Re: [zeromq-dev] recv() on a ZMQ_REQ socket is slow

[Doron Somech]

It is part of 4.2, a new thread safe socket types.

You can read more here:
https://github.com/zeromq/libzmq/blob/master/doc/zmq_socket.txt#L68

Anyway if you send requests one-by-one you will enjoy zeromq
performance only at the server side, able to handle high throughput of
requests.
I don't recommend to use the REP socket on the server side, try to use
a pattern from the zeromq guide, the load balancing might be right:
http://zguide.zeromq.org/page:all#toc69







On Mon, Oct 10, 2016 at 9:25 AM, Dimos Stamatakis  wrote:
> Hi Doron,
>
> thanks for your response! We actually prefer to have synchronous behavior,
> since we will be using it for RPC calls and we want to know the status of
> the operation before proceeding to the next one.
>
> What is the client-server patter you mentioned? I didn't find it in the
> documentation.
>
> Thanks,
>
> Dimos
>
> On Sat, Oct 1, 2016 at 10:32 AM, Doron Somech  wrote:
>>
>> REQ-REP pattern is slow because zeromq is not tuned for one message at a
>> time but for batch of messages. I suggest to use the dealer-router or better
>> the client-server.  You can use uuid or just sequnce number for request
>> identifier. However if your use case is one message at the time so the
>> benefit of zeromq will be throughput at the server side.
>>
>>
>> On Thu, Sep 29, 2016, 01:30 Dimos Stamatakis  wrote:
>>>
>>> Hi everyone,
>>>
>>> I have been testing the ZeroMQ library combined with Thrift to compare
>>> the performance. I have a simple ZeroMQ example where I create ZMQ_REP and
>>> ZMQ_REQ sockets for a simple client-server communication. In the example,
>>> client simply sends a message to the server and waits for a reply. The only
>>> slow part I measured is the client receive, which makes sense. But it is
>>> almost three times slower than a native TCP socket.
>>> So the actual benchmark is the Thrift with ZeroMQ, as officially released
>>> by apache:
>>>
>>> https://github.com/apache/thrift/tree/master/contrib/zeromq
>>>
>>> I measured the overhead of using ZeroMQ for Thrift's communication,
>>> instead of a native TCP socket.
>>> The client response is much higher when using ZeroMQ and I was expecting
>>> to be caused by the copying that must be done from Thrift data structures to
>>> ZeroMQ data structures (zmq::message_t).
>>> However the copying is negligible. The actual overhead is the recv() of
>>> the client, waiting for the server to reply. Is it normal for a ZeroMQ
>>> REQ-REP socket to be almost three times slower than a native TCP socket? Is
>>> there something I can do to optimize it? I am using the default send and
>>> recv with no flags.
>>>
>>> I thought that maybe something is wrong with the way Thrift-ZeroMQ is
>>> implemented so I also ran the hello example:
>>> http://zguide.zeromq.org/cpp:hwserver
>>> This also takes more time in the recv().
>>>
>>>
>>> Many thanks in advance,
>>> Dimos
>>> ___
>>> zeromq-dev mailing list
>>> zeromq-dev@lists.zeromq.org
>>> http://lists.zeromq.org/mailman/listinfo/zeromq-dev
>>
>>
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>
>
>
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Re: [zeromq-dev] recv() on a ZMQ_REQ socket is slow

[Dimos Stamatakis]

Hi Doron,

thanks for your response! We actually prefer to have synchronous behavior,
since we will be using it for RPC calls and we want to know the status of
the operation before proceeding to the next one.

What is the client-server patter you mentioned? I didn't find it in the
documentation.

Thanks,

Dimos

On Sat, Oct 1, 2016 at 10:32 AM, Doron Somech  wrote:

