2964136 - Heap memory fragmentation

• SQL: "HANA_Memory_TopConsumers_TimeSlices" (SAP Note 1969700) gives high value for item "Heap (Fragmentation)".
  
  Example:

     ;SNAPSHOT_TIME ;KEY_FIGURE ;VALUE_TOTAL ;DETAIL_1 ;VALUE_1 ;PCT_1;

  1 ;2020/08/28 10:00:00;Space used (GB); 100;Heap (Fragmentation); 25; 25;

  2 ;2020/08/28 09:00:00;Space used (GB); 100;Heap (Fragmentation); 25; 25;

  3 ;2020/08/28 08:00:00;Space used (GB); 100;Heap (Fragmentation); 25; 25;

  
  
  
• SQL: "HANA_Memory_ProcessMemory" (SAP Note 1969700) gives high value for column "FRAG_GB".
  
  Example:
  

  -------------------------------------------------------------------------------------------------------
  |HOST   |PORT |PAL_GB |ALLOC_GB|HEAP_USED_GB|FREE_GB|FRAG_GB|ALLOC_PCT|HEAP_USED_PCT|FREE_PCT|FRAG_PCT|
  -------------------------------------------------------------------------------------------------------
  |saphana|30003| 176.55|  176.14|      155.34|   0.00|  20.80|    99.77|        87.98|    0.00|   11.78|
  -------------------------------------------------------------------------------------------------------

  
  
  
• HANA DB trace shows high value for "Heap memory fragmentation"
  
  Example:
  

  Failed to allocate 2565818396904 byte. ... Heap memory fragmentation: 58% (this value may be high if defragmentation does not help solving the current memory request)
  

• Hana DB trace file shows the "OUT OF MEMORY" error as below :
  
  Example:

Memory mmReportMemoryProblems.cpp(01978) : OUT OF MEMORY occurred.
Host: xxxxxxxxxx
Executable: hdbindexserver
PID: xxxxx
Failed to allocate xxmb (xxxxxb).
Allocation failure type: GLOBAL_ALLOCATION_LIMIT (early exit)

Image /data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental.

• HANA database platform 1.0
• HANA database platform 2.0

OOM, dump, run time, rtedump, Failed to allocate, mm poolallocator, hdbcons, resman , KBA , HAN-DB , SAP HANA Database , HAN-DB-PERF , SAP HANA Database Performance , Problem