[roskilli]

Curious: What is your strategy on replication? Is it some form of synchronous replication or asynchronous (i.e. active/passive with potential for data loss in event of hard loss of primary)? Also curious why you might look at UDP replication given unless using a protocol like QUIC on top of it, UDP replication would be inherently lossy (i.e. not even eventually consistent).

[bluestreak]

The strategy is to multicast data to several nodes simultaneously. Data packets are sequence to allow receiver identify data loss. When loss is detected receiver finds breathing space to send a NACK. The packet and the nack would identify missing data chunk with O(1) complexity and sender then re-sends. Overall this method is lossless and avoids overhead of contacting nodes individually and sending same data over the network multiple times. This is useful in scenarios where several nodes participate in query execution and getting them up to date quickly is important.

[judofyr]

This reminds me a bit of Aeron (https://github.com/real-logic/aeron) which is a reliable UDP uni/multicast transport library with built-in flow control. It's written in Java and seems to have superb performance (I haven't used it myself). Might be an interesting alternative if you don't want to write it all yourself.