JBS active agents and JES2 cold start

The concept of active agent is implemented in the TM code by using a binary mask. Each system is represented by a bit in a mask field. If an agent is active on a system, its corresponding bit is turned to one. This allows JBS code to be very effective when it is necessary to find out what systems a particular job can be run on. The correspondence between the bits and the JES2 members depends on the member numbers defined by the JES2 configuration MEMBER statements. The agent mask fields (along with the other agent information) are saved in the TM control file.

If an installation changes JES2 member numbers in the JES2 configuration and cold starts JES2, the existing bits in the saved active agent masks are going to be interpreted differently. The result is that after such a JES2 cold start some agents may become active on the systems they were not initially intended to be active on.

To prevent this issue, we recommend deactivating all JBS agents before implementing such JES2 changes and activating the agents after a JES2 cold start is completed.

To deactivate and activate JBS agents the 'JBS DEACTIVATE ...' and 'JBS ACTIVATE ...' commands can be used. To do this for several agents it could be more convenient to place the commands in a sequential file and to execute them by using a single 'TM BATCH ...' command. Refer to the ThruPut Manager Command-Reference-Guide for more information about the commands.