[QPID-949] Implement Flow To Disk

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Incomplete
• Affects Version/s: M2.1, M4, 0.5
• Component/s: Broker-J
• Assignee: Robert Godfrey
• Reporter: Marnie McCormack
• Created: 22/Apr/08 18:27
• Updated: 02/Jun/09 09:59
• Resolved: 02/Jun/09 09:55

Description

Currently, the Java Broker can do one of two things with a message it has to deliver:

1. Keep transient messages in memory until delivered
2. Write persistent messages to a message store (like BDB) and keep in memory until delivery complete

This means that the broker is not able to avoid OoM exceptions i.e. send enough messages to the broker, especially if your consumers are not active, and you could bring the broker done once it explodes its available heap.

RG to add more details and design proposal here please

Sub-Tasks

• Move shared state from AMQMessage to QueueEntry: Resolved
• Merge *MessageHandles to AMQMessage: Resolved
• Provide unified message creation mechanism (MessageFactory): Resolved
• Create TransactionLog and RoutingTable interfaces from MessageStore: Closed
• Move reference counting from AMQMessage and Queue classes to TransactionLog: Resolved
• Add new _queue*Memory, _flowed properties to SimpleAMQQueue: Resolved
• Create QueueBacking Interface and FileQueueBacking implementation: Resolved
• Update QueueEntries and AMQMessage to use QueueBacking: Resolved
• Update SimpleAMQQueue to ensure queue remains in defined limits: Resolved
• Update AMQPriorityQueue, potentially creating Purger thread: Resolved
• Create Message Inhaler to restore flowed messages: Resolved
• Add properties to QueueDeclare to enable flow-to-disk extensions: Resolved