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An initial MSO Logon request may contain any of the following parameters:
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In this section: Planning for MSO Load Balancing MSO Load Balancing Requirements Consistent Destination Environment Define Load Balancing Group Names to SAF Consistently use the APPLICATION Parameter in All Service Blocks |
The following FOCEXEC lines will retrieve the value that was specified at Logon into the variable, USERPARM.
-SET &USERPARM = MSOINFO('USERPARM','A256');
-TYPE USERPARM IS: &USERPARM
The VTAM user initiates the MSO Logon by entering the VTAM LOGON command and specifying an applid as follows:
The user sees the MSO Logon Screen as shown in the MSO FOCUS Logon Screen. At that time the lower right hand section of the screen displays the default service and application. When Load Balancing is turned on for the region presenting the screen, application is the field that controls the connection possibilities for the user. The default application is the APPLNAME= setting for the first service block in the MSO region that is displaying the screen.
Only one of the fields, SERVICE or APPLICATION may be specified. If there are no entries in these fields, the Logon request is processed using the default application name displayed on the panel. If using Fast Logon with only the userid specified, the MSO Logon Screen is displayed with both the default service and default application names in the input fields. The user should blank out one of these fields, enter any of the other fields they desire and press Enter.
VTAM users may also use a Fast Logon to specify one or more of the fields that appear on the MSO VTAM Logon Screen. The following is the syntax for VTAM fast Logon:
LOGON APPLID(msoapplid) DATA(userid/password/service/account/newpass/group/
application/userparm/applgroup)
Parameters not specified are indicated by a double /. Below is an illustration of a Fast Logon request specifying userid, password, account number, application name, and user information.
LOGON APPLID(MMMMM203) DATA(MYUSR1/PASSWORD//ACCT99476///PAYROLL/YEAREND/MSOGRP1)
TSO users must pre-allocate certain data sets and then invoke the MSUSER module to connect to MSO. See the OS/390 and MVS Installation Guide for a CLIST example that allocates the required data sets.
The MSUSER module may be invoked as a command or via the CALL command. The format for the command invocations is:
MSUSER application,applgroup,service,account,userparm
or
MSUSER 'application,applgroup,service,account,userparm'
The fields are positional and must be specified in the order listed. Skipped fields are represented by null commas. To specify only account and userparm use the following syntax.
MSUSER ',,,ACCT123,USERDATA'
The parameter string must be enclosed in single quotes if initial input fields are skipped. The commas are unconditional field delimiters and may not be specified as part of the data. Single quotes may be included within the data by entering two single quotes. Entering single quotes around a comma insures that the comma is not treated as data.
The format for invoking MSUSER with the CALL command is below. The parameter string must always be enclosed in single quotes. The parameter parsing is the same as described for the command invocation above.
CALL 'prefix.FOCLIB.LOAD(MSUSER)' 'application,applgroup,service,account,userparm'
The Information Builders provided module, MSOCICS, provides the capability of specifying the same four parameters. The format for the command is:
MSO APPL(application_name)|SERVICE(service_name)
APPLGROUP(groupname)
ACCT(account_information)
USERPARM(user_information)
The MSOCICS module must have a CICS transaction ID assigned to it. The screen should be cleared before entering the MSO transaction.
Those installations that call Information Builders MSOCICS transaction from a program must pass the control block structure illustrated below. The CICS-MSO Interface block should be passed in the CICS commarea when the MSO module MSOCICS is invoked via EXEC CICS XCTL. The storage for the second block, CICS - MSO Logon Buffer, should be obtained using EXEC CICS GETMAIN.
Prior to entering data into any of the fields in this structure, the interface block should be initialized to nulls (X'00') and the Log buffer should be initialized to blanks (X'40').
The field contents for these two control blocks are:
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Field Name |
Length |
Type |
Contents |
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func |
4 bytes |
numeric |
1 - signifies MSO Logon |
|
msoname |
4 bytes |
character |
MSO CICS transaction name |
|
logbuff |
4 bytes |
31 bit address |
Pointer to MSO log buffer |
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application |
8 bytes |
character |
Load Balancing application name |
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service |
8 bytes |
character |
Service Block name |
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group name |
8 bytes |
character |
Load Balancing Group name |
|
account |
40 bytes |
character |
MSO account information |
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user parm |
256 bytes |
character |
User information available to executing FOCEXEC |
The most important consideration in planning for Load Balancing is to make sure that when the user arrives at their destination it is where they expected to be. The MSO user expects the characteristics of their environment to be the same every time they Logon with the same application name. Application names are merely addresses to MSO Load Balancing. They are a way of ensuring that the user is serviced by an MSO region that has the application as a valid address. The actual names have no meaning beyond this.
The IBI Subsystem must be active and the MSO program libraries must be APF authorized to support this feature.
When the Load Balancing defaults are set in the IBI Subsystem for the group or application name, it takes effect for all non specific MSO access requests. The initially contacted MSO region, in this case, does not control the Load Balancing Group that the user is placed into.
All MSO regions running the same applications should have the same operating environment. The same application must run identically in each region.
For planning purposes, the following considerations affect the execution characteristics of an MSO region.
Global Allocations
The libraries allocated for FOCUS libraries should be identical. If different Master File allocations are made, for example, then the same application may behave differently.
Profile Data Sets
The need for profile data sets is reduced with the availability of Load Balancing. Profiles tailor the environment when users were logging on to the same MSO region. If used, it is imperative that all MSO regions in a target sub-group have identical profiles for each user. The easiest way to affect this is to allocate the same MSO profile data set.
Configuration Parameters
The following MSO Configuration File parameters affect the execution environment of an MSO region. They should be identical across Load Balancing sub-groups.
EXTSEC
When set to NO, all users have the same security access as the MSO region in which they are executing. When set to YES, each user executes with the established security for the userid.
PRIVATEDD
This parameter affects the logical search order of FOCUS libraries and files.
MSO Exits
Ensures that all MSO exits are identical.
Define Load Balancing APPLGROUP names as entities in the APPL class. There is a SAF READ access check based upon the APPLGROUP name for jobs attempting to start a MSO Load Balancing Region.
The IBM RACF® product does not fail the request for an undefined entity. However, the security check is effectively nullified.
The CA-ACF2® SAF product fails a request for an undefined entity. In this environment, Load Balancing requires defined application names and users with READ access.
When the APPLICATION parameter is introduced into a MSO Load Balancing group all service blocks should have this parameter specified. This avoids confusion resulting from the application name defaulting to the service block name when the parameter is not used.
The MAXIMUM setting in the MSO Configuration File for each MSO region should not be set too low as compared to the amount of virtual storage that is available below and above the 16-megabyte line. This avoids the operational difficulty of having a MSO Logon request denied for a particular region when less then the minimum amount of storage is left above or below the 16m line.
The console provides a look into the MSO region showing very useful information about the MSO users' activities. It is a valuable aid in problem determination.
To make administration easier, keep the number of subsets of MSO regions in an APPLGROUP to a minimum. The less subsetting, the more effectively the Load Balancing algorithm can balance Logons across MSO regions.
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