Parameter changes make system stall/unresposive

Question

Could a slight increase in either parameter create a huge backlash in the system:
1. ztta/roll_area or
2. abap/heap_area_total ??
I've researched each and understand what they do, but still want to ask if this could create issues. I reviewed response times for the day and compared it to passed days to find them quite similiar, but we still ran into an issue with 'slowness' all day. The dialog processes filled up and it hour glassed for a good minute. Then it would react like the bottleneck cleared and everything would go back to 'normal' for a bit. This happened pretty much all day today. The 2 parameters were changed to fix an ABAP dump we received daily.
Thanks for the help,
Ryan

Answer 1

We are running on OS400 V6R1 OS, the LPAR has roughly 200GBs of memory.</p>
I changed
ztta/roll_area went from 5000000 to 7500000 and
abap/heap_area_total went from 2000000000 to 3500000000.</p>
ST02 is showing:</br>
Date + Time of Snapshot: 09/01/2010     09:25:26    Startup:   08/28/2010 18:45:10</br>
Roll memory     Dialog session   kB      7,324</br>
                 Nondialog sess.         kB      7,324</br>
                 Available                    kB    524,288</br>
                 in shared memory      kB    524,288</br>
                 on disk                       kB          0</br>
                 Used                          kB    280,690</br>
                 Maximum used           kB    338,416</br>
Paging memory   Session buffer   kB      1,200</br>
                 Available                        kB  2,000,000</br>
                 in shared memory          kB  1,048,576</br>
                 on disk                           kB    951,424</br>
                 Used                              kB    387,407</br>
                 Maximum used               kB    569,304</br>
Extended memory Dialog session   kB  1,953,125</br>
                 Nondialog sess.              kB  1,953,125</br>
                 Available                         kB 46,133,248</br>
                 Used                               kB 31,203,328</br>
                 Maximum used                kB 39,948,288</br>
Heap memory     Dialog session   kB  1,953,125</br>
                 Nondialog sess.            kB  1,953,125</br>
                 Used                             kB          0</br>
                 Maximum used              kB  3,417,949</p>
The ABAP dump i was referring it is a TSV_TNEW_PAGE_ALLOC_FAILED, more info is:</br>
Short text</br>
    No more storage space available for extending an internal table.</p>
What happened?</br>
    You attempted to extend an internal table, but the required space was
    not available.</p>
What can you do?</br>
    Note which actions and input led to the error.
    For further help in handling the problem, contact your SAP administrato
    You can use the ABAP dump analysis transaction ST22 to view and manage
    termination messages, in particular for long term reference.</br>
    Try to find out (e.g. by targetted data selection) whether the
    transaction will run with less main memory.</br>
    If there is a temporary bottleneck, execute the transaction again.</br>
    If the error persists, ask your system administrator to check the
    following profile parameters:</br>
    o  ztta/roll_area            (1.000.000 - 15.000.000)</br>
           Classic roll area per user and internal mode
           usual amount of roll area per user and internal mode
    o  ztta/roll_extension       (10.000.000 - 500.000.000)</br>
           Amount of memory per user in extended memory (EM)
    o  abap/heap_area_total      (100.000.000 - 1.500.000.000)</br>
           Amount of memory (malloc) for all users of an application
           server. If several background processes are running on
           one server, temporary bottlenecks may occur.</br>
           Of course, the amount of memory (in bytes) must also be
           available on the machine (main memory or file system swap).</br>
           Caution:</br>
           The operating system must be set up so that there is also
           enough memory for each process. Usually, the maximum address
           space is too small.</br>
          Ask your hardware manufacturer or your competence center
        about this.</br>
        In this case, consult your hardware vendor</br>
abap/heap_area_dia:        (10.000.000 - 1.000.000.000)</br>
        Restriction of memory allocated to the heap with malloc
        for each dialog process.</br>
Parameters for background processes:</br>
abap/heap_area_nondia:        (10.000.000 - 1.000.000.000)</br>
        Restriction of memory allocated to the heap with malloc
        for each background process.</br>
Other memory-relevant parameters are:</br>
em/initial_size_MB:         (35-1200)</br>
        Extended memory area from which all users of an
        application server can satisfy their memory requirement.
or analysis
The internal table "\FUNCTION-POOL=SCMS_R3DB\FORM=DB_PACK\DATA=PHIO_DATA-CONT_B
IN" could not be further extended. To enable
error handling, the table had to be delete before this log was written.
As a result, the table is displayed further down or, if you branch to
the ABAP Debugger, with 0 rows.</br>
At the time of the termination, the following data was determined for
the relevant internal table:</br>
Memory location: "Session memory"</br>
Row width: 1022</br>
Number of rows: 378832</br>
Allocated rows: 378832</br>
Newly requested rows: 16 (in 1 blocks)</br>
to correct the error
The amount of storage space (in bytes) filled at termination time was:</p>
Roll area...................... 7219584</br>
Extended memory (EM)........... 2002781760</br>
Assigned memory (HEAP)......... 2000061360</br>
Short area..................... " "</br>
Paging area.................... 122880</br>
Maximum address space.......... 4294967295</br>
If the error occures in a non-modified SAP program, you may be able to
find an interim solution in an SAP Note.</br>
If you have access to SAP Notes, carry out a search with the following
keywords:</br>
"TSV_TNEW_PAGE_ALLOC_FAILED" " "
"SAPLSCMS_R3DB" or "LSCMS_R3DBF01"
"DB_PACK"
If you cannot solve the problem yourself and want to send an error
notification to SAP, include the following information:
1. The description of the current problem (short dump)
    To save the description, choose "System->List->Save->Local File
(Unconverted)".</br>
2. Corresponding system log
    Display the system log by calling transaction SM21.
    Restrict the time interval to 10 minutes before and five minutes
after the short dump. Then choose "System->List->Save->Local File
(Unconverted)".</br>
3. If the problem occurs in a problem of your own or a modified SAP
program: The source code of the program
    In the editor, choose "Utilities->More
Utilities->Upload/Download->Download".</br>
4. Details about the conditions under which the error occurred or which
actions and input led to the error.</br>
Memory consumption</br>
Roll.... 7219584</br>
EM...... 2002781760</br>
Heap.... 2000061360</br>
Page.... 122880</br>
MM Used. 3960623456</br>
MM Free. 40162736</p>
I've got a customer message message open on this but I've got more back from you guys then that message. Thanks for the info.
Edited by: Ryan Cossette on Sep 1, 2010 4:45 PM