Starting a Sink Machine
To begin SU, you or your system administrator must log onto the sink machine user ID,
load the program that runs SU, and, optionally, disconnect the terminal from the sink
machine.
Syntax: How to Start a Sink Machine
IUCVMAIN [password] [ECHO|STAT|TRACE]
or
FOCUS SU [password] [ECHO|STAT|TRACE] (IUCV [NODISC]
where:
- password
- Is an optional string of up to eight characters. The password is important only for
remotely stopping the sink machine from a source machine. However, it is a positional
parameter, so it must be included in order to specify additional options such as the
ECHO or STAT trace options. ACIGROUP is a special password described in Security
Considerations. A password is needed if you want to use the ECHO/STAT parameters,
which are also positional.
- ECHO
- Records activity in a simple HLIPRINT file. NOECHO disables recording. If no FILEDEF
has been issued for ECHO or STAT, the output goes to the console. If a FILEDEF for
HLIPRINT already exists, this FILEDEF will be honored.
- If the LRECL in the FILEDEF is too short, the output is truncated. If it is too long, the
output will be padded to the specified length, and the additional bytes may contain
extraneous data.
- To avoid problems, make sure the FILEDEF for ECHO specified an LRECL of 88 or the
FILEDEF for STAT specifies and LRECL of 133.
- STAT
- Records activity in an extended HLIPRINT file. NOSTAT disables recording.
- TRACE
- Records activity in an extended HLIPRINT file in addition to activating the traces
described in Tracing Sink Machine Processing. All trace output will go to the console
unless you FILEDEF ddnames FSTRACE and HLIPRINT prior to starting the sink
machine.
- IUCV
- Is required if you use the FOCUS SU command instead of the IUCVMAIN command to
start the sink machine.
- NODISC
- Prevents the server from disconnecting immediately after starting.
You can write your own EXEC to start the sink machine and include other SU commands.
Refer to the REXX EXEC named FOCUSSU EXEC that is shipped with FOCUS.
When the sink machine has started, it will display a list of startup messages that confirm
your options followed a Server started message similar to the following:
Server started. Release: 7.6.4 created 20071114
You can issue SU commands while the server is running. If you want to generate a list of
server commands that you can issue, either press Enter twice or issue the ? query:
?
The following screen displays the list of valid server commands. These commands are
described in subsequent sections:
Available commands:
? - shows this help screen
STOP - soft shutdown (waits for users to exit)
HX - hard shutdown (stops immediately)
GO - resumes normal operation after incomplete STOP
? SERVER - server status (suspended or active)
? USERS - lists active users and opened FCBs
? RELEASE - prints server release level
TRACEON - turns on traces (needs IBITRACE/FSTRACE dds)
TRACEOFF - turns off traces
APPLON - turns on APPL-level traces
APPLOFF - turns off APPL-level traces
Maximum Number of Users
The maximum number of users connected to a sink machine is 512 and is determined by
the directory setting MAXCONN described in Directory Requirements.
There can be a maximum of 4096 open FCBs, but they can reference a maximum of 256
files.
Note: When the number of source machines reaches the maximum allowed, the source
machine will issue the following error message:
(FOC542) SU. COMMUNICATION NOT AVAILABLE TO CENTRAL DATABASE MACHINE
The HLIPRINT file will contain the following message:
(FOC528) SU. TOO MANY FILES OPEN ON THE CENTRAL DATABASE MACHINE