Web Services Runtime performance is affected by the heap size setting in the MWS Grid node. If the heap size is too low, you will see warnings and errors indicating that the node is low on memory. In this situation, MWS may fail to accept new connections or temporarily go offline.
Optimum heap size is determined by the number of concurrent requests and the actual size of the messages, which depend on the type of programs you run and the amount of data they return. Therefore, you may need to tweak the heap size periodically.
As a starting point, Infor recommends the following:
Modify the heap size for the application node