[IGNITE-14198] Define interface for meta storage client

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0-alpha2
• Labels: iep-61 ignite-3
• Assignee: Andrey N. Gura
• Reporter: Andrey N. Gura
• Created: 17/Feb/21 12:56
• Updated: 29/Mar/21 23:39
• Resolved: 29/Mar/21 23:39

Description

Interface for meta storage client should be defined in order to unblock development and unit-testing.

Interface implementation is not needed on this stage.

We need to crystallize the metastorage interface prototype from the IEP to understand how it will be integrated with other system components.

Need to cover:

• Asynchrony aspects
• Possible error codes (connection failure -> unknown result vs Raft failure -> known result, etc)
• Complex multi-updates (aka transactions)
• Watchers. Each node can watch all updates and filter locally or adjust the watched ranges dynamically (consistency is important here)

These interfaces are considered "client" interfaces as they will be available on all nodes in the cluster

Issue Links

• Dependent: IGNITE-14414 Cluster initialization flow
• duplicates: IGNITE-13800 Provide distributed metastorage interface
• is depended upon by: IGNITE-14077 Implement distributed SchemaManager.
• links to: GitHub Pull Request #64