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Because buffers operate on a per-connection basis, for 1:N replication, you must separately specify as many as the number of connections separately.
Memory Buffer
Memory allocated by the kernel is limited in its available capacity. Allocating too much for the system's usable capacity can affect system performance and should be allocated at an appropriate level.
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The file buffer can be allocated as much space as the space on the disk where the file buffer is located. Up to several tens of TBs Tera Bytes can be allocated and can operate at large capacity, typically tens of gigabytes. If a file buffer is configured as a path of the system volume, it is recommended to operate as a separate disk path because file buffer read/write I/O can affect the overall system performance.