The following information is from Microsoft SA Support
On the Newsfeed section of MySite we can see the posts added by colleagues and events on different entities we follow. Newsfeed functionality is supported by Distributed Cache service. The feeds are stored on distributed cache and displayed from it.
There are some settings on User Profile application related to feed cache:
FeedCacheTTLHours, FeedCacheLastModifiedTimeTtlDeltaHours, FeedCacheObjectCountLimit, FeedCacheRoomForGrowth.
FeedCacheTTLHours controls which is the oldest post displayed on Newsfeed. The value is in hours with a default of 168 (7 days).
$upa = Get-SPServiceApplication | where {$_.TypeName -Like "User Profile Service Application"} $upa.FeedCacheTTLHours = 96 $upa.Update()
After we modify the value we need to unload the application domain that hosts the FeedCacheService.svc (on IIS check under "SharePoint Web Services" the site containing the UPA services). We can recycle the corresponding application pool or just execute an iisreset. We need to perform this on all servers that hosts UPA services (servers where "User Profile Service" service is started).
If we use a value greater than 168 the PowerShell command will execute and the setting will be validated but will not be effective. That is because the "time to live" value for feed cache is hard coded to 7 days. So the cached entries will expire after 7 days.
