Failover is documented to not work very well in MongoDB (data loss): http://aphyr.com/posts/284-call-me-maybe-mongodb
On the postgres side RepMgr makes dealing with replication quite easy: https://github.com/2ndQuadrant/repmgr
See also this recent thread on the PostgreSQL mailing list: http://postgresql.nabble.com/Fully-automatic-streaming-repli...
Failures are just a property of distributed systems, some fail in ways that are better for you, some fail in ways that are worse, but sooner or later they all fail. It's a tradeoff which one you choose.
MongoDB loses acknowledged writes in its supposed "highest consistency" mode.
PostgreSQL does not.
That's a pretty fundamental difference, don't you think?
MongoDB is about the last database I'd pick for any given scenario, but I acknowledge that there are people that have a usecase where it might be a good fit because the tradeoffs work out for them.
Bullshit.
I'd love to use PostgreSQL but we don't have resources to manage a decent replica set installation with all the sysop burden..
Quirky bolt-on solutions, and those requiring a contract with EnterpriseDB or others need not apply.
I really don't mean for this to be as snarky as it sounds... I'd really love these features in PostgreSQL along with PLv8, I'd rather use that than MongoDB... unfortunately having a good in the box solution for MongoDB over PostgreSQL is a bigger breaking point than lack of Joins in my use case.