AppFabric session state provider - LRU eviction has been disabled for the cache used to store Session - appfabric

Question

I'm using AppFabric to share session between 2 or more different Web Applications.
But I got a problem which said: "Expected the Session item 'FULL_NAME' to be present in the cache, but it could not be found, indicating that the current Session is corrupted. Please verify that LRU eviction has been disabled for the cache used to store Session."
My configuration:
<dataCacheClient>
<hosts>
<host name="CACHE1" cachePort="22233" />
<host name="CACHE2" cachePort="22233" />
<host name="CACHE3" cachePort="22233" />
</hosts>
<machineKey validationKey="C7415df6847D0C0B5146F5605B5973EBD59kjh67EE6414ECD534A95F528F153B6B5F42CFFA9EBF65B2169F7DA5D801C0F9053454A159505253DC687A" decryptionKey="3AE9EE73F1A2781B73DEC6C3fgdgdfD28E0C730284DD314118DA8B" validation="SHA1" decryption="AES" />
<sessionState timeout="40" mode="Custom" customProvider="AFCacheSessionStateProvider">
<providers>
<add name="AFCacheSessionStateProvider" type="Microsoft.Web.DistributedCache.DistributedCacheSessionStateStoreProvider, Microsoft.Web.DistributedCache" cacheName="XXXXX" shareID="YYYYY" retryCount="10" useBlobMode="false" />
</providers>
</sessionState>
is there anyone know what is problem?

Answer 1

It's not the asp.net config you need to check, it's the cache itself.
On a cache host, see the output of the command Get-CacheConfig XXXXX - as the docs say you will see output like this: check the EvictionType:
CacheName : Cache1
TimeToLive : 10 mins
CacheType : Partitioned
Secondaries : 0
IsExpirable : True
EvictionType : LRU
NotificationsEnabled : False
For more information on eviction settings, see the Expiration and Eviction documentation. If your eviction type is not LRU, check cache memory usage, as that page states:
When the memory consumption of the cache service on a cache server
exceeds the low watermark threshold, AppFabric starts evicting objects
that have already expired. When memory consumption exceeds the high
watermark threshold, objects are evicted from memory, regardless of
whether they have expired or not, until memory consumption goes back
down to the low watermark.
There's an expiration troubleshooting page with more info.