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If you do not set anything, it is basically a blocking mode. In Blocking mode, it waits until there is enough space in the TX transmission buffer to transmit duplicate data.
The disconnect mode can be set to temporarily relieve the local I/O load by disconnecting the replication connection.
Ahead mode responds to congestion by automatically re-synchronizing when congestion is released by first writing the primary node's I / O to the local disk while maintaining the replication connection and recording the area as out-of-sync. The primary node that is in the Ahead state becomes the Ahead data state compared to the Secondary node. And at this point, the secondary becomes the behind data state, but the data on the standby node is available in a consistent state. When the congestion state is released, replication to the secondary automatically resumes and background synchronization is performed automatically for out-of-sync blocks that were not replicated in the Ahead state. The congestion mode is generally useful in a network link environment with variable bandwidth, such as a wide area replication environment through a shared connection between data centers or cloud instances.
Online Verification
Online Verification is a function that checks the integrity of block-specific data between nodes during device operation. Integrity checks efficiently use network bandwidth and do not duplicate checks.
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