1.2. The Top Six Differences between MRG Messaging 2 and 3

These are the most significant differences between MRG 2 and MRG 3:
  1. The broker and the C++ messaging library (qpid::messaging) now offer amqp1.0 support via the Apache Proton library (note that transactions are not yet available over amqp1.0).
  2. Clustering has been replaced with a new High Availability implementation.
  3. Queue Threshold alerts are now edge-triggered, rather than level-triggered. This improves alert rate limiting.
  4. The flow-to-disk implementation has been changed to disk-paged queues to more efficiently use memory.
  5. The ring-strict limit policy has been dropped.
  6. The messaging journal has been replaced with a new implementation - the dynamically-expanding Linear Store.