Replication and Binary Logging Options and Variables slave-start  command line option also sets this system variable. You can use the system variable in place of the command line option to allow access to this feature using MySQL Server’s privilege structure, so that database administrators do not need any privileged access to the operating system. Multithreaded replicas are not currently supported by NDB Cluster, which silently ignores the setting for this variable. See Section 23.6.3, “Known Issues in NDB Cluster Replication” , for more information. This variable works in combination with the  slave_checkpoint_period  system variable in such a way that, when either limit is exceeded, the checkpoint is executed and the counters tracking both the number of transactions and the time elapsed since the last checkpoint are reset. The minimum allowed value for this variable is 32, unless the server was built using  -DWITH_DEBUG , in which case the minimum value is 1. The effective value is always a multiple of 8; you can set it to a value that is not such a multiple, but the server rounds it down to the next lower multiple of 8 before storing the value. ( Exception : No such rounding is performed by the debug server.) Regardless of how the server was built, the default value is 512, and the maximum allowed value is 524280. 3528 • slave_checkpoint_period • slave_checkpoint_group Note Command-Line Format --slave-checkpoint-period=# System Variable slave_checkpoint_period Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 300 Minimum Value 1 Command-Line Format --slave-checkpoint-group=# System Variable slave_checkpoint_group Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 512 Minimum Value 32 Maximum Value 524280 Block Size 8 Sets the maximum number of transactions that can be processed by a multithreaded replica before a checkpoint operation is called to update its status as shown by  SHOW REPLICA | SLAVE STATUS . Setting this variable has no effect on replicas for which multithreading is not enabled. Setting this variable has no immediate effect. The state of the variable applies on all subsequent  START REPLICA | SLAVE  commands.