[IGNITE-16331] [Extensions] Add implementation of pluggable topology validator.

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Component/s: extensions
• Labels: important
• Ignite Flags: Docs Required, Release Notes Required
• Assignee: Mikhail Petrov
• Reporter: Mikhail Petrov
• Created: 19/Jan/22 09:31
• Updated: 07/Feb/22 14:25
• Resolved: 21/Jan/22 10:53

Description

It is needed to add an implementation of the Ignite plugin to solve the problem of data inconsistency in case of a cluster split into several independent parts due to network problems.

This problem can be solved by providing the guarantee that
after cluster segmentation, no more than one segment can process write requests to all caches.

It is proposed to
1. reuse Ignite topology validation mechanism to block cache writes
2. automatically apply topology validation logic for all caches through CacheTopologyValidatorProvider
3. rely on remaining Ignite baseline nodes in the topology to determine
what segment can continue to process write requests, if any
4. automatically switch state of the segment to READ-ONLY if it is considered as write blocked
5. change segment state to ACTIVE mode to automatically restore write availability to all caches

Issue Links

• is related to: IGNITE-16143 Adds an ability for plugins to provide cache topology validator as extension.
• links to: GitHub Pull Request #86
• links to: TC suite