The AppServer architecture provides potential for improvements in performance, security, and deployment at the expense of server resources. By locating AppServer processes on the same machine as your database server, you might require:
Additional memory (physical and virtual)
Disk space (to locate application code to be run by AppServer agents)
Actual memory requirements that extend beyond database needs vary, depending on the number and configuration of AppServer brokers, AppServer agents, and NameServers, the number of clients to be serviced, the operating mode, as well as the actual ABL procedures to be executed by the AppServer agents, based on a set of hardware guidelines.
You can thus use the following guidelines to help identify physical memory requirements for an AppServer configuration:
AppServer agents — Each AppServer agent adds a minimum of 4MB. For a state-aware or state-reset AppServer, the client connection adds another 100KB.
AppServer brokers — AppServer broker memory depends on the operating system and its message traffic, but might run from about 50MB to 80MB (round numbers). For a stateless or state-free AppServer, each concurrent connected client adds about 100K to broker memory. This reflects concurrent client connections to the broker for stateless operating mode and concurrent client messages handled by the broker for state-free operating mode.
Additional memory (physical and virtual)