Record new decisions about async content tracker

search-services/alfresco-search/doc/architecture/decisions/0007-message-driven-content-tracker.md

@@ -4,7 +4,7 @@ Date: 09/04/2019
 
 ## Status
 
-Approved
+~~Approved~~ Postponed, see [version 2](0009-message-driven-content-tracker-next-gen.md)
 
 ## Context
 

search-services/alfresco-search/doc/architecture/decisions/0009-message-driven-content-tracker-next-gen.md

@@ -0,0 +1,28 @@
+# Message Driven Content Tracker v2
+
+Date: 05/02/2020
+
+## Status
+
+WIP
+
+## Context
+
+This is a second iteration of content tracking via message bus design. See [previous version](0007-message-driven-content-tracker.md).
+
+New content tracker implementation will be based on new Search Services architecture (SS v2.0 or next gen). Main context behind this decision is almost the same as for v1 - get more throughput by leveraging new Transform Service.
+
+## Decision
+
+The decision is based on [version 1](0007-message-driven-content-tracker.md). The main differences are:
+* Shared File Store may not be the right option as it is only available for Enterprise. Alternatively the URL to content can point to other locations. (TBC)
+* The change in behaviour requires a major release of Search Services, most likely version 2.0.
+* The changes in Content Repository will be available from version 6.3.
+* The synchronous transformation APIs will remain functional until 7.0.
+
+Details of the architecture to be clarified (WIP).
+
+## Consequences
+Additional latency will be introduced due to the extra calls when using the Transform Service. Also the transformation capabilities are much more limited.
+
+This design highlights a major difference in behaviour, which requires a major release of Search Services.