Many MVS sites utilize multiple machines in the complex to distribute function and workload. Users of such systems are not usually explicitly aware of the topology of the system. The JES2 multiple access spool facility and MVS sysplex function are two examples of software that connect several machines into a common environment.
Most IOF functions can be executed from any CPU in a complex. For example, any job on the JES2 output queue can be selected and reviewed by IOF from any CPU in the JES2 multiple access spool complex. However, some IOF functions must be executed on a specific CPU. Some examples are:
The MAS command on the IOF Option Menu displays the status of each machine attached to the local Multiple Access Spool (MAS) system. The MAS display is most useful to operators and systems programmers responsible for operation and tuning of the MAS complex.
An IOF server is a task that provides IOF function to an IOF client session running on another CPU. Each site can optionally have one or more IOF servers running on each MVS CPU. IOF servers provide IOF services to users on other CPUs through IOF client sessions.
An IOF client session communicates with an IOF server to perform IOF functions on a remote CPU. An interactive IOF session becomes a client when the AT command is entered. AT starts an IOF server session on another CPU. In the future IOF client sessions may also be possible from OS/2, Windows, UNIX or other platforms.
When an interactive IOF client session displays a panel that was built by an IOF server, the left part of the top line of the display indicates the system name of the server system. The example panel shown below was produced by an IOF server on system T91F. Note that CPU and I/O time used is displayed for jobs running on another CPU.
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The AT primary command is used to start a server session on another CPU. AT can be entered on any IOF panel to initiate a nested IOF session at the remote site.
Once an IOF server session is initiated, subsequent IOF commands are processed by the server. IOF displays are returned to the client session that initiated the server session. To exit from a server session, enter the END command repeatedly, or enter /X to jump to the IOF exit command. Exiting from the server session causes control to be returned to the IOF client session at the point where the remote session was initiated.
AT? is used to determine the names and alias names of remote CPUs that support the server function. The display will include the system id (SYSID) of the remote cpu. Typically, the numbers 1 through n (where n is the highest system number) are used as aliases for the names.
Syntax
AT cpu-name/alias function
cpu-name/alias. The name or alias of the remote server system.
function. Any IOF command or option that can be entered on the IOF Primary Option Menu.
Examples
AT? Determine remote server names.
AT 2 Go to the IOF Option Menu on remote 2.
AT IPO9 PR IOF printer display on IPO9.
AT 4 M IOF Monitor display on remote 4.
AT 2 %CHKOUT Invoke the %CHKOUT REXX exec on remote 2.
The AT line command on the IOF Job List Menu for a running job starts a server session on the CPU where the job is running. The IOF Job List Menu displays the current CPU and I/O time for the running job.
The job can be selected and browsed just as it would be on your original system. Additionally, the sysout data set buffers that have not been written yet to the spool also can be browsed.
AT Line Command on the MAS Display
The AT line command on the IOF MAS display starts a server session on the selected system and produces the MAS display.
The IOF print check (PC) command determines why output will not print by checking sysout characteristics against JES2 printer setup. When printers are attached to a single remote CPU running an IOF server, PC automatically uses the server to check printer status.
When printers are attached to more than one CPU, then the name of the remote system must be entered as a parm to the PC command. To enter a system name, enter PC name as a line command to the left of the item if the name is no more then four characters. If the name is five or more characters, enter menu PC name in the command input area where menu is the menu number of the item to be checked.
The L option on the IOF Option Menu can be used to display the system log for alternate systems. The sysid of the alternate system can be specified on the L command to browse the syslog for that system from the spool data. For example, L 3090 causes the syslog for sysid 3090 to be browsed. This method does not permit browsing the latest syslog data that is still resident in buffers, however, unless sysid 3090 is the current system.
An alternate way to browse syslog for 3090 is to enter AT 3090 L. This starts a server session on the 3090 system and browses the log from that system. Using this method the latest syslog data can be displayed.
To display and control devices and initiators on a remote system 4, enter AT 4 D. The Device Option Menu from system 4 will be displayed. The specific devices or initiators can be displayed from this option menu.
You alternately can enter, AT 4 INIT, to display initiators or AT 4 PR to display printers attached to system 4.