<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12pt"><div><span>Running this now: netstat -t -n | grep :5672</span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span><br></span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>As far as the prefetch goes, we are using a value of 500. When using a value like 1, we saw pretty bad performance.</span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style:
normal;"><span><br></span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;">
</div><div class="p1">My understanding of pre-fetch was the consumer asks for that number of messages and then has to send an acknowledge before more messages are sent to it. If we have memory issues when there are almost no messages then our pre-fetch values seems an unlikely cause.</div><div class="p1"><br></div><div class="p1" style="color: rgb(0, 0, 0); font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;">
</div><div class="p1">If we set prefetch really low, I could see us having a lot of messages in the queue. Setting it high or unlimited should actually be better for the server.</div><div class="p1"><br></div><div class="p1" style="color: rgb(0, 0, 0); font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;">Nonetheless, I'll try it after this current batch with netstat runs to explosion.</div><div class="p1" style="color: rgb(0, 0, 0); font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><br></div><div class="p1" style="color: rgb(0, 0, 0); font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;">Still no luck reproducing the issue with a
simple test program...</div><div class="yahoo_quoted" style="display: block;"> <br> <br> <div style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 12pt;"> <div style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 12pt;"> <div dir="ltr"> <font size="2" face="Arial"> On Tuesday, October 22, 2013 7:31 AM, Emile Joubert <emile@rabbitmq.com> wrote:<br> </font> </div> <div class="y_msg_container"><br clear="none">Hi Brian,<br clear="none"><br clear="none">On 21/10/13 19:50, Brian Hammond wrote:<br clear="none">> Do you have a specific set of arguments in mind for netstat? If not I'll<br clear="none">> go look at the man page.<br clear="none"><br clear="none">netstat shows this information by default.<br clear="none"><br clear="none">> I'll provide more information as my tests progress.<br clear="none"><br clear="none"><br
clear="none">From the reports it appears that all consumers are either using<br clear="none">unlimited prefetch or a value of 500. It is likely that the broker<br clear="none">memory use will be reduced if consumers use a much lower prefetch count,<br clear="none">say 1. Would it be possible for you to try that? The reason why it might<br clear="none">help in your particular case is most of the memory is being consumed by<br clear="none">the Erlang processes that write to the network.<br clear="none"><br clear="none">I realise that it might be difficult for you to make this change to all<br clear="none">consumers. Let me know if this is too onerous so we can discuss<br clear="none">alternatives.<div class="yqt0809069702" id="yqtfd32512"><br clear="none"><br clear="none"><br clear="none"><br clear="none"><br clear="none">-Emile<br clear="none"><br clear="none"><br clear="none"><br clear="none"><br clear="none"></div><br><br></div> </div> </div> </div>
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