[aries-journaled-events] branch master updated: Some ideas for goals and requirements

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The following commit(s) were added to refs/heads/master by this push:
     new f71aaa9  Some ideas for goals and requirements
f71aaa9 is described below

commit f71aaa91cf13a2e6a08140a20e18d8b2a08e4106
Author: Christian Schneider <cs...@adobe.com>
AuthorDate: Mon Dec 31 09:38:50 2018 +0100

    Some ideas for goals and requirements
---
 Readme.md | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/Readme.md b/Readme.md
index 3aea49d..4d5a783 100644
--- a/Readme.md
+++ b/Readme.md
@@ -1,3 +1,21 @@
 # Apache Aries Journaled events
 
 This subproject provides an API (possibly as spec) and backends for journaled streams of events. These extend the publish/subscribe model with means to start consume from an point in the stored event stream history.
+
+## Goals
+
+* Provide traditional publish / subscribe semantics
+* Allow consuming a stream from any point in the history (given it is not yet evicted)
+
+## Non goals (to be discussed)
+
+* No coverage of extreme scaling like Apache Kafka. So no sharding support in the API (like partitions).
+
+## Requirements
+
+* Messages sent to a topic must be journaled and must be available to all consumers
+* Consumers must be able to start consuming messages from any point in the history that is still available
+* If a consumer specifies a position that is not available anymore then it must start with the oldest message
+* Each consumer must receive messages in the same order they were sent
+* The journal of each topic may evict messages that are older than a certain retention time
+