If you are encountering initialization statement errors, you may have to restart JES2 with the LIST option to determine the failure. Initialization statement errors are most readily visible in the LIST output JES2 creates during initialization. To collect additional information about a problem, you should start JES2 traces 1, 2, 3, 6, 7, 11, 12, 13, 17, 18, 19, and 20 before starting JES2. However, you will not be able to start these traces if JES2 performs a hot start. For a loop, if you can determine where the loop is, set a SLIP trap to determine what processing occurred before JES2 started looping. After the first occurrence of the loop, you can determine where the loop is by examining the JES2 entries in the system trace table in the dump and using that information to set the SLIP trap. Start a GTF trace with the TIME=YES and SUB=MSTR parameters. See the following:

• z/OS Problem Management for more information about the system trace table and SLIP traps.
• z/OS MVS Diagnosis: Tools and Service Aids for more information about GTF and GTF traces.
• z/OS MVS System Commands for more information about the SLIP command.