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<p class="MsoNormal">I have a problem where I need to be able to do “sticky session” based on some identity, but be able to tell varnish which identity belongs to which backend.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">In my case, I have a value in the request header(oauth token) which should always go to the same backend. I begin by sending the request to a random backend, and if the users session does not live on that backend I get X-Accel-Redirect
header back telling me which backend that request should go to. I can easily do that part using a restart and send the request to the correct one.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">But from then on I want to remember that that specific identity should always go to that given backend.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I’m not aware of being able to store any such mapping inside varnish, so I thought about using the memcached vmod to store the mapping and then looking it up on each request. I have not tried it yet so I’m not sure what the performance
hit will be on that extra memcached lookup per request. But in fact, I think it’s an overkill since all I need is way to access a in memory hashtable within my vcl.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Would it be possible to “control” the client backend director, mapping a specific identity to a backend ?<o:p></o:p></p>
<p class="MsoNormal">Is there a known way to access a hashtable which is shared by the workee threads within a varnish instance, possibly using inline c?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="IS" style="color:#1F497D">Best regards,<o:p></o:p></span></p>
<p class="MsoNormal"><b><span lang="IS" style="color:#1F497D"><o:p> </o:p></span></b></p>
<p class="MsoNormal"><b><span lang="IS" style="color:#1F497D">Oddur Snær Magnússon<o:p></o:p></span></b></p>
<p class="MsoNormal"><span lang="IS" style="color:#1F497D">Senior Programmer </span>
<span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D">| CCP Games | Reykjavík | Iceland</span><span lang="IS" style="color:#1F497D"><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="IS" style="color:#1F497D">:wq<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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