<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:14pt"><div class="" style=""><br style=""></div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal" class="">Our performance tests show that ISC BIND (authoritative only setup) doesn't perform well on RHEL 6.4 in comparison with FreeBSD 7: <a href="https://www.dropbox.com/s/aig6ns6jbbir4wi/bind_perf.png" class="" style="">bind_perf.png</a></div><div style="width:450px; font-family: 'Georgia', 'Times', 'Times New Roman', 'serif'" contenteditable="false" id="enhancrCard_0" class=""><table class="" cellspacing="0" cellpadding="0" style="width:450px; height:170px; display: block"><tbody class="" style=""><tr class="" style=""><td colspan="6" class=""
style="height: 1px; background-color: #e5e5e5"><div class="" style="height: 1px; background-color: #e5e5e5"></div></td></tr><tr class="" style=""><td rowspan="2" class="" style="width: 1px; background-color: #e5e5e5"><div class="" style="width: 1px; background-color: #e5e5e5"></div></td><td class="" rowspan="2" style="vertical-align: middle; width: 168px; height: 168px; background-color: #000000"><div class="" style="width: 168px" align="center"><a href="https://www.dropbox.com/s/aig6ns6jbbir4wi/bind_perf.png" class="" style="text-decoration: none !important; color: #000000 !important"><img alt="image" src="https://photos-2.dropbox.com/t/0/AABXop1o1NOAJh1tYuYz5stpOIfdkuafcjM8bF_-B6KqQA/12/22706918/png/320x320/1/_/0/2/bind_perf.png/M-O0lngG2xJXtA8jFDPcEYxfmAieXxnXUtR5rS3dcZE" class="" width="168" height="168" style="display: block; margin: auto"></a></div></td><td rowspan="2" class="" style="width: 1px; background-color: #e5e5e5"><div class=""
style="width: 1px; background-color: #e5e5e5"></div></td><td class="" colspan="2" style="width: 100%; vertical-align: middle; font-family: 'Georgia', 'Times', 'Times New Roman', 'serif'"><div class="" style="line-height:16.5px; background-color: #ffffff; height: 130px; width: 279px"><div class="" style="word-wrap: break-word; padding: 7px 20px 0px 14px"><span class="" style=""></span><span class="" style=""></span><a href="https://www.dropbox.com/s/aig6ns6jbbir4wi/bind_perf.png" class="" style="text-decoration: none !important; color: #000000 !important"><span class="" style="margin: 0; font-weight: normal; font-size: 18px; line-height: 21px; max-height: 43px; color: #000000; overflow: hidden !important; display: inline-block">bind_perf.png</span></a><div style="font-size: 13px; line-height: 20px; color: #999999; max-height: 81px; font-family: 'Georgia', 'Times', 'Times New Roman', 'serif';overflow: hidden" class="">Shared with
Dropbox</div></div></div></td><td class="" rowspan="2" style="width: 1px; background-color: #e5e5e5"><div class="" style="width: 1px; background-color: #e5e5e5"></div></td></tr><tr class="" style=""><td class="" style="width: 100%; vertical-align: middle; font-family: 'Arial', 'Helvetica Neue', 'Helvetica', 'sans-serif'"><div class="" style="font-size: 0pt; padding: 7px 20px 9px 15px"><a href="https://www.dropbox.com/s/aig6ns6jbbir4wi/bind_perf.png" class="" style="color: black; text-decoration: none !important;cursor:pointer !important" target="_blank"><span class="" style="display: inline-block; line-height: 11px; max-width: 179px; min-width: 119px; overflow: hidden; max-height: 13px; word-break: break-all"><span class="" style="vertical-align:middle; font-size: 9px; line-height: 11px; color: #999999; -moz-text-size-adjust: none; -ms-text-size-adjust: none; -webkit-text-size-adjust:none; text-size-adjust:none">View on <span style="font-weight: bold"
class="">www.dropbox.com</span></span></span></a></div></td><td class="" style="vertical-align: middle; width: 100px; font-family: 'Arial', 'Helvetica Neue', 'Helvetica', 'sans-serif'"><div class="" style="padding: 9px 20px 12px 0px; max-width: 100px; min-width: 80px; overflow: hidden; text-align: right; line-height: 11px; max-height: 13px; font-size: 0pt"><span class="" style="vertical-align:middle; font-size: 9px; line-height: 11px; color: #999999; -moz-text-size-adjust: none; -ms-text-size-adjust: none; -webkit-text-size-adjust:none; text-size-adjust:none">Preview by Yahoo</span></div></td></tr><tr class="" style=""><td class="" colspan="6" style="height: 1px; background-color: #e5e5e5"><div class="" style="height: 1px; background-color: #e5e5e5"></div></td></tr></tbody></table></div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color:
