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z/TPF ECB heap diagnostics and performance improvements (PJ48166)

By Barry Goldberg posted 15 hours ago

  

APAR PJ48166 provides diagnostic and performance improvements to help you tune your z/TPF system for ECB heap usage and to help with diagnostics .

The following changes were made to improve ECB heap usage tuning.

Data collection and reduction added a 31-bit virtual ECB heap storage usage report. This report contains information about the number of ECBs that exceeded the preallocated 31-bit ECB heap.  You can use this report to better determine what an acceptable preallocated ECB heap size should be.

TPF 31-BIT PREALLOCATED ECB HEAP STORAGE USAGE REPORT    SYSTEM  WIDE        

                                                                             

   CLASS UPPER   FREQUENCY   PERCENT    FREQUENCY DIAGRAM  (SCALE =       1/1)

      LIMIT      OBSERVED    OF TOTAL                                        

                                                                             

         0KB            6       66.00%   |******                             

        24KB            0        0.00%   |                                   

        32KB            0        0.00%   |                                   

        40KB            0        0.00%   |                                   

        48KB            0        0.00%   |                                   

        56KB            2       22.00%   |**                                 

        64KB            0        0.00%   |                                   

        72KB            0        0.00%   |                                   

        80KB            0        0.00%   |                                   

    >   80KB            1       11.00%   |*                                  

                                                                             

TPF 31-BIT VIRTUAL ECB HEAP STORAGE USAGE REPORT         SYSTEM  WIDE         

                                                                              

REPORT ONLY INCLUDES ECBS THAT EXCEEDED THE PREALLOCATED ECB HEAP             

                                                                              

   CLASS UPPER   FREQUENCY   PERCENT    FREQUENCY DIAGRAM  (SCALE =       1/1)

      LIMIT      OBSERVED    OF TOTAL                                         

                                                                              

        88KB            0        0.00%   |                                    

        96KB            0        0.00%   |                                    

       104KB            0        0.00%   |                                    

       112KB            0        0.00%   |                                    

       120KB            0        0.00%   |                                    

       128KB            0        0.00%   |                                    

       136KB            0        0.00%   |                                    

       144KB            1      100.00%   |*                                   

       152KB            0        0.00%   |                                    

    >  152KB            0        0.00%   |                                    

                                                                              

The ZMOWN online report, ZECBM online report, and RTMC name-value pair collection are enhanced to include many ECB heap metrics. This includes the number of allocations and frees for each ECB heap available list, the number of 1 MB frames needed to back ECB heap, and high-water marks for heap usage. Additionally, you can use the HAVL parameter on the ZDECB command to display the number of ECB heap requests that were fulfilled by each of the ECB heap available lists for a long running ECB.

AAES0008I 00 ==> zdecb havl 12045000

CSMP0097I 09.35.59 CPU-B SS-BSS  SSU-HPN  IS-01 _

DECB0125I 09.35.59 COUNT OF ECB HEAP AVAILABLE LIST REQUESTS FILLED FOR

 ECB 12045000 MAIN THREAD ECB 12084000

SETNAME = SSL

ECB HEAP AVL LIST BUFFER SIZES:  AVL1 32 , AVL2 64 , AVL3 128 , AVL4 256

LIST  31 BIT SHARED AVLS          64 BIT SHARED AVLS _

AVL1               611                         0

AVL2               217                         0

AVL3               182                         0

AVL4               640                         0

AVL5              1325                         0

LIST  31 BIT UNIQUE AVLS          64 BIT UNIQUE AVLS _

AVL1             15272                         0

AVL2              4033                         0

AVL3               941                         0

AVL4               576                         0

NUMBER OF THREADS  5

END OF DISPLAY+

ECB heap is enhanced to support separate ECB heap available list sizes for shared SSL and Java. These values are configured in the ECB heap configuration file (/sys/tpf_pbfiles/tpf-fdes/apps/ibmeheap/ibm_ECB_heap.json). The ECB heap configuration file contains values that were tested by IBM for optimal performance with shared SSL and Java on z/TPF. You can enter ZCTKA DISPLAY HEAP SETNAME to display the shared SSL and Java ECB heap available list sizes.  Previously, if you defined large buffer sizes for the default ECB heap available list sizes, shared SSL and Java ECBs might use a large amount of memory, and possibly run out of memory. With PJ48166, shared SSL and Java do not use the buffer sizes for the default ECB heap available list buffer sizes. Instead, they use the buffer sizes that are defined in the configuration file. With this support, you can define large default buffer sizes without impacting shared SSL and Java[LU2] .  Both shared SSL and JAVA ECBS might use less memory over time with these customized ECB heap available list sizes.

AAES0008I 00 ==> zctka display heap setname

CSMP0097I 15.15.31 CPU-B SS-BSS  SSU-HPN  IS-01

CTKA0175I 15.15.31 ECB HEAP AVAILABLE LIST SET NAME SIZE DISPLAY

  SETNAME     AVL1       AVL2      AVL3      AVL4

    JAVA        32        256      2048      4096

     SSL        32         64       128       256  _

  DEFAULT       64        256      1024      4096

END OF DISPLAY+

 To help improve debugging, the trace name at the time of the ECB heap allocation or free is included in the following places:

·       The ZDECB HEAPTRACE online display

·       The HEAP TRACE dump area

·       The IN-USE HEAP BUFFER dump area

·       The AVAILABLE HEAP BUFFER dump area[LU3] 

 The trace name is not set by programs with fast path linkage like CPP1, which includes the C++ new and delete operations. Therefore, the recorded trace name reflects the last program the ECB entered that did not have special linkage.

zdecb heaptr 1200f000

CSMP0097I 08.21.44 CPU-B SS-BSS  SSU-HPN  IS-01

DECB0223I 08.21.44 THE HEAP TRACE FOR ECB 1200F000 STARTED

LOADMOD  LOADSET          TRC      OBJECT NAME

  OR

OBJ DSP  IS   TIMESTAMP           API  BUFFER ADDR        SIZE

CISO     LOADSET-BASE     TRC-CFVS OBJECT-filedoalloc                      _

00000068 03   00 E19BA761 344C125A m   000000001A824FF8 00002000

CISO     LOADSET-BASE     TRC-CFVS OBJECT-iofdopen

00000124 03   00 E19BA761 344BB420 m   000000001A822DA8 00000250

CISO     LOADSET-BASE     TRC-CFVS OBJECT-filedoalloc                      _

00000068 03   00 E19BA761 344B184C m   000000001A81EFF8 00002000

CISO     LOADSET-BASE     TRC-CFVS OBJECT-iofdopen

00000124 03   00 E19BA761 344A9050 m   000000001A81CDA8 00000250

CISO     LOADSET-BASE     TRC-CFVS OBJECT-filedoalloc                      _

00000068 03   00 E19BA761 3449F84A m   000000001A818FF8 00002000


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