msg_pool_block_size
To lessen the overhead costs associated with malloc and free, the server pre-allocates pools of storage for messages. This parameter determines the behavior of these pools. Performance varies depending on operating system platform and usage patterns.
msg_pool_block_size = size
The size argument determines the approximate number of internal message structs that a block or pool can accommodate (not the number of bytes).
msg_pool_block_size instructs the server to allocate an expandable pool. Each time the server exhausts the pool, the server increases the pool by this size, as long as additional storage is available. The value may be in the range 32 to 65536.
When this parameter is not present, the default is msg_pool_block_size 128.