In order to isolate the Endevor run-time environment from the Mainframe Access address space, and improve the concurrency (and hence scalability) of Endevor accesses, Mainframe Access will schedule the execution of the Endevor API in an independent processing region referred to as an Endevor Dependent Region. This is a special purpose address space that Mainframe Access creates dynamically and shares with all Mainframe Access/Endevor users. It is serially assigned to whatever thread is in need of Endevor API services.
Multiple Endevor dependent regions may be started to meet your throughput requirements. The sample SERVERS member contains a definition for an Endevor address space group that allows a maximum of 2 address spaces to be started for Endevor processing. This value can be increased if the demands of your Endevor usage will benefit from greater concurrency.
You will need to update the started task JCL for dependent regions before you can use the Endevor support. Review the sample JCL member MFAAS and follow the instructions in that member to add your Endevor AUTHLIB and CONLIB program libraries to the STEPLIB concatenation. If you use Processor Groups to compile and relink automatically, specify DYNAMNBR=300 on the EXEC statement and eliminate the pre-allocation of SYSPRINT and SYSTERM which conflict with Endevor procedures to allocate compile and link output files.
For those sites where the logged in users may not have the authority to create transient files using their USERID as the High-Level Qualifier (HLQ), there is a configuration parameter to set that HLQ to some other value where all users have READ/WRITE/ALTER access.
ENDEVOR_DSNQUALIFIER="prefix" --- OVERRIDE FOR ENDEVOR ACCESS
In addition, the Endevor Dependent Region will automatically shutdown after a pre-defined idle period. The default is 30 minutes. This automatic shutdown feature allows Endevor resource allocation to quiesce with non-use, and thereby permits overnight backups to run without manual intervention. This idle period is defined as two scan intervals as specified in the Dependent Region parameter file:
DSS_SCAN_INTERVAL="15" --- idle timeout for shutdown
By default, the Endevor Dependent Region will create a new VIO file (DDNAME=ENDVMSG) to be used as the Endevor transaction log for all subsequent transactions within that dependent region. The DCB attributes are:
PS,FBA,LRECL=133,UNIT=VIO,DISP=(NEW,DELETE),DSN=&MSGLOG
This file will effectively be a memory resident file, buffered by JES. Note that during initialization there is no end-user profile in effect. That means the VIO file will be owned by the started task. Therefore, the started task security profile must allow any end-user to write to this file. Endevor will OPEN the file as the transaction log. This behavior can be taken as the default, or specified by:
VIO_FOR_ENDEVOR_LOG=”1” default VIO
If this causes a security violation at your site, you may configure the log to be disk-resident, provided the HLQ will allow universal READ/WRITE access to the log. To override the default, use:
VIO_FOR_ENDEVOR_LOG=”0” use DISK
Now Mainframe Access will supply overrides to disk as follows:
UNIT=SYSALLDA,DSNAME=prefix.jobname.ASnnnnn.MSGLOG
where the jobname and address space number will ensure uniqueness. The prefix will be taken from the ENDEVOR_ DSNQUALIFIER described above.