<div dir="ltr">So, I observe a consensus here of "long migrations suck"m +1 to that.<div>I also observe a consensus that we need to get no-downtime schema changes working. It seems super important. Also +1 to that.<br>
</div><div><br></div><div style>Getting back to the original review, it got -2'd because Michael would like to make sure that the benefit outweighs the cost of the downtime. I completely agree with that, so far we've heard arguments from both Jay and Boris as to why this is faster/slower but I think some sort of evidence other than hearsay is needed. Can we get some sort of benchmark result that clearly illustrates the performance consequences of the migration in the long run?</div>
<div style><br></div><div style>-Mike</div><div style><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Thu, Oct 24, 2013 at 4:53 PM, Boris Pavlovic <span dir="ltr"><<a href="mailto:boris@pavlovic.me" target="_blank">boris@pavlovic.me</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">Michael,<div class="im"><div><br></div><div><br></div><div><span style="font-family:arial,sans-serif;font-size:13px">>> - pruning isn't done by the system automatically, so we have to </span><span style="font-family:arial,sans-serif;font-size:13px">assume it never happens</span><br>
</div><div><span style="font-family:arial,sans-serif;font-size:13px"><br></span></div><div><span style="font-family:arial,sans-serif;font-size:13px"><br></span></div></div><div>We are working around it <a href="https://blueprints.launchpad.net/nova/+spec/db-purge-engine" target="_blank">https://blueprints.launchpad.net/nova/+spec/db-purge-engine</a></div>
<div class="im">
<div><br></div><div><br></div><div><br></div><div><span style="font-family:arial,sans-serif;font-size:13px">>> - we need to have a clearer consensus about what we think the maximum</span><br style="font-family:arial,sans-serif;font-size:13px">
<span style="font-family:arial,sans-serif;font-size:13px">>> </span><span style="font-family:arial,sans-serif;font-size:13px">size of a nova deployment is. Are we really saying we don't support</span><br style="font-family:arial,sans-serif;font-size:13px">
<span style="font-family:arial,sans-serif;font-size:13px">>> </span><span style="font-family:arial,sans-serif;font-size:13px">nova installs with a million instances? If so what is the maximum</span><br style="font-family:arial,sans-serif;font-size:13px">
<span style="font-family:arial,sans-serif;font-size:13px">>> </span><span style="font-family:arial,sans-serif;font-size:13px">number of instances we're targeting? Having a top level size in mind</span><br style="font-family:arial,sans-serif;font-size:13px">
<span style="font-family:arial,sans-serif;font-size:13px">>> </span><span style="font-family:arial,sans-serif;font-size:13px">isn't a bad thing, but I don't think we have one at the moment that we</span><br style="font-family:arial,sans-serif;font-size:13px">
<span style="font-family:arial,sans-serif;font-size:13px">>> </span><span style="font-family:arial,sans-serif;font-size:13px">all agree on. Until that happens I'm going to continue targeting the</span><br style="font-family:arial,sans-serif;font-size:13px">
<span style="font-family:arial,sans-serif;font-size:13px">>> </span><span style="font-family:arial,sans-serif;font-size:13px">largest databases people have told me about (plus a fudge factor).</span><br></div><div>
<span style="font-family:arial,sans-serif;font-size:13px"><br>
</span></div><div><span style="font-family:arial,sans-serif;font-size:13px"><br></span></div></div><div><span style="font-family:arial,sans-serif;font-size:13px">Rally </span><font face="arial, sans-serif"><a href="https://wiki.openstack.org/wiki/Rally" target="_blank">https://wiki.openstack.org/wiki/Rally</a></font><span style="font-family:arial,sans-serif;font-size:13px"> should help us to determine this. </span></div>
<div><span style="font-family:arial,sans-serif;font-size:13px"><br></span></div><div><font face="arial, sans-serif">At this moment I can just use theoretical knowledges. </font></div><div><font face="arial, sans-serif">(and they said even 1mln instances in current nova implementation won't work)</font></div>
<div><font face="arial, sans-serif"><br></font></div><div><font face="arial, sans-serif"><br></font></div><div><font face="arial, sans-serif"><br></font></div><div><font face="arial, sans-serif">Best regards,</font></div>
<div>Boris Pavlovic</div><div><br></div></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><br><div class="gmail_quote">On Fri, Oct 25, 2013 at 2:35 AM, Michael Still <span dir="ltr"><<a href="mailto:mikal@stillhq.com" target="_blank">mikal@stillhq.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div>On Fri, Oct 25, 2013 at 9:07 AM, Boris Pavlovic <<a href="mailto:boris@pavlovic.me" target="_blank">boris@pavlovic.me</a>> wrote:<br>
> Johannes,<br>
><br>
> +1, purging should help here a lot.<br>
<br>
</div>Sure, but my point is more:<br>
<br>
- pruning isn't done by the system automatically, so we have to<br>
assume it never happens<br>
<br>
- we need to have a clearer consensus about what we think the maximum<br>
size of a nova deployment is. Are we really saying we don't support<br>
nova installs with a million instances? If so what is the maximum<br>
number of instances we're targeting? Having a top level size in mind<br>
isn't a bad thing, but I don't think we have one at the moment that we<br>
all agree on. Until that happens I'm going to continue targeting the<br>
largest databases people have told me about (plus a fudge factor).<br>
<span><font color="#888888"><br>
Michael<br>
<br>
--<br>
Rackspace Australia<br>
</font></span><div><div><br>
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