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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks Marvin,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Reading the docs[1], the sentence:<o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">“Any keys that hash to the unavailable host will be written or retrieved from a backup host.” kind of leads me to think that session keys are replicated to all
the hosts, if a key that hashes to an unavailable host can be retrieved from a backup host. But what you said makes me think that keys are not replicated across nodes.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Basically, I am trying to figure out if a session is lost when Idp tries to retrieve it from a now unavailable(timing out) node; or is that session available
for retrieval from the backup node?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">-josh
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> users [mailto:users-bounces@shibboleth.net]
<b>On Behalf Of </b>Marvin Addison<br>
<b>Sent:</b> Wednesday, August 23, 2017 12:07 PM<br>
<b>To:</b> Shib Users <users@shibboleth.net><br>
<b>Subject:</b> Re: MemcachedStorage and IdP3<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Wed, Aug 23, 2017 at 1:18 PM O'Dowd, Josh <<a href="mailto:Josh.O%27Dowd@mso.umt.edu">Josh.O'Dowd@mso.umt.edu</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">My question is, in “Redistribute” mode, if the storage piece only writes to one of our 2 nodes, due to a failure on one of them, would a retrieval attempt check both nodes for that
session, since our clients are configured to know about both nodes?<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">No. A node is selected based on a hash function applied to the key; if the selected node is not available, a backup node is selected. If backup node is not available, another backup is chosen and so on until either a functional node is
located or there are no more nodes available. The key is written to or read from the first selected node. If an out-of-service node comes back up, it will be selected in preference to a backup and the read will be served from that node. In any case it's a
first-one-wins approach.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Marvin<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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