transparent; font-style: normal" class=""><br class="" style=""></div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal" class="">The "Drop Rate" is the ratio of the amount response never received and the amount of requests were sent. BIND is configured with 24 worker threads and 24 UPD listener, same as the CPU threads we have. <span style="background-color: transparent; font-size: 14pt" class="">BIND process already has '-20' nice priority set on RHEL and '20' on the FreeBSD host.</span><span style="background-color: transparent; font-size: 14pt;">The test hosts running RHEL 6.4 and FreeBSD 7 are identical in term of hardware:</span></div><div class="" style="background-color: transparent"><span class="" style="background-color: transparent">2 x Xeon E5-2430, 24GB DDR3 RAM, 1Gb/s
NIC. </span></div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal" class=""><br class="" style=""></div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal" class="">We conducted the tests by having our load generators re-play BIND query logs using our custom scripts and send the queries to the test server at a given rate, say, 200,00 query per seconds. The queries are preloaded into the memory so that's no overhead for our load generators to read queries from disk while sending test queries.</div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent;
font-style: normal" class=""><br class="" style=""></div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal" class="">What we've observed that socket receiving queue (Recv-Q from netstat) drained very fast on FreeBSD but got back up pretty fast on RHEL 6 when we ramped up the test traffic. With net.core.rmem_default set to 40MB, it only helps RHEL to be able to handle 180,000qps before we start to see receive buffer overruns again and drop rate increases linearly.</div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal" class=""><br class="" style=""></div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica,
Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal" class="">We are using governor performance on RHEL because default governor ondemand really hurts performance.<br class="" style=""></div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal" class=""><br class="" style=""></div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal" class="">vmstat output gathered from RHEL and FreeBSD hosts showed that FreeBSD is scheduling those BIND threads more efficiently than RHEL as the number of running processes is quite stable on FreeBSD and context switches/interrupts ratio is lower and user space CPU utilization is better than RHEL. The below links
showed vmstat gathered with 1-second interval during the test run (200k qps) which lasted for about 60 seconds. </div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal" class=""><br class="" style=""></div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal" class=""><a href="https://www.dropbox.com/s/176bllly9gu9435/vmstat_from_freebsd.txt" class="" style="">vmstat_from_freebsd.txt</a><br class="" style=""></div><div style="width:450px; font-family: 'Georgia', 'Times', 'Times New Roman', 'serif'" contenteditable="false" id="enhancrCard_1" class=""><table class="" cellspacing="0" cellpadding="0" style="width:450px; height:170px; display: block"><tbody class=""
