[enhancement] investigate looking up multiple root servers instead of waiting on 1

[sonhmai]

          this is one of the root server: a.root-servers.net

https://www.iana.org/domains/root/servers

_Originally posted by @neitomic in https://github.com/neitomic/doh-server/pull/15#discussion_r1659498791_

pub async fn recursive_lookup(socket: &UdpSocket, qname: &str, qtype: QueryType) -> Result<DnsPacket> {
    let mut ns: Ipv4Addr = "198.41.0.4".parse::<Ipv4Addr>()?;

TODO

• investigate looking up multiple root servers instead of waiting on 1.
• benchmark whether it enables better perf: higher throughput, lower latency
• if it does, implement

[neitomic]

What is the strategy? Fire multiple and wait for the first?

[sonhmai]

What is the strategy? Fire multiple and wait for the first?

sounds good. haven't thought about it yet, haha