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  1. Blazegraph (by SYSTAP)
  2. BLZG-1575 Small slot optimization meta-ticket
  3. BLZG-1646

BytesAppData counter can not be tracked accurately and should be removed

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    Details

    • Type: Sub-task
    • Status: Done
    • Priority: Medium
    • Resolution: Done
    • Affects Version/s: None
    • Fix Version/s: BLAZEGRAPH_2_0_0
    • Component/s: None
    • Labels:
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      Description

      BytesAppData is a known bug. See below (StorageStats.java). The problem is that we do not know how much of the slot was in use when we do the delete.

      This is confusing. I suggest that we remove the BytesAppData counter since it can not be tracked accurately (without adding a header into the allocation for the #of bytes in the slot that are actually in use).

      /**
      		 * BytesAppData: The #of bytes in the allocated slots which are used by
      		 * application data (including the record checksum).
      		 * 
      		 * FIXME BLZG-1551 : The data reported here is bad. It is pretty clear
      		 * that {@link #m_sizeDeletes} is not being tracked correctly in the
      		 * {@link StorageStats}. Thus while we know the user data in the slots
      		 * for each slot size, we do not know how much user data was in those
      		 * slots when they were recycled. However, this should never return a
      		 * native number! Instead we could always fall back to (slotsAllocated -
      		 * slotsRecycled) * slotSize
      		 */
      		public long usedStore() {
      			return m_sizeAllocations - m_sizeDeletes;
      		}
      
      

      See BLZG-1551

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              Assignee:
              bryanthompson bryanthompson
              Reporter:
              bryanthompson bryanthompson
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                Updated:
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