Design Decision: Near-term target for node HA¶
Background / Context¶
Designing for high availability is a complex task which can only be delivered over an operationally-significant timeline. It is therefore important to determine the target state in the near term as a precursor to longer term outcomes.
1. No HA¶
- Reduces developer distractions.
- No backstop if we miss our targets for fuller HA.
- No answer at all for simple DR modes.
2. Hot-cold (see HA design doc)¶
- Flushes out lots of basic deployment issues that will be of benefit later.
- If stuff slips we at least have a backstop position with hot-cold.
- For now, the only DR story we have is essentially a continuation of this mode
- The intent of decisions such as using a loadbalancer is to minimise code changes
- Distracts from the work for more complete forms of HA.
- Involves creating a few components that are not much use later, for instance the mutual exclusion lock.
Recommendation and justification¶
Proceed with Option 2: Hot-cold.