[zeromq-dev] Router - router communication
Hi, I am building a Replicated State Machine (RSM) protocol and using ZeroMQ's router sockets for NxN communication between the nodes. All the nodes have pre-determined identities, so I use 1 router socket per node for all communication. Regarding the version, I am using ZeroMQ version 4.2.0 and Ubuntu 14.04.4 OS. I am having trouble with lost messages during failover, it doesn't happen always but a few times when I bring down a primary node (a clean exit which unbinds and disconnects from all endpoints), the backup nodes are unable to talk to each other to intiate the failover. A zmq_msg_send call at the source doesn't return any error but the destination never receives the message. I would appreciate any insight on what could be going wrong. -Pulkit ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev
Re: [zeromq-dev] Empty message does not close ZMQ_STREAM socket?
Hi,
I figured that and that is why I set the reconnection time to ten minutes. What
is Happening now is that i receive an empty message at the Client when it is
connected. The Server then sends the first empty messge to drop the Connection,
but this has no effect. The second message then drops the Connection which is
fine.
Best wishes
Jens
Gesendet von Outlook-Mail für Windows 10 Telefon
Von: KIU Shueng Chuan
Gesendet: Montag, 21. März 2016 17:30
An: ZeroMQ development list
Betreff: Re: [zeromq-dev] Empty message does not close ZMQ_STREAM socket?
Hi Jens,
Because the client is using ZMQ_STREAM, when it gets disconnected it
immediately reattempts a reconnect.
So the first empty message is for connect. Second empty message is for
disconnect. And the 3rd empty message is for the reconnect. And so on.
On 22 Mar 2016 12:07 am, "Auer, Jens" wrote:
Hi,
I tried that before and thought that sending the close message repetitively
would do the trick. To better see if the socket is really closed, I set the
reconnect interval to ten minutes in the client by setting
int tenminutes = 6;
client.setsockopt(ZMQ_RECONNECT_IVL, &tenminutes, sizeof(tenminutes));
Now, when I use the following server which is basically taken from the manpage,
I can close the socket by sending the close message twice. Removing the
ZMQ_SNDMORE flag does not change anything.
int main(int argc, char* argv[]) {
int n = std::atoi(argv[1]);
void *ctx = zmq_ctx_new ();
/* Create ZMQ_STREAM socket */
void *socket = zmq_socket (ctx, ZMQ_STREAM);
int rc = zmq_bind (socket, "tcp://127.0.0.1:5000");
/* Data structure to hold the ZMQ_STREAM ID */
uint8_t id [256];
size_t id_size = 256;
/* Data structure to hold the ZMQ_STREAM received data */
uint8_t raw [256];
size_t raw_size = 256;
for(int i=0; i != n; ++i)
{
/* Get HTTP request; ID frame and then request */
id_size = zmq_recv (socket, id, 256, 0);
assert (id_size > 0);
std::cout << id_size << std::endl;
raw_size = zmq_recv (socket, raw, 256, 0);
/* Closes the connection by sending the ID frame followed by a zero
response */
zmq_send (socket, id, id_size, ZMQ_SNDMORE);
zmq_send (socket, 0, 0, 0);
/* NOTE: If we don't use ZMQ_SNDMORE, then we won't be able to send
more */
/* message to any client */
}
std::cout << "Done" << std::endl;
int i;
std::cin >> i;
zmq_close (socket); zmq_ctx_destroy (ctx);
return 0;
}
Cheers,
Jens
--
Jens Auer | CGI | Software-Engineer
CGI (Germany) GmbH & Co. KG
Rheinstraße 95 | 64295 Darmstadt | Germany
T: +49 6151 36860 154
jens.a...@cgi.com
Unsere Pflichtangaben gemäß § 35a GmbHG / §§ 161, 125a HGB finden Sie unter
de.cgi.com/pflichtangaben.
CONFIDENTIALITY NOTICE: Proprietary/Confidential information belonging to CGI
Group Inc. and its affiliates may be contained in this message. If you are not
a recipient indicated or intended in this message (or responsible for delivery
of this message to such person), or you think for any reason that this message
may have been addressed to you in error, you may not use or copy or deliver
this message to anyone else. In such case, you should destroy this message and
are asked to notify the sender by reply e-mail.
Von: zeromq-dev-boun...@lists.zeromq.org [zeromq-dev-boun...@lists.zeromq.org]"
im Auftrag von "KIU Shueng Chuan [nixch...@gmail.com]
Gesendet: Montag, 21. März 2016 15:38
An: ZeroMQ development list
Betreff: Re: [zeromq-dev] Empty message does not close ZMQ_STREAM socket?
Hi Jens,
I tried out the pair of programs in your original post. Indeed, I got the
behavior that you described using ZeroMQ 4.1.2.
Putting the server code into a while loop did the trick.
```c++
server.bind(address);
while (1)
{
// recv connection
// send disconnection
}
int i;
std::cin >> i;
```
I think in my own code, I have only ever used it in this forever loop fashion.
Hmm...
