<div dir="ltr"><div class="gmail_default" style="font-size:small;font-family:'courier new',monospace">Hi Narayan, thanks fir the prompted response, let me try to give you some insights.</div><div class="gmail_default" style="font-size:small;font-family:'courier new',monospace">
Since like you said, our setup can reach the maximum bandwidth in some tests, but we cant achieve the THROUGHPUT we want, we run avg of 14vms on 128GB of ram compute nodes, and while all those vms are runing, we run a test between two compute nodes with a c++ aplication that sends 50 packets per second (lower than our 1500bytes MTU) and waits from the response from the target server lower than 10ms.</div>
<div class="gmail_default" style="font-size:small;font-family:'courier new',monospace">This test runs on the br100 interface on both compute nodes (passign through eth0-eth1, bond0 and br100) and while all vms are running (using high throughput low bandwidth applications) we see this simple tests showing thenths of thousands responses higher than 10ms, actually 99% of this slow responses are taking 20/21ms, i dont seem to find whats that magic delay value means, we are starting to look traversing what interfaces are adding the delay.</div>
<div class="gmail_default" style="font-size:small;font-family:'courier new',monospace"><br></div><div class="gmail_default" style="font-size:small;font-family:'courier new',monospace">Let me show you what our settings look like regarding networking (i will take the vms out of the picture)</div>
<div class="gmail_default" style="font-size:small;font-family:'courier new',monospace"><br></div><div class="gmail_default" style="font-size:small;font-family:'courier new',monospace">COMPUTE HOST</div>
<div class="gmail_default" style="font-size:small;font-family:'courier new',monospace">------------</div><div class="gmail_default" style="font-size:small;font-family:'courier new',monospace">2x1Gb bonded interfaces (no jumbo frames, 1500MTU since jumbo frames are a separate project)</div>
<div class="gmail_default" style="font-size:small;font-family:'courier new',monospace"><br></div><div class="gmail_default" style="font-size:small;font-family:'courier new',monospace">Ethernet ring settings on both interfaces:</div>
<blockquote style="margin:0 0 0 40px;border:none;padding:0px"><div class="gmail_default" style="font-size:small;font-family:'courier new',monospace">RX 256</div><div class="gmail_default" style="font-size:small;font-family:'courier new',monospace">
TX 256</div></blockquote><div class="gmail_default" style="font-size:small;font-family:'courier new',monospace"><br></div><div class="gmail_default" style="font-size:small;font-family:'courier new',monospace">
Ethernet txqueuelen on both interfaces:</div><blockquote style="margin:0 0 0 40px;border:none;padding:0px"><div class="gmail_default" style="font-size:small;font-family:'courier new',monospace">txqueuelen 1000</div>
</blockquote><div class="gmail_default" style="font-size:small;font-family:'courier new',monospace"><br></div><div class="gmail_default" style="font-size:small;font-family:'courier new',monospace">sysctl settings:</div>
<blockquote style="margin:0 0 0 40px;border:none;padding:0px"><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_max_tw_buckets = 3600000</font></div></div><div class="gmail_default">
<div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_max_syn_backlog = 30000</font></div></div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.core.netdev_max_backlog = 50000</font></div>
</div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.core.somaxconn = 16384</font></div></div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.core.rmem_max = 16777216</font></div>
</div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.core.wmem_max = 16777216</font></div></div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_rmem = 4096 87380 16777216</font></div>
</div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_wmem = 4096 65536 16777216</font></div></div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.core.rmem_default = 16777216</font></div>
</div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.core.wmem_default = 16777216</font></div></div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_congestion_control = cubic</font></div>
</div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.ip_local_port_range = 1024 65000</font></div></div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_fin_timeout = 5</font></div>
</div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_keepalive_time = 5</font></div></div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_tw_recycle = 1</font></div>
</div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_tw_reuse = 1</font></div></div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">vm.swappiness = 0</font></div>
</div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_syncookies = 1</font></div></div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_timestamps = 1</font></div>
</div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_max_orphans = 60000</font></div></div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_synack_retries = 3</font></div>
