: Set RFC 27 authentication domain
1536 Sets the domain for ZAP (ZMQ RFC 27) authentication. A ZAP domain must
1537 be specified to enable authentication. When the ZAP domain is empty,
1538 which is the default, ZAP authentication is disabled. This is not
1539 compatible with previous versions of libzmq, so it can be controlled by
1540 ZMQ_ZAP_ENFORCE_DOMAIN which for now is disabled by default. See
1541 http://rfc.zeromq.org/spec:27 for more details.
1542
1543
1544 Option value type character string
1545
1546 Option value unit N/A
1547
1548 Default value empty
1549
1550 Applicable socket types all, when using TCP
1551 transport
1552
1553
1554 ZMQ_ZAP_ENFORCE_DOMAIN: Set ZAP domain handling to strictly adhere the RFC
1555 The ZAP (ZMQ RFC 27) authentication protocol specifies that a domain
1556 must always be set. Older versions of libzmq did not follow the spec
1557 and allowed an empty domain to be set. This option can be used to
1558 enabled or disable the stricter, backward incompatible behaviour. For
1559 now it is disabled by default, but in a future version it will be
1560 enabled by default.
1561
1562
1563 Option value type int
1564
1565 Option value unit 0, 1
1566
1567 Default value 0
1568
1569 Applicable socket types all, when using ZAP
1570
1571
1572 ZMQ_TCP_ACCEPT_FILTER: Assign filters to allow new TCP connections
1573 Assign an arbitrary number of filters that will be applied for each new
1574 TCP transport connection on a listening socket. If no filters are
1575 applied, then the TCP transport allows connections from any IP address.
1576 If at least one filter is applied then new connection source ip should
1577 be matched. To clear all filters call zmq_setsockopt(socket,
1578 ZMQ_TCP_ACCEPT_FILTER, NULL, 0). Filter is a null-terminated string
1579 with ipv6 or ipv4 CIDR.
1580
1581 Note
1582 This option is deprecated, please use authentication via the ZAP
1583 API and IP address allowing / blocking.
1584
1585
1586 Option value type binary data
1587
1588 Option value unit N/A
1589
1590 Default value no filters (allow from
1591 all)
1592
1593 Applicable socket types all listening sockets,
1594 when using TCP transports.
1595
1596
1597 ZMQ_IPC_FILTER_GID: Assign group ID filters to allow new IPC connections
1598 Assign an arbitrary number of filters that will be applied for each new
1599 IPC transport connection on a listening socket. If no IPC filters are
1600 applied, then the IPC transport allows connections from any process. If
1601 at least one UID, GID, or PID filter is applied then new connection
1602 credentials should be matched. To clear all GID filters call
1603 zmq_setsockopt(socket, ZMQ_IPC_FILTER_GID, NULL, 0).
1604
1605 Note
1606 GID filters are only available on platforms supporting SO_PEERCRED
1607 or LOCAL_PEERCRED socket options (currently only Linux and later
1608 versions of OS X).
1609
1610 Note
1611 This option is deprecated, please use authentication via the ZAP
1612 API and IPC allowing / blocking.
1613
1614
1615 Option value type gid_t
1616
1617 Option value unit N/A
1618
1619 Default value no filters (allow from
1620 all)
1621
1622 Applicable socket types all listening sockets,
1623 when using IPC transports.
1624
1625
1626 ZMQ_IPC_FILTER_PID: Assign process ID filters to allow new IPC connections
1627 Assign an arbitrary number of filters that will be applied for each new
1628 IPC transport connection on a listening socket. If no IPC filters are
1629 applied, then the IPC transport allows connections from any process. If
1630 at least one UID, GID, or PID filter is applied then new connection
1631 credentials should be matched. To clear all PID filters call
1632 zmq_setsockopt(socket, ZMQ_IPC_FILTER_PID, NULL, 0).
1633
1634 Note
1635 PID filters are only available on platforms supporting the
1636 SO_PEERCRED socket option (currently only Linux).
1637
1638 Note
1639 This option is deprecated, please use authentication via the ZAP
1640 API and IPC allowing / blocking.
1641
1642
1643 Option value type pid_t
1644
1645 Option value unit N/A
1646
1647 Default value no filters (allow from
1648 all)
1649
1650 Applicable socket types all listening sockets,
1651 when using IPC transports.
