The importance of avoiding single points of failure

In the aftermath of this huge storm in the USA, a number of web sites I use on a daily basis are either offline or threatening to go offline or operating on reduced functionality. If your business relies on your site and your data being available, you need to make sure that all parts of it can suffer a major event like this and yet continue. That means having failover systems that you can rapidly bring online. In the Postgres world, that means having at least one standby replica that you can activate on very short notice. This replica should be placed either in the cloud or in an alternative data centre, but in either case in some physical location far from where your primary is. For example, if your major data centre is on the east coast, the backup should possibly be on the west coast. There is no excuse these days for not having a good disaster recovery plan. Most large businesses I am familiar with have long learned this lesson, but it's one I have seen ignored many times by smaller and even medium sized businesses. The other thing I have often seen is having a DR plan that's never been tested. That's as bad as having a backup mechanism that's never been tested. Just the other day I saw a business suffer 100% data loss because they had never tested their backups, which turned out to be useless. It's like running with scissors.