JVM profile statistics

These statistics can be accessed online using the EXEC CICS® COLLECT STATISTICS JVMPROFILE command, and are mapped by the DFHSJRDS DSECT. For programming information about the EXEC CICS COLLECT STATISTICS command, see the CICS System Programming Reference manual.

Statistics for JVM profiles are collected for each JVM profile in each execution key (CICS key and user key), because the same profile can be used to create JVMs in either execution key.

This section contains the following statistics:

JVM profiles: Resource statistics

Table 80. JVM profiles: Resource statistics
DFHSTUP name Field name Description
JVM profile name SJR_PROFILE_NAME is the name of this JVM profile.

Reset characteristic: not reset

 

JVM path name SJR_PROFILE_PATH_NAME is the full HFS path name for this JVM profile.

Reset characteristic: not reset

 

NOT IN THE DFHSTUP REPORT SJR_PROFILE_CLASS_CACHE shows whether JVMs with this JVM profile use the shared class cache.

Reset characteristic: not reset

 

NOT IN THE DFHSTUP REPORT SJR_PROFILE_MODES shows the number of execution keys in which JVMs with this JVM profile can be created (in CICS Transaction Server for z/OS®, Version 3 Release 1, there are two -- CICS key and user key).

Reset characteristic: not reset

 

[Used as column headers] SJR_STORAGE_KEY is the execution key to which these statistics apply (CICS key or user key). A JVM profile can be used to create JVMs for either execution key.

Reset characteristic: not reset

 

Total number of requests for this profile SJR_PROFILE_REQUESTS is the number of requests that applications have made to run a Java™ program in a JVM with this execution key and profile.

Reset characteristic: reset to zero

 

Current number of JVMs for this profile SJR_CURR_PROFILE_USE is the number of JVMs with this execution key and profile that are currently in the JVM pool.

Reset characteristic: not reset

 

Peak number of JVMs for this profile SJR_PEAK_PROFILE_USE is the peak number of JVMs with this execution key and profile that the JVM pool has contained.

Reset characteristic: reset to current value

 

Number of new JVMs created for this profile SJR_NEW_JVMS_CREATED is the number of new JVMs that were created with this execution key and profile. Because JVMs can be reused, the number of new JVMs created with a particular execution key and profile can be lower than the number of requests for JVMs with that execution key and profile.

Reset characteristic: reset to zero

 

Number of times JVMs were unresettable for this profile SJR_JVMS_UNRESETTABLE is the number of JVMs with this execution key and profile that could not be reset, and therefore could not be reused by another request.

Reset characteristic: reset to zero

 

Number of times this profile stole a TCB SJR_MISMATCH_STEALER is the number of times that an application's request for a JVM with this execution key and profile resulted in a mismatch or a steal. (This count includes both mismatches and steals.) In order to fulfil the application's request, a free JVM with another profile was destroyed and re-initialized (mismatch), and if necessary its TCB was also destroyed and re-created (steal). This situation occurs when:
  • there is not a suitable existing JVM (with the correct JVM profile and execution key) that the application's request can reuse
  • and a new JVM cannot be created because the MAXJVMTCBS limit has been reached
  • and CICS decides that the request should be allowed to perform a mismatch or a steal to obtain a JVM, either because it has exceeded the critical period for waiting, or because the type of JVM that the request will create, is a type that is in demand in the CICS region.
Java Applications in CICS explains this in more detail.

Reset characteristic: reset to zero

 

Number of times this profile was the victim of TCB stealing SJR_MISMATCH_VICTIM is the number of times that a free JVM with this profile was taken, destroyed and re-initialized (mismatch), and if necessary its TCB was also destroyed and re-created (steal), in order to fulfil an application's request for a JVM with a different profile. (This count includes both mismatches and steals.) JVM profiles that are not often requested by applications are more likely to be victims of TCB mismatch or stealing, because JVMs created with such profiles spend longer waiting in the JVM pool to be reused.

Reset characteristic: reset to zero

 

Number of JVMs destroyed due to Short on Storage SJR_JVMS_DESTROYED_SOS is the number of times that JVMs with this execution key and profile were destroyed due to a short-on-storage condition. When CICS is notified of a short-on-storage condition by its storage monitor for JVMs, it might destroy JVMs in the JVM pool that are not currently in use.

Reset characteristic: reset to zero

 

Peak Language Environment® heap storage used SJR_LE_HEAP_HWM is the highest amount of Language Environment heap storage that was used by a JVM with this execution key and profile. This information is only recorded if the profile for the JVM specifies LEHEAPSTATS=YES, otherwise this field is zero.

Reset characteristic: reset to zero

 

Peak nonsystem heap storage used SJR_JVM_HEAP_HWM is the highest amount of nonsystem heap storage that was used by a JVM with this execution key and profile.

Reset characteristic: reset to zero

 

-Xmx value for this profile SJR_PROFILE_XMX_VALUE is the value of the -Xmx parameter set in this JVM profile. The -Xmx parameter specifies the maximum total size of the middleware and transient heaps in the JVM.

Reset characteristic: not reset

 

JVM profiles: Summary resource statistics

Summary statistics are not available online.

Table 81. JVM profiles: Summary resource statistics
DFHSTUP name Description
JVM profile name is the name of this JVM profile.

 

JVM path name is the full HFS path name for this JVM profile.

 

Total number of requests for this profile is the number of requests that applications have made to run a Java program in a JVM with this profile.

 

Peak number of JVMs for this profile is the peak number of JVMs with this profile that the JVM pool has contained.

 

Number of new JVMs created for this profile is the number of new JVMs that were created with this profile.

 

Number of times JVMs were unresettable for this profile is the number of JVMs with this profile that could not be reset, and therefore could not be reused by another request.

 

Number of times this profile stole a TCB is the number of times that an application's request for a JVM with this profile resulted in a mismatch or a steal. (This count includes both mismatches and steals.)

 

Number of times this profile was the victim of TCB stealing is the number of times that a free JVM with this profile was mismatched or stolen in order to fulfil an application's request for a JVM with a different profile. (This count includes both mismatches and steals.)

 

Peak Language Environment heap storage used is the highest amount of Language Environment heap storage that was used by a JVM with this profile. This information is only recorded if the profile for the JVM specifies LEHEAPSTATS=YES, otherwise this field is zero.

 

Peak nonsystem heap storage used is the highest amount of nonsystem heap storage that was used by a JVM with this profile.

 

Number of JVMs destroyed due to Short-on-Storage is the number of times that JVMs with this profile were destroyed due to a short-on-storage condition.

 

-Xmx value for this profile is the value of the -Xmx parameter set in this JVM profile. The -Xmx parameter specifies the maximum total size of the middleware and transient heaps in the JVM.

 

Related reference
Back to full list of statistics and DFHSTUP reports
Appendix A. CICS statistics tables
Interpreting these statistics
Interpreting JVM statistics
DFH0STAT reports for these statistics
JVM Profiles Report
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