mariadb/mysql-test/suite
Julius Goryavsky 2c734c980e MDEV-9519: Data corruption will happen on the Galera cluster size change
If we have a 2+ node cluster which is replicating from an async master
and the binlog_format is set to STATEMENT and multi-row inserts are executed
on a table with an auto_increment column such that values are automatically
generated by MySQL, then the server node generates wrong auto_increment
values, which are different from what was generated on the async master.

In the title of the MDEV-9519 it was proposed to ban start slave on a Galera
if master binlog_format = statement and wsrep_auto_increment_control = 1,
but the problem can be solved without such a restriction.

The causes and fixes:

1. We need to improve processing of changing the auto-increment values
after changing the cluster size.

2. If wsrep auto_increment_control switched on during operation of
the node, then we should immediately update the auto_increment_increment
and auto_increment_offset global variables, without waiting of the next
invocation of the wsrep_view_handler_cb() callback. In the current version
these variables retain its initial values if wsrep_auto_increment_control
is switched on during operation of the node, which leads to inconsistent
results on the different nodes in some scenarios.

3. If wsrep auto_increment_control switched off during operation of the node,
then we must return the original values of the auto_increment_increment and
auto_increment_offset global variables, as the user has set. To make this
possible, we need to add a "shadow copies" of these variables (which stores
the latest values set by the user).

https://jira.mariadb.org/browse/MDEV-9519
2019-02-26 07:45:11 +02:00
..
archive
binlog
binlog_encryption
csv
encryption
engines
federated
funcs_1
funcs_2
galera
galera_3nodes
gcol
handler
heap
innodb
innodb_fts
innodb_gis
innodb_zip
jp
json
large_tests
maria
mariabackup
mtr/t
mtr2
multi_source
optimizer_unfixed_bugs
parts
percona
perfschema
perfschema_stress
plugins
roles
rpl
storage_engine
stress
sys_vars
unit
vcol
wsrep