<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">
<div><br class="webkit-block-placeholder"></div><div><span class="Apple-tab-span" style="white-space:pre"> </span>[I responded to this off-list because I somehow received a copy in my inbox that didn't include the list]<br class="webkit-block-placeholder"></div><br><div><div>On Jul 4, 2007, at 2:15 , a. wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Isn't it true that a memcached server more likely "goes down" becaouse its machine has been restarted, or the process crashed?</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">So usually you'll end up with an empty server which does not have stale data.</div></span></blockquote><br></div><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "> The scenario we were discussing here was a server going down (causing all requests to go to another server), coming back (writes causing updates to the server that isn't primary), and then going down again (causing stale reads).</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "> It's not the server that went down, but the next server in the list whose freshness is a concern.</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><br class="webkit-block-placeholder"></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><br class="webkit-block-placeholder"></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><span class="Apple-tab-span" style="white-space:pre"> </span>Losing connectivity to a node does cause a failure mode where the secondary was updated, and then the primary comes back with stale data. Sending a flush on reconnect would prevent that from being a problem, but could wreak havoc on your primary data store when a client has a network instability.<br class="webkit-block-placeholder"></div></div><br><div> <span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div>-- </div><div>Dustin Sallings</div><br class="Apple-interchange-newline"></span> </div><br></body></html>