<div dir="ltr">Thank you for your reply.<div><br></div><div>You replied:</div><div><span style="font-size:12.8px">> With Config1 and Config2 you have 160 hash points per each server (duplicates are removed)</span></div><div><span style="font-size:12.8px"><br></span></div><div><span style="font-size:12.8px">Does that mean</span></div><div><span style="font-size:12.8px">I could just shorten the whole config to</span></div><div><div style=""><span style="font-size:12.8px"> upstream ImageCluster {</span></div><div style=""><span style="font-size:12.8px"> server 10.1.1.1;</span></div><div style=""><span style="font-size:12.8px"> server 10.1.1.2;</span><br></div><div style=""><span style="font-size:12.8px"> server 10.1.1.3;</span><br></div><div style=""><span style="font-size:12.8px"> hash $cachekey consistent;</span><br></div><div style=""><span style="font-size:12.8px"> }</span></div></div><div style=""><span style="font-size:12.8px">and it would be exactly the same and keep the hashes exactly the same as before?</span></div><div style=""><span style="font-size:12.8px"><br></span></div><div style=""><span style="font-size:12.8px">If I wanted to "weight" the servers to all initially weight=4 and then slowly optimize the weightings.</span></div><div style=""><span style="font-size:12.8px">Would it be a good idea to slowly add the weightings as</span></div><div style=""><span style="font-size:12.8px">weight=2 -restart and wait-> weight=3 -restart and wait-> weight=4</span><br></div><div style=""><span style="font-size:12.8px">(the servers have really high load, and sudden changes in hash can cause problems)</span></div><div style=""><span style="font-size:12.8px">or would it be okay to just change at once like</span></div><div style=""><span style="font-size:12.8px"><div> upstream ImageCluster {</div><div> server 10.1.1.1 weight=4;</div><div> server 10.1.1.2 weight=4;</div><div> server 10.1.1.3 weight=4;</div><div><br></div><div> hash $cachekey consistent;</div><div> }</div></span></div><div style=""><span style="font-size:12.8px"><br></span></div><div style=""><span style="font-size:12.8px">Again, thanks for your reply.</span></div><div style=""><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Jan 22, 2016 at 1:05 AM, Roman Arutyunyan <span dir="ltr"><<a href="mailto:arut@nginx.com" target="_blank">arut@nginx.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi,<br>
<div><div class="h5"><br>
> On 21 Jan 2016, at 15:41, highclass99 <<a href="mailto:highclass99@gmail.com">highclass99@gmail.com</a>> wrote:<br>
><br>
> I have a question about "hash $cachekey" consistent;<br>
> Would the following Config 1, Config 2, Config 3 be exactly the same of different?<br>
> i.e. if I swap the configurations would the cache keys stay consistent?<br>
> The reason I am asking is I have a large configuration similar to Config 2 and am not sure it would be "safe" to clean up the order and merge duplicates as weighted config values.<br>
><br>
> Thank you.<br>
><br>
> Would the following be different of the same?<br>
> Config 1:<br>
> upstream ImageCluster {<br>
> server 10.1.1.1;<br>
> server 10.1.1.1;<br>
> server 10.1.1.2;<br>
> server 10.1.1.2;<br>
> server 10.1.1.3;<br>
> server 10.1.1.3;<br>
><br>
> hash $cachekey consistent;<br>
> }<br>
><br>
> Config 2:<br>
> upstream ImageCluster {<br>
> server 10.1.1.2;<br>
> server 10.1.1.2;<br>
> server 10.1.1.1;<br>
> server 10.1.1.1;<br>
> server 10.1.1.3;<br>
> server 10.1.1.3;<br>
><br>
> hash $cachekey consistent;<br>
> }<br>
<br>
</div></div>These two are the same. With consistent hash balancer the order of servers<br>
does not matter.<br>
<span class=""><br>
> Config 3:<br>
> upstream ImageCluster {<br>
> server 10.1.1.1 weight=2;<br>
> server 10.1.1.2 weight=2;<br>
> server 10.1.1.3 weight=2;<br>
><br>
> hash $cachekey consistent;<br>
> }<br>
<br>
</span>This one is different.<br>
<br>
With Config1 and Config2 you have 160 hash points per each server (duplicates are removed).<br>
With Config3 you have 320 points per each server.<br>
<br>
Statistically all configurations are similar.<br>
<br>
--<br>
Roman Arutyunyan<br>
<br>
<br>
<br>
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</blockquote></div><br></div>