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Problem:
========
180511 11:07:58 [ERROR] Slave I/O: Unexpected master's heartbeat data:
heartbeat is not compatible with local info;the event's data: log_file_name
mysql-bin.000009 log_pos 1054262041, Error_code: 1623
Analysis:
=========
In replication setup when master server doesn't have any events to send to
slave server it sends an 'Heartbeat_log_event'. This event carries the
current binary log filename and offset details. The offset values is stored
within 4 bytes of event header. When the size of binary log is higher than
UINT32_MAX the log_pos values will not fit in 4 bytes memory. It overflows
and hence slave stops with an error.
Fix:
===
Since we cannot extend the common_header of Log_event class, a greater than
4GB value of Log_event::log_pos is made to be transported with a HeartBeat
event's sub-header. Log_event::log_pos in such case is set to zero to
indicate that the 8 byte sub-header is allocated in the event.
In case of cross version replication following behaviour is expected
OLD - Server without fix
NEW - Server with fix
OLD<->NEW : works bidirectionally as long as the binlog offset is
(normally) within 4GB.
When log_pos > UINT32_MAX
OLD->NEW : The 'log_pos' is bound to overflow and NEW slave may report
an invalid event/incompatible heart beat event error.
NEW->OLD : Since patched server sets log_pos=0 on overflow, OLD slave will
report invalid event error.
17 lines
456 B
Text
17 lines
456 B
Text
include/master-slave.inc
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[connection master]
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connection master;
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SET @saved_dbug = @@GLOBAL.debug_dbug;
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SET @@global.debug_dbug= 'd,simulate_pos_4G';
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connection slave;
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include/stop_slave.inc
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CHANGE MASTER TO MASTER_HEARTBEAT_PERIOD=0.001;
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include/start_slave.inc
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connection master;
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SET @@GLOBAL.debug_dbug = @saved_dbug;
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connection slave;
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connection master;
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CREATE TABLE t (f INT) ENGINE=INNODB;
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INSERT INTO t VALUES (10);
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DROP TABLE t;
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include/rpl_end.inc
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