IEF352I Address Space Unavailable and High Number of Reserved Address Spaces Consumed
 Technote (FAQ)
 
Problem
If you experience the following error:
IEF352I Address Space Unavailable condition and you see that a high number of reserved address spaces are being used this is a hardware problem.
 
Cause
The root cause of this problem stems from the hardware.


Review the MVS® Extended Addressability Guide for an explanation on RSVNONR.
There is a LXSET SYSTEM(YES) macro in the WebSphere® Application Server Daemon. The MVS Extended Addressability guide points out that address spaces that use SYSTEM(YES) on the LXSET will be non-reusable for the life of the IPL.

The WebSphere Application Server Control Regions (CRs) use SYSTEM(NO). However, the RRS address space PC's over to the CRs and the CRs PC over to RRS. Since the WebSphere CR address space IDs are "known" by the RRS address space, these WebSphere CR ASIDs that were brought down will not be reused until RRS (and other resource managers involved) is recycled or you IPL.

This may be a condition more limited to a test system in that in a production system since you are more likely to recycle WebSphere Application Server Control Regions in a test system whereas in production they would be recycled less frequently.

This behavior of reserving ASIDs from reuse is dictated by the current hardware design. The hardware is attempting to prevent a PC into an address space which has been dismantled and reconstructed for some other purpose like a TSO user or OMVS shell.

 
Solution
You can resolve or avoid this problem by doing one of the following:

1. You can increase RSVNONR in your IEASYSxx PARMLIB member. See the MVS Initialization and Tuning Reference for the details. Find a balance between the MAXUSER and RSVNONR parameters in the parmlib member IEASYSxx. If you increase the value of RSVNONR this will increase the number of ASIDs that are available. The combination of MAXUSR, RSVNONR and RSVSTRT must not exceed the maximum number. The balance comes in making sure there is enough CSA storage to handle the numbers you choose. If you make changes to these IEASYSxx settings, you will need to IPL to pick up the changes.

2. The other alternative is to shut down and restart RRS and the other resource managers(DB2®,WebSphere MQ, etc) to allow the ASIDs to be added back to the pool. The WebSphere Application Server for z/OS environment should be stopped also prior to shutting down RRS. You can determine how disruptive this is in your environment.
 
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server for z/OS > Hangs/Performance Degradation
Operating system(s): z/OS
Software version: 6.0.1
Software edition:
Reference #: 1175390
IBM Group: Software Group
Modified date: Aug 31, 2004