[SLING-10077] Mode to raise events only locally

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Content Distribution Journal Core 0.1.18
• Fix Version/s: Content Distribution Journal Core 0.1.24
• Assignee: Roxana-Elena Balasoiu
• Reporter: Timothee Maret
• Created: 20/Jan/21 10:04
• Updated: 25/Feb/22 14:45
• Resolved: 25/Feb/22 09:12

Description

Currently the o/a/s/d/a/p/queued and o/a/s/d/a/p/distributed events are raised as local events in each author instance of a cluster. Handling those events in each author instance makes sense for use cases that require maintaining a distributed data structure like a cache. However, some use cases like content invalidation, would need to handle the events only once (deduplicate events).

Deduplicating events will be done by leveraging the Sling Discovery API. When deduplicating is set, only the leader instance will sent distributed events.

Prior suggested approach of distributing events through the cluster is not a good option because it could overload the repository due to steady and frequent commits required to support the distribution of events through the cluster.

Issue Links

• incorporates: SLING-10583 Ensure o/a/s/d/a/p/distributed events are raised at least once
• links to: GitHub Pull Request #99