5 ms·
That's why you use multiple providers.
by bitJericho 11y ago
That's why you use multiple providers.
- dsr_ 11y agoSuppose you have multiple providers, but one of them screws up and authoritatively denies the existence of all of your hosts?
- bitJericho 11y agoThat's what you keep an extremely low ttl for.
- Karunamon 11y agoWhich doesn't mean much when a nontrivial amount of ISPs out there don't respect the TTL settings. Source: Days-long service degradation caused by customer ISP's caching bad DNS information well beyond the 10 minute TTL we had set.
- jbaptiste 11y agoEven with multi providers, DNS issues are a cluster fuck.
- bitJericho 11y agoYeah I mean it takes work to do it correctly. I wouldn't call it a cluster fuck.
- takeda 11y agoOnly if you don't know what you're doing. The problem with DNS is that it might work even when it is misconfigured, and misconfiguration is the source of strange issues.
- camikazeg 11y agoI think that we all have areas where we don't know what we're doing. This is one of mine. With all the talk of how obvious/important/easy it is to have a failover in place in case this happens, I'm having trouble finding a good resource about setting up a redundant DNS. Running a droplet on Digital Ocean with Debian and Nginx.
- zaroth 11y agoSounds like we're begging for someone to write a nice blog post for how they set up redundant DNS across multiple providers "the right way"... Sounds like it would hit the front page in short order if anyone is willing to share how they think this should be mitigated, and specifically how to expect common clients to behavior in that case when faced with the various types of outages that may occur!
- vidarh 11y agoUnless you use a better resolver than the standard glibc resolver on Linux (e.g. dnsmasq, bind or similar running locally and pointing resolv.conf at it), you appear doomed to slow lookups etc. if your first resolv.conf entry fails, as most of the resolv.conf options that might have helped (if you'd set them) simply don't work or doesn't do anything particularly useful in the versions used in the Linux distro's I've tested it on.
- pbarnes_1 11y agounbound is great for this.
- scurvy 11y agoI'll bite. You can have multiple NS records but only a single SOA. The .com registry minimum TTL for SOA is a day. How in the world would "multiple providers" help you in a 6 hour outage?
- bitJericho 11y agoYou can have multiple NS records. You should have ns records that point to different companies DNS servers, and preferably different continents.
- scurvy 11y agoThat's great for NS records. What about SOA?
- bitJericho 11y agoSoa isn't used for resolving names afaik.
- deleted 11y ago[deleted]
- scurvy 11y agoYou're right. Sorry I meant the NS glue records. Those have a 1 day minimum TTL. If you're not already running multiple providers, switching after one is down won't help much.