On Mon, Mar 21, 2016 at 9:11 PM, Auer, Jens wrote:
Hi,
Thanks for the suggestion. I have modified my example to copy the id into a new
message, but it did not change anything. I have also tried a second version of
the server side which is basically the example provided at the bottom of the
manual page:
int main2(int argc, char* argv[]) {
int n = std::atoi(argv[1]);
void *ctx = zmq_ctx_new ();
/* Create ZMQ_STREAM socket */
void *socket = zmq_socket (ctx, ZMQ_STREAM);
int rc = zmq_bind (socket, "tcp://127.0.0.1:5000");
/* Data structure to hold the ZMQ_STREAM ID */
uint8_t id [256];
size_t id_size = 256;
/* Data structure to hold the ZMQ_STREAM received data */
uint8_t raw [256];
size_t raw_size = 256;
for(int i=0; i != n; ++i)
{
/* Get HTTP request; ID frame and then request */
id_size = zmq_recv (socket, id, 256, 0);
Re: [zeromq-dev] Empty message does not close ZMQ_STREAM socket?
Hi Jens,
Because the client is using ZMQ_STREAM, when it gets disconnected it
immediately reattempts a reconnect.
So the first empty message is for connect. Second empty message is for
disconnect. And the 3rd empty message is for the reconnect. And so on.
On 22 Mar 2016 12:07 am, "Auer, Jens" wrote:
> Hi,
>
> I tried that before and thought that sending the close message
> repetitively would do the trick. To better see if the socket is really
> closed, I set the reconnect interval to ten minutes in the client by setting
> int tenminutes = 6;
> client.setsockopt(ZMQ_RECONNECT_IVL, &tenminutes, sizeof(tenminutes));
>
> Now, when I use the following server which is basically taken from the
> manpage, I can close the socket by sending the close message twice.
> Removing the ZMQ_SNDMORE flag does not change anything.
>
> int main(int argc, char* argv[]) {
> int n = std::atoi(argv[1]);
> void *ctx = zmq_ctx_new ();
> /* Create ZMQ_STREAM socket */
> void *socket = zmq_socket (ctx, ZMQ_STREAM);
>
> int rc = zmq_bind (socket, "tcp://127.0.0.1:5000");
> /* Data structure to hold the ZMQ_STREAM ID */
> uint8_t id [256];
> size_t id_size = 256;
> /* Data structure to hold the ZMQ_STREAM received data */
> uint8_t raw [256];
> size_t raw_size = 256;
> for(int i=0; i != n; ++i)
> {
> /* Get HTTP request; ID frame and then request */
> id_size = zmq_recv (socket, id, 256, 0);
> assert (id_size > 0);
> std::cout << id_size << std::endl;
> raw_size = zmq_recv (socket, raw, 256, 0);
>
> /* Closes the connection by sending the ID frame followed by a
> zero response */
> zmq_send (socket, id, id_size, ZMQ_SNDMORE);
> zmq_send (socket, 0, 0, 0);
> /* NOTE: If we don't use ZMQ_SNDMORE, then we won't be able to
> send more */
> /* message to any client */
> }
> std::cout << "Done" << std::endl;
> int i;
> std::cin >> i;
> zmq_close (socket); zmq_ctx_destroy (ctx);
> return 0;
> }
>
> Cheers,
> Jens
>
> --
> *Jens Auer *| CGI | Software-Engineer
> CGI (Germany) GmbH & Co. KG
> Rheinstraße 95 | 64295 Darmstadt | Germany
> T: +49 6151 36860 154
> *jens.a...@cgi.com*
> Unsere Pflichtangaben gemäß § 35a GmbHG / §§ 161, 125a HGB finden Sie unter
> *de.cgi.com/pflichtangaben* .
>
> CONFIDENTIALITY NOTICE: Proprietary/Confidential information belonging to
> CGI Group Inc. and its affiliates may be contained in this message. If you
> are not a recipient indicated or intended in this message (or responsible
> for delivery of this message to such person), or you think for any reason
> that this message may have been addressed to you in error, you may not use
> or copy or deliver this message to anyone else. In such case, you should
> destroy this message and are asked to notify the sender by reply e-mail.
> --
> *Von:* zeromq-dev-boun...@lists.zeromq.org [
> zeromq-dev-boun...@lists.zeromq.org]" im Auftrag von "KIU Shueng Chuan [
> nixch...@gmail.com]
> *Gesendet:* Montag, 21. März 2016 15:38
> *An:* ZeroMQ development list
> *Betreff:* Re: [zeromq-dev] Empty message does not close ZMQ_STREAM
> socket?
>
> Hi Jens,
>
> I tried out the pair of programs in your original post. Indeed, I got the
> behavior that you described using ZeroMQ 4.1.2.
>
> Putting the server code into a while loop did the trick.
> ```c++
> server.bind(address);
> while (1)
> {
>// recv connection
>// send disconnection
> }
> int i;
> std::cin >> i;
>
> ```
>
> I think in my own code, I have only ever used it in this forever loop
> fashion. Hmm...
>
>
> On Mon, Mar 21, 2016 at 9:11 PM, Auer, Jens wrote:
>
>> Hi,
>>
>>
>>
>> Thanks for the suggestion. I have modified my example to copy the id into
>> a new message, but it did not change anything. I have also tried a second
>> version of the server side which is basically the example provided at the
>> bottom of the manual page:
>>
>> int main2(int argc, char* argv[]) {
>>
>> int n = std::atoi(argv[1]);
>>
>> void *ctx = zmq_ctx_new ();
>>
>> /* Create ZMQ_STREAM socket */
>>
>> void *socket = zmq_socket (ctx, ZMQ_STREAM);
>>
>>
>>
>> int rc = zmq_bind (socket, "tcp://127.0.0.1:5000");
>>
>> /* Data structure to hold the ZMQ_STREAM ID */
>>
>> uint8_t id [256];
>>
>> size_t id_size = 256;
>>
>> /* Data structure to hold the ZMQ_STREAM received data */
>>
>> uint8_t raw [256];
>>
>> size_t raw_size = 256;
>>
>> for(int i=0; i != n; ++i)
>>
>> {
>>
>> /* Get HTTP request; ID frame and then request */
>>
>> id_size = zmq_recv (socket, id, 256, 0);
>>
>> assert (id_size > 0);
>>
>> std::cout << id_size << std::endl;
>>
>> raw_size = zmq_recv (socket, raw, 256, 0);
>>
>>
>>
>> /* C
Re: [zeromq-dev] Empty message does not close ZMQ_STREAM socket?
