What is the upper limit to the number of "get" statements in a single FTP execution? I would like to get 24 files from a Unix directory to the mainframe in a single job step. The maximum size of any one of the files would approach 100 MB.
There's no technical limit to the number of requests that I'm aware of; it's more a timing issue in how rapidly you make the requests. FTP does require the IP implementation to wait a fixed time after the close of a socket before it can be reused. A large number (more than 1000) of requests can run up against limits in releasing sockets, but 24 files shouldn't push that limit at all. You may possibly run into timeouts WRT firewalls and so on with files of that size, but that's a different animal.
You may want to investigate some of the new products coming out that provide NJE over IP for open systems if you expect to move these files regularly. There seems to be some good tooling coming out, and that opens up a lot of nice options for system management as well as the file transfer functions.