H06.16 Release Version Update Compendium

2 Operating System
AF_UNIX Release 2
The AF_UNIX protocol family is used for interprocess communication within a single system.
AF_UNIX Release 2 provides a redesigned implementation of the socket-based interface to this
protocol family. This new design provides a simpler, more reliable implementation that also
provides better compatibility with open systems, backward compatibility with the previous
implementation, and better performance.
Interoperabilty
All systems running this and later RVUs are running AF_UNIX Release 2 software, which
completely replaces AF_UNIX Release 1 software:
• AF_UNIX Release 2 sockets in compatibility mode, which use AF_UNIX Release 1 semantics,
are restricted to communicating with other AF_UNIX Release 2 sockets in compatibility
mode within the same system.
• AF_UNIX Release 2 sockets in portability mode, which use AF_UNIX Release 2 semantics,
are restricted to communicating with other AF_UNIX Release 2 sockets in portability mode
within the same system.
Migration
AF_UNIX Release 2 software completely replaces earlier versions of AF_UNIX Release 1 software.
There is no application migration required for AF_UNIX Release 2. The AF_UNIX Release 1
semantics remain available along with the AF_UNIX Release 2 semantics. AF_UNIX Release 1
semantics are the default semantics. You can choose which semantics to use either
programmatically or by setting the Guardian DEFINE =_AFUNIX_PROCESS_NAME.
AF_UNIX Release 2 software replaces the $ZPLS process pair with a per-processor process,
$ZLSnn, where nn is the processor number.
When migrating to AF_UNIX Release 2:
• If you start $ZPLS in a startup script using the SCF START SERVER command, and failure
to start $ZPLS causes the script to be aborted and steps following the failing one to be omitted,
modify the script to remove the command to start $ZPLS.
• If you use the STARTOSS utility to start OSS processes, modify the
target-volume.ZOSSINS.OSSINFIL file by changing the line
SERVER #ZPLS
to
* SERVER #ZPLS
NOTE: target-volume is normally $SYSTEM.
This prevents the STARTOSS utility from issuing an error during execution.
AF_UNIX Release 2 11