I'm researching for a project whereby a web-hosting solution must be in place that guarantees the highest possible uptime, without fail. This means that cross-site servers are a must, and due to the nature of the project, an Active-Passive setup is the most likely (whereby one site is responsible for hosting, until a fault occurs or a manual intervention is done, at which point the passive site takes over and they switch titles).
The problem I have is that the load balancer is going to be a single point of failure. Now, Digital Ocean did a great article on this, but unfortunately solved the problem using a "floating IP", which is a problem for 2 reasons:
That said, their diagram did perfectly illustrate what I'm trying to achieve (albeit with an internal IP, whereas mine would be public):
One other common solution is to have 2 (or more) load balancers, with a DNS record for each site attached to domain.com, so that every user will have the ability to try every load balancer in case one goes down, however this seems to have its own problems:
Finally another option is to use a virtual IP, however due to the need for the redundant server(s) to be located in a different geographical area, it seems that the same-subnet limitation of virtual IPs makes this approach unsuitable.
Am I missing a fundamental, and commonly known solution to a cross-site solution with no single point of failure? Thanks in advance
The problem I have is that the load balancer is going to be a single point of failure. Now, Digital Ocean did a great article on this, but unfortunately solved the problem using a "floating IP", which is a problem for 2 reasons:
- It's a product, not a technology, so we'd be tied to a provider of said floating IP
- The service responsible for dealing with the floating IP still represents a single point of failure
That said, their diagram did perfectly illustrate what I'm trying to achieve (albeit with an internal IP, whereas mine would be public):
One other common solution is to have 2 (or more) load balancers, with a DNS record for each site attached to domain.com, so that every user will have the ability to try every load balancer in case one goes down, however this seems to have its own problems:
- Some clients will not rotate to the next IP if the first fails
- The timeouts for failing to a 2nd IP can be large
- This approach puts a lot of responsibility on the user
- If a change needs to be made, the TTL of the DNS record becomes important
Finally another option is to use a virtual IP, however due to the need for the redundant server(s) to be located in a different geographical area, it seems that the same-subnet limitation of virtual IPs makes this approach unsuitable.
Am I missing a fundamental, and commonly known solution to a cross-site solution with no single point of failure? Thanks in advance