I put a change into master which should probably go into v3, too: https://github.com/FreeRADIUS/freeradius-server/blob/master/src/main/connect... The connection pool re-uses connections based on “most recently used”. But the exact definition of MRU is important. It turns out that “last returned to the pool” is a bad metric. Because the connection could be blocked / slow. And re-using that connection would mean re-using a blocked / slow connection. The solution is to define MRU as “most recently removed from the pool, and returned to the pool”. This change prioritizes connections which are fast. The code is a bit complicated, because it has to keep track of more information. But it should result in systems which are more stable. Alan DeKok.