System Throttling

dsTest may enact system throttling - regulating the speed of transaction processing - if your test exceeds the licensed transactions-per-second (TPS) available to it or to avoid overloading socket connections when the associated send queues begin to fill, indicating that the peer or network is unable to handle the configured level of transactions.

Three phases of increasing processing delays may be enacted until TPS falls into an acceptable range or until the socket is no longer backlogged.

Phase 1: minor delay of transactions/messages

Phase 2: increased delay of transactions/messages

Phase 3: transactions/messages will be dropped as needed

In the case of throttling due to license restrictions, dsTest allows one second worth of overage per phase. For example, if the configured TPS is 1000, a total of 1000 extra transactions will be allowed in a second before phase 1 is entered. Phase 2 will be entered if the TPS overage exceeds 3000, and phase 3 will be entered at 4000.

In the case of throttling due to socket backlog, please note that throttling may prevent errors from being generated and alerting you to the fact that there is a bottleneck that is preventing you from achieving the TPS configured in your test. You can use the Allow Overrun setting in your socket configuration to prevent throttling and permit the system to maintain the rate defined in your test.

Notifications will indicate any change in the throttling phase, and they will contain three counts for the impacted transactions/messages in each phase:

Throttling Phase 1 entered (0 - phase 1, 0 - phase 2, 0 - phase 3)

Throttling Phase 2 entered (0 - phase 1, 0 - phase 2, 0 - phase 3)

Throttling Phase 3 entered (0 - phase 1, 0 - phase 2, 0 - phase 3)

System Throttling Update: Throttling Clear  (0 - phase 1, 0 - phase 2, 0 - phase 3)

Throttling Clear indicates that the system is not currently throttling after 5 seconds of acceptable TPS.

Refer to the Server Notifications topic for more information on registering for notifications and the types of notifications dsTest generates.