Concurrent DML test sometimes failed with a 'Blocks are missing' error

Build tested: 5.5.2-1

Test environment: single server Centos 8 VM

This error does not happen all the time or infrequent. I encountered it one out of few test runs.

The test is part of the Autopilot concurrency.concurDML test.

The following is essentially what the tests does

1. Load a 1g dbt3 database using LDI using cpimport
2. Run queries on all table continuously in the back ground until the update test (next step) is done. The following example is for the supplier table:

select count(*) from supplier where s_suppkey < 0;

select count(*) from supplier where s_comment > 'zzzz';

3. Run update and roll back test concurrently

set autocommit=0;

update supplier set s_suppkey=-1;

update supplier set s_comment='zzzz-1';

rollback;

update supplier set s_suppkey=-2;

update supplier set s_comment='zzzz-2';

rollback;

.

.

.

update supplier set s_suppkey=-100;

update supplier set s_comment='zzzz-100';

rollback;

The idea is that the queries in step 2 should always return 0 rows since auto commit is off and updates always got rolled back. There seem to be some type of timing issue in this concurrency scenario. This test was done on a single VM. I don't know if this issue would occur more frequent in a high speed environment.

The query in step 2 returned the follow error:

ERROR 1815 (HY000) at line 2: Internal error: IDB-2031: Blocks are missing. Alter or drop table in progress?