</div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_ecn=1</font></div></div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_sack=1</font></div>
</div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_dsack=1</font></div></div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.route.flush = 1</font></div>
</div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv6.route.flush = 1</font></div></div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.netfilter.ip_conntrack_udp_timeout = 30</font></div>
</div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.netfilter.ip_conntrack_tcp_timeout_close = 10</font></div></div><div class="gmail_default"><div class="gmail_default">
<font face="courier new, monospace">net.ipv4.netfilter.ip_conntrack_tcp_timeout_time_wait = 120</font></div></div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.netfilter.ip_conntrack_tcp_timeout_close_wait = 60</font></div>
</div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.netfilter.ip_conntrack_max = 1200000</font></div></div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.netfilter.ip_conntrack_tcp_timeout_established = 432000</font></div>
</div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.netfilter.ip_conntrack_tcp_timeout_syn_recv = 60</font></div></div><div class="gmail_default"><div class="gmail_default">
<font face="courier new, monospace">net.ipv4.netfilter.ip_conntrack_tcp_timeout_syn_sent = 120</font></div></div><div class="gmail_default"><div class="gmail_default"><font face="courier new, monospace">net.ipv4.tcp_keepalive_time = 90</font></div>
<div class="gmail_default"><font face="courier new, monospace"><br></font></div></div></blockquote><font face="courier new, monospace"><div class="gmail_default" style="font-family:'courier new',monospace;font-size:small;color:rgb(0,0,0);display:inline">
One other tip i can add is that allways the delay is on the RX side, this means, the server responding.</div></font><div><font face="courier new, monospace"><font color="#000000"><div class="gmail_default" style="font-family:'courier new',monospace;font-size:small;color:rgb(0,0,0);display:inline">
So, we were thinking about going upper with ring or txqueuelen settings.</div></font></font></div><div><font face="courier new, monospace"><font color="#000000"><div class="gmail_default" style="font-family:'courier new',monospace;font-size:small;color:rgb(0,0,0);display:inline">
<br></div></font></font></div><div><font face="courier new, monospace"><font color="#000000"><div class="gmail_default" style="font-family:'courier new',monospace;font-size:small;color:rgb(0,0,0);display:inline">
Any idea ?</div>
<br></font></font><div class="gmail_default"><div style="font-family:'courier new',monospace;font-size:small"><br></div></div>
</div></div><div class="gmail_extra"><br clear="all"><div><div><font><b><br></b></font></div><div><font><b><img src="http://s14.postimage.org/sg1lztqep/cloudbuilders_Logo_last_small.png" width="96" height="58"><br></b></font></div>
<font><b>Alejandro Comisario <br>
#melicloud CloudBuilders</b></font><br>
<font color="#666666"><span style="font-size:6pt;color:gray" lang="ES">Arias 3751, Piso 7 (C1430CRG) <br>
Ciudad de Buenos Aires -
Argentina<br>
Cel: +549(11) 15-3770-1857<br>
Tel : +54(11) 4640-8443</span></font></div>
<br><br><div class="gmail_quote">On Wed, Jan 15, 2014 at 12:32 AM, Narayan Desai <span dir="ltr"><<a href="mailto:narayan.desai@gmail.com" target="_blank">narayan.desai@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">We don't have a workload remotely like that (generally, we have a lot more demand for bandwidth, but we also generally run faster networks than that as well), but 1k pps sounds awfully low. Like low by several orders of magnitude.<div>
<br></div><div>I didn't measure pps in our benchmarking, but did manage to saturate a 10GE link from a VM (actually we did this on 10 nodes at a time to saturate a 100GE wide area link), and all of those settings are here:</div>
<div><a href="http://buriedlede.blogspot.com/2012/11/driving-100-gigabit-network-with.html" target="_blank">http://buriedlede.blogspot.com/2012/11/driving-100-gigabit-network-with.html</a></div><div><br></div><div>I'd start trying to do some fault isolation; see if you can get NAT out of the mix, for example, or see if it is a network stack tuning problem. You probably need to crank up some of your buffer sizes, even if you don't need to mess with your TCP windows. </div>
<div><br></div><div>Can you actually saturate your 2x1ge lag with bandwidth? (single or ganged flows?)</div><div> -nld</div></div><div class="gmail_extra"><br><br><div class="gmail_quote"><div><div class="h5">On Tue, Jan 14, 2014 at 3:52 PM, Alejandro Comisario <span dir="ltr"><<a href="mailto:alejandro.comisario@mercadolibre.com" target="_blank">alejandro.comisario@mercadolibre.com</a>></span> wrote:<br>
</div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="h5"><div dir="ltr"><div class="gmail_default" style="font-size:small;font-family:courier new,monospace">
Wow, its kinda hard to imagine we are the only ones that have only 100Mb/s bandwidth but 50.000 requests per minute on each compute, i mean, lots of throughput, almost none bandwith.</div>
