4 ms·
Would be interesting to know what these fail over patterns are. As DNS takes a while to propagate, I thought DNS records already indicate fail over addresses.
by omk 5y ago
Would be interesting to know what these fail over patterns are. As DNS takes a while to propagate, I thought DNS records already indicate fail over addresses.
- kayfox 5y agoI think only MX records indicate any priority for each additional record returned, for A records theres no indication of which records have priority over others and the usual behavior of authoritative DNS servers is to rotate the order in which records for the same thing are returned, so effectively returning more than one record for the same question results in a distribution of requests to the IPs returned rather than any sort of failover behavior. In the case of the software Microsoft uses, it monitors endpoints for the websites in question and then changes which IP(s) are returned based on the availability of those endpoints, the geographic region and other factors.
- bombcar 5y agoSome reliability systems change the routing for the IPs instead of updating the DNS as BGP can propagate faster than DNS caching. Priority for A records would a nice feature.