The code I posted works both as a stand alone and an actor based
server (the close works as well). You should be able to come close to
just copy/pasting them to working code.
Note I do pass a valid array here: zmq_send (socket, 0, 0, 0);
Also I am not sure about
/* NOTE: If we don't use ZMQ_SNDMORE, then we won't be able to
send more */
I am not a heavily experienced user of zmq but my code works fine with
multiple clients, it closes the one that it intended to, others still
work. I understood sendmore as being per connection but maybe im off.
Cheers,
Greg
On Mon, Mar 21, 2016 at 4:06 PM, Auer, Jens wrote:
> Hi,
>
> I tried that before and thought that sending the close message repetitively
> would do the trick. To better see if the socket is really closed, I set the
> reconnect interval to ten minutes in the client by setting
> int tenminutes = 6;
> client.setsockopt(ZMQ_RECONNECT_IVL, &tenminutes, sizeof(tenminutes));
>
> Now, when I use the following server which is basically taken from the
> manpage, I can close the socket by sending the close message twice. Removing
> the ZMQ_SNDMORE flag does not change anything.
>
> int main(int argc, char* argv[]) {
> int n = std::atoi(argv[1]);
> void *ctx = zmq_ctx_new ();
> /* Create ZMQ_STREAM socket */
> void *socket = zmq_socket (ctx, ZMQ_STREAM);
>
> int rc = zmq_bind (socket, "tcp://127.0.0.1:5000");
> /* Data structure to hold the ZMQ_STREAM ID */
> uint8_t id [256];
> size_t id_size = 256;
> /* Data structure to hold the ZMQ_STREAM received data */
> uint8_t raw [256];
> size_t raw_size = 256;
> for(int i=0; i != n; ++i)
> {
> /* Get HTTP request; ID frame and then request */
> id_size = zmq_recv (socket, id, 256, 0);
> assert (id_size > 0);
> std::cout << id_size << std::endl;
> raw_size = zmq_recv (socket, raw, 256, 0);
>
> /* Closes the connection by sending the ID frame followed by a zero
> response */
> zmq_send (socket, id, id_size, ZMQ_SNDMORE);
> zmq_send (socket, 0, 0, 0);
> /* NOTE: If we don't use ZMQ_SNDMORE, then we won't be able to send
> more */
> /* message to any client */
> }
> std::cout << "Done" << std::endl;
> int i;
> std::cin >> i;
> zmq_close (socket); zmq_ctx_destroy (ctx);
> return 0;
> }
>
> Cheers,
> Jens
>
> --
> Jens Auer | CGI | Software-Engineer
> CGI (Germany) GmbH & Co. KG
> Rheinstraße 95 | 64295 Darmstadt | Germany
> T: +49 6151 36860 154
> jens.a...@cgi.com
> Unsere Pflichtangaben gemäß § 35a GmbHG / §§ 161, 125a HGB finden Sie unter
> de.cgi.com/pflichtangaben.
>
> CONFIDENTIALITY NOTICE: Proprietary/Confidential information belonging to
> CGI Group Inc. and its affiliates may be contained in this message. If you
> are not a recipient indicated or intended in this message (or responsible
> for delivery of this message to such person), or you think for any reason
> that this message may have been addressed to you in error, you may not use
> or copy or deliver this message to anyone else. In such case, you should
> destroy this message and are asked to notify the sender by reply e-mail.
>
> Von: zeromq-dev-boun...@lists.zeromq.org
> [zeromq-dev-boun...@lists.zeromq.org]" im Auftrag von "KIU Shueng Chuan
> [nixch...@gmail.com]
> Gesendet: Montag, 21. März 2016 15:38
> An: ZeroMQ development list
> Betreff: Re: [zeromq-dev] Empty message does not close ZMQ_STREAM socket?
>
> Hi Jens,
>
> I tried out the pair of programs in your original post. Indeed, I got the
> behavior that you described using ZeroMQ 4.1.2.
>
> Putting the server code into a while loop did the trick.
> ```c++
> server.bind(address);
> while (1)
> {
>// recv connection
>// send disconnection
> }
> int i;
> std::cin >> i;
>
> ```
>
> I think in my own code, I have only ever used it in this forever loop
> fashion. Hmm...
>
>
> On Mon, Mar 21, 2016 at 9:11 PM, Auer, Jens wrote:
>>
>> Hi,
>>
>>
>>
>> Thanks for the suggestion. I have modified my example to copy the id into
>> a new message, but it did not change anything. I have also tried a second
>> version of the server side which is basically the example provided at the
>> bottom of the manual page:
>>
>> int main2(int argc, char* argv[]) {
>>
>> int n = std::atoi(argv[1]);
>>
>> void *ctx = zmq_ctx_new ();
>>
>> /* Create ZMQ_STREAM socket */
>>
>> void *socket = zmq_socket (ctx, ZMQ_STREAM);
>>
>>
>>
>> int rc = zmq_bind (socket, "tcp://127.0.0.1:5000");
>>
>> /* Data structure to hold the ZMQ_STREAM ID */
>>
>> uint8_t id [256];
>>
>> size_t id_size = 256;
>>
>> /* Data structure to hold the ZMQ_STREAM received data */
>>
>> uint8_t raw [256];
>>
>> size_t raw_size = 256;
>>
>> for(int i=0; i != n; ++i)
>>
>> {
>>
>> /* Get HTTP request; ID frame and then
Re: [zeromq-dev] Empty message does not close ZMQ_STREAM socket?
