Re: pg_basebackup and replication slots

<div dir="ltr">On 29 July 2015 at 11:43, Andres Freund <span dir="ltr"><<a href="mailto:andres@anarazel.de"
target="_blank">andres@anarazel.de</a>></span>wrote:<br /><div class="gmail_extra"><div
class="gmail_quote"><blockquoteclass="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc
solid;padding-left:1ex">On2015-07-29 09:17:04 +0100, Simon Riggs wrote:<br /><span class="">> On 29 July 2015 at
09:09,Andres Freund <<a href="mailto:andres@anarazel.de">andres@anarazel.de</a>> wrote:<br /> > > The point
ofusing a temporary slot is to not have a<br /> > > leftover slot afterwards, reserving resources. Especially
importantif<br /> > > the basebackup actually failed...<br /> > ><br /> ><br /> > Creating a slot and
thendeleting it if the session disconnects does not<br /> > successfully provide the functionality desired above.<br
/><br/></span>Uh? If you create the slot, start streaming, and then start the<br /> basebackup, it does. It does *not*
guaranteethat the base backup can be<br /> converted into a replica, but it's sufficient to guarantee it can<br />
broughtout of recovery.<br /></blockquote></div><div class="gmail_extra"><br /></div><div class="gmail_extra">Perhaps
weare misunderstanding the word "it" here. "it can be brought out of recovery"?</div><div class="gmail_extra"><br
/></div><divclass="gmail_extra">You appear to be saying that a backup that disconnects before completion is useful in
someway. How so?</div><div class="gmail_extra"><br /></div>If the slot is cleaned up on disconnect, as suggested, then
youend up with half a backup and WAL is cleaned up. The only possible use for slots is to reserve resources (as you
say);the resources will clearly not be reserved if we drop the slot on disconnect. What use is that?<br /></div><div
class="gmail_extra"><br/></div><div class="gmail_extra">-- <br /><div class="gmail_signature"><div dir="ltr"><span
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