Re:Bye Bye Mongo, Hello Postgres
by darkarmani on Thursday December 20, 2018 @01:23PM
(#18727528)
> the whole promise of mongo is/was distributed (HA+LB)
Yes. It is so easy to bring up a mongo cluster and feel like you have HA. Don't worry it won't be proven wrong until you have writes during your cluster degradation and are unlucky.
it works. 4.0 gives you transactions.
it's pretty great.
and, most importantly, as far as I know the default replica set config is safe. (durable, consistent, atomic) it handles a lot of failover scenarios for you automatically. and you have to manually intervene to get into a bad state - which might be okay for that particular business case (better than full downtime)
the whole promise of mongo is/was distributed (HA+LB), which was all the rage back then, when AWS AZs dropped like flies every few weeks and scaling was seen as the problem. go fast, break things was the mantra.
and it's still not trivial to do pgsql maintenance without downtime, whereas in a clustered/distributed "solution", you can enjoy certain additional freedoms. this includes the freedom to shoot yourself in the foot (data inconsistency, but you had to fight a bit for that state by promoting a non latest slave to master).