PPDRL: A Pretraining-and-Policy-Based Deep Reinforcement Learning Approach for QoS-Aware Service Composition
Table 1
Six quality criteria for an atomic service.
Quality criterion
Description
Execution price:
represents The fee that a service requester has to pay for invoking .
Execution duration:
measures the expected delay in seconds between the moment when a request is sent and the moment when the results are received.
Availability:
, where is the number of successful invocations of and is the number of total Invocations of , during a constant time interval set by an administrator of the service provider.
Throughput:
, where is the number of total invocations of and is the given time interval.
Successful execution rate:
, where is the number of times that the service has been successfully completed within the maximum expected time frame and is the total number of invocations.
Reliability:
, where is the number of error response messages and is the total response messages.
