[SLING-5131] Introduce ConsistencyService to discovery.commons

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: Discovery Commons 1.0.0
• Component/s: Extensions
• Assignee: Stefan Egli
• Reporter: Stefan Egli
• Created: 08/Oct/15 14:24
• Updated: 02/Nov/15 16:49
• Resolved: 08/Oct/15 14:35

Description

As described in SLING-4627 doing any kind of discovery implementation on top of an eventually consistent repository requires synchronization with this very repository in order to ensure all events of an old incarnation of a view are processed before a new incarnation of a view is announced to everybody. Thus a cluster-wide synchronization is required.

Such a synchronization can be achieved fairly straight-forward by storing a well-defined 'sync token' into a location which is known to everybody else in the cluster - and having everybody wait for seeing this token before continuing.

Issue Links

• supercedes: SLING-4627 TOPOLOGY_CHANGED in an eventually consistent repository