Hi,
I tried that before and thought that sending the close message repetitively
would do the trick. To better see if the socket is really closed, I set the
reconnect interval to ten minutes in the client by setting
int tenminutes = 6;
client.setsockopt(ZMQ_RECONNECT_IVL, &tenminutes, sizeof(tenminutes));
Now, when I use the following server which is basically taken from the manpage,
I can close the socket by sending the close message twice. Removing the
ZMQ_SNDMORE flag does not change anything.
int main(int argc, char* argv[]) {
int n = std::atoi(argv[1]);
void *ctx = zmq_ctx_new ();
/* Create ZMQ_STREAM socket */
void *socket = zmq_socket (ctx, ZMQ_STREAM);
int rc = zmq_bind (socket, "tcp://127.0.0.1:5000");
/* Data structure to hold the ZMQ_STREAM ID */
uint8_t id [256];
size_t id_size = 256;
/* Data structure to hold the ZMQ_STREAM received data */
uint8_t raw [256];
size_t raw_size = 256;
for(int i=0; i != n; ++i)
{
/* Get HTTP request; ID frame and then request */
id_size = zmq_recv (socket, id, 256, 0);
assert (id_size > 0);
std::cout << id_size << std::endl;
raw_size = zmq_recv (socket, raw, 256, 0);
/* Closes the connection by sending the ID frame followed by a zero
response */
zmq_send (socket, id, id_size, ZMQ_SNDMORE);
zmq_send (socket, 0, 0, 0);
/* NOTE: If we don't use ZMQ_SNDMORE, then we won't be able to send
more */
/* message to any client */
}
std::cout << "Done" << std::endl;
int i;
std::cin >> i;
zmq_close (socket); zmq_ctx_destroy (ctx);
return 0;
}
Cheers,
Jens
--
Jens Auer | CGI | Software-Engineer
CGI (Germany) GmbH & Co. KG
Rheinstraße 95 | 64295 Darmstadt | Germany
T: +49 6151 36860 154
jens.a...@cgi.com
Unsere Pflichtangaben gemäß § 35a GmbHG / §§ 161, 125a HGB finden Sie unter
de.cgi.com/pflichtangaben.
CONFIDENTIALITY NOTICE: Proprietary/Confidential information belonging to CGI
Group Inc. and its affiliates may be contained in this message. If you are not
a recipient indicated or intended in this message (or responsible for delivery
of this message to such person), or you think for any reason that this message
may have been addressed to you in error, you may not use or copy or deliver
this message to anyone else. In such case, you should destroy this message and
are asked to notify the sender by reply e-mail.
Von: zeromq-dev-boun...@lists.zeromq.org [zeromq-dev-boun...@lists.zeromq.org]"
im Auftrag von "KIU Shueng Chuan [nixch...@gmail.com]
Gesendet: Montag, 21. März 2016 15:38
An: ZeroMQ development list
Betreff: Re: [zeromq-dev] Empty message does not close ZMQ_STREAM socket?
Hi Jens,
I tried out the pair of programs in your original post. Indeed, I got the
behavior that you described using ZeroMQ 4.1.2.
Putting the server code into a while loop did the trick.
```c++
server.bind(address);
while (1)
{
// recv connection
// send disconnection
}
int i;
std::cin >> i;
```
I think in my own code, I have only ever used it in this forever loop fashion.
Hmm...
On Mon, Mar 21, 2016 at 9:11 PM, Auer, Jens
mailto:jens.a...@cgi.com>> wrote:
Hi,
Thanks for the suggestion. I have modified my example to copy the id into a new
message, but it did not change anything. I have also tried a second version of
the server side which is basically the example provided at the bottom of the
manual page:
int main2(int argc, char* argv[]) {
int n = std::atoi(argv[1]);
void *ctx = zmq_ctx_new ();
/* Create ZMQ_STREAM socket */
void *socket = zmq_socket (ctx, ZMQ_STREAM);
int rc = zmq_bind (socket,
"tcp://127.0.0.1:5000");
/* Data structure to hold the ZMQ_STREAM ID */
uint8_t id [256];
size_t id_size = 256;
/* Data structure to hold the ZMQ_STREAM received data */
uint8_t raw [256];
size_t raw_size = 256;
for(int i=0; i != n; ++i)
{
/* Get HTTP request; ID frame and then request */
id_size = zmq_recv (socket, id, 256, 0);
assert (id_size > 0);
std::cout << id_size << std::endl;
raw_size = zmq_recv (socket, raw, 256, 0);
/* Closes the connection by sending the ID frame followed by a
zero response */
zmq_send (socket, id, id_size, ZMQ_SNDMORE);
zmq_send (socket, 0, 0, ZMQ_SNDMORE);
/* NOTE: If we don't use ZMQ_SNDMORE, then we won't be able to
send more */
/* message to any client */
}
std::cout << "Done" << std::endl;
int i;
std::cin >> i;
zmq_close (socket); zmq_ctx_destroy (ctx);
return 0;
}
This has the same problem as described before that the socket is not clo
Re: [zeromq-dev] Empty message does not close ZMQ_STREAM socket?
