Sharding Strategies

Steps

• MongoDB replicaSet - ES Sharded
• Sharded MongoDB - ES Sharded
• Multi-repository

Non Sharded

Infrastructure level sharding

App Level Sharding

Constraints

As much as possible, we want each of the "sharding" step to provide a smooth transition.
In the context of a real-life deployment, it may not be realistic to expect that to go from x Millions to y Billions, we need to fully export/reimport data.

This means that we need to identify:

• migrate MongoDB from simple ReplicaSet to Sharded Cluster
  • https://docs.mongodb.com/manual/tutorial/convert-replica-set-to-replicated-shard-cluster/
• impact of adding shards to an ES cluster

Questions

• Shard MongoDB only on UID?
• Gain from multi-collections in the same MongoDB cluster?
• for ES when do we add shards?
• Should we simply maximize the number of shards from the beginning