IP Services: Ensure storage availability for ancillary input queue for Enterprise Extender traffic

Description: In z/OS V1R13, the processing of IPAQENET and IPAQENET6 INTERFACE statements is enhanced. Coding the WORKLOADQ parameter on these INTERFACE statements now enables the QDIO inbound workload queueing function for Enterprise Extender (EE) traffic. An additional ancillary input queue (AIQ) is established for inbound traffic for EE if HPR=RTP is specified as a VTAM start option. Each AIQ increases storage utilization by an amount equal to 36K of fixed ECSA, plus potentially the READSTORAGE value (64K multiplied by the number of SBALs) of fixed CSM 4K data space storage. If you have configured QDIO inbound workload queuing, you must ensure that there is sufficient fixed ECSA and 4K CSM dataspace storage for the AIQ for EE traffic.

Element or feature:

Communications Server.

When change was introduced:

z/OS V1R13.

Applies to migration from:

z/OS V1R12.

Timing:

Before installing z/OS V2R1.

Is the migration action required?

No, but recommended if you have the WORKLOADQ parameter specified on the INTERFACE statement and you have concerns about using additional storage.

Target system hardware requirements:

This migration action is required only if you are using OSA-Express3, or later, features on an IBM z Systems server.

Target system software requirements:

None.

Other system (coexistence or fallback) requirements:

None.

Restrictions:

None.

System impacts:

Each AIQ increases storage utilization by an amount equal to 36K of fixed ECSA plus potentially the READSTORAGE value (64K multiplied by the number of SBALs) of fixed CSM 4K data space storage.

Related IBM Health Checker for z/OS check:

None.

Steps to take: Follow these steps:

Verify if you are using EE; you are using EE if HPR=RTP is defined as a VTAM start option and if an EE XCA Major Node is defined and active. If you are using EE, continue with steps 2-5. If you have HPR=RTP defined as a VTAM start option but do not have an EE XCA Major Node defined and active, continue with steps 2, 3 and 5. Otherwise there is no increase in storage usage and no further action is required.
Count the total number of OSA-Express3, and later, interfaces that are coded with the WORKLOADQ parameter on the IPAQENET and IPAQENET6 INTERFACE statements. Make a note of the number.
Verify that sufficient ECSA is available. To do this, multiply the total number of OSA-Express3, and later, interfaces that have inbound workload queueing enabled (you determined this number in step 2) by 36K. The resulting number indicates how much new ECSA is required. Use the DISPLAY CSM command to verify that sufficient ECSA is available to enable this function.
Verify that sufficient real storage is available. 64-bit real storage is used for the dataspace read buffers. Multiply the total number of OSA-Express3, and later, interfaces that have inbound workload queueing enabled (determined in step 2) by 64K and by 126 (8064K). The maximum number of read buffers per queue is 126. The resulting number is approximately the amount of additional 64-bit real storage that is required for the data space read buffers for all the new EE input queues.
If sufficient storage is not available, either increase the available storage or consider defining some of the OSA-Express3, and later, INTERFACE statements with the NOWORKLOADQ parameter.

Reference information: Performance improvements for Enterprise Extender traffic in z/OS V2R1.0 Communications Server: New Function Summary.