Question & Answer
Question
Setting the SYSSMS CTRACE without specifying a COMP= parameter or with a COMP=SSF parameter has the unintended effect of enabling CTRACE processing for many system tasks and jobs.
Cause
The PDSE product is composed of a number of subcomponents. One of these subcomponents, System Services Facility (SSF), is used to implement common system functions. Included in these common system functions is virtual storage management implemented by the SSF Virtual Storage Manager (VSM) sub component. A number of DFSMS components use SSF VSM for cell pool management including PDSE, VSAM RLS, VSAM TFS, DFM, HFS, and CMM.
Other SSF sub components include:
The implementation of a generic SYSSMS CTRACE results in tracing being activated in every address space that uses any of the identified SSF sub components. The result of starting a generic SYSSMS CTRACE is that CTRACE processing is started in what appears to be unrelated address spaces.
Other SSF sub components include:
- Initialization and Termination Control (ITC)
- Application Request Manager (ARM)
- Error Recovery Services (ERS)
- Trace Services (TRC)
- Dump Services (DMP)
- Common Hash Facility(CHF)
- Translation Map Manager (TMM)
- Subcomponent Access Control (SAC)
- Recording Services (RCS)
The implementation of a generic SYSSMS CTRACE results in tracing being activated in every address space that uses any of the identified SSF sub components. The result of starting a generic SYSSMS CTRACE is that CTRACE processing is started in what appears to be unrelated address spaces.
Answer
CTRACE has two initialization parameters that can be used to limit tracing to identified jobs or ASIDs.
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ASID=(nnnn[,nnnn]...) Specifies the address space identifiers (ASIDs) of address spaces to be used as a filter for tracing. Events in these ASIDs are to be recorded by the component trace.
The parameter contains a list of 0 to 16 hexadecimal ASIDs separated by commas. An empty ASID list, ASID=(), turns off filtering by address spaces. In the ASID parameter, list all address spaces to be traced; address spaces specified for previous traces are not traced unless listed.
JOBNAME=(name[,name]...) Specifies the names of jobs to be used as a filter for tracing. Events in these jobs are to be recorded by the component trace. Events in these jobs are to be recorded by the component trace.
The parameter contains a list of 0 to 16 job names separated by commas. An empty job list,
JOBNAME=(), turns off filtering by jobs. In the JOBNAME parameter, list all jobs to be traced; jobs specified for previous traces are not traced unless listed.
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Including one of the two parameters limits the scope the CTRACE and avoid the situation of starting the CTRACE for what might appear to be unrelated JOBS or address spaces.
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ASID=(nnnn[,nnnn]...) Specifies the address space identifiers (ASIDs) of address spaces to be used as a filter for tracing. Events in these ASIDs are to be recorded by the component trace.
The parameter contains a list of 0 to 16 hexadecimal ASIDs separated by commas. An empty ASID list, ASID=(), turns off filtering by address spaces. In the ASID parameter, list all address spaces to be traced; address spaces specified for previous traces are not traced unless listed.
JOBNAME=(name[,name]...) Specifies the names of jobs to be used as a filter for tracing. Events in these jobs are to be recorded by the component trace. Events in these jobs are to be recorded by the component trace.
The parameter contains a list of 0 to 16 job names separated by commas. An empty job list,
JOBNAME=(), turns off filtering by jobs. In the JOBNAME parameter, list all jobs to be traced; jobs specified for previous traces are not traced unless listed.
________________________________________________________________
Including one of the two parameters limits the scope the CTRACE and avoid the situation of starting the CTRACE for what might appear to be unrelated JOBS or address spaces.
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Document Information
Modified date:
03 September 2021
UID
isg3T1011117