PQ76463: MAX_SRS CALCULATION SHOULD INCLUDE DEFAULT TRANSACTION CLASSIFICATION.

APAR status
Closed as documentation error.

Error description
When deploying a new application in a WebSphere for z/OS server,
the customer notices that the application is not available via
a web browser for several minutes after the "Open for Business"
message appears on the console. Traces of the server region show
that the work request from the browser is received and queued to
WLM promptly, but the work request times out before WLM has a
chance to initiate the work in the J2EE server region. This
cycle repeats a few times before WLM manages to give the work
request to the server region. It might take 5 to 10 minutes.
Traces show that the user has defined 2 transaction classes. The
requests coming from the user's browser do not fall within
either of those two classes, and so they are assigned the
"default" transaction class. WLM manages each transaction class
under a different J2EE server region, but the customer had set
MAX_SRS=1. In this case WLM assigned the first transaction class
to the one server region that was up, and when work for a
different transaction class came in, WLM had to wait for the
server region to idle.  After the server region becomes idle it
switches the server region to the other transaction class, and
the work request progresses. Our Operations and Administration
book and the Installation and Customization books tell the user
to calculate MAX_SRS as MIN_SRS times the number of transaction
classes defined. The books make no mention of the default
transaction class, but it should.  MAX_SRS should have been set
to 3 in this case. If it had been set to 3 then this problem
would not have occurred.
Local fix
ensure MAX_SRS is at least equal to the number of defined
transaction classes plus one.
Problem summary
****************************************************************
* USERS AFFECTED: All users of WebSphere Application Server    *
*                 version 4.0.1 for z/OS and OS/390            *
****************************************************************
* PROBLEM DESCRIPTION: MAX_SRS calculation is not correctly    *
*                      documented.                             *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
Need to update three docs to include the correct MAX_SRS
calculation.
Problem conclusion
A change to V4.0.1 WebSphere for z/OS: Installation and
Customization, GA22-7834-07, and V4.0.1 WebSphere for z/OS:
Assembling J2EE Applications, SA22-7836-06, will be available in
the next refresh of the documentation. To access the latest
online documentation, go to the product library page at:

www.ibm.com/software/webservers/appserv/zos_os390/library/

The change is to pages 353 and 331, respectively, which now
read:

MAX_SRS=nn
Specifies the total number of server regions allowed by workload
management to run concurrently in the server's application
environment. That is, workload management will not start more
server regions for a particular application environment than are
specified through this environment variable.
Use this environment variable to limit the number of server
regions created by workload management for a server. The default
is zero, which means there is no limit.
Attention: If you specify MAX_SRS, you must ensure that you
specify a MAX_SRS value that is greater than or equal to the
number of unique service classes you have defined in the WLM
classification rules for WebSphere for z/OS.
Example: MAX_SRS=10
****************************************************************
A change to V4.0.1 WebSphere for z/OS: Operations and
Administration, SA22-7835-05, will be available in
the next refresh of the documentation. To access the latest
online documentation, go to the product library page at:

www.ibm.com/software/webservers/appserv/zos_os390/library/

The change is to page 86, which now reads:

Note: When the WLM configuration is set to no limit, you can
control the maximum and minimum number of server regions by
specifying the environment variables MAX_SRS=x and MIN_SRS=y in
the server?s current.env file. Caution: If you specify MAX_SRS,
you must ensure that you specify a MAX_SRS value that is greater
than or equal to the number of unique service classes you have
defined in the WLM classification rules for WebSphere for z/OS.
Temporary fix Comments
APAR information
APAR number PQ76463
Reported component name WASKBASE
Reported component ID 5655A9801
Reported release 401
Status CLOSED DOC
PE NoPE
HIPER NoHIPER
Submitted date 2003-07-17
Closed date 2003-10-20
Last modified date 2003-10-20

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Fix information

Applicable component levels


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server for z/OS
Operating system(s):
Software version: 401
Software edition:
Reference #: PQ76463
IBM Group: Software Group
Modified date: Oct 20, 2003