Updated on 2023-03-15 GMT+08:00

Freezing an Index

Precautions

  • Before freezing an index, ensure no data is being written to it. The index will be set to read only before being frozen, and data write will fail.
  • After an index is frozen,
    • It becomes read-only.
    • The index data will be dumped to OBS. This process occupies network bandwidth.
    • The query latency of a dumped index will increase. During aggregation, the latency of processing complex queries and reading a large volume of data is long.
    • It cannot be unfrozen. That is, a read-only index cannot be changed to writable.
    • After the freezing is complete, the index data in your local disks will be deleted.

Procedure

  1. Log in to the CSS management console.
  2. Choose Clusters in the navigation pane. On the Clusters page, locate the target cluster and click Access Kibana in the Operation column.
  3. Click Dev Tools in the navigation tree on the left.
  4. Run the following command to freeze a specified index and dump it to OBS:
    POST ${index_name}/_freeze_low_cost
    Table 1 Parameter description

    Parameter

    Description

    index_name

    Name of the index to be frozen.

    Information similar to the following is displayed:

    {
        "freeze_uuid": "pdsRgUtSTymVDWR_HoTGFw"
    }
    Table 2 Response parameter

    Parameter

    Description

    freeze_uuid

    After an index freezing request is submitted, an asynchronous job will be started. The request returns the asynchronous job ID, which can be used to query the progress of the asynchronous job.

    After an index freezing request is submitted, data cannot be written to the index. During the index freezing, query requests are not affected. After the freezing is complete, the index is closed and then opened. During this period, the index cannot be queried, and the cluster may be in the red status for a short time. The index is restored after being opened.

  5. Run the following command to check the freezing task progress:
    GET _freeze_low_cost_progress/${freeze_uuid}
    Table 3 Parameter description

    Parameter

    Description

    freeze_uuid

    Asynchronous task ID, which is obtained in 4.

    Information similar to the following is displayed:

    {
    
      "stage" : "STARTED",
      "shards_stats" : {
        "INIT" : 0,
        "FAILURE" : 0,
        "DONE" : 0,
        "STARTED" : 3,
        "ABORTED" : 0
      },
      "indices" : {
        "data1" : [
          {
            "uuid" : "7OS-G1-tRke2jHZPlckexg",
            "index" : {
              "name" : "data1",
              "index_id" : "4b5PHXJITLaS6AurImfQ9A",
              "shard" : 2
            },
            "start_ms" : 1611972010852,
            "end_ms" : -1,
            "total_time" : "10.5s",
            "total_time_in_millis" : 10505,
            "stage" : "STARTED",
            "failure" : null,
            "size" : {
              "total_bytes" : 3211446689,
              "finished_bytes" : 222491269,
              "percent" : "6.0%"
            },
            "file" : {
              "total_files" : 271,
              "finished_files" : 12,
              "percent" : "4.0%"
            },
            "rate_limit" : {
              "paused_times" : 1,
              "paused_nanos" : 946460970
            }
          },
          {
            "uuid" : "7OS-G1-tRke2jHZPlckexg",
            "index" : {
              "name" : "data1",
              "index_id" : "4b5PHXJITLaS6AurImfQ9A",
              "shard" : 0
            },
            "start_ms" : 1611972010998,
            "end_ms" : -1,
            "total_time" : "10.3s",
            "total_time_in_millis" : 10359,
            "stage" : "STARTED",
            "failure" : null,
            "size" : {
              "total_bytes" : 3221418186,
              "finished_bytes" : 272347118,
              "percent" : "8.0%"
            },
            "file" : {
              "total_files" : 372,
              "finished_files" : 16,
              "percent" : "4.0%"
            },
            "rate_limit" : {
              "paused_times" : 5,
              "paused_nanos" : 8269016764
            }
          },
          {
            "uuid" : "7OS-G1-tRke2jHZPlckexg",
            "index" : {
              "name" : "data1",
              "index_id" : "4b5PHXJITLaS6AurImfQ9A",
              "shard" : 1
            },
            "start_ms" : 1611972011021,
            "end_ms" : -1,
            "total_time" : "10.3s",
            "total_time_in_millis" : 10336,
            "stage" : "STARTED",
            "failure" : null,
            "size" : {
              "total_bytes" : 3220787498,
              "finished_bytes" : 305789614,
              "percent" : "9.0%"
            },
            "file" : {
              "total_files" : 323,
              "finished_files" : 14,
              "percent" : "4.0%"
            },
            "rate_limit" : {
              "paused_times" : 3,
              "paused_nanos" : 6057933087
            }
          }
        ]
      }
    }
    Table 4 Response parameters

