OSI/AS SCF Reference Manual

Table Of Contents
OSI/AS Trace Facility
OSI/AS SCF Reference Manual424121-001
3-89
L5 PROVL5 Issue Writeread
SU Name
shows the name by which APS knows this connection.
Session ID
an internal field that shows a sequence number that is assigned to the connection by
this TAPS process.
Request ID
an internal field that shows the address of the buffer that controls the user request
that inspired the attach call.
MCW
an internal field that shows the Message Control Word (MCW). The MCW tells
OSI/TS to issue a transport attach (which is a value of %H8000).
L5 PROV—L5 Issue Writeread
This trace record shows that a NOWAIT file-system writeread has been issued to a
transport subdevice. The FS Error shows the FS result returned. An FS Error of zero
means that the IO initiated correctly. This does not necessarily mean that it will
complete correctly.
L5 PROV—L5 Issue Transport Attach and L5 PROV—L5 Issue Transport Connect are
always followed by L5 PROV—L5 Issue Writeread. The amount of data written for the
message control word (MCW) is always 2 bytes.
An attach, also known as a passive connect, may remain outstanding for a considerable
time if there is no incoming transport connect for the TSAP and NSAP that the attach
represents.
If an attach completes with an error, this may indicate a problem with the configuration
or may indicate that a component of the OSI subsystem has a problem.
A connect, also known as an active connect, completes as soon as the lower layer
components of the subsystem have tried to establish the connection. An error indicates
that the remote OSI transport service provider cannot be contacted.
A Tag value of 7 means that a session loopback connection is being established. A
loopback connect does not involve I/O.
A Tag value of 12 can mean that connection status information is being sought from
transport. This occurs after a transport error or following an attach or connect
completion.
08:20:07.420 >000.000 #66 TAPS L5 PROV
L5 Issue Writeread Su Name #ZMF0021 File ID %H00012278
Tag %H00000002 DCB Addr %H001ADEC6 Write Count 00002 Read Count
00034 FS Error 00000