> REQ-REP pattern is slow because zeromq is not tuned for one message at a
> time but for batch of messages. I suggest to use the dealer-router or
> better the client-server.  You can use uuid or just sequnce number for
> request identifier. However if your use case is one message at the time so
> the benefit of zeromq will be throughput at the server side.
>
> On Thu, Sep 29, 2016, 01:30 Dimos Stamatakis  wrote:
>
>> Hi everyone,
>>
>> I have been testing the ZeroMQ library combined with Thrift to compare
>> the performance. I have a simple ZeroMQ example where I create ZMQ_REP and
>> ZMQ_REQ sockets for a simple client-server communication. In the example,
>> client simply sends a message to the server and waits for a reply. The only
>> slow part I measured is the client receive, which makes sense. But it is
>> almost three times slower than a native TCP socket.
>> So the actual benchmark is the Thrift with ZeroMQ, as officially released
>> by apache:
>>
>> https://github.com/apache/thrift/tree/master/contrib/zeromq
>>
>> I measured the overhead of using ZeroMQ for Thrift's communication,
>> instead of a native TCP socket.
>> The client response is much higher when using ZeroMQ and I was expecting
>> to be caused by the copying that must be done from Thrift data structures
>> to ZeroMQ data structures (zmq::message_t).
>> However the copying is negligible. The actual overhead is the recv() of
>> the client, waiting for the server to reply. Is it normal for a ZeroMQ
>> REQ-REP socket to be almost three times slower than a native TCP socket? Is
>> there something I can do to optimize it? I am using the default send and
>> recv with no flags.
>>
>> I thought that maybe something is wrong with the way Thrift-ZeroMQ is
>> implemented so I also ran the hello example:
>> http://zguide.zeromq.org/cpp:hwserver
>> This also takes more time in the recv().
>>
>>
>> Many thanks in advance,
>> Dimos
>> ___
>> zeromq-dev mailing list
>> zeromq-dev@lists.zeromq.org
>> http://lists.zeromq.org/mailman/listinfo/zeromq-dev
>
>
> ___
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Re: [zeromq-dev] recv() on a ZMQ_REQ socket is slow

[Doron Somech]

REQ-REP pattern is slow because zeromq is not tuned for one message at a
time but for batch of messages. I suggest to use the dealer-router or
better the client-server.  You can use uuid or just sequnce number for
request identifier. However if your use case is one message at the time so
the benefit of zeromq will be throughput at the server side.

On Thu, Sep 29, 2016, 01:30 Dimos Stamatakis  wrote:

> Hi everyone,
>
> I have been testing the ZeroMQ library combined with Thrift to compare the
> performance. I have a simple ZeroMQ example where I create ZMQ_REP and
> ZMQ_REQ sockets for a simple client-server communication. In the example,
> client simply sends a message to the server and waits for a reply. The only
> slow part I measured is the client receive, which makes sense. But it is
> almost three times slower than a native TCP socket.
> So the actual benchmark is the Thrift with ZeroMQ, as officially released
> by apache:
>
> https://github.com/apache/thrift/tree/master/contrib/zeromq
>
> I measured the overhead of using ZeroMQ for Thrift's communication,
> instead of a native TCP socket.
> The client response is much higher when using ZeroMQ and I was expecting
> to be caused by the copying that must be done from Thrift data structures
> to ZeroMQ data structures (zmq::message_t).
> However the copying is negligible. The actual overhead is the recv() of
> the client, waiting for the server to reply. Is it normal for a ZeroMQ
> REQ-REP socket to be almost three times slower than a native TCP socket? Is
> there something I can do to optimize it? I am using the default send and
> recv with no flags.
>
> I thought that maybe something is wrong with the way Thrift-ZeroMQ is
> implemented so I also ran the hello example:
> http://zguide.zeromq.org/cpp:hwserver
> This also takes more time in the recv().
>
>
> Many thanks in advance,
> Dimos
> ___
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> zeromq-dev@lists.zeromq.org
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[zeromq-dev] recv() on a ZMQ_REQ socket is slow

[Dimos Stamatakis]

Hi everyone,

I have been testing the ZeroMQ library combined with Thrift to compare the
performance. I have a simple ZeroMQ example where I create ZMQ_REP and
ZMQ_REQ sockets for a simple client-server communication. In the example,
client simply sends a message to the server and waits for a reply. The only
slow part I measured is the client receive, which makes sense. But it is
almost three times slower than a native TCP socket.
So the actual benchmark is the Thrift with ZeroMQ, as officially released
by apache:

https://github.com/apache/thrift/tree/master/contrib/zeromq

I measured the overhead of using ZeroMQ for Thrift's communication, instead
of a native TCP socket.
The client response is much higher when using ZeroMQ and I was expecting to
be caused by the copying that must be done from Thrift data structures to
ZeroMQ data structures (zmq::message_t).
However the copying is negligible. The actual overhead is the recv() of the
client, waiting for the server to reply. Is it normal for a ZeroMQ REQ-REP
socket to be almost three times slower than a native TCP socket? Is there
something I can do to optimize it? I am using the default send and recv
with no flags.

I thought that maybe something is wrong with the way Thrift-ZeroMQ is
implemented so I also ran the hello example:
http://zguide.zeromq.org/cpp:hwserver
This also takes more time in the recv().


Many thanks in advance,
Dimos
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