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2 Commits

Author SHA1 Message Date
Brandon Nesterenko
5ab5ff08b0 MDEV-19801: Change defaults for CHANGE MASTER TO so that GTID-based replication is used by default if master supports it
This commit makes replicas crash-safe by default by changing the
Using_Gtid value to be Slave_Pos on a fresh slave start and after
RESET SLAVE is issued. If the primary server does not support GTIDs
(i.e., version < 10), the replica will fall back to Using_Gtid=No on
slave start and after RESET SLAVE.

The following additional informational messages/warnings are added:

 1. When Using_Gtid is automatically changed. That is, if RESET
SLAVE reverts Using_Gtid back to Slave_Pos, or Using_Gtid is
inferred to No from a CHANGE MASTER TO given with log coordinates
without MASTER_USE_GTID.
 2. If options are ignored in CHANGE MASTER TO. If CHANGE MASTER TO
is given with log coordinates, yet also specifies
MASTER_USE_GTID=Slave_Pos, a warning message is given that the log
coordinate options are ignored.

Additionally, an MTR macro has been added for RESET SLAVE,
reset_slave.inc, which provides modes/options for resetting a slave
in log coordinate or gtid modes. When in log coordinates mode, the
macro will execute CHANGE MASTER TO MASTER_USE_GTID=No after the
RESET SLAVE command. When in GTID mode, an extra parameter,
reset_slave_keep_gtid_state, can be set to reset or preserve the
value of gtid_slave_pos.

Reviewed By:
===========
Andrei Elkin <andrei.elkin@mariadb.com>
2022-07-26 13:31:27 -06:00
Sachin Setiya
27664ef29d MDEV-20574 Position of events reported by mysqlbinlog is wrong with encrypted binlogs, SHOW BINLOG EVENTS reports the correct one.
Analysis

Mysqlbinlog output for encrypted binary log
#Q> insert into tab1 values (3,'row 003')
#190912 17:36:35 server id 10221  end_log_pos 980 CRC32 0x53bcb3d3  Table_map: `test`.`tab1` mapped to number 19
# at 940
#190912 17:36:35 server id 10221  end_log_pos 1026 CRC32 0xf2ae5136     Write_rows: table id 19 flags: STMT_END_F

Here we can see Table_map_log_event ends at 980 but Next event starts at 940.
And the reason for that is we do not send START_ENCRYPTION_EVENT to the slave

Solution:-
Send Start_encryption_log_event as Ignorable_log_event to slave(mysqlbinlog),
So that mysqlbinlog can update its log_pos.
Since Slave can request multiple FORMAT_DESCRIPTION_EVENT while master does not
have so We only update slave master pos when master actually have the
FORMAT_DESCRIPTION_EVENT. Similar logic should be applied for START_ENCRYPTION_EVENT.

Also added the test case when new server reads the data from old server which
does not send START_ENCRYPTION_EVENT to slave.

Master Slave Upgrade Scenario.
When Slave is updated first, Slave will have extra logic of handling
START_ENCRYPTION_EVENT But master willnot be sending START_ENCRYPTION_EVENT.
So there will be no issue.
When Master is updated first, It will send  START_ENCRYPTION_EVENT to
slave , But slave will ignore this event in queue_event.
2019-10-08 14:35:34 +05:30