A use case where a huge number of entries are added and expire in a short period the reaper is not able to handle that and will have increasing backlog which cause OOM error.

The TRACE messages within the logfiles are
TRACE [org.infinispan.expiration.impl.ClusterExpirationManager] (pool-9-thread-1) Purging data container of expired entries
TRACE [org.infinispan.expiration.impl.ClusterExpirationManager] (pool-9-thread-1) Submitting expiration removal for key WrappedByteArray

which had lifespan of 480000
..... 1,900,000 more
TRACE [org.infinispan.expiration.impl.ClusterExpirationManager] (pool-9-thread-1) Purging data container completed in 15.45 minutes

As shown the reaper run for >15 minutes but the lifespan is set to 480sec==8min so there is a massive overlap and the reaper is not able to delete the entries fast enough from the cache