rocksdb.group_min_max test hangs

rocksdb.group_min_max 'write_prepared'   w1 [ fail ]  timeout after 900 seconds

        Test ended at 2019-07-20 08:48:31

Test case timeout after 900 seconds

== /dev/shm/var/1/log/group_min_max.log == 

d	b	a

d	b	b

select distinct a1,a2,b from t1 where (a2 >= 'b') and (b = 'a');

a1	a2	b

a	b	a

b	b	a

c	b	a

d	b	a

select distinct a1,a2,b,c from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121');

a1	a2	b	c

a	b	a	i121

select distinct a1,a2,b from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c');

a1	a2	b

select distinct b from t1 where (a2 >= 'b') and (b = 'a');

b

a

select distinct a1 from t1 where a1 in ('a', 'd') and a2 = 'b';

a1

a

select distinct a1 from t1 where a1 in ('a', 'd') and a2 = 'e';

 == /dev/shm/var/1/tmp/analyze-timeout-mysqld.1.err ==

mysqltest: Could not open connection 'default' after 500 attempts: 2002 Can't connect to local MySQL server through socket '/dev/shm/var/tmp/1/mysqld.1.sock' (111)