Definition
Garbage collects messages that have been seen by all members of a cluster. Each member has to store all messages because it may be asked to retransmit. Only when we are sure that all members have seen a message can it be removed from the retransmission buffers. STABLE periodically gossips its highest and lowest messages seen. The lowest value is used to compute the min (all lowest seqnos for all members), and messages with a seqno below that min can safely be discarded.
Note that STABLE can also be configured to run when N bytes have been received (size-based gossipping). This is recommended when sending messages at a high rate, because time based gossiping might accumulate messages faster than STABLE can garbage collect them.
Configuration Example
<pbcast.STABLE desired_avg_gossip="20000" stability_delay="1000" max_bytes="0"></pbcast>
Configuration Parameters
Name | Description |
---|---|
desired_avg_gossip | Average time to send a STABLE message. Default is 20000 msec |
id | Give the protocol a different ID if needed so we can have multiple instances of it in the same stack |
level | Sets the logger level (see javadocs) |
max_bytes | Maximum number of bytes received in all messages before sending a STABLE message is triggered. Default is 0 (disabled) |
name | Give the protocol a different name if needed so we can have multiple instances of it in the same stack |
stability_delay | Delay before stability message is sent. Default is 6000 msec |
stats | Determines whether to collect statistics (and expose them via JMX). Default is true |
See also Protocol Configuration Common Parameters.
Comments