Buffer and Performance Settings for Transports

This topic explains buffer and performance parameters that are common to several transport protocols.

GUI Parameter JSON Attribute Description
Send Behavior backlog_full_wait This parameter governs the behavior of the transport when the bus is full (that is, it cannot accept any more outbound messages).
Non-Blocking
When the bus is full, the transport holds outbound messages in a backlog buffer in process memory until the bus can accept them.
Blocking
When the bus is full, then the transport blocks send calls in the program.

For more information, see Send: Blocking versus Non-Blocking

Buffer Sizes: Backlog backlog_size Required with non-blocking send.

This parameter determines the size, in bytes, of the backlog buffer. The default value is 64 megabytes.

With zero bytes of backlog buffer, a non-blocking send call immediately discards its message if the transport cannot accept outbound data.

Receive Spin Limit recv_spin_limit This parameter governs blocking behavior of threads when waiting for message data to arrive.

The default value for most transport protocols is 0.0 seconds. However, for shared memory and direct shared memory transports the default value is 0.01 seconds.

Warning: Do not adjust this parameter unless you thoroughly understand the material in Receive Spin Limit.