Latency processing

The simulators can be configured introduce latency, which is used to simulate the amount of time that is taken while interacting with the genuine external services. The latency is controlled on a per simulator basis by the user defined properties (UDP) for the simulator.

User defined property for latency

This property defines a variable amount of latency that is to be introduced by external services during debtor or creditor checks. It is used to simulate the amount of processing time that is used by the external service. The default value is 100 (milliseconds).

User defined property for fixed latency model

This property defines the mode that is used to calculate the latency. It indicates whether the latency is added independently of the IBM® MQ wait time. The default value is TRUE.

Fixed latency mode = TRUE: The latency time is calculated by adding the amount of latency from the UDP value to the amount of time that the compute node of the simulator spent processing. It does not consider the amount of time that the message spent on the input IBM MQ queue or the processing time of the node itself. The effective latency within the compute node of the simulator matches the UDP value. However, the total latency for interacting with the simulator includes the IBM MQ wait time and is usually longer than the value specified in the user defined property.

Fixed latency mode = FALSE: In this mode, the amount of time that the message spent on the input queue of the simulator is calculated. It is the difference between the IBM MQ put time of the message and the current time of the compute node of the simulator. This calculated time is compared to the latency time that is specified in the latency UDP.; If the latency value in the UDP is greater than the amount time that was used by the simulator so far, the simulator node sleeps until the latency time is reached. When the simulator compute node exits, the latency, which includes the processing time used by its compute node and also the amount of time that the message spent on the input queue of the simulator, matches the UDP value.

User defined properties for additional latency

Several simulators have user defined properties that allow the user to add additional latency during processing. These properties are used to cause a timeout to occur during certain stages of processing. The following table shows the properties used to add additional latency for the simulators.

Table 1. Additional latency properties for the simulators
Simulator	User defined properties
Accountancy	Acct_AgtToAddLtcy Acct_AddtlLtcy
Clearing and settlement mechanism for SCTInst	CSM_DbtrAgtToAddLtcy CSM_AddtlLtcy
Clearing and settlement mechanism for TCH	CSM_InstgAgtToAddLtcy CSM_InstgAgtRptRspAddLtcy CSM_AddtlLtcy
Fraud screening	SOF_CrdtAgtToAddLtcy SOF_AddtlLtcy
Sanction screening	SOS_DbtrAgtToAddLtcy SOS_AddtlLtcy

Important: When configuring the additional latency properties, take into consideration that the simulator instance that is processing a message with an additional latency does not receive messages that arrive concurrently. To avoid this, increase the number of additional instances for this simulator.