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Displaying posts with tag: backup snapshot (reset)
Re-Slaving a Crashed MySQL Master Server in Semisynchronous Replication Setup

In a MySQL 5.7 master-slave setup that uses the default semisynchronous replication setting for rpl_semi_sync_master_wait_point, a crash of the master and failover to the slave is considered to be lossless. However, when the crashed master comes back, you may find that it has transactions that are not present in the current master (which was previously a slave). This behavior may be puzzling, given that semisynchronous replication is supposed to be lossless, but this is actually an expected behavior in MySQL. Why exactly this happens is explained in full detail in the …

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Video: Building a MySQL Slave and Keeping it in Sync

Last night at the Boston MySQL User Group I presented on how to get a consistent snapshot to build a slave, how to use mk-table-checksum to check for differences between masters and slaves on an ongoing basis, and how to use tools such as mk-table-sync and mysqldump to sync the data if there are any discrepancies.

The slides are online at

The video can be watched on youtube at or directly in your browser with the embedded player below:

Showing entries 1 to 2