SNA XCOMM0186E SENSE 0835 0017 with DEST member on 2 systems
Article ID: 370895
Updated On:
Products
Issue/Introduction
Using an XCOM SNA transfer and just implemented a standard list of DEST (destination) members for 2 systems XCOMA and XCOMB in a SYSPLEX. Previously they had separate members.
Since doing this problems were encountered using one called XCOM1D (which is a remote XCOM system) which previously was only defined on one of the 2 systems i.e.
XCOMM0186E XCOM1D RC 10 FDBK2 01 SENSE 0835 0017 OPNDST
Disabling the DEST member on XCOMB allows the transfer to work.
XCOM1D is defined as:* * DEST XCOM1D* *************************************** TYPE=DEST GETSESS=YES PARSESS=YES WINNERS=8 LOSERS=8 LU=XCOM1D LOGMODE=XCOMMODE
Environment
XCOM Data Transport for z/OS
Resolution
The XCOM DEST member for XCOM1D is configured to support parallel SNA sessions as evidenced by the keywords PARSESS, WINNERS, and LOSERS.
TYPE=DEST
GETSESS=YES
PARSESS=YES
WINNERS=8
LOSERS=8
LU=XCOM1D
LOGMODE=XCOMMODE
This causes the XCOM instance where the DEST member has been enabled to treat communication with the specified LU (XCOM1D) as an ILU (Independent Logical Unit).
By definition, ILUs are capable of multiple, parallel sessions over the same LU. One of those sessions is pre-defined by SNA protocol to be an SNASVCMG session (SNA Services Manager). This session controls the parallel session limits via the SNA CNOS command.
In order to support an ILU as described above, a reciprocal ILU definition is required on the remote partner. If simply add this DEST PARSESS definition on XCOMB without having that matching ILU definition on XCOM1D, it will fail. The 0835 0017 is a clear indication that one side of the expected ILU connection is not configured correctly. This is an SNA restriction, not XCOM.
Unless an ILU definition is added on XCOM1D for XCOMB similar to what must already exist on XCOM1D for XCOMA, this configuration will not work.
When DISABLE the XCOM1D DEST member on XCOMB, the session reverts to using a DLU (Dependent Logical Unit) which BINDs a single session. That is supported without a DEST member and does not require any definition on the remote XCOM partner system.
In summary the root cause of this problem is that XCOM1D was defined as an ILU (by adding the DEST member) but that was not reciprocated on the partner XCOM.
There are three options to resolve this problem:
- Add the ILU definition for XCOMB on XCOM1D.
- Remove the DEST member from XCOMB.
- Remove the PARSESS, WINNERS, and LOSERS parameters from the DEST member on XCOMB.
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