I couldn't find a lot of docs on this stuff so I experimented a bit to
try learning about ZMQ_STREAM. Here are two echo servers (one a simple
program the other as an actor
https://github.com/gregoryyoung/zmq-stream-echo/blob/master/src/echoactorserver.c)
I was curious about this question so added this functionality (exit closes now).
The main difference I see in my code is you still set:
server.send(empty, ZMQ_SNDMORE );
ZMQ_SENDMORE which I don't think you really want to be sending more?
Cheers,
Greg
On Mon, Mar 21, 2016 at 9:06 AM, Auer, Jens wrote:
> Hi,
>
> I am trying to close a TCP socket over a ZMQ_STREAM by sending an identity
> frame followed by an empty message, as described in the manual ("To close a
> specific connection, send the identity frame followed by a zero-length
> message"). I have a simple client/server example:
> #include
> #include
> #include
>
> int main2() {
> std::string address = "tcp://127.0.0.1:5000";
>
> zmq::context_t zmq;
> zmq::socket_t server(zmq, ZMQ_STREAM);
>
> server.bind(address);
>
> zmq::message_t id;
> zmq::message_t m;
> server.recv(&id);
> server.recv(&m);
> std::cout << "Connection received: " << id.size() << std::endl;
>
> zmq::message_t empty{};
>
> server.send(id, ZMQ_SNDMORE);
> server.send(empty, ZMQ_SNDMORE );
>
> int i;
> std::cin >> i;
>
> return 0;
> }
>
> #include
> #include
>
> int main() {
> std::string address = "tcp://127.0.0.1:5000";
>
> zmq::context_t zmq;
> zmq::socket_t client(zmq, ZMQ_STREAM);
>
> client.connect(address);
>
> zmq::message_t m3;
> zmq::message_t m4;
> client.recv(&m3);
> client.recv(&m4);
>
> std::cout << "Connection established" << std::endl;
>
> {
> zmq::message_t m5;
> zmq::message_t m6;
> client.recv(&m5);
> client.recv(&m6);
> }
>
> std::cout << "Connection closed" << std::endl;
> int i;
> std::cin >> i;
>
> return 0;
> }
>
> When I start the server and then the client, the server will receive the
> connection message, but the empty message does not close the socket:
> ./stream_s 2
> Connection received: 5
> /tmp/stream_c
> Connection established
>
> tcp0 0 127.0.0.1:5000 0.0.0.0:* LISTEN
> 32615/./stream_s
> tcp0 0 127.0.0.1:5000 127.0.0.1:34270
> ESTABLISHED 32615/./stream_s
> tcp0 0 127.0.0.1:34270 127.0.0.1:5000
> ESTABLISHED 32618/stream_c
>
> I have also created a second example where the server sends the close
> message twice. Here, the client actually receives the close message as an
> empty message. Why is this even possible over a ZMQ_STREAM socket?
>
> I am using ZeroMQ 4.1.4, so the notification messages should be enabled by
> default without setting ZMQ_STREAM_NOTIFY, and I have also tested 4.1.2 to
> check for a regression.
>
> Best wishes,
> Jens
>
> ___
> zeromq-dev mailing list
> zeromq-dev@lists.zeromq.org
> http://lists.zeromq.org/mailman/listinfo/zeromq-dev
>
--
Studying for the Turing test
___
zeromq-dev mailing list
zeromq-dev@lists.zeromq.org
http://lists.zeromq.org/mailman/listinfo/zeromq-dev
Re: [zeromq-dev] Empty message does not close ZMQ_STREAM socket?
Hi Jens,
I tried out the pair of programs in your original post. Indeed, I got the
behavior that you described using ZeroMQ 4.1.2.
Putting the server code into a while loop did the trick.
```c++
server.bind(address);
while (1)
{
// recv connection
// send disconnection
}
int i;
std::cin >> i;
```
I think in my own code, I have only ever used it in this forever loop
fashion. Hmm...
On Mon, Mar 21, 2016 at 9:11 PM, Auer, Jens wrote:
> Hi,
>
>
>
> Thanks for the suggestion. I have modified my example to copy the id into
> a new message, but it did not change anything. I have also tried a second
> version of the server side which is basically the example provided at the
> bottom of the manual page:
>
> int main2(int argc, char* argv[]) {
>
> int n = std::atoi(argv[1]);
>
> void *ctx = zmq_ctx_new ();
>
> /* Create ZMQ_STREAM socket */
>
> void *socket = zmq_socket (ctx, ZMQ_STREAM);
>
>
>
> int rc = zmq_bind (socket, "tcp://127.0.0.1:5000");
>
> /* Data structure to hold the ZMQ_STREAM ID */
>
> uint8_t id [256];
>
> size_t id_size = 256;
>
> /* Data structure to hold the ZMQ_STREAM received data */
>
> uint8_t raw [256];
>
> size_t raw_size = 256;
>
> for(int i=0; i != n; ++i)
>
> {
>
> /* Get HTTP request; ID frame and then request */
>
> id_size = zmq_recv (socket, id, 256, 0);
>
> assert (id_size > 0);
>
> std::cout << id_size << std::endl;
>
> raw_size = zmq_recv (socket, raw, 256, 0);
>
>
>
> /* Closes the connection by sending the ID frame followed
> by a zero response */
>
> zmq_send (socket, id, id_size, ZMQ_SNDMORE);
>
> zmq_send (socket, 0, 0, ZMQ_SNDMORE);
>
> /* NOTE: If we don't use ZMQ_SNDMORE, then we won't be
> able to send more */
>
> /* message to any client */
>
> }
>
> std::cout << "Done" << std::endl;
>
> int i;
>
> std::cin >> i;
>
> zmq_close (socket); zmq_ctx_destroy (ctx);
>
> return 0;
>
> }
>
>
>
> This has the same problem as described before that the socket is not
> closed and I even receive an empty message at the client’s side.