    Parameter

    Description

    stage

    Status. Its value can be:

    • INIT: The instance has just started or is being initialized.
    • FAILURE: failed
    • DONE: complete
    • STARTED: started
    • ABORTED: Canceled. This field is reserved.

    shards_stats

    Numbers of shards in each state.

    indices

    Index status details.

    Table 5 Return values of indices

    Parameter

    Description

    uuid

    UUID of the freezing operation

    index

    Index and shard information

    start_ms

    Start time

    end_ms

    End time. If no end time is specified, the value -1 is displayed.

    total_time

    Time spent

    total_time_in_millis

    Time spent, in milliseconds

    stage

    Status of the current shard.

    failure

    Failure cause. If no failure occurs, null is displayed.

    size.total_bytes

    Size of files to be frozen, in bytes

    size.finished_bytes

    Frozen bytes

    size.percent

    Percentage of frozen bytes

    file.total_bytes

    Number of files to be frozen

    file.finished_bytes

    Number of frozen files

    file.percent

    Percentage of frozen files

    rate_limit.paused_times

    Number of times that freezing is suspended due to rate limit

    rate_limit.paused_nanos

    Duration of freezing task suspension due to rate limit, in nanoseconds

    The following parameters are added to a frozen index. For details, see Table 6.

    Table 6 Frozen index parameters

    Parameter

    Description

    index.frozen_low_cost

    Whether an index is frozen. The value is true.

    index.blocks.write

    Whether data writing is denied in a frozen index. The value is true.

    index.store.type

    Storage type of an index. The value is obs.

  6. After an index is frozen, its data will be cached. Run the following command to check the current cache status: For details about the cache, see Configuring Cache.
    GET _frozen_stats
    GET _frozen_stats/${node_id}
    Table 7 Parameter description

    Parameter

    Description

    node_id

    Node ID, which can be used to obtain the cache status of a node.

    Information similar to the following is displayed:

