3445711 - LOB tables consuming the HANA page cache under "Pool/PersistenceManager/PersistentSpace/DefaultPageProvider:DataPage"

• Pool/PersistenceManager/PersistentSpace/DefaultPageProvider:DataPage Allocator is highly consuming on the HANA Tenant DB as per the indexserver trace :
  
  

  [37131]{-1}[143/1124566864] 2024-03-12 11:22:58.371336 w ResMan           ResourceContainerShrink.cpp(03332) : Information about shrink at 2024-03-12 11:22:58 368 Local:
  Reason for shrink: Reserve for HBA, user size:  2985712576
  ShrinkCaller
   
  
  ...
  
  
  IPMM NearDRAM short info:
  GLOBAL_ALLOCATION_LIMIT (GAL) = 720.51gb (773645848576b), SHARED_MEMORY = 36.79gb (39511269376b), CODE_SIZE = 3.15gb (3392131072b), NVM_ALLOCATED_SIZE = 0b, OOM_RESERVATION_ALLOCATOR_SIZE = 96.14mb (100810752b)
  PID=13635 (hdbindexserver), PAL=720.63gb (773780066304b), AB=673.72gb (723408850944b), UA=0, U=648.83gb (696679752315b), FRO=0b, FSL=0b, FMC=0b
  [Some processes may have been skipped]
  Total allocated memory= 720.72gb (773871439872b)
  Total used memory     = 693.15gb (744273316585b)
  Sum AB                = 730968039424
  Sum Used              = 701369916137
  Heap memory fragmentation: 3
  Top "M_HEAP_MEMORY" allocators (component, name, size). Ordered descending by inclusive_size_in_use.
   1: System:                                     /                                                                    648.83gb (696679752315b)
   2: System:                                     Pool                                                                 639.34gb (686493732641b)
   3: System:                                     Pool/PersistenceManager                                              373.12gb (400635069536b)
   4: System:                                     Pool/PersistenceManager/PersistentSpace                              351.31gb (377217235960b)
   5: System:                                     Pool/PersistenceManager/PersistentSpace/DefaultPageProvider:DataPage 303.73gb (326134881824b)
   6: System:                                     Pool/ColumnStore                                                     229.84gb (246797320271b)
   7: Column Store Tables:                        Pool/ColumnStore/Main                                                213.50gb (229251932447b)
   8: Column Store Tables:                        Pool/ColumnStore/Main/Dictionary                                     81.54gb (87563505351b)
   9: Column Store Tables:                        Pool/ColumnStore/Main/Dictionary/RoDict                              75.29gb (80844653651b)
  10: Column Store Tables:                        Pool/ColumnStore/Main/Compressed                                     56.06gb (60197000836b)
  11: Column Store Tables:                        Pool/ColumnStore/Main/Compressed/Indirect                            43.69gb (46920891908b)
  12: System:                                     Pool/PersistenceManager/PersistentSpace/LOBPage                      41.01gb (44044018448b)
  13: Column Store Tables:                        Pool/ColumnStore/Main/Index                                          40.62gb (43625991988b)
  14: Column Store Tables:                        Pool/ColumnStore/Main/Index/Single                                   36.89gb (39617064036b)
  15: Column Store Tables:                        Pool/ColumnStore/Main/Uncompressed                                   30.44gb (32687992776b)
  16: Statement Execution & Intermediate Results: Pool/ColumnStore/Transient                                           9.73gb (10450023648b)
  17: Column Store Tables:                        Pool/PersistenceManager/UnifiedTableContainer                        9.72gb (10444584664b)
  18: Row Store Tables:                           Pool/RowStoreTables                                                  9.20gb (9888742856b)
  19: Row Store Tables:                           Pool/RowStoreTables/CpbTree                                          9.19gb (9876399184b)
  20: System:                                     AllocateOnlyAllocator-unlimited                                      8.87gb (9529860752b)

   

• Hdbcons output (2222218) mm bl -t Pool/PersistenceManager/PersistentSpace/DefaultPageProvider:DataPage shows 325 GB consumed on "PageAccess::LimitedLogicalPageResourceProvider::providePageInternal" for page access from disk : 
  
  

  > mm bl -t Pool/PersistenceManager/PersistentSpace/DefaultPageProvider:DataPage
  
  ## Start command at: 2024-03-12 12:16:06.055
  325581011000b (5013049 blocks incl. 189.22mb (198416440b) meta data) in use at: Dumping saved stack trace 9223512417582058623, 1 frames:
  0: 0x00007facef620c7f in PageAccess::LimitedLogicalPageResourceProvider::providePageInternal(PageAccess::LogicalPageControlBlock&, PageAccess::SizeClass)+0x5b at DataAccess/PageAccess/impl/LimitedResourceProvider.cpp:180 (libhdbdataaccess.so)
  
  Top 20 allocators:
  Pool/PersistenceManager/PersistentSpace/DefaultPageProvider:DataPage: 303.22gb (325581011000b) (5013049 blocks incl. 189.22mb (198416440b) meta data)
  [OK]
  
  ## Finish command at: 2024-03-12 12:16:15.697 command took: 9.632 sec
  
  

• HANA_Memory_Overview_xxx.txt reveals very large consumption of the heap allocator and large LOB tables under "Disk size" :
  
  

  HANA heap memory (used),     629,   629 (hostname),   303 (Pool/PersistenceManager/PersistentSpace/DefaultPageProvider:DataPage)
   , , ,    73 (Pool/ColumnStore/Main/Dictionary/RoDict)
   , , ,    44 (Pool/ColumnStore/Main/Compressed/Indirect)
   , , ,    41 (Pool/PersistenceManager/PersistentSpace/LOBPage)
   , , ,    36 (Pool/ColumnStore/Main/Index/Single)
   , , ,    29 (Pool/ColumnStore/Main/Uncompressed)
   , , ,     9 (Pool/RowStoreTables/CpbTree)
   , , ,     7 (AllocateOnlyAllocator-unlimited/FLA-UL<24592,1>/MemoryMapLevel3Nodes)
   , , ,     7 (Pool/ColumnStore/Main/Compressed/Sparse)
   , , ,     7 (Pool/PersistenceManager/UnifiedTableContainer)
   , , , 
  
  
  Column store size,     211,   211 (hostname),    25 (CDPOS)
   , , ,    11 (COEP)
   , , ,    10 (GLFUNCA)
   , , ,     9 (KEPH)
   , , ,     9 (BSEG)
   , , ,     8 (CKIS)
   , , ,     7 (BSIS)
   , , ,     5 (COSB)
   , , ,     5 (MSEG)
   , , ,     5 (SOC3)
   , , , 
  
  ......
  
  Disk size,    1239,  1239 (global),   435 (ODQDATA_F)
   , , ,   383 (SOFFCONT1)
   , , ,    27 (CDPOS)
   , , ,    15 (COEP)
   , , ,    14 (LTEX)
   , , ,    13 (SCMON_DATA)
   , , ,    11 (SWWCNTP0)
   , , ,    11 (CMFP)
   , , ,    10 (GLFUNCA)
   , , ,    10 (ZHENM_GEM_LOG)

SAP HANA Platform Edition 2.0        

w ResMan, ResourceContainerShrink.cpp, LOBs, MEM_SIZE_MB, technical tables, FLOB, File LOB , KBA , HAN-DB , SAP HANA Database , HAN-DB-PER , SAP HANA Database Persistence , Problem