>
>
>
> Cheers,
>
> Jens
>
>
>
> *--*
>
> *Dr. Jens Auer *| CGI | Software Engineer
>
> CGI Deutschland Ltd. & Co. KG
> Rheinstraße 95 | 64295 Darmstadt | Germany
>
> T: +49 6151 36860 154
>
> jens.a...@cgi.com
>
> Unsere Pflichtangaben gemäß § 35a GmbHG / §§ 161, 125a HGB finden Sie
> unter de.cgi.com/pflichtangaben.
>
>
>
> CONFIDENTIALITY NOTICE: Proprietary/Confidential information belonging to
> CGI Group Inc. and its affiliates may be contained in this message. If you
> are not a recipient indicated or intended in this message (or responsible
> for delivery of this message to such person), or you think for any reason
> that this message may have been addressed to you in error, you may not use
> or copy or deliver this message to anyone else. In such case, you should
> destroy this message and are asked to notify the sender by reply e-mail.
>
>
>
> *From:* zeromq-dev-boun...@lists.zeromq.org [mailto:
> zeromq-dev-boun...@lists.zeromq.org] *On Behalf Of *KIU Shueng Chuan
> *Sent:* 21 March 2016 11:43
> *To:* ZeroMQ development list
> *Subject:* Re: [zeromq-dev] Empty message does not close ZMQ_STREAM
> socket?
>
>
>
> There's something in the manpage that your code doesn't do.
>
> > To open a connection to a server, use the zmq_connect call, and then
> fetch the socket identity using the ZMQ_IDENTITY zmq_getsockopt call.
>
> I don't recall if this was strictly necessary but I see in my code that I
> did fetch the identity but immediately discarded it.
>
> I have some python scripts here where the server code disconnects the
> client.
> https://github.com/pijyoi/test_zmqstream
> See zmqstream_publisher.py and zmqstream_subscriber.py
>
> On 21 Mar 2016 5:07 pm, "Auer, Jens" wrote:
>
> Hi,
>
> I am trying to close a TCP socket over a ZMQ_STREAM by sending an identity
> frame followed by an empty message, as described in the manual ("To close a
> specific connection, send the identity frame followed by a zero-length
> message"). I have a simple client/server example:
> #include
> #include
> #include
>
> int main2() {
> std::string address = "tcp://127.0.0.1:5000";
>
> zmq::context_t zmq;
> zmq::socket_t server(zmq, ZMQ_STREAM);
>
> server.bind(address);
>
> zmq::message_t id;
> zmq::message_t m;
> server.recv(&id);
> server.recv(&m);
> std::cout << "Connection received: " << id.size() << std::endl;
>
> zmq::message_t empty{};
>
> server.send(id, ZMQ_SNDMORE);
> server.send(empty, ZMQ_SNDMORE );
>
> int i;
> std::cin >> i;
>
> return 0;
> }
>
> #include
> #include
>
> int main() {
> std::string address = "tcp://127.0.0.1:5000";
>
> zmq::context_t zmq;
> zmq
Re: [zeromq-dev] Empty message does not close ZMQ_STREAM socket?
Hi,
Thanks for the suggestion. I have modified my example to copy the id into a new
message, but it did not change anything. I have also tried a second version of
the server side which is basically the example provided at the bottom of the
manual page:
int main2(int argc, char* argv[]) {
int n = std::atoi(argv[1]);
void *ctx = zmq_ctx_new ();
/* Create ZMQ_STREAM socket */
void *socket = zmq_socket (ctx, ZMQ_STREAM);
int rc = zmq_bind (socket, "tcp://127.0.0.1:5000");
/* Data structure to hold the ZMQ_STREAM ID */
uint8_t id [256];
size_t id_size = 256;
/* Data structure to hold the ZMQ_STREAM received data */
uint8_t raw [256];
size_t raw_size = 256;
for(int i=0; i != n; ++i)
{
/* Get HTTP request; ID frame and then request */
id_size = zmq_recv (socket, id, 256, 0);
assert (id_size > 0);
std::cout << id_size << std::endl;
raw_size = zmq_recv (socket, raw, 256, 0);
/* Closes the connection by sending the ID frame followed by a
zero response */
zmq_send (socket, id, id_size, ZMQ_SNDMORE);
zmq_send (socket, 0, 0, ZMQ_SNDMORE);
/* NOTE: If we don't use ZMQ_SNDMORE, then we won't be able to
send more */
/* message to any client */
}
std::cout << "Done" << std::endl;
int i;
std::cin >> i;
zmq_close (socket); zmq_ctx_destroy (ctx);
return 0;
}
This has the same problem as described before that the socket is not closed and
I even receive an empty message at the client’s side.
Cheers,
Jens
--
Dr. Jens Auer | CGI | Software Engineer
CGI Deutschland Ltd. & Co. KG
Rheinstraße 95 | 64295 Darmstadt | Germany
T: +49 6151 36860 154
jens.a...@cgi.com
Unsere Pflichtangaben gemäß § 35a GmbHG / §§ 161, 125a HGB finden Sie unter
de.cgi.com/pflichtangaben.
