<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; color: rgb(0, 0, 0); font-size: 14px; font-family: Calibri, sans-serif;"><div><div>Brian,</div><div><br></div><div><font face="Calibri,sans-serif">The "last update of RDAP database" event action is analogous to the ">>> Last update of WHOIS database:" field in the Whois output. You may find the definition of this field in section 8 of <a href="https://www.icann.org/resources/pages/registry-agreement-raa-rdds-2015-04-27-en">https://www.icann.org/resources/pages/registry-agreement-raa-rdds-2015-04-27-en</a>.</font></div><div><br></div><div><font face="Calibri,sans-serif">I</font> am going to follow on this with you offline.</div><div><br></div><div>Regards,</div><div>Gustavo</div></div><div><br></div><span id="OLK_SRC_BODY_SECTION"><div style="font-family:Calibri; font-size:11pt; text-align:left; color:black; BORDER-BOTTOM: medium none; BORDER-LEFT: medium none; PADDING-BOTTOM: 0in; PADDING-LEFT: 0in; PADDING-RIGHT: 0in; BORDER-TOP: #b5c4df 1pt solid; BORDER-RIGHT: medium none; PADDING-TOP: 3pt"><span style="font-weight:bold">From: </span> <<a href="mailto:gtld-tech-bounces@icann.org">gtld-tech-bounces@icann.org</a>> on behalf of Brian Mountford via gtld-tech <<a href="mailto:gtld-tech@icann.org">gtld-tech@icann.org</a>><br><span style="font-weight:bold">Reply-To: </span> Brian Mountford <<a href="mailto:mountford@google.com">mountford@google.com</a>><br><span style="font-weight:bold">Date: </span> Thursday, August 11, 2016 at 11:25<br><span style="font-weight:bold">To: </span> "<a href="mailto:gtld-tech@icann.org">gtld-tech@icann.org</a>" <<a href="mailto:gtld-tech@icann.org">gtld-tech@icann.org</a>><br><span style="font-weight:bold">Subject: </span> [gtld-tech] "last update of RDAP database"<br></div><div><br></div><blockquote id="MAC_OUTLOOK_ATTRIBUTION_BLOCKQUOTE" style="BORDER-LEFT: #b5c4df 5 solid; PADDING:0 0 0 5; MARGIN:0 0 0 5;"><div><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><div><div dir="ltr">ICANN RDAP tech folks,
<div><br></div><div>I wanted to comment on an aspect of the ICANN operational profile. 1.4.12, 1.4.13 and 1.5.14 indicate that domains, nameservers and entities should include an event with type "last update of RDAP database". It sounds like you are assuming that the database
will have a timestamp as of which all data are consistent, like a snapshot. Modern distributed databases don't necessarily have such a timestamp. If the database is "eventually consistent" (see
<a href="https://en.wikipedia.org/wiki/Eventual_consistency">https://en.wikipedia.org/wiki/Eventual_consistency</a>), updates to a particular object may not show up in database reads until some time later. Technically, the only guarantee is that the new, updated
value will show up eventually.</div><div><br></div><div>So when we return a "last update time", that doesn't mean that the data being returned in the RDAP response is as fresh as what was written on or before the last update time. The read may lag behind the update. I am going to go ahead and set the last update
time to the current time, because that's when the most recent update could have occurred. But that will not mean that the returned data is current as of that time, because such a guarantee is impossible in an eventually consistent database.</div><div><br></div><div>Thanks.</div><div><br></div><div>Brian</div></div></div></div></blockquote></span></body></html>