[SLING-12378] Simplify handling of topology changes

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Fix Version/s: Content Distribution Journal Core 0.6.0
• Component/s: Content Distribution
• Assignee: Christian Schneider
• Reporter: Christian Schneider
• Created: 12/Jul/24 07:08
• Updated: 26/Nov/24 11:03

Description

Currently we have a complex system to build a Topology and notify on changes.

• DiscoveryService receives Discovery message
• DiscoveryService calls TopologyViewManager to update State of a subscriber (publish pod in k8s)
• States are kept forever even if the subscriber dies

Then every 5s we create a TopologyView which contains the alive subscribers (reported with TTL).

Then we compute a diff between old and new topology view and call a listener with the diffs. At the end we set the new view as current view.

I propose we remove view and diff and simply notify the listener when we receive a DiscoveryMessage. When asked for the current view we simply compute the view from the alive states.