CONFIDENTIALITY NOTICE: Proprietary/Confidential information belonging to CGI
Group Inc. and its affiliates may be contained in this message. If you are not
a recipient indicated or intended in this message (or responsible for delivery
of this message to such person), or you think for any reason that this message
may have been addressed to you in error, you may not use or copy or deliver
this message to anyone else. In such case, you should destroy this message and
are asked to notify the sender by reply e-mail.
From: zeromq-dev-boun...@lists.zeromq.org
[mailto:zeromq-dev-boun...@lists.zeromq.org] On Behalf Of KIU Shueng Chuan
Sent: 21 March 2016 11:43
To: ZeroMQ development list
Subject: Re: [zeromq-dev] Empty message does not close ZMQ_STREAM socket?
There's something in the manpage that your code doesn't do.
> To open a connection to a server, use the zmq_connect call, and then fetch
> the socket identity using the ZMQ_IDENTITY zmq_getsockopt call.
I don't recall if this was strictly necessary but I see in my code that I did
fetch the identity but immediately discarded it.
I have some python scripts here where the server code disconnects the client.
https://github.com/pijyoi/test_zmqstream
See zmqstream_publisher.py and zmqstream_subscriber.py
On 21 Mar 2016 5:07 pm, "Auer, Jens"
mailto:jens.a...@cgi.com>> wrote:
Hi,
I am trying to close a TCP socket over a ZMQ_STREAM by sending an identity
frame followed by an empty message, as described in the manual ("To close a
specific connection, send the identity frame followed by a zero-length
message"). I have a simple client/server example:
#include
#include
#include
int main2() {
std::string address = "tcp://127.0.0.1:5000";
zmq::context_t zmq;
zmq::socket_t server(zmq, ZMQ_STREAM);
server.bind(address);
zmq::message_t id;
zmq::message_t m;
server.recv(&id);
server.recv(&m);
std::cout << "Connection received: " << id.size() << std::endl;
zmq::message_t empty{};
server.send(id, ZMQ_SNDMORE);
server.send(empty, ZMQ_SNDMORE );
int i;
std::cin >> i;
return 0;
}
#include
#include
int main() {
std::string address = "tcp://127.0.0.1:5000";
zmq::context_t zmq;
zmq::socket_t client(zmq, ZMQ_STREAM);
client.connect(address);
zmq::message_t m3;
zmq::message_t m4;
client.recv(&m3);
client.recv(&m4);
std::cout << "Connection established" << std::endl;
{
zmq::message_t m5;
zmq::message_t m6;
client.recv(&m5);
client.recv(&m6);
}
std::cout << "Connection closed" << std::endl;
int i;
std::cin >> i;
return 0;
}
When I start the server and then the client, the server will receive the
connection message, but the empty message does not close the socket:
./stream_s 2
Connection received: 5
/tmp/stream_c
Connection established
t
Re: [zeromq-dev] Newbie questions re HWM and Async/Sync io
On 21 March 2016 at 08:15, Aaron Koolen-Bourke wrote: > Hi all. > Thing is, from what I can tell I then need to move to polling and not > blocking receives, which not only keeps the thread busy looping, but seems > to be quite expensive (There seems to be a sleep timer in there or some > such). This just kills performance. Is there any support for a completely > event driven system in ZMQ/CZMQ? Hi Aaron, CZMQ uses libzmq's poll APIs, which depending on your system will pick out the best option to poll on file descriptors. On Linux for example it will use epoll, on Windows it will use select and so on. So there's no busy looping, so don't worry about performances. Sorry but I'm not sure about the HWM issue, hopefully someone else can give their 2c on that. Kind regards, Luca Boccassi ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev
Re: [zeromq-dev] Empty message does not close ZMQ_STREAM socket?
There's something in the manpage that your code doesn't do.
> To open a connection to a server, use the zmq_connect call, and then
fetch the socket identity using the ZMQ_IDENTITY zmq_getsockopt call.
I don't recall if this was strictly necessary but I see in my code that I
did fetch the identity but immediately discarded it.
I have some python scripts here where the server code disconnects the
client.
https://github.com/pijyoi/test_zmqstream
See zmqstream_publisher.py and zmqstream_subscriber.py
On 21 Mar 2016 5:07 pm, "Auer, Jens" wrote:
> Hi,
>
> I am trying to close a TCP socket over a ZMQ_STREAM by sending an identity
> frame followed by an empty message, as described in the manual ("To close a
> specific connection, send the identity frame followed by a zero-length
> message"). I have a simple client/server example:
> #include
> #include
> #include
>
> int main2() {
> std::string address = "tcp://127.0.0.1:5000";
>
> zmq::context_t zmq;
> zmq::socket_t server(zmq, ZMQ_STREAM);
>
> server.bind(address);
>
> zmq::message_t id;
> zmq::message_t m;
> server.recv(&id);
> server.recv(&m);
> std::cout << "Connection received: " << id.size() << std::endl;
>
> zmq::message_t empty{};
>
> server.send(id, ZMQ_SNDMORE);
> server.send(empty, ZMQ_SNDMORE );
>
> int i;
> std::cin >> i;
>
> return 0;
> }
>
> #include
> #include
>
> int main() {
> std::string address = "tcp://127.0.0.1:5000";
>
> zmq::context_t zmq;
> zmq::socket_t client(zmq, ZMQ_STREAM);
>
> client.connect(address);
>
> zmq::message_t m3;
> zmq::message_t m4;
> client.recv(&m3);
> client.recv(&m4);
>
> std::cout << "Connection established" << std::endl;
>
> {
> zmq::message_t m5;
> zmq::message_t m6;
> client.recv(&m5);
> client.recv(&m6);
> }
>
> std::cout << "Connection closed" << std::endl;
> int i;
> std::cin >> i;
>
> return 0;
> }
>
> When I start the server and then the client, the server will receive the
> connection message, but the empty message does not close the socket:
> ./stream_s 2
> Connection received: 5
> /tmp/stream_c
> Connection established
>
> tcp0 0 127.0.0.1:5000 0.0.0.0:*
> LISTEN 32615/./stream_s
> tcp0 0 127.0.0.1:5000 127.0.0.1:34270
> ESTABLISHED 32615/./stream_s
> tcp0 0 127.0.0.1:34270 127.0.0.1:5000
> ESTABLISHED 32618/stream_c
>
> I have also created a second example where the server sends the close
> message twice. Here, the client actually receives the close message as an
> empty message. Why is this even possible over a ZMQ_STREAM socket?