style=""><tr class="" style=""><td colspan="6" class="" style="height: 1px; background-color: #e5e5e5"><div class="" style="height: 1px; background-color: #e5e5e5"></div></td></tr><tr class="" style=""><td rowspan="2" class="" style="width: 1px; background-color: #e5e5e5"><div class="" style="width: 1px; background-color: #e5e5e5"></div></td><td class="" rowspan="2" style="vertical-align: middle; width: 168px; height: 168px; background-color: #000000"><div class="" style="width: 168px" align="center"><a href="https://www.dropbox.com/s/176bllly9gu9435/vmstat_from_freebsd.txt" class="" style="text-decoration: none !important; color: #000000 !important"><img alt="image" src="https://www.dropbox.com/static/images/icons128/page_white_text.png" class="" width="168" height="168" style="display: block; margin: auto"></a></div></td><td rowspan="2" class="" style="width: 1px; background-color: #e5e5e5"><div class="" style="width: 1px; background-color:
#e5e5e5"></div></td><td class="" colspan="2" style="width: 100%; vertical-align: middle; font-family: 'Georgia', 'Times', 'Times New Roman', 'serif'"><div class="" style="line-height:16.5px; background-color: #ffffff; height: 130px; width: 279px"><div class="" style="word-wrap: break-word; padding: 7px 20px 0px 14px"><span class="" style=""></span><span class="" style=""></span><a href="https://www.dropbox.com/s/176bllly9gu9435/vmstat_from_freebsd.txt" class="" style="text-decoration: none !important; color: #000000 !important"><span class="" style="margin: 0; font-weight: normal; font-size: 18px; line-height: 21px; max-height: 43px; color: #000000; overflow: hidden !important; display: inline-block">vmstat_from_freebsd.txt</span></a><div style="font-size: 13px; line-height: 20px; color: #999999; max-height: 81px; font-family: 'Georgia', 'Times', 'Times New Roman', 'serif';overflow: hidden" class="">Shared with Dropbox</div></div></div></td><td class=""
rowspan="2" style="width: 1px; background-color: #e5e5e5"><div class="" style="width: 1px; background-color: #e5e5e5"></div></td></tr><tr class="" style=""><td class="" style="width: 100%; vertical-align: middle; font-family: 'Arial', 'Helvetica Neue', 'Helvetica', 'sans-serif'"><div class="" style="font-size: 0pt; padding: 7px 20px 9px 15px"><a href="https://www.dropbox.com/s/176bllly9gu9435/vmstat_from_freebsd.txt" class="" style="color: black; text-decoration: none !important;cursor:pointer !important" target="_blank"><span class="" style="display: inline-block; line-height: 11px; max-width: 179px; min-width: 119px; overflow: hidden; max-height: 13px; word-break: break-all"><span class="" style="vertical-align:middle; font-size: 9px; line-height: 11px; color: #999999; -moz-text-size-adjust: none; -ms-text-size-adjust: none; -webkit-text-size-adjust:none; text-size-adjust:none">View on <span style="font-weight: bold"
class="">www.dropbox.com</span></span></span></a></div></td><td class="" style="vertical-align: middle; width: 100px; font-family: 'Arial', 'Helvetica Neue', 'Helvetica', 'sans-serif'"><div class="" style="padding: 9px 20px 12px 0px; max-width: 100px; min-width: 80px; overflow: hidden; text-align: right; line-height: 11px; max-height: 13px; font-size: 0pt"><span class="" style="vertical-align:middle; font-size: 9px; line-height: 11px; color: #999999; -moz-text-size-adjust: none; -ms-text-size-adjust: none; -webkit-text-size-adjust:none; text-size-adjust:none">Preview by Yahoo</span></div></td></tr><tr class="" style=""><td class="" colspan="6" style="height: 1px; background-color: #e5e5e5"><div class="" style="height: 1px; background-color: #e5e5e5"></div></td></tr></tbody></table></div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color:
transparent; font-style: normal" class=""><br class="" style=""></div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal" class=""><a href="https://www.dropbox.com/s/1ymr6y2o5lzs4fg/vmstat_from_rhel6.txt" class="" style="">vmstat_from_rhel6.txt</a><br class="" style=""></div><div style="width:450px; font-family: 'Georgia', 'Times', 'Times New Roman', 'serif'" contenteditable="false" id="enhancrCard_2" class=""><table class="" cellspacing="0" cellpadding="0" style="width:450px; height:170px; display: block"><tbody class="" style=""><tr class="" style=""><td colspan="6" class="" style="height: 1px; background-color: #e5e5e5"><div class="" style="height: 1px; background-color: #e5e5e5"></div></td></tr><tr class="" style=""><td rowspan="2" class="" style="width: 1px; background-color: #e5e5e5"><div class=""
