clickhouse-fotokopi makinesi 

Bir kümedeki tablolardan başka bir (veya aynı) kümedeki tablolara veri kopyalar.

Birden fazla çalıştırabilirsiniz clickhouse-copier aynı işi gerçekleştirmek için farklı sunuculardaki örnekler. ZooKeeper süreçleri senkronize etmek için kullanılır.

Başladıktan sonra, clickhouse-copier:

  • ZooKeeper bağlanır ve alır:

    • Kopyalama işleri.
    • Kopyalama işlerinin durumu.
  • İşleri gerçekleştirir.

    Her çalışan işlem seçer “closest” kaynak kümenin parçası ve verileri hedef kümeye kopyalar, gerekirse verileri yeniden şekillendirir.

clickhouse-copier ZooKeeper değişiklikleri izler ve anında uygular.

Ağ trafiğini azaltmak için çalıştırmanızı öneririz clickhouse-copier kaynak verilerin bulunduğu aynı sunucuda.

Clickhouse çalışan-fotokopi 

Yardımcı program el ile çalıştırılmalıdır:

$ clickhouse-copier copier --daemon --config zookeeper.xml --task-path /task/path --base-dir /path/to/dir

Parametre:

  • daemon — Starts clickhouse-copier daemon modunda.
  • config — The path to the zookeeper.xml ZooKeeper bağlantı parametreleri ile dosya.
  • task-path — The path to the ZooKeeper node. This node is used for syncing clickhouse-copier süreçleri ve depolama görevleri. Görevler saklanır $task-path/description.
  • task-file — Optional path to file with task configuration for initial upload to ZooKeeper.
  • task-upload-force — Force upload task-file düğüm zaten var olsa bile.
  • base-dir — The path to logs and auxiliary files. When it starts, clickhouse-copier oluşturuyor clickhouse-copier_YYYYMMHHSS_<PID> içinde alt dizinler $base-dir. Bu parametre atlanırsa, dizinler aşağıdaki dizinde oluşturulur clickhouse-copier başlatıldı.

Zookeeper biçimi.xml 

<yandex>
    <logger>
        <level>trace</level>
        <size>100M</size>
        <count>3</count>
    </logger>

    <zookeeper>
        <node index="1">
            <host>127.0.0.1</host>
            <port>2181</port>
        </node>
    </zookeeper>
</yandex>

Kopyalama görevlerinin yapılandırması 

<yandex>
    <!-- Configuration of clusters as in an ordinary server config -->
    <remote_servers>
        <source_cluster>
            <shard>
                <internal_replication>false</internal_replication>
                    <replica>
                        <host>127.0.0.1</host>
                        <port>9000</port>
                    </replica>
            </shard>
            ...
        </source_cluster>

        <destination_cluster>
        ...
        </destination_cluster>
    </remote_servers>

    <!-- How many simultaneously active workers are possible. If you run more workers superfluous workers will sleep. -->
    <max_workers>2</max_workers>

    <!-- Setting used to fetch (pull) data from source cluster tables -->
    <settings_pull>
        <readonly>1</readonly>
    </settings_pull>

    <!-- Setting used to insert (push) data to destination cluster tables -->
    <settings_push>
        <readonly>0</readonly>
    </settings_push>

    <!-- Common setting for fetch (pull) and insert (push) operations. Also, copier process context uses it.
         They are overlaid by <settings_pull/> and <settings_push/> respectively. -->
    <settings>
        <connect_timeout>3</connect_timeout>
        <!-- Sync insert is set forcibly, leave it here just in case. -->
        <insert_distributed_sync>1</insert_distributed_sync>
    </settings>

    <!-- Copying tasks description.
         You could specify several table task in the same task description (in the same ZooKeeper node), they will be performed
         sequentially.
    -->
    <tables>
        <!-- A table task, copies one table. -->
        <table_hits>
            <!-- Source cluster name (from <remote_servers/> section) and tables in it that should be copied -->
            <cluster_pull>source_cluster</cluster_pull>
            <database_pull>test</database_pull>
            <table_pull>hits</table_pull>

            <!-- Destination cluster name and tables in which the data should be inserted -->
            <cluster_push>destination_cluster</cluster_push>
            <database_push>test</database_push>
            <table_push>hits2</table_push>

            <!-- Engine of destination tables.
                 If destination tables have not be created, workers create them using columns definition from source tables and engine
                 definition from here.

                 NOTE: If the first worker starts insert data and detects that destination partition is not empty then the partition will
                 be dropped and refilled, take it into account if you already have some data in destination tables. You could directly
                 specify partitions that should be copied in <enabled_partitions/>, they should be in quoted format like partition column of
                 system.parts table.
            -->
            <engine>
            ENGINE=ReplicatedMergeTree('/clickhouse/tables/{cluster}/{shard}/hits2', '{replica}')
            PARTITION BY toMonday(date)
            ORDER BY (CounterID, EventDate)
            </engine>

            <!-- Sharding key used to insert data to destination cluster -->
            <sharding_key>jumpConsistentHash(intHash64(UserID), 2)</sharding_key>

            <!-- Optional expression that filter data while pull them from source servers -->
            <where_condition>CounterID != 0</where_condition>

            <!-- This section specifies partitions that should be copied, other partition will be ignored.
                 Partition names should have the same format as
                 partition column of system.parts table (i.e. a quoted text).
                 Since partition key of source and destination cluster could be different,
                 these partition names specify destination partitions.

                 NOTE: In spite of this section is optional (if it is not specified, all partitions will be copied),
                 it is strictly recommended to specify them explicitly.
                 If you already have some ready partitions on destination cluster they
                 will be removed at the start of the copying since they will be interpeted
                 as unfinished data from the previous copying!!!
            -->
            <enabled_partitions>
                <partition>'2018-02-26'</partition>
                <partition>'2018-03-05'</partition>
                ...
            </enabled_partitions>
        </table_hits>

        <!-- Next table to copy. It is not copied until previous table is copying. -->
        </table_visits>
        ...
        </table_visits>
        ...
    </tables>
</yandex>

clickhouse-copier değişiklikleri izler /task/path/description ve onları anında uygular. Örneğin, değerini değiştirirseniz max_workers, görevleri çalıştıran süreçlerin sayısı da değişecektir.

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