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<div class="moz-cite-prefix">On 5/14/17 7:15 PM, Tom Scavo wrote:<br>
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<blockquote type="cite"
cite="mid:CAEtu=dPnOMdP6Db6PT7qtiwLBzqn4tZS2+ha4hASRqowxDdTfg@mail.gmail.com"><br>
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<pre wrap="">3) it's going to expire before the next scheduled refresh
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but how do you know that?</pre>
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Each refresh operation computes the date/time for the next refresh
and schedules it. So the resolver knows it because it decided it.<br>
<br>
<blockquote type="cite"
cite="mid:CAEtu=dPnOMdP6Db6PT7qtiwLBzqn4tZS2+ha4hASRqowxDdTfg@mail.gmail.com"><br>
<pre wrap="">
Well, you just said "next scheduled refresh," but that is a configured
event, right?</pre>
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Well, it's computed, based on both resolver configuration and the
metadata's validUntil and cacheDuration. (None of this is new, nor
has it changed in a long time).<br>
<br>
<br>
<blockquote type="cite"
cite="mid:CAEtu=dPnOMdP6Db6PT7qtiwLBzqn4tZS2+ha4hASRqowxDdTfg@mail.gmail.com">
<pre wrap="">Yeah, I guess so, but that's a bit of a concern. It means that
changing the validity interval on the file may breaking existing
configurations. For example, suppose a federation has the following
characteristics:
</pre>
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Well, nothing is going to "break". This is just about logging a
WARN. And remember that it also logs if the metadata will expire
before the next refresh, so that takes care of the case of some
assumptions changing.<br>
<br>
<br>
<blockquote type="cite"
cite="mid:CAEtu=dPnOMdP6Db6PT7qtiwLBzqn4tZS2+ha4hASRqowxDdTfg@mail.gmail.com">
<pre wrap="">
For the current operation, expirationWarningThreshold might be set to
PT7D (or more). For the future operation, PT3D makes sense.</pre>
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<br>
Well, I personally think both of those are way too long. I think
probably 24 hours is the most that makes sense - unless you really
don't want to get notified and have to do something on a weekend, in
which case maybe it's longer. (But I don't see how IT devops people
can really get away with that these days...) But each person will
have their own requirements. It's really more of an operational
question of how paranoid you want to be.<br>
<br>
<blockquote type="cite"
cite="mid:CAEtu=dPnOMdP6Db6PT7qtiwLBzqn4tZS2+ha4hASRqowxDdTfg@mail.gmail.com">
<pre wrap="">
Clearly PT7D won't work for the future operation. Should deployers be
advised to configure PT3D for the current operation so that they don't
have to reconfigure in the future?
</pre>
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Maybe. But if fundamental assumptions about the metadata publishing
change, then I think many of the config params (e.g. min- and
maxCacheDuration) might have to be revisited by the deployer. We
can't deal with everything.<br>
<br>
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