[zeromq-dev] Weird behavior with zmq_proxy performance

Bruno D. Rodrigues bruno.rodrigues at litux.org
Tue Nov 19 13:30:23 CET 2013


all test files are C. the local_thr and remote_thr are the existing ones, just switching bind() to connect(). the proxy is the C code from the CC1 book. ;) can’t be simpler than that

On Nov 19, 2013, at 12:28, Pieter Hintjens <ph at imatix.com> wrote:

> I'll put together a test case in C and see if I can reproduce the problem...
> 
> On Tue, Nov 19, 2013 at 1:13 PM, Bruno D. Rodrigues
> <bruno.rodrigues at litux.org> wrote:
>> as requested I’ve created a ticket and updated the branch with the latest
>> code and a perf/README.txt explaining how to run it (basically the
>> instructions below)
>> 
>> https://github.com/zeromq/libzmq/issues/757
>> 
>> 
>> On Nov 10, 2013, at 13:08, Bruno D. Rodrigues <bruno.rodrigues at litux.org>
>> wrote:
>> 
>> I’ve branched the code to add the proxy code for testing:
>> https://github.com/davipt/libzmq/tree/fix-002-proxy_lat_thr
>> 
>> This now allows me:
>> 
>> 1. current PUSH/PULL end-to-end test:
>> 
>> idavi:perf bruno$ ./local_thr tcp://127.0.0.1:5555 500 10000000 &
>> local_thr bind-to=tcp://127.0.0.1:5555 message-size=500
>> message-count=10000000 type=0 check=0 connect=0
>> 
>> idavi:perf bruno$ ./remote_thr tcp://127.0.0.1:5555 500 10000000 &
>> remote_thr connect-to=tcp://127.0.0.1:5555 message-size=500
>> message-count=10000000 type=0 check=0
>> 
>> message size: 500 [B]
>> message count: 10000000
>> mean throughput: 1380100 [msg/s]
>> mean throughput: 5520.400 [Mb/s]
>> 
>> 2. PUB/SUB end-to-end test:
>> 
>> idavi:perf bruno$ ./local_thr tcp://127.0.0.1:5555 500 10000000 1 &
>> local_thr bind-to=tcp://127.0.0.1:5555 message-size=500
>> message-count=10000000 type=1 check=0 connect=0
>> 
>> idavi:perf bruno$ ./remote_thr tcp://127.0.0.1:5555 500 10000000 1 &
>> remote_thr connect-to=tcp://127.0.0.1:5555 message-size=500
>> message-count=10000000 type=1 check=0
>> 
>> message size: 500 [B]
>> message count: 10000000
>> mean throughput: 971666 [msg/s]
>> mean throughput: 3886.664 [Mb/s]
>> 
>> 3. same test via zmq_proxy, by switching local_lat from bind to connect:
>> 
>> idavi:perf bruno$ ./proxy tcp://*:8881 tcp://*:8882 &
>> Proxy type=PULL|PUSH in=tcp://*:8881 out=tcp://*:8882
>> 
>> idavi:perf bruno$ ./local_thr tcp://127.0.0.1:8882 500 10000000 32 &
>> local_thr bind-to=tcp://127.0.0.1:8882 message-size=500 message-count=100000
>> type=32 check=0 connect=32
>> 
>> idavi:perf bruno$ ./remote_thr tcp://127.0.0.1:8881 500 10000000 &
>> remote_thr connect-to=tcp://127.0.0.1:8881 message-size=500
>> message-count=10000000 type=0 check=0
>> 
>> message size: 500 [B]
>> message count: 10000000
>> mean throughput: 92974 [msg/s]
>> mean throughput: 371.896 [Mb/s]
>> 
>> 4. same test via proxy and PUB/SUB, including checking if every message
>> arrives (*)
>> 
>> idavi:perf bruno$ ./proxy tcp://*:8881 tcp://*:8882 1 &
>> Proxy type=XSUB|XPUB in=tcp://*:8881 out=tcp://*:8882
>> 
>> idavi:perf bruno$ ./local_thr tcp://127.0.0.1:8882 500 10000000 49 &
>> local_thr bind-to=tcp://127.0.0.1:8882 message-size=500
>> message-count=10000000 type=49 check=16 connect=32
>> 
>> idavi:perf bruno$ ./remote_thr tcp://127.0.0.1:8881 500 10000000 17 &
>> remote_thr connect-to=tcp://127.0.0.1:8881 message-size=500
>> message-count=10000000 type=17 check=16
>> 
>> message size: 500 [B]
>> message count: 10000000
>> mean throughput: 88721 [msg/s]
>> mean throughput: 354.884 [Mb/s]
>> 
>> (*) if check is enabled on the remote_thr, the message, if size>16, will
>> contain a counter. On the local_thr it will then verify if the counter comes
>> at the expected order and without loosing any message. Hence why the
>> remote_thr needs to increase the HWM and sleep for one second in case of
>> PUB/SUB.
>> 
>> 
>> So, then again, what is happening with the zmq_proxy?
>> 
>> 
>> 
>> 
>> On Nov 7, 2013, at 22:15, Bruno D. Rodrigues <bruno.rodrigues at litux.org>
>> wrote:
>> 
>> I’ve been testing a lot of combinations of ZeroMQ over Java, between the
>> pure jeromq base and the jzmq JNI libzmq C code. Albeit my impression so far
>> is that jeromq is way faster than the binding - not that the code isn’t
>> great, but my feeling so far is that the JNI jump slows everything down - at
>> a certain point I felt the need for a simple zmq_proxy network node and I
>> was pretty sure that the C code must be faster than the jeromq. I have some
>> ideas that can improve the jeromq proxy code, but it felt easier to just
>> compile the zmq_proxy code from the book.
>> 
>> Unfortunately something went completely wrong on my side so I need your help
>> to understand what is happening here.
>> 
>> Context:
>> MacOSX Mavericks fully updated, MBPro i7 4x2 CPU 2.2Ghz 16GB
>> libzmq from git head
>> (same for jeromq and libzmq, albeit I’m using my own fork so I can send
>> pulls back)
>> my data are json lines that goes from about 100 bytes to some multi MB
>> exceptions, but the average of those million messages is about 500bytes.
>> 
>> Test 1: pure local_thr and remote_thr:
>> 
>> iDavi:perf bruno$ ./local_thr tcp://127.0.0.1:8881 500 1000000 &
>> iDavi:perf bruno$ time ./remote_thr tcp://127.0.0.1:8881 500 1000000 &
>> real 0m0.732s
>> user 0m0.516s
>> sys 0m0.394s
>> message size: 500 [B]
>> message count: 1000000
>> mean throughput: 1418029 [msg/s]
>> mean throughput: 5672.116 [Mb/s]
>> 
>> Test 2: change local_thr to perform connect instead of bind, and put a proxy
>> in the middle.
>> The proxy is the first C code example from the book, available here
>> https://gist.github.com/davipt/7361477
>> iDavi:c bruno$ gcc -o proxy proxy.c -I /usr/local/include/ -L
>> /usr/local/lib/ -lzmq
>> iDavi:c bruno$ ./proxy tcp://*:8881 tcp://*:8882 1
>> Proxy type=PULL/PUSH in=tcp://*:8881 out=tcp://*:8882
>> 
>> iDavi:perf bruno$ ./local_thr tcp://127.0.0.1:8882 500 1000000 &
>> iDavi:perf bruno$ time ./remote_thr tcp://127.0.0.1:8881 500 1000000 &
>> iDavi:perf bruno$ message size: 500 [B]
>> message count: 1000000
>> mean throughput: 74764 [msg/s]
>> mean throughput: 299.056 [Mb/s]
>> 
>> real 0m10.358s
>> user 0m0.668s
>> sys 0m0.508s
>> 
>> 
>> Test3: use the jeromq equivalent of the proxy:
>> https://gist.github.com/davipt/7361623
>> 
>> iDavi:perf bruno$ ./local_thr tcp://127.0.0.1:8882 500 1000000 &
>> [1] 15816
>> iDavi:perf bruno$ time ./remote_thr tcp://127.0.0.1:8881 500 1000000 &
>> [2] 15830
>> iDavi:perf bruno$
>> real 0m3.429s
>> user 0m0.654s
>> sys 0m0.509s
>> message size: 500 [B]
>> message count: 1000000
>> mean throughput: 293532 [msg/s]
>> mean throughput: 1174.128 [Mb/s]
>> 
>> This performance coming out of Java is okish, it’s here just for comparison,
>> and I’ll spend some time looking at it.
>> 
>> The core question is the C proxy - why 10 times slower than the no-proxy
>> version?
>> 
>> One thing I noticed, by coincidence, is that on the upper side of the proxy,
>> both with the C “producer” as well as the java one, tcpdump shows me
>> consistently packets of 16332 (or the MTU size if using ethernet, 1438 I
>> think). This value is consistent for the 4 combinations of producers and
>> proxies (jeromq vs c).
>> 
>> But on the other side of the proxy, the result is completely different. With
>> the jeromq proxy, I see packets of 8192 bytes, but with the C code I see
>> packets of either 509 or 1010. It feels like the proxy is sending the
>> messages one by one. Again, this value is consistent with the PULL consumer
>> after the proxy, being it C or java.
>> 
>> So this is something on the proxy “backend” socket side of the zmq_proxy.
>> 
>> Also, I see quite similar behavior with a PUB - [XSUB+Proxy+XPUB] - SUB
>> version.
>> 
>> What do I need to tweak on the proxy.c ?
>> 
>> Thanks in advance
>> 
>> 
>> 
>> 
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>> 
> 
> 
> 
> -- 
> -
> Pieter Hintjens
> CEO of iMatix.com
> Founder of ZeroMQ community
> blog: http://hintjens.com
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