]
Bela Ban commented on JGRP-2172:
--------------------------------
I'm thinking of NB_UFC and NB_MFC: all messages are either directly sent (if we have
enough credits) or queued. The NB_FC flag would not be needed. The max_queue_size (in
bytes) determines how much data can be queued at any given time until a caller thread
blocks.
This means that a sender cannot control the behavior for individual messages; instead the
behavior is the same for all messages and is defined by the choice of flow control
protocol.
Non-blocking flow control
-------------------------
Key: JGRP-2172
URL:
https://issues.jboss.org/browse/JGRP-2172
Project: JGroups
Issue Type: Feature Request
Reporter: Bela Ban
Assignee: Bela Ban
Fix For: 4.0.4
Sending a message through FlowControl (UFC, MFC) should not block if
{{Message.Flag.NB_FC}} (non-blocking flow control) is set.
Instead, the message should be added to a queue (bounded if {{max_size}} > 0, else
unbounded). The max queue size is given in bytes, so we can estimate what the memory
penalty for reaching that size would be (if bounded).
The queued messages are sent when credits arrive. TBD: when credits arrive, should
blocked threads or queued messages be released first?
Non-blocking flow control can be used by both external and internal threads.
If the queue is unbounded, then it is the responsibility of the application (e.g.
Infinispan) to make sure the queue doesn't grow to an untenable size.