[Design of JBossCache] - JBCACHE-1154 - Introduce ability to mark nodes as resident -
by mircea.markus
Nodes marked resident would be ignored by the eviction algorithms both when checking whether to trigger the eviction and when proceeding with the actual eviction of nodes. E.g. if the eviction policy for a region is "keep LRU 10 nodes" - the resident nodes won't be counted within those 10 nodes, and also won't be evicted when the threshold is reached.
How to specify whether a node is resident or not?
1. statically only, within the config file. There would be a flag on each node indicating this: Node.isResident.
2. dynamically - having a flag on node that can be set to true (default to false - enforced by backward compatibility). Node.setResident, Node.isResident
3. a combination of 1 and 2
Some notes on static configurations(1&3):
configuration module is on it's way to significantly change, we would like to keep the changes in this area to a minimum; also at the moment is not possible to specify nodes using regexp-like notations (out of scope) so it is a bit restrictive. Any critical requirements to have this implemented at this point?
Other notes:
1.When moving node from one region to another - I think it would make sense to also transfer the value of resident flag rather than reset it to false(fits better to what moving means)
2.Backward compatibility should be assured by having flag's default value set to false.
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17 years, 4 months