Schedule based auto scaling decider

[mielastic]

Description

Currently Elasticsearch only offers reactive or proactive storage deciders for auto scaling of data nodes. This is a feature request to add a "schedule" based decider to scale up/down based on a set schedule, peak hours, off peak hours etc. This will allow users to setup auto scaling based on predictable load changes so that they can increase or decrease Elasticsearch capacity at specific times.

For example, customer has a very large Elasticsearch cluster, where they experience a regular daily traffic pattern where load increases during regular business hours and declines toward the end of the day. They can configure a scaling schedule that aligns with this pattern to optimize costs and performance. i.e cluster has sufficient capacity to handle the day time peak traffic, but does not over-provision unneeded capacity at other times.

[elasticsearchmachine]

Pinging @elastic/es-distributed-coordination (Team:Distributed Coordination)