Slave Performance Too Slow With Row Based Events For Table Without Primary Key (Doc ID 2271864.1)

Last updated on DECEMBER 18, 2017

Applies to:

Symptoms

The replication slave SQL thread cannot keep up while processing row based events from the master's binary log. For example:

Changes

Several changes may cause this to start happening, for example:

• A new table without a primary key has been added to the system.
• The primary key was removed from an existing table.
• The binlog_format option was changed from STATEMENT to MIXED or ROW or from MIXED to ROW. See also <Note 1507802.1>.
• Upgrading from MySQL 5.6 or earlier to MySQL 5.7 or later while using the deafult value for binlog_format as the default changed from STATEMENT to ROW.
• The workload changed with binlog_format = MIXED. When the format is set to MIXED, MySQL will automatically use the row based format, if the statement is considered potential non-deterministic.

Cause