3644902 - Temporary, large memory utilization by a work process

During the execution of a report (be it on dialog or background job mode), it is observed that the work process shows a very large memory utilization, going beyond the quotas allowed by the parameters "abap/heap_area_dia" or "abap/heap_area_nondia".

If SAP is running on Linux, and depending on the specific situation and server resources (RAM / physical memory), this can even reach a point where Linux triggers the "Out of Memory killer", in which case entries similar to the below would be observed on the "/var/log/messages" file:

[date and time] [hostname] kernel: [ 2534.526334][T25300] Out of memory: Killed process [PID of work process] (SAP_SID_xx_Wzz) total-vm:184311896kB, anon-rss:65237552kB, file-rss:0kB, shmem-rss:6828516kB, UID:61235 pgtables:155232kB oom_score_adj:0 

If the server has enough resources, and the memory utilization is not that high, it can be observed that the memory is freed even before the report finishes the execution (so, there is no memory leak occurring).

If SAP is running with an SAP kernel version equal to or higher than what is listed on the SAP Note 2733232, triggering a "Write Stack" on the work process (transaction SM50, select the work process, then access the menu Administration  -> Work Process -> Write Stack) reveals that the SAP kernel level tag "DBI_MM" is showing large memory consumption:

(...)
M  ------------------ c-stack end ------------------
M
M  SECTION: Proc Memory
M  Top 50 PROC memory consumers by user tag ID (in bytes)
M  ------------------------------------------------------------------------------
M    Tag      Allocations                Smallest              Biggest                 Sum
M    'DBI_MM'   26996                     102.424           37.749.336       56.647.708.480
M    'abstor'     130                     119.272            5.274.760          484.175.808
M    'DBSL-0'     471                         160            1.907.008            6.117.064 
(...)

• ABAP Platform based product
• SAP NetWeaver ABAP based product

High, Huge, Large, Memory, Usage, Consumption, oom , KBA , BC-CST-MM , Memory Management , BC-DB-DBI , DB Independent Database Interface , MM-PUR-PO , Purchase Orders , Problem