HP 3000 Manuals HP 3000 Manuals
GLOSSARY artificial member A process that has been explicitly placed in a workgroup via the :ALTPROC command or AIFPROCPUT, instead of naturally meeting the membership criteria of the workgroup. circular scheduling subqueues A name for the CS, DS, and ES scheduling subqueues on systems running version 4.7 or earlier of MPE/iX. These subqueues are considered circular because the priority of processes decays over time, circulating within the bounds of the established base and limit values for the subqueue. For example, a process in the CS subqueue will start at the base priority of 152 and decay towards the limit of 200. At some point, depending upon the boost property set for the subqueue, the process is boosted back to the base priority of 152 to continue execution. CPU scheduling The access a process has to the CPU. The MPE/iX Scheduler allocates CPU time to processes based on their priority. The system manager can control a process' priority (and hence, how much of the CPU it receives relative to other processes) via the creation of workgroups. process A program currently being executed. purge-pending workgroups A workgroup that the system manager has purged (via the PURGEWG command) that still has member processes which have not yet died or migrated to another workgroup. purgescan A review of all processes (scan) that occurs after the system manager issues the PURGEWG command. stream To submit a job for processing, either to begin now or at some specified time in the future. system-defined workgroups The five default workgroups present on all systems running Release 5.0 of MPE/iX: AS_Default, BS_Default, CS_Default, DS_Default, and ES_Default. Each system-defined workgroup corresponds to a traditional scheduling subqueue. The AS_Default workgroup, for example, corresponds to the AS subqueue. system-wide scan A review of all system and user processes to determine their appropriate workgroup membership. A system-wide scan occurs after the system manager alters the existing workgroup configuration, for example, after purging a workgroup. traditional scheduling subqueues The five scheduling subqueues available on systems running Release 4.7 or earlier of MPE/iX. The AS and BS scheduling subqueues are used for non-decayable (i.e. linear) system processes, while the remaining three subqueues, CS, DS, and ES, are used for decayable (i.e. circularly-scheduled) user processes. On MPE/iX 5.0 systems, the traditional scheduling subqueues are replaced by five system-defined workgroups. tune To modify the scheduling characteristics of a subqueue or workgroup. System managers use the :NEWWG command to define scheduling characteristics for new workgroups that they are creating. Subsequently, they can use the :ALTWG command to change (or tune) these characteristics. Or, they can use the :TUNE command (from which the expression "to tune" is derived) to modify the CS, DS, and ES subqueues; that is, the CS_Default, DS_Default, and ES_Default workgroups. user-defined workgroups A workgroup that the system manager creates using the :NEWWG command. All user-defined workgroups have a unique workgroup name, a set of membership criteria (which must include at least one of MEMB_LOGON, MEMB_PROGRAM, or MEMB_QUEUE), and assigned scheduling characteristics (such as base and limit priority, timeslice, CPU percentage bounds, and so on). The system manager creates user-defined workgroups to partition the system workload for greater control over CPU scheduling. workgroups Entities that dictate the behavior of the user processes that belong to them. Membership in a workgroup is dynamic and can be determined by a number of factors, including the logon, program, and scheduling subqueue attribute of the process. On all systems, there are five system-defined workgroups. Using the Workload Manager, system managers can create user-defined workgroups.