aborted query can return successful sql status

[Seppo Jaakola]

It can happen, that a transaction, which was aborted by high priority transaction, will result success code to the client. This seems to happen only when the aborted transaction was in idle state when aborted.

To reproduce, start two nodes use two connections, targeted at separate nodes, and proceed as follows:

mysql-1> create table t (i int) engine=innodb;
mysql-1> insert into t values (1);
mysql-1> begin;
mysql-1> update t set i=2 where i=1;

mysql-2> delete from t where i=1;

mysql-1> commit;

Commit in session 1 will return success code, although transaction was aborted.

[Seppo Jaakola (seppo-jaakola)]

This seems to relate to the retry autocommit feature. If my.cnf has:

wsrep_retry_autocommit=0

, then the problem does not reproduce

[Seppo Jaakola (seppo-jaakola)]

A fix was committed (CS 2957).
Setting BF abort immunity was made too late, and an aborted idle multi-statement transaction could be defined as retry'able. This avoided returning error code. However, retrying did not happen either, just successful return for client.