1652
1653
1654 ZMQ_IPC_FILTER_UID: Assign user ID filters to allow new IPC connections
1655 Assign an arbitrary number of filters that will be applied for each new
1656 IPC transport connection on a listening socket. If no IPC filters are
1657 applied, then the IPC transport allows connections from any process. If
1658 at least one UID, GID, or PID filter is applied then new connection
1659 credentials should be matched. To clear all UID filters call
1660 zmq_setsockopt(socket, ZMQ_IPC_FILTER_UID, NULL, 0).
1661
1662 Note
1663 UID filters are only available on platforms supporting SO_PEERCRED
1664 or LOCAL_PEERCRED socket options (currently only Linux and later
1665 versions of OS X).
1666
1667 Note
1668 This option is deprecated, please use authentication via the ZAP
1669 API and IPC allowing / blocking.
1670
1671
1672 Option value type uid_t
1673
1674
1675 Option value unit N/A
1676
1677 Default value no filters (allow from
1678 all)
1679
1680 Applicable socket types all listening sockets,
1681 when using IPC transports.
1682
1683
1684 ZMQ_IPV4ONLY: Use IPv4-only on socket
1685 Set the IPv4-only option for the socket. This option is deprecated.
1686 Please use the ZMQ_IPV6 option.
1687
1688
1689 Option value type int
1690
1691 Option value unit boolean
1692
1693 Default value 1 (true)
1694
1695 Applicable socket types all, when using TCP
1696 transports.
1697
1698
1699 ZMQ_VMCI_BUFFER_SIZE: Set buffer size of the VMCI socket
1700 The ZMQ_VMCI_BUFFER_SIZE option shall set the size of the underlying
1701 buffer for the socket. Used during negotiation before the connection is
1702 established.
1703
1704
1705 Option value type uint64_t
1706
1707 Option value unit bytes
1708
1709 Default value 65546
1710
1711 Applicable socket types all, when using VMCI
1712 transport
1713
1714
1715 ZMQ_VMCI_BUFFER_MIN_SIZE: Set min buffer size of the VMCI socket
1716 The ZMQ_VMCI_BUFFER_MIN_SIZE option shall set the min size of the
1717 underlying buffer for the socket. Used during negotiation before the
1718 connection is established.
1719
1720
1721 Option value type uint64_t
1722
1723 Option value unit bytes
1724
1725 Default value 128
1726
1727 Applicable socket types all, when using VMCI
1728 transport
1729
1730
1731 ZMQ_VMCI_BUFFER_MAX_SIZE: Set max buffer size of the VMCI socket
1732 The ZMQ_VMCI_BUFFER_MAX_SIZE option shall set the max size of the
1733 underlying buffer for the socket. Used during negotiation before the
1734 connection is established.
1735
1736
1737 Option value type uint64_t
1738
1739 Option value unit bytes
1740
1741
1742
1743 Default value 262144
1744
1745 Applicable socket types all, when using VMCI
1746 transport
1747
1748
1749 ZMQ_VMCI_CONNECT_TIMEOUT: Set connection timeout of the VMCI socket
1750 The ZMQ_VMCI_CONNECT_TIMEOUT option shall set connection timeout for
1751 the socket.
1752
1753
1754 Option value type int
1755
1756 Option value unit milliseconds
1757
1758 Default value -1
1759
1760 Applicable socket types all, when using VMCI
1761 transport
1762
1763
1764 ZMQ_MULTICAST_LOOP: Control multicast local loopback
1765 For multicast UDP sender sockets this option sets whether the data sent
1766 should be looped back on local listening sockets.
1767
1768
1769 Option value type int
1770
1771 Option value unit 0, 1
1772
1773 Default value 1
1774
1775 Applicable socket types ZMQ_RADIO, when using UDP
1776 multicast transport
1777
1778
1779 ZMQ_ROUTER_NOTIFY: Send connect and disconnect notifications
1780 Enable connect and disconnect notifications on a ROUTER socket. When
1781 enabled, the socket delivers a zero-length message (with routing-id as
1782 first frame) when a peer connects or disconnects. It’s possible to
1783 notify both events for a peer by OR-ing the flag values. This option
1784 only applies to stream oriented (tcp, ipc) transports.
