Cache manager evict buckets when
(i) the total disk utilized by WARM and Cold Buckets exceeds max_cache_size
or
(ii)The current free space for partition falls below eviction_padding+minFreeSpace
max_cache_size Specifies the maximum space, in megabytes, per partition, that the cache can occupy on disk. If this value is exceeded, the cache manager starts evicting buckets.
If max_cache_size=0 it means this feature is not used, and has no maximum size, in this case, the eviction will happen when the $SPLUNK_DB partition's free space drops below eviction_padding+minFreeSpace.
The total cache usage is calculated by the Cache manager as the sum of all NONE hot buckets size.
When $SPLUNK_HOME and $SPLUNK_DB are on different partitions, assuming all of the caches in $SPLUNK_DB will account for disk spaces in that partitions only.
DEBUG on CacheManager shows entries stats for cache manager
07-08-2020 19:19:58.806 +0000 DEBUG CacheManager - The system has freebytes=944143511552 with minfreebytes=471859200000 cachereserve=471859208192 totalpadding=943718408192 buckets_size=0 maxSize=0
07-08-2020 19:19:58.887 +0000 DEBUG CacheManager - The system has freebytes=944141152256 with minfreebytes=471859200000 cachereserve=471859208192 totalpadding=943718408192 buckets_size=0 maxSize=0
Where
- Freebytes>> freeBytes
- Minfreebytes >>minFreeBytes
- Cachereserve >> evictionReservedBytes
- Totalpadding >> minFreeBytes + evictionReservedBytes
- buckets_size >> max_cache_size
