Hi!

Ignite 2.x has a mechanism called page eviction
<https://apacheignite.readme.io/v2.6/docs/evictions#section-off-heap-memory>.
It's configured using DataRegion#pageEvictionMode
<https://ignite.apache.org/releases/latest/javadoc/org/apache/ignite/configuration/DataRegionConfiguration.html#setPageEvictionMode-org.apache.ignite.configuration.DataPageEvictionMode->
.
Page eviction removes entries from a data region until either
DataRegionConfiguration#evictionThreshold
<https://ignite.apache.org/releases/latest/javadoc/org/apache/ignite/configuration/DataRegionConfiguration.html#setEvictionThreshold-double->
is
reached,
or DataRegionConfiguration#emptyPagesPoolSize
<https://ignite.apache.org/releases/latest/javadoc/org/apache/ignite/configuration/DataRegionConfiguration.html#setEmptyPagesPoolSize-int->
pages
are available in the free list.
It's applied only when persistence is disabled. Otherwise data is just
spilled to disk.

Ignite 1.x has a different kind of eviction, since it doesn't have page
memory nor data regions.
It removes data until occupied memory is bellow LruEvictionPolisy#maxSize
<https://ignite.apache.org/releases/1.9.0/javadoc/org/apache/ignite/cache/eviction/lru/LruEvictionPolicy.html#setMaxSize(int)>
.
This is similar to on-heap eviction policy
<https://apacheignite.readme.io/v2.6/docs/evictions#section-on-heap-cache>
in Ignite 2.x, but you don't need to use it
unless you know exactly what you're doing and what an on-heap cache is.

Denis

пт, 2 нояб. 2018 г. в 21:35, HEWA WIDANA GAMAGE, SUBASH <
[email protected]>:

> Hi all,
>
> This is to understand how eviction works in Ignite cache.
>
>
>
> For example, let’s say the LRU eviction policy is set to max 100MB. Then,
> when the cache size reached 100MB, how much of LRU entries will get evicted
> ? Is there any low water mark/percentage ? Like eviction policy will remove
> 20% of the cache, and then let it again reach back to 100MB to clean up
> again.
>
>
>
> Also please confirm whether the behavior is same in Ignite 1.9 vs 2.6.
>

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