gmane.network.zeromq.devel

Re: Hints about async pattern

Marco Trapanese — 2012-05-23T17:54:37

Il 23/05/2012 19:19, Marco Trapanese ha scritto:



Perhaps I found a simple solution. I don't know if it's a good practice, 
please feel free to tell me what you think.

The server send a dummy message to test the client. If the client 
acknowledges, the server sends the actual message.

In this way if the client is down only the dummy message is in the 
queue, the clients acks when reconnects but the server will ignore it.

If the connection is lost just after the ack (very unlikely) the client 
will receive the naked message, without the dummy one. So it will reject it.

In other words, I'm going to test the connection a while before send the 
message.

What do you think about?

Marco

Re: Hints about async pattern

Marco Trapanese — 2012-05-23T17:19:19

Il 09/04/2012 18:42, Chuck Remes ha scritto:

 > to worry about pings and pongs to limit the queue size. You could
 > limit by message count or by byte count depending on how you
 > implemented the flow control.


I'm playing with this solution.
Because my application send commands I must be sure that each message 
sent by the server is received by the client at the moment.
If a client is down it *must not* receive any old message when the 
connection will be recovered.

If I understand correctly, the credit-based flow control mechanism 
replaces the HWM allowing me to set the queue size down to 1 message 
without any related issue.

Thus after each message received, the clients send back the 
TRANSIT_SLICE. When the server doesn't receive the credit anymore stops 
the transmissions.

Well, it's a kind of a req-rep (or ack) protocol.

Anyway, the (unique) message sent after a client disconnection will stay 
in the queue until the client will be reconnected. And the client will 
receive the message, won't it?

Downloads site - removed historic folder

Pieter Hintjens — 2012-05-23T16:11:05

Hi all,

We used to move old versions of 0MQ tarballs into /historic.

People rightly complained because this kept breaking things for anyone
linking to a tarball.

I've killed that folder and all past and present releases of 0MQ and
related projects are now simply in the main downloads directory at
http://download.zeromq.org/

-Pieter

Ps. if you were linking to a tarball in /historic sorry, you'll have
one last fix to make.

Re: ZeroMQ for Android

Pieter Hintjens — 2012-05-23T14:26:34


Sure. Victor Perron also added some new information yesterday.

-Pieter

ZeroMQ for Android

Boris Gulay — 2012-05-23T14:20:19

I've successfully compiled and tested libzmq v2.2 for Android using
latest ndk (r8). I've used static linking for libuuid and libzmq, so I
have only one native file to copy on the device: libjzmq. I believe it;s
better than compile al libraries to .so because on android all such
files are private to the application and separate files just slows down
startup of the application.

Should I write new description of the build process on android page?

_______________________________________________
zeromq-dev mailing list
zeromq-dev< at >lists.zeromq.org
http://lists.zeromq.org/mailman/listinfo/zeromq-dev

Re: Code-style question

Marco Trapanese — 2012-05-23T11:42:49

Il 23/05/2012 13:32, Andrew Hume ha scritto:



Thanks for you hints!
Marco

Re: Code-style question

Andrew Hume — 2012-05-23T11:32:19

as you point out, "commands" are different from "data".

in my world, we are all using identical intel hardware/software, so data is sent as C structs.

commands are different. the time spent parsing/generating commands is almost unmeasurably small,
so i hew to Plan 9 style and simply send blank-delimited words.
i use a very efficient field splitter, and then use strcmp, as in

nf = split(msg, f, " ");
if(nf < 1) return;
if(strcmp(f[0], "func1") == 0){
func1(strtol(f[1], 10, 0), f[2]);
} else if(strcmp(f[0], "func2") == 0){
so on ...
} else {
// rats; complain
}

its not terribly elegant, but it is straightforward and easy to maintain.
and having regular text makes it easier to manually scan and debug.
i have used something like JSON before, but it seemed like a lot of unnecessary work.

On May 22, 2012, at 11:11 AM, Marco Trapanese wrote:



------------------
Andrew Hume  (best -> Telework) +1 623-551-2845
andrew< at >research.att.com  (Work) +1 973-236-2014
AT&T Labs - Research; member of USENIX and

Re: Code-style question

Marco Trapanese — 2012-05-23T07:58:15

Il 23/05/2012 09:28, Ivan Pechorin ha scritto:



Ok, thank you a lot.
Marco

Re: Code-style question

Ivan Pechorin — 2012-05-23T07:28:11

2012/5/23 Marco Trapanese <marcotrapanese< at >gmail.com>

When you have to send commands, do you use a fields to represent the

Yes
_______________________________________________
zeromq-dev mailing list
zeromq-dev< at >lists.zeromq.org
http://lists.zeromq.org/mailman/listinfo/zeromq-dev

Re: Code-style question

Marco Trapanese — 2012-05-23T07:07:39

Il 23/05/2012 08:33, Ivan Pechorin ha scritto:



Thanks for your answer.
Currently I use something like that for the data (I use the 
serialization utility provided by Qt). I think protobuf is butter 
because is not tied to a specific environment.

