You can start one or more servers for the same server name. Each of these servers is a server instance. The servers can be started in any address space on any system in the sysplex and each server instance has a server id that uniquely identifies the instance.

A server instance is in essence a task running the XCF Server stub. This routine runs in an infinite loop, suspending when there are no requests to process. When a request arrives, the work unit is resumed, and the XCF Server stub calls the server exit routine to process the request.

The term server can refer to the collection of all the server instances for a particular server name, or it can refer to a single server instance.

The first call to the server is an initialize server request. The server exit routine can perform any suitable initialization. When initialization is complete, XCF starts the XCF Server stub loop, and the server is eligible to process work.