Spider test instability caused by ER_NET_READ_ERROR

spider/bugfix.mdev_27240                 w6 [ fail ]

        Test ended at 2023-08-30 08:48:28

CURRENT_TEST: spider/bugfix.mdev_27240

mysqltest: At line 18: query 'LOCK TABLE tbl_a READ' failed with wrong errno ER_NET_READ_ERROR (1158): 'Got an error reading communication packets', instead of ER_CONNECT_TO_FOREIGN_DATA_SOURCE (1429)...

The result from queries just before the failure was:

for master_1

for child2

for child3

CREATE DATABASE auto_test_local;

USE auto_test_local;

CREATE TABLE tbl_a (a INT KEY) ENGINE=SPIDER;

SELECT a.z FROM tbl_a AS a,tbl_a b WHERE a.z=b.z;

ERROR 42S22: Unknown column 'a.z' in 'field list'

ALTER TABLE tbl_a CHANGE c c INT;

ERROR 42S22: Unknown column 'c' in 'tbl_a'

LOCK TABLE tbl_a READ;