>
> I am using ZeroMQ 4.1.4, so the notification messages should be enabled by
> default without setting ZMQ_STREAM_NOTIFY, and I have also tested 4.1.2 to
> check for a regression.
>
> Best wishes,
> Jens
>
> ___
> zeromq-dev mailing list
> zeromq-dev@lists.zeromq.org
> http://lists.zeromq.org/mailman/listinfo/zeromq-dev
>
>
___
zeromq-dev mailing list
zeromq-dev@lists.zeromq.org
http://lists.zeromq.org/mailman/listinfo/zeromq-dev
[zeromq-dev] Empty message does not close ZMQ_STREAM socket?
Hi,
I am trying to close a TCP socket over a ZMQ_STREAM by sending an identity
frame followed by an empty message, as described in the manual ("To close a
specific connection, send the identity frame followed by a zero-length
message"). I have a simple client/server example:
#include
#include
#include
int main2() {
std::string address = "tcp://127.0.0.1:5000";
zmq::context_t zmq;
zmq::socket_t server(zmq, ZMQ_STREAM);
server.bind(address);
zmq::message_t id;
zmq::message_t m;
server.recv(&id);
server.recv(&m);
std::cout << "Connection received: " << id.size() << std::endl;
zmq::message_t empty{};
server.send(id, ZMQ_SNDMORE);
server.send(empty, ZMQ_SNDMORE );
int i;
std::cin >> i;
return 0;
}
#include
#include
int main() {
std::string address = "tcp://127.0.0.1:5000";
zmq::context_t zmq;
zmq::socket_t client(zmq, ZMQ_STREAM);
client.connect(address);
zmq::message_t m3;
zmq::message_t m4;
client.recv(&m3);
client.recv(&m4);
std::cout << "Connection established" << std::endl;
{
zmq::message_t m5;
zmq::message_t m6;
client.recv(&m5);
client.recv(&m6);
}
std::cout << "Connection closed" << std::endl;
int i;
std::cin >> i;
return 0;
}
When I start the server and then the client, the server will receive the
connection message, but the empty message does not close the socket:
./stream_s 2
Connection received: 5
/tmp/stream_c
Connection established
tcp0 0 127.0.0.1:5000 0.0.0.0:* LISTEN
32615/./stream_s
tcp0 0 127.0.0.1:5000 127.0.0.1:34270 ESTABLISHED
32615/./stream_s
tcp0 0 127.0.0.1:34270 127.0.0.1:5000 ESTABLISHED
32618/stream_c
I have also created a second example where the server sends the close message
twice. Here, the client actually receives the close message as an empty
message. Why is this even possible over a ZMQ_STREAM socket?
I am using ZeroMQ 4.1.4, so the notification messages should be enabled by
default without setting ZMQ_STREAM_NOTIFY, and I have also tested 4.1.2 to
check for a regression.
Best wishes,
Jens
___
zeromq-dev mailing list
zeromq-dev@lists.zeromq.org
http://lists.zeromq.org/mailman/listinfo/zeromq-dev
[zeromq-dev] Newbie questions re HWM and Async/Sync io
Hi all. Slowly getting my ZMQ evaluation application together but I've discovered a couple of things I'm hoping have some as-yet undiscovered (to me) answers. I was noticing that my message feeder was blocking at the HWM and latency was taking a hit so I've been experimenting with different HWM values along the pipeline. 2000, (workers*1000) and various things like that. However I have noticed that sometimes I'll use a value at one point in the chain and the whole program hangs. Everyone is blocked on waiting for messages. This doesn't make obvious sense to me. NOTE: I'm waiting for a start signal before any messages are sent so I'm not setting the HWM "mid action". Is there any info on why it might hang and how to avoid it? I'm worried that it's not deterministic with value and could just happen in a real application. Secondly I've noticed that when I try and write something like a worker in the "recommended way" by using ZMQ messages for all communication - messages, start, stop etc. I get to the point where I need to both receive some data on a socket, and get a command that signals I should cleanup and exit my thread (I'm using CZMQ actors). Thing is, from what I can tell I then need to move to polling and not blocking receives, which not only keeps the thread busy looping, but seems to be quite expensive (There seems to be a sleep timer in there or some such). This just kills performance. Is there any support for a completely event driven system in ZMQ/CZMQ? Many thanks Aaron CZMQ, ZMQ 4.1.4, Windows ___ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev
