<div dir="ltr">Thank you, Scott!<div><br></div><div>I performed some tests and here are my results (5000 concurrent HTTP clients with cowboy on every node):</div><div> * {delay_send, true} has almost no effect</div><div> * kernel parameter {dist_nodelay, false} (disables nodelay socket option on dist port) gives 25% more service rps (32K to 40K) with large latency (98% is at 30 ms vs 4 ms in default setup)</div>
<div> * latency slowly increases up to 250 ms, then jumps to 550..650 ms. Possibly related to tcp retransmit.</div><div><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, Jul 9, 2014 at 7:30 AM, Scott Lystig Fritchie <span dir="ltr"><<a href="mailto:fritchie@snookles.com" target="_blank">fritchie@snookles.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Danil Zagoskin <<a href="mailto:z@gosk.in">z@gosk.in</a>> wrote:<br>
<br>
dz> If yes, how can I change this behavior by cost of couple of<br>
dz> millisecods latency?<br>
<br>
Hi, Danil. Have you tried the configuration setting mentioned in the<br>
4th paragraph of the Description of<br>
<a href="http://www.erlang.org/doc/man/inet.html" target="_blank">http://www.erlang.org/doc/man/inet.html</a> ?<br>
<br>
Using the Kernel configuration parameters mentioned above, one can<br>
set default options for all TCP sockets on a node. This should be<br>
used with care, but options like {delay_send,true} might be<br>
specified in this way. An example of starting an Erlang node with<br>
all sockets using delayed send could look like this:<br>
<br>
$ erl -sname test -kernel \<br>
inet_default_connect_options '[{delay_send,true}]' \<br>
inet_default_listen_options '[{delay_send,true}]'<br>
<br>
Note that 'sndbuf' and 'recbuf' can be set this way also.<br>
<span class="HOEnZb"><font color="#888888"><br>
-Scott<br>
</font></span></blockquote></div><br><br clear="all"><div><br></div>-- <br><div dir="ltr"><div><font face="'courier new', monospace">Danil Zagoskin | <a href="mailto:z@gosk.in" target="_blank">z@gosk.in</a></font></div>
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