    {
      "_nodes" : {
        "total" : 3,
        "successful" : 3,
        "failed" : 0
      },
      "cluster_name" : "css-zzz1",
      "nodes" : {
        "7uwKO38RRoaON37YsXhCYw" : {
          "name" : "css-zzz1-ess-esn-2-1",
          "transport_address" : "10.0.0.247:9300",
          "host" : "10.0.0.247",
          "ip" : "10.0.0.247",
          "block_cache" : {
            "default" : {
              "type" : "memory",
              "block_cache_capacity" : 8192,
              "block_cache_blocksize" : 8192,
              "block_cache_size" : 12,
              "block_cache_hit" : 14,
              "block_cache_miss" : 0,
              "block_cache_eviction" : 0,
              "block_cache_store_fail" : 0
            }
          },
          "obs_stats" : {
            "list" : {
              "obs_list_count" : 17,
              "obs_list_ms" : 265,
              "obs_list_avg_ms" : 15
            },
            "get_meta" : {
              "obs_get_meta_count" : 79,
              "obs_get_meta_ms" : 183,
              "obs_get_meta_avg_ms" : 2
            },
            "get_obj" : {
              "obs_get_obj_count" : 12,
              "obs_get_obj_ms" : 123,
              "obs_get_obj_avg_ms" : 10
            },
            "put_obj" : {
              "obs_put_obj_count" : 12,
              "obs_put_obj_ms" : 2451,
              "obs_put_obj_avg_ms" : 204
            },
            "obs_op_total" : {
              "obs_op_total_ms" : 3022,
              "obs_op_total_count" : 120,
              "obs_op_avg_ms" : 25
            }
          },
          "reader_cache" : {
            "hit_count" : 0,
            "miss_count" : 1,
            "load_success_count" : 1,
            "load_exception_count" : 0,
            "total_load_time" : 291194714,
            "eviction_count" : 0
          }
        },
        "73EDpEqoQES749umJqxOzQ" : {
          "name" : "css-zzz1-ess-esn-3-1",
          "transport_address" : "10.0.0.201:9300",
          "host" : "10.0.0.201",
          "ip" : "10.0.0.201",
          "block_cache" : {
            "default" : {
              "type" : "memory",
              "block_cache_capacity" : 8192,
              "block_cache_blocksize" : 8192,
              "block_cache_size" : 12,
              "block_cache_hit" : 14,
              "block_cache_miss" : 0,
              "block_cache_eviction" : 0,
              "block_cache_store_fail" : 0
            }
          },
          "obs_stats" : {
            "list" : {
              "obs_list_count" : 17,
              "obs_list_ms" : 309,
              "obs_list_avg_ms" : 18
            },
            "get_meta" : {
              "obs_get_meta_count" : 79,
              "obs_get_meta_ms" : 216,
              "obs_get_meta_avg_ms" : 2
            },
            "get_obj" : {
              "obs_get_obj_count" : 12,
              "obs_get_obj_ms" : 140,
              "obs_get_obj_avg_ms" : 11
            },
            "put_obj" : {
              "obs_put_obj_count" : 12,
              "obs_put_obj_ms" : 1081,
              "obs_put_obj_avg_ms" : 90
            },
            "obs_op_total" : {
              "obs_op_total_ms" : 1746,
              "obs_op_total_count" : 120,
              "obs_op_avg_ms" : 14
            }
          },
          "reader_cache" : {
            "hit_count" : 0,
            "miss_count" : 1,
            "load_success_count" : 1,
            "load_exception_count" : 0,
            "total_load_time" : 367179751,
            "eviction_count" : 0
          }
        },
        "EF8WoLCUQbqJl1Pkqo9-OA" : {
          "name" : "css-zzz1-ess-esn-1-1",
          "transport_address" : "10.0.0.18:9300",
          "host" : "10.0.0.18",
          "ip" : "10.0.0.18",
          "block_cache" : {
            "default" : {
              "type" : "memory",
              "block_cache_capacity" : 8192,
              "block_cache_blocksize" : 8192,
              "block_cache_size" : 12,
              "block_cache_hit" : 14,
              "block_cache_miss" : 0,
              "block_cache_eviction" : 0,
              "block_cache_store_fail" : 0
            }
          },
          "obs_stats" : {
            "list" : {
              "obs_list_count" : 17,
              "obs_list_ms" : 220,
              "obs_list_avg_ms" : 12
            },
            "get_meta" : {
              "obs_get_meta_count" : 79,
              "obs_get_meta_ms" : 139,
              "obs_get_meta_avg_ms" : 1
            },
            "get_obj" : {
              "obs_get_obj_count" : 12,
              "obs_get_obj_ms" : 82,
              "obs_get_obj_avg_ms" : 6
            },
            "put_obj" : {
              "obs_put_obj_count" : 12,
              "obs_put_obj_ms" : 879,
              "obs_put_obj_avg_ms" : 73
            },
            "obs_op_total" : {
              "obs_op_total_ms" : 1320,
              "obs_op_total_count" : 120,
              "obs_op_avg_ms" : 11
            }
          },
          "reader_cache" : {
            "hit_count" : 0,
            "miss_count" : 1,
            "load_success_count" : 1,
            "load_exception_count" : 0,
            "total_load_time" : 235706838,
            "eviction_count" : 0
          }
        }
      }
    }
    
  7. Run the following command to reset the cache status:
    POST _frozen_stats/reset

    Information similar to the following is displayed:

    {
      "_nodes" : {
        "total" : 1,
        "successful" : 1,
        "failed" : 0
      },
      "cluster_name" : "Es-0325-007_01",
      "nodes" : {
        "mqTdk2YRSPyOSXfesREFSg" : {
          "result" : "ok"
        }
      }
    }

    This command is used to debug performance issues. If you reset the cache status and run this command, you can check the cache command status. You do not need to run this command during service running.

  8. Run the following command to check all the frozen indexes:
    GET _cat/freeze_indices

    Information similar to the following is displayed:

    green open data2 0bNtxWDtRbOSkS4JYaUgMQ 3 0  5 0  7.9kb  7.9kb
    green open data3 oYMLvw31QnyasqUNuyP6RA 3 0 51 0 23.5kb 23.5kb
    The parameters and return values of this command are the same as those of _cat/indices of Elasticsearch.