<div class="gmail_default" style="font-size:small;font-family:courier new,monospace"><br></div><div class="gmail_default" style="font-size:small;font-family:courier new,monospace">Everyone has their networking performance figured out ?</div>
<div class="gmail_default" style="font-size:small;font-family:courier new,monospace">No one to share some "SUPER THROUGHPUT" sysctl / ethtool / power / etc settings on the compute side ?</div><div class="gmail_default" style="font-size:small;font-family:courier new,monospace">
<br></div><div class="gmail_default" style="font-size:small;font-family:courier new,monospace">Best regards.</div><div class="gmail_extra"><br clear="all"><div><div><font><b><div class="gmail_default" style="font-size:small;display:inline;font-family:'courier new',monospace">
alejandrito</div></b></font></div></div><div><div><br><div class="gmail_quote">On Sat, Jan 11, 2014 at 4:12 PM, Alejandro Comisario <span dir="ltr"><<a href="mailto:alejandro.comisario@mercadolibre.com" target="_blank">alejandro.comisario@mercadolibre.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div style="font-size:small;font-family:'courier new',monospace">Well, its been a long time since we use nova with KVM, we got over the many thousand vms, and still, something doesnt feel right.</div>
<div style="font-size:small;font-family:'courier new',monospace">We are using ubuntu 12.04 kernel 3.2.0-[40-48], tuned sysctl with lots of parameters, and everything ... works, you can say, quite well.</div>
<div style="font-size:small;font-family:'courier new',monospace"><br></div><div style="font-size:small;font-family:'courier new',monospace">
But here's the deal, we have an special networking scenario that is, EVERYTHING IS APIS, everything is throughput, no bandwidth.</div><div style="font-size:small;font-family:'courier new',monospace">
Every 2x1Gb bonded compute node, doesnt get over the [200Mb/s - 400Mb/s] but its handling hundreds of thousands requests per minute to the vms.</div><div style="font-size:small;font-family:'courier new',monospace">
<br></div><div style="font-size:small;font-family:'courier new',monospace">And once in a while, gives you the sensation that everything goes to hell, timeouts from aplications over there, response times from apis going from 10ms to 200ms over there, 20ms delays happening between the vm ETH0 and the VNET interface, etc.</div>
<div style="font-size:small;font-family:'courier new',monospace">So, since its a massive scenario to tune, we never kinda, nailedon WHERE TO give this 1, 2 or 3 final buffer/ring/affinity tune to make everything work from the compute side.</div>
<div style="font-size:small;font-family:'courier new',monospace"><br></div><div style="font-size:small;font-family:'courier new',monospace">
I know its a little awkward, but im craving, and jaunting for community real life examples regarding "HIGH THROUGHPUT" tuning with KVM scenarios, dark linux or if someone can help me go through configurations that might sound weird / unnecesary / incorrect.</div>
<div style="font-size:small;font-family:'courier new',monospace"><br></div><div style="font-size:small;font-family:'courier new',monospace">
For those who are wondering, well ... i dont know what you have, lets start with this.</div><div style="font-size:small;font-family:'courier new',monospace"><br></div><div style="font-size:small;font-family:'courier new',monospace">
COMPUTE NODES (99% of them, different vendors, but ...)</div><div style="font-size:small;font-family:'courier new',monospace">* 128/256 GB of ram</div><div style="font-size:small;font-family:'courier new',monospace">
* 2 hexacores with HT enabled</div><div style="font-size:small;font-family:'courier new',monospace">* 2x1Gb bonded interfaces (want to know the more than 20 models we are using, just ask for it)</div>
<div style="font-size:small;font-family:'courier new',monospace">* Multi queue interfaces, pined via irq to different cores</div><div style="font-size:small;font-family:'courier new',monospace">
* ubuntu 12.04 kernel 3.2.0-[40-48]</div><div style="font-size:small;font-family:'courier new',monospace">* Linux bridges, no VLAN, no open-vswitch</div><div style="font-size:small;font-family:'courier new',monospace">
<br></div><div style="font-size:small;font-family:'courier new',monospace">I want to try to keep the networking appliances ( TOR's, AGGR, CORES ) as out of the picture as possible.</div>
<div style="font-size:small;font-family:'courier new',monospace">im thinking "i hope this thread gets great, in time"</div><div style="font-size:small;font-family:'courier new',monospace">
<br></div><div style="font-size:small;font-family:'courier new',monospace">So, ready to learn as much as i can.</div><div style="font-size:small;font-family:'courier new',monospace">
Thank you openstack community, as allways.</div><div style="font-size:small;font-family:'courier new',monospace"><br></div><div style="font-size:small;font-family:'courier new',monospace">
alejandrito</div><div><br></div>
</div>
</blockquote></div><br></div></div></div></div>
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