tree 2fedcc60c736ddaf7a6cb71de3dc6d2388110ef9
parent 60c8bc757cc4184cbd4870bd1c8385c8abf86bb7
author Antonio Barone <syntonyze@gmail.com> 1603729283 +0100
committer Antonio Barone <syntonyze@gmail.com> 1604651451 +0100

Evict cache entries when free space gets low

Chronicle-map cannot expand indefinitely, but only to an upper limit
which is based on the maxBloatFactor.

When the number of possible expansions drops to zero and the percentage
of free space in the last available segment falls under a configurable
threshold (percentageFreeSpaceEvictionThreshold), cold cache entries are
evicted from chronicle-map.

Hot entries are kept in an LRU in-memory cache that holds a configurable
fraction of the cache size.

A cold cache entry is an entry that does not belong to this hot-cache and
thus subject to eviction, in random order.

Bug: Issue 13536
Change-Id: Iaf94a041943fb0680c2e3a222f3adda19915ae19