  In this research, the system was designed to solve problems related to High
Availability on FDS (Fraud Detection System) servers that cannot be loaded
balanced using the Round Robin method, resulting in changes to ISO 8583
messages. As a result, a method that can be used as High availability to
maintain the Availability of the FDS Server without changing the message
received is required. High availability will be achieved through the Active
Passive Failover method, which will transfer data flows in the event of an
operational failure on the FDS server. The transfer is based on CPU Load
parameters and ISO 8583 messages, which are checked at each stage. The
waterfall method was used in this research. The waterfall is a straightforward
classic model with a linear system flow, with the output of each stage serving
as the input for the next. The primary goals of this research are to ensure
that data in ISO 8583 format can be streamed without changing messages, to
measure the effectiveness of the Active Passive Failover method in performing
High availability using ISO 8583 message parameters and CPU Load, and to
increase the level of Availability and reliability of the FDS Server. This
research's error rate decreased by 0.83%, and the SLA (Service Level Agreement)
increased from 99.13% to 99.96%.
