4 ms·

If you lose a single instance on RDS and you don't have replication set up, you'll also have downtime. (Maybe not with Aurora?) And +1 to the sibling comment;

If you lose a single instance on RDS and you don't have replication set up, you'll also have downtime. (Maybe not with Aurora?) And +1 to the sibling comment; Fly makes it very clear that single instance postgres isn't HA, and talks about what you need to do architecturally to maintain uptime.

marcinzm 3y ago
Downtime but limited downtime since the data is stored with redundantly across multiple machines in the same AZ. So unless the AZ goes down (which is a different failure than what happened here) you can restart the DB on a different instance pretty quickly and I'm guessing AWS will do it automatically for you. edit: Remove triple as not certain about level of redundancy
- truetraveller 3y ago
  I don't believe their RDS / EBS has 3x redundancy. With SSD, that would be super costly for them. But if that's correct, that would be incredible.
  - marcinzm 3y ago
    May not be 3x but it is replicated so even a total instance failure would not make you lose data: >Amazon EBS volumes are designed to be highly available, reliable, and durable. At no additional charge to you, Amazon EBS volume data is replicated across multiple servers in an Availability Zone to prevent the loss of data from the failure of any single component. For more details, see the Amazon EBS Service Level Agreement. https://aws.amazon.com/ebs/features/#Amazon_EBS_availability_and_durability https://aws.amazon.com/ebs/features/#Amazon_EBS_availability...
williamdclt 3y ago
> Maybe not with Aurora If a read replica fails, I'd expect no downtime (possibly a few errors as connections get cut off abruptly). Although there's always the risk that the remaining instances aren't able to handle the additional load. If the master fails, you'll get a ~2min downtime
api 3y ago
Yeah but you won't lose your data. They have backup infrastructure and EBS is rock solid. Down time is one thing. Data loss is something else.

marcinzm 3y ago

Downtime but limited downtime since the data is stored with redundantly across multiple machines in the same AZ. So unless the AZ goes down (which is a different failure than what happened here) you can restart the DB on a different instance pretty quickly and I'm guessing AWS will do it automatically for you. edit: Remove triple as not certain about level of redundancy

truetraveller 3y ago
I don't believe their RDS / EBS has 3x redundancy. With SSD, that would be super costly for them. But if that's correct, that would be incredible.
- marcinzm 3y ago
  May not be 3x but it is replicated so even a total instance failure would not make you lose data: >Amazon EBS volumes are designed to be highly available, reliable, and durable. At no additional charge to you, Amazon EBS volume data is replicated across multiple servers in an Availability Zone to prevent the loss of data from the failure of any single component. For more details, see the Amazon EBS Service Level Agreement. https://aws.amazon.com/ebs/features/#Amazon_EBS_availability_and_durability https://aws.amazon.com/ebs/features/#Amazon_EBS_availability...

williamdclt 3y ago

> Maybe not with Aurora If a read replica fails, I'd expect no downtime (possibly a few errors as connections get cut off abruptly). Although there's always the risk that the remaining instances aren't able to handle the additional load. If the master fails, you'll get a ~2min downtime

api 3y ago

Yeah but you won't lose your data. They have backup infrastructure and EBS is rock solid. Down time is one thing. Data loss is something else.