As the article points out, the data gets written to the WAL on the slave before the transaction is committed on the master Then the article is wrong, it doe

As the article points out, the data gets written to the WAL on the slave before the transaction is committed on the master Then the article is wrong, it doesn't. I can reboot or kill the slave and the master will still happily accept transactions. It's also pretty clear from tcpdump that the data only goes on commit, and it's one way from the master->slave.