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  1. Couchbase Server
  2. MB-7218

couchbase server does not raise an alert when hashtable is mostly consumed by key+metadata

    Details

    • Type: Bug
    • Status: Closed
    • Priority: Major
    • Resolution: Duplicate
    • Affects Version/s: 1.8.1, 2.0
    • Fix Version/s: 2.1.0
    • Component/s: couchbase-bucket
    • Security Level: Public
    • Labels:
      None

      Description

      Amount of active item metadata consuming RAM in this bucket (measured from vb_active_meta_data_memory)

      ui right now is using vb_active_meta_data_memory.

      in the below example there are 20M items on a node where high watermark 3.1 GB , 90 % of items are less than 32 bytes. so memory is mostly used by the key+metadata

      curr_items: 10398801
      curr_items_tot: 20800098
      curr_temp_items: 0
      ep_access_scanner_num_items: 0
      ep_chk_max_items: 5000
      ep_diskqueue_items: 0
      ep_items_rm_from_checkpoints: 22036291
      ep_total_del_items: 2050118
      ep_total_new_items: 23366776
      ep_uncommitted_items: 0
      ep_warmup_min_items_threshold: 100
      vb_active_curr_items: 10398801
      vb_active_num_ref_items: 840854
      vb_pending_curr_items: 0
      vb_pending_num_ref_items: 0
      vb_replica_curr_items: 10401297
      vb_replica_num_ref_items: 654973

      couchbase-macbook-13:management farshid$ ./cbstats 10.3.3.59:11210 all | grep mem
      ep_diskqueue_memory: 0
      ep_mem_high_wat: 3145728000
      ep_mem_low_wat: 2516582400
      ep_mem_tracker_enabled: true
      ep_mutation_mem_threshold: 0
      ep_warmup_min_memory_threshold: 100
      mem_used: 3272857616
      vb_active_ht_memory: 50398208
      vb_active_itm_memory: 987886095
      vb_active_meta_data_memory: 904695687
      vb_active_perc_mem_resident: 0
      vb_active_queue_memory: 0
      vb_pending_ht_memory: 0
      vb_pending_itm_memory: 0
      vb_pending_meta_data_memory: 0
      vb_pending_perc_mem_resident: 0
      vb_pending_queue_memory: 0
      vb_replica_ht_memory: 61012880
      vb_replica_itm_memory: 988123215
      vb_replica_meta_data_memory: 904912839
      vb_replica_perc_mem_resident: 0
      vb_replica_queue_memory: 0

      couchbase-macbook-13:management farshid$ ./cbstats 10.3.3.59:11210 memory
      bytes: 3272854448
      ep_kv_size: 2225610486
      ep_max_data_size: 4194304000
      ep_mem_high_wat: 3145728000
      ep_mem_low_wat: 2516582400
      ep_mem_tracker_enabled: true
      ep_oom_errors: 0
      ep_overhead: 113025616
      ep_tmp_oom_errors: 0
      ep_value_size: 332801568
      mem_used: 3272854448
      tcmalloc_current_thread_cache_bytes: 2953344
      tcmalloc_max_thread_cache_bytes: 4194304
      tcmalloc_unmapped_bytes: 0
      total_allocated_bytes: 3347676192
      total_fragmentation_bytes: 53306336
      total_free_bytes: 707207168
      total_heap_bytes: 4108189696

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        Activity

        Hide
        farshid Farshid Ghods (Inactive) added a comment -

        this issue exists on 1.x releases as well

        Show
        farshid Farshid Ghods (Inactive) added a comment - this issue exists on 1.x releases as well
        Hide
        farshid Farshid Ghods (Inactive) added a comment -

        the below two stats might not work in 2.0 and previous releases

        Metadata overhead is more than 50%
        Bucket memory on a node is entirely used for metadata

        Show
        farshid Farshid Ghods (Inactive) added a comment - the below two stats might not work in 2.0 and previous releases Metadata overhead is more than 50% Bucket memory on a node is entirely used for metadata
        Hide
        mikew Mike Wiederhold added a comment -

        Duplicate of MB-7354

        Show
        mikew Mike Wiederhold added a comment - Duplicate of MB-7354
        Hide
        maria Maria McDuff (Inactive) added a comment -
        Show
        maria Maria McDuff (Inactive) added a comment - MB-7354

          People

          • Assignee:
            mikew Mike Wiederhold
            Reporter:
            farshid Farshid Ghods (Inactive)
          • Votes:
            0 Vote for this issue
            Watchers:
            2 Start watching this issue

            Dates

            • Created:
              Updated:
              Resolved:

              Gerrit Reviews

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