I read through the protobuf doc but I see examples about the exchange of 
pure data ( = variables).

When you have to send commands, do you use a fields to represent the 
enum of the desired command and the others the parameters, don't you?

Bye
Marco

Re: Code-style question

Ivan Pechorin — 2012-05-23T06:33:03

2012/5/23 Marco Trapanese <marcotrapanese< at >gmail.com>


 We tend to send protobuf (see http://code.google.com/p/protobuf/)
_______________________________________________
zeromq-dev mailing list
zeromq-dev< at >lists.zeromq.org
http://lists.zeromq.org/mailman/listinfo/zeromq-dev

Re: Code-style question

Marco Trapanese — 2012-05-23T05:39:13

Il 22/05/2012 20:54, Pieter Hintjens ha scritto:



Hi Pieter,

I know this is the default answer :)
I read the guide, indeed.

But the examples exchange messages with fun payloads, like these:

- "hello" / "world"
- "I'm ready"
- "ok"
- "We don't want to see this"
- "This is the workload"

or just a counter to simulate some data.

I'm asking what you actually send in your messages.
Strings like above? Integers (enum/#define) like in my example?

Of course, if the answer is still in the guide I admit I don't see it.
Anyway, which example you had in mind when you suggest me to read the 
guide? I'll read it another time.

Thanks again!
Marco

Re: June meetup / drinkup in Bay Are?

Brian Knox — 2012-05-23T00:21:43

I'll be in San Jose for most of the week, but I'll probably hit up our San
Francisco office at some point - I'll stay in touch!

Brian

On Tue, May 22, 2012 at 7:20 PM, Pieter Hintjens <ph< at >imatix.com> wrote:

_______________________________________________
zeromq-dev mailing list
zeromq-dev< at >lists.zeromq.org
http://lists.zeromq.org/mailman/listinfo/zeromq-dev

Re: June meetup / drinkup in Bay Are?

Pieter Hintjens — 2012-05-22T23:20:00


No worries, we'll do a drink-up on the 8th, and I'll be there a few
days beforehand. Saturday is just more convenient for a whole-day
meeting.

-Pieter

Re: June meetup / drinkup in Bay Are?

Brian Knox — 2012-05-22T22:28:21

Oh man, I'll miss you by one day... I fly back on the 9th!  I wonder if I
can change my tickets.

On Tue, May 22, 2012 at 4:58 PM, Pieter Hintjens <ph< at >imatix.com> wrote:

_______________________________________________
zeromq-dev mailing list
zeromq-dev< at >lists.zeromq.org
http://lists.zeromq.org/mailman/listinfo/zeromq-dev

June meetup / drinkup in Bay Are?

Pieter Hintjens — 2012-05-22T20:58:01

Hi all,

Any interest in a meetup in the Bay Area on the 9th of June?

We have office space downtown SF.

-Pieter

Re: Strict aliasing problem

Pieter Hintjens — 2012-05-22T21:02:30

Lourens,

Shoot us a pull request then so people can enjoy your lovely work :-)

-Pieter

On Tue, May 22, 2012 at 3:54 PM, Lourens Naudé
<lourens< at >methodmissing.com> wrote:

Re: Strict aliasing problem

Lourens Naudé — 2012-05-22T20:54:19

Hi Guys,

Updated again with feedback thus far :

https://github.com/methodmissing/libzmq/compare/monitor-regressions

- Lourens

On Mon, May 21, 2012 at 9:58 PM, Pieter Hintjens <ph< at >imatix.com> wrote:

_______________________________________________
zeromq-dev mailing list
zeromq-dev< at >lists.zeromq.org
http://lists.zeromq.org/mailman/listinfo/zeromq-dev

Re: Code-style question

Pieter Hintjens — 2012-05-22T18:54:57

Marco,

Please read the Guide, it has examples that show how to create and
work with protocols like this.

-
Pieter

On Tue, May 22, 2012 at 1:11 PM, Marco Trapanese
<marcotrapanese< at >gmail.com> wrote:

Code-style question

Marco Trapanese — 2012-05-22T18:11:51

Hello,

currently I'm using zmq on several projects to control remote 
applications. In fact, I send 'commands' rather 'data'.

The architecture of the whole software is pretty simple. There are the 
basic functions that do the hard job (my own API). Let's call 'em 
func1(), func2() ...

Then I wrote a raw protocol to call these functions through the zmq 
connection. After a message is received, I check the first part to 
decode the command and the followings to get the parameters (if any). 
Something like this:

void parseMessage() {
// receive the message, get cmd, argc and argv[]

switch (cmd) {
case CMD1:
func1();
break;

case CMD2:
if (argc == 1) func2(argv[0]);
break;
}
}


I wonder how do you implement such an interface. Do you use a method 
like this or there is something more flexible/elegant?

Thanks
Marco

Re: std::numeric_limits invalid

Steven McCoy — 2012-05-22T13:57:38

I added two patches to the PGM address resolution Jira issue.  Most
convenient option at the present.