Zero-downtime deployments possible?

[cormip]

I have my Meteor app running on a pair of AWS EC2 instances behind an ELB. It appears that there's a short period (45-60 seconds?) during deployment that site visitors receive a 503 Bad Gateway error when trying to access the site during deployments.

Is it possible to configure MUP (and the ELB) to perform zero-downtime deployments? I'm not enough of an AWS expert to know if ELB removes a host from service only from health checks or any user-originating request that fails. Or, what it takes for ELB to bring a host back online. It seems this would be key to making it work. The 2nd part would be having MUP perform the update sequentially, where the next instance is updated only once the first instance is upgraded and responding again.

Any insights on how to make this work would be appreciated.

[cormip]

Somehow was not aware of mup-aws-beanstalk plugin, which is exactly what I was looking for.