<div dir="ltr">Hi!<div><br></div><div>Please check your recbuf and sndbuf port options.<div>After you establish a conection, log buffer sizes somehow, e.g. io:format("Socket buffers: ~w~n", [inet:getopts(S, [recbuf, sndbuf])]).</div><div><br></div><div>Large socket buffers are nice thing to have (for high throughput), but they can eat all your memory really fast.</div><div>If they are not set explicitly by your application, you can check inet_default_connect_options kernel app environment variable or your operating system defaults (rmem_default).</div><div><br></div></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Sep 22, 2016 at 12:41 PM, 叶少波 <span dir="ltr"><<a href="mailto:shaobo.ye@qingteng.cn" target="_blank">shaobo.ye@qingteng.cn</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div>Hi experts,</div><div><br></div><div>I wrote a server that accepts TCP connections. The listen socket starts with the options below:</div><div><div> -define(TCP_OPTS, [</div><div> binary,</div><div> {backlog, 256},</div><div> {packet, 0},</div><div> {active, false},</div><div> {reuseaddr, true},</div><div> {nodelay, false},</div><div> {delay_send, true},</div><div> {keepalive, true},</div><div> {send_timeout, 60000},</div><div> {exit_on_close, true}</div><div>]).</div></div><div>On the server node every new connection will spawn a new gen_server to handle it.</div><div><br></div><div>And then I spawn 5000 gen_servers on another erlang node(I call it Client node), every gen_server will connect to the server via TCP.</div><div><br></div><div>It is a really simple case.</div><div><br></div><div>After setup 5000 connections I found the binary memory on server node was used up to 17G;</div><div>and the binary memory on the Client node was 42M. It is a huge difference.</div><div><br></div><div>Then I rebooted the erlang node with "+Mim true" and "+Mis true"; after re-setup 5000 connections again, I used </div><div>instrument:memory_status(<wbr>types) to check the memory status, I found the dry_binary allocated 17G memory:</div><div><div>[{drv_binary,[{sizes,<wbr>1844114912,1844116842,<wbr>1844116842},</div><div> {blocks,5227,5724,5724}]},</div><div> {code,[{sizes,39944997,<wbr>39955374,39955374},</div><div> {blocks,1321,1321,1321}]},</div><div> {heap,[{sizes,28000216,<wbr>78942872,78942872},</div><div> {blocks,5263,5267,5267}]},</div><div> {old_heap,[{sizes,21132056,<wbr>72481264,72481264},</div><div> {blocks,2940,4736,4736}]},</div><div> {binary,[{sizes,17908918,<wbr>21738516,21738516},</div><div> {blocks,25087,35039,35039}]},</div><div> {proc_tab,[{sizes,12582975,<wbr>12582975,12582975},</div><div> {blocks,1,1,1}]},</div><div> {export_entry,[{sizes,<wbr>7108992,7108992,7108992},</div><div> {blocks,40392,40392,40392}]},</div><div> {db_term,[{sizes,6930120,<wbr>6930200,6930200},</div><div> {blocks,13149,13150,13150}]},</div><div> {port_tab,[{sizes,6291519,<wbr>6291519,6291519},{blocks,1,1,<wbr>1}]},</div><div> {proc,[{sizes,4211200,<wbr>4212800,4212800},</div><div> {blocks,5264,5266,5266}]},</div><div> {port,[{sizes,3392108,<wbr>3393432,3393432},</div><div> {blocks,5101,5103,5103}]},</div></div><div>.......</div><div><br></div><div>My question is : How can I decrease the drv_binary memory? What parameter caused the server used so much memory?</div><div><br></div><div>Thanks,</div><div>BRs/Michael</div><div><br></div><div><br></div><div><br></div><div><u></u><u></u></div><br>______________________________<wbr>_________________<br>
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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><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></div></div>
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