pg_paxos

Somewhat tangential, but I'm kind of sad that not much more was done with pg_paxos[1]. Group Replication[2] just made it into MySQL 5.7.17 and is GA; it uses a variant of Paxos to commit transactions. Even though most people will probably do fine with streaming replication or semisync, it would be nice to have support in Postgres for use cases that need an even stronger level of consistency. 1: https://github.com/citusdata/pg_paxos 2: http://mysqlhighavailability.com/mysql-group-replication-a-q...

I've written something similar for PostgreSQL using Paxos: https://github.com/citusdata/pg_paxos . It can replicate tables across a set of PostgreSQL servers. pg_paxos is an extension that uses PostgreSQL's query execution hooks so it doesn't require any external components. An advantage of pg_paxos is that you can do reads and writes on any node. Would love to know what people think and whether it's something you would use (if rigorously tested). Small warning: it replicates SQL queries and doesn't stop you from using volatile functions like now() yet, which would give inconsistent results. A possible application is a reliable cron service. Each cron node tries to add an entry to a replicated locks table with the same primary key on any of the PostgreSQL nodes. Only one will succeed and then runs the cron job. Some more details in these