<div dir="ltr"><div>Hi Eric,<br><br></div><div>Depends on how long you can live without
dynamic updates, and how many dynamic updates it's acceptable to lose
in the event of a master failure. Journal files are synced every 15
minutes, so in the event of a master failure (in a single-master
situation), you've lost at most 15 minutes' worth of updates. Stand up a
new master (with config management software, doable in a few minutes),
and you're good to go.<br></div><div><br>But why have just a single
master? If you're worried about the primary going down, just have a
warm standby ready to go. To keep zone data in sync, you could use
shared storage, a replicated database (BIND does support a database
backend), or perhaps some sort of also-notify configuration. To do the
failover itself, you could use something like Pacemaker/Corosync, ucarp,
or similar. Just pass a VIP back/forth between the two -- your NS
records would only use the VIP.<br><br></div><div>The big issue I see
with converting a slave to a master is that you'd have to change all of
your zone definitions, change your named.conf, and do so under time
pressure. Then, when the master came back online, you'd have to change
your zone definitions again. With config management software, not that
hard to do, but servers are cheap these days -- easier just to create a
failover pair (or group) for your master, then stand up as many slaves
(doing update forwarding) as you need. If you purchase a DNS appliance
(Infoblox, SolidServer, Bluecat, etc.), this is how they handle things.<br><br></div><div>Separate
issue: you might think about trying out RHEL 6 -- it's using a much
newer version of BIND which has some updated tools (particularly rndc
freeze/thaw, HTTP stats interface).<br><br></div>John</div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Sep 11, 2014 at 4:48 AM, <span dir="ltr"><<a href="mailto:Eric.BERTHIAUME.external@banque-france.fr" target="_blank">Eric.BERTHIAUME.external@banque-france.fr</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div link="blue" vlink="purple" lang="FR"><div><p class="MsoNormal"><span lang="EN-US">Hello DNS gurus,<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US">New on the list, I’ve been tasked by my manager to revamp our dns infrastructure. I think this list is the best place to get answers.<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US">Bind 9.3.6-16 running on RHEL5.7<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US">Right now everything run’s on manually editing zone files but we have recently integrated vmware orchestrator (automatic deployment of linux vm’s) in the mix and that complicates things for automated processes. Add Autosys to this and you have one big messy DNS infrastructure and of course no team wants to change their work flows (classic).<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US">So I’ve written a basic script that would allow everyone (admin’s, vmware, autosys) to use dynamic updates with nsupdate for all tasks. Everything works dandy but a simple question remains:<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US">If the primary goes down for whatever reason, how can we quickly continue to update our DNS records on the secondary? What are the options?<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p><u></u><span lang="EN-US"><span>-<span style="font:7.0pt "Times New Roman""> </span></span></span><u></u><span lang="EN-US">Classic slave/master change manually editing the named.conf? What happens to everything in the jnl file on the master if it crashes before the dump and zone transfer? Lost?<u></u><u></u></span></p><p><u></u><span lang="EN-US"><span>-<span style="font:7.0pt "Times New Roman""> </span></span></span><u></u><span lang="EN-US">Nsupdate special ninja trick? Read something about updating the SOA through dynamic update but didn’t fully understand that process.<u></u><u></u></span></p><p><u></u><span lang="EN-US"><span>-<span style="font:7.0pt "Times New Roman""> </span></span></span><u></u><span lang="EN-US">Pray that we get the primary up?<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US">The last option would normally be the logical choice but like I said our DNS infrastructure is a mess and those autosys process control DNS records for their “failover” feature (yeah I know) so we need a super-lightning-fast switch if we do not want production to stop.<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US">Of course the best solution would be something automatic but I haven’t seen anything anywhere. If it’s manual so be it maybe I would be able to write a script that could be used by support and minimize human errors.<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US">I’m already at least pushing for a more recent bind version and of course if a special feature exist (maybe I’ve missed it) that provides an easier solution that would be a super argument to push for something with more features.<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US">Thanks in advance.<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US">Eric<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p></div><p>**************************************************************<br>Ce courrier électronique, y compris les pièces jointes, est à l'attention exclusive des destinataires désignés et revêt un caractère confidentiel.<br>Si vous recevez ce courrier électronique par erreur, merci d'en informer sans délai l'expéditeur et de supprimer son contenu et ses pièces jointes.</p>
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