style="width: 1px; background-color: #e5e5e5"></div></td><td class="" rowspan="2" style="vertical-align: middle; width: 168px; height: 168px; background-color: #000000"><div class="" style="width: 168px" align="center"><a href="https://www.dropbox.com/s/1ymr6y2o5lzs4fg/vmstat_from_rhel6.txt" class="" style="text-decoration: none !important; color: #000000 !important"><img alt="image" src="https://www.dropbox.com/static/images/icons128/page_white_text.png" class="" width="168" height="168" style="display: block; margin: auto"></a></div></td><td rowspan="2" class="" style="width: 1px; background-color: #e5e5e5"><div class="" style="width: 1px; background-color: #e5e5e5"></div></td><td class="" colspan="2" style="width: 100%; vertical-align: middle; font-family: 'Georgia', 'Times', 'Times New Roman', 'serif'"><div class="" style="line-height:16.5px; background-color: #ffffff; height: 130px; width: 279px"><div class="" style="word-wrap: break-word; padding:
7px 20px 0px 14px"><span class="" style=""></span><span class="" style=""></span><a href="https://www.dropbox.com/s/1ymr6y2o5lzs4fg/vmstat_from_rhel6.txt" class="" style="text-decoration: none !important; color: #000000 !important"><span class="" style="margin: 0; font-weight: normal; font-size: 18px; line-height: 21px; max-height: 43px; color: #000000; overflow: hidden !important; display: inline-block">vmstat_from_rhel6.txt</span></a><div style="font-size: 13px; line-height: 20px; color: #999999; max-height: 81px; font-family: 'Georgia', 'Times', 'Times New Roman', 'serif';overflow: hidden" class="">Shared with Dropbox</div></div></div></td><td class="" rowspan="2" style="width: 1px; background-color: #e5e5e5"><div class="" style="width: 1px; background-color: #e5e5e5"></div></td></tr><tr class="" style=""><td class="" style="width: 100%; vertical-align: middle; font-family: 'Arial', 'Helvetica Neue', 'Helvetica', 'sans-serif'"><div class=""
style="font-size: 0pt; padding: 7px 20px 9px 15px"><a href="https://www.dropbox.com/s/1ymr6y2o5lzs4fg/vmstat_from_rhel6.txt" class="" style="color: black; text-decoration: none !important;cursor:pointer !important" target="_blank"><span class="" style="display: inline-block; line-height: 11px; max-width: 179px; min-width: 119px; overflow: hidden; max-height: 13px; word-break: break-all"><span class="" style="vertical-align:middle; font-size: 9px; line-height: 11px; color: #999999; -moz-text-size-adjust: none; -ms-text-size-adjust: none; -webkit-text-size-adjust:none; text-size-adjust:none">View on <span style="font-weight: bold" class="">www.dropbox.com</span></span></span></a></div></td><td class="" style="vertical-align: middle; width: 100px; font-family: 'Arial', 'Helvetica Neue', 'Helvetica', 'sans-serif'"><div class="" style="padding: 9px 20px 12px 0px; max-width: 100px; min-width: 80px; overflow: hidden; text-align: right; line-height: 11px;
max-height: 13px; font-size: 0pt"><span class="" style="vertical-align:middle; font-size: 9px; line-height: 11px; color: #999999; -moz-text-size-adjust: none; -ms-text-size-adjust: none; -webkit-text-size-adjust:none; text-size-adjust:none">Preview by Yahoo</span></div></td></tr><tr class="" style=""><td class="" colspan="6" style="height: 1px; background-color: #e5e5e5"><div class="" style="height: 1px; background-color: #e5e5e5"></div></td></tr></tbody></table></div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal" class=""><br class="" style=""></div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal" class=""><br class="" style=""></div><div style="color: rgb(0, 0, 0);
font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal" class=""><span style="background-color: transparent;">Anyone has ideas on how to tune the scheduler on RHEL6 to work better for BIND?</span><br></div><div style="color: rgb(0, 0, 0); font-size: 19px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal" class=""><br class="" style=""></div></div></body></html>