1785
1786 Note
1787 in DRAFT state, not yet available in stable releases.
1788
1789
1790 Option value type int
1791
1792 Option value unit 0, ZMQ_NOTIFY_CONNECT,
1793 ZMQ_NOTIFY_DISCONNECT,
1794 ZMQ_NOTIFY_CONNECT |
1795 ZMQ_NOTIFY_DISCONNECT
1796
1797 Default value 0
1798
1799 Applicable socket types ZMQ_ROUTER
1800
1801
1802 ZMQ_IN_BATCH_SIZE: Maximal receive batch size
1803 Sets the maximal amount of messages that can be received in a single
1804 recv system call. WARNING: this option should almost never be changed.
1805 The default has been chosen to offer the best compromise between
1806 latency and throughtput. In the vast majority of cases, changing this
1807 option will result in worst result if not outright breakages.
1808
1809 Cannot be zero.
1810
1811 Note
1812 in DRAFT state, not yet available in stable releases.
1813
1814
1815 Option value type int
1816
1817 Option value unit messages
1818
1819 Default value 8192
1820
1821 Applicable socket types All, when using TCP, IPC,
1822 PGM or NORM transport.
1823
1824
1825 ZMQ_OUT_BATCH_SIZE: Maximal send batch size
1826 Sets the maximal amount of messages that can be sent in a single send
1827 system call. WARNING: this option should almost never be changed. The
1828 default has been chosen to offer the best compromise between latency
1829 and throughtput. In the vast majority of cases, changing this option
1830 will result in worst result if not outright breakages.
1831
1832 Cannot be zero.
1833
1834 Note
1835 in DRAFT state, not yet available in stable releases.
1836
1837
1838 Option value type int
1839
1840 Option value unit messages
1841
1842 Default value 8192
1843
1844 Applicable socket types All, when using TCP, IPC,
1845 PGM or NORM transport.
1846
1847
1849 The zmq_setsockopt() function shall return zero if successful.
1850 Otherwise it shall return -1 and set errno to one of the values defined
1851 below.
1852
1854 EINVAL
1855 The requested option option_name is unknown, or the requested
1856 option_len or option_value is invalid.
1857
1858 ETERM
1859 The 0MQ context associated with the specified socket was
1860 terminated.
1861
1862 ENOTSOCK
1863 The provided socket was invalid.
1864
1865 EINTR
1866 The operation was interrupted by delivery of a signal.
1867
1869 Subscribing to messages on a ZMQ_SUB socket.
1870
1871 /* Subscribe to all messages */
1872 rc = zmq_setsockopt (socket, ZMQ_SUBSCRIBE, "", 0);
1873 assert (rc == 0);
1874 /* Subscribe to messages prefixed with "ANIMALS.CATS" */
1875 rc = zmq_setsockopt (socket, ZMQ_SUBSCRIBE, "ANIMALS.CATS", 12);
1876
1877 Setting I/O thread affinity.
1878
1879 int64_t affinity;
1880 /* Incoming connections on TCP port 5555 shall be handled by I/O thread 1 */
1881 affinity = 1;
1882 rc = zmq_setsockopt (socket, ZMQ_AFFINITY, &affinity, sizeof (affinity));
1883 assert (rc);
1884 rc = zmq_bind (socket, "tcp://lo:5555");
1885 assert (rc);
1886 /* Incoming connections on TCP port 5556 shall be handled by I/O thread 2 */
1887 affinity = 2;
1888 rc = zmq_setsockopt (socket, ZMQ_AFFINITY, &affinity, sizeof (affinity));
1889 assert (rc);
1890 rc = zmq_bind (socket, "tcp://lo:5556");
1891 assert (rc);
1892
1893
1895 zmq_getsockopt(3) zmq_socket(3) zmq_plain(7) zmq_curve(7) zmq(7)
1896
1898 This page was written by the 0MQ community. To make a change please
1899 read the 0MQ Contribution Policy at
1900 http://www.zeromq.org/docs:contributing.
1901
1902
1903
19040MQ 4.3.4 01/22/2022 ZMQ_SETSOCKOPT(3)