Look at the keys, there is content in the cache:
[admin@redis ~]$ redis-cli
127.0.0.1:6379> keys *
(empty list or set)
127.0.0.1:6379> select 1
OK
127.0.0.1:6379[1]> keys *
1) "3d249bbe820535b87213da5a861cfcb7"
2) "d6b1628d4f49ff60eceb20b2c100c80e"
3) "0ce403ee979ec63e5376b831c389e0ab"
4) "a33a845cee6720e8ebab00f23101231d"
5) "12db657833ffc06e30a8683c8bd1294e"
6) "dc1b766a130327bb3832eed829217c28"
7) "efeeb276d6b8787c71a77c0aa468ff86"
8) "549353689543f63254d69caf18ff598d"
9) "c906d2ef55e2686ed1fbee06468faa49"
Flush the cache:
127.0.0.1:6379[1]> flushall
OK
Check the cache again (demonstrating it is cleared):
127.0.0.1:6379> keys *
(empty list or set)
127.0.0.1:6379> select 1
OK
127.0.0.1:6379[1]> keys *
(empty list or set)