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From userx <gagan...@gmail.com>
Subject Persistent store and eviction policy.
Date Thu, 10 Aug 2017 02:38:35 GMT
Hi team,

I was going through the documentation of durable memory at

As per the documentation, durable memory comes into picture when
PersistentStore configuration is enabled. Now durable memory uses both
RAM(hot data) and disk (superset). When the RAM part reaches a threshold
(80% by default as per the documentation), the durable data retains only hot
data in RAM and rest on the disk.

So does that mean that there is a default eviction policy which comes into
existence ? Or does the user explicitly has to mention the same in
configuration ? What happens if he does not mention the eviction policy in
configuration ?

Suppose there are 2 nodes N1 (different physical box) and N2 (different
physical box) and the data is distributed in PARTITIONED mode and persistent
store is enabled. 

Here is the example of entries

N1-> "1","X"
N2-> "2","Y"

Suppose N1 crashes and goes down and does not come up at all for say 5
hours. Is "1" retrievable at all during that time if N1 went down after an
entry to its WAL file or we loose N1 ? If say the entry was not able to be
made in WAL file and should we have configured a back up as N3 (different
physical box), would it have saved "1" ?

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