Details

    • Type: Task
    • Status: Closed
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: WT2.5.2
    • Labels:

      Description

      When the cache is small we can allow internal pages to grow large enough that the cache becomes stuck.

      The test/format configuration at the bottom of this report ended up with a cache containing 4 pages. Two pages for the metadata (that can't be evicted). Two internal pages in a tree:

      0x98f790: row-store internal
              disk 0x98f710, entries 7, dirty, disk-alloc, write generation=2
      0x7fa9880b5e70: row-store internal
              disk 0x7fa98806b000, entries 4981, dirty, disk-alloc, write generation=6
      

      The configured cache size is 2MB and these 4 pages take up 2.5 MB. The second page with nearly 5000 entries is so large we can no longer make progress.

      ############################################
      #  RUN PARAMETERS
      ############################################
      abort=0
      auto_throttle=1
      firstfit=0
      bitcnt=8
      bloom=1
      bloom_bit_count=7
      bloom_hash_count=14
      bloom_oldest=0
      cache=2
      checkpoints=1
      checksum=uncompressed
      chunk_size=3
      compaction=0
      compression=bzip-raw
      data_extend=0
      data_source=table
      delete_pct=28
      dictionary=0
      evict_max=2
      file_type=row-store
      backups=0
      huffman_key=0
      huffman_value=0
      insert_pct=3
      internal_key_truncation=1
      internal_page_max=16
      isolation=snapshot
      key_gap=3
      key_max=72
      key_min=28
      leak_memory=0
      leaf_page_max=13
      logging=0
      logging_archive=0
      logging_prealloc=0
      lsm_worker_threads=4
      merge_max=20
      mmap=1
      ops=100000
      prefix_compression=1
      prefix_compression_min=6
      repeat_data_pct=3
      reverse=0
      rows=100000
      runs=100
      split_pct=67
      statistics=1
      statistics_server=0
      threads=16
      timer=20
      value_max=3805
      value_min=16
      wiredtiger_config=
      write_pct=59
      ############################################
      

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              • Assignee:
                alexander.gorrod Alexander Gorrod
                Reporter:
                alexander.gorrod Alexander Gorrod
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                Dates

                • Created:
                  Updated:
                  Resolved: