system.zookeeper
----------------

Allows reading data from the ZooKeeper cluster defined in the config.
The query must have a 'path' equality condition in the WHERE clause. This is the path in ZooKeeper for the children that you want to get data for.

Query SELECT * FROM system.zookeeper WHERE path = '/clickhouse' outputs data for all children on the /clickhouse node.
To output data for all root nodes, write path = '/'.
If the path specified in 'path' doesn't exist, an exception will be thrown.

Columns:

.. code-block:: text

  name String          - Name of the node.
  path String          - Path to the node.
  value String         - Value of the node.
  dataLength Int32     - Size of the value.
  numChildren Int32    - Number of children.
  czxid Int64          - ID of the transaction that created the node.
  mzxid Int64          - ID of the transaction that last changed the node.
  pzxid Int64          - ID of the transaction that last added or removed children.
  ctime DateTime       - Time of node creation.
  mtime DateTime       - Time of the last node modification.
  version Int32        - Node version - the number of times the node was changed.
  cversion Int32       - Number of added or removed children.
  aversion Int32       - Number of changes to ACL.
  ephemeralOwner Int64 - For ephemeral nodes, the ID of the session that owns this node.

Example:

.. code-block:: text

  SELECT *
  FROM system.zookeeper
  WHERE path = '/clickhouse/tables/01-08/visits/replicas'
  FORMAT Vertical

  Row 1:
  ──────
  name:           example01-08-1.yandex.ru
  value:
  czxid:          932998691229
  mzxid:          932998691229
  ctime:          2015-03-27 16:49:51
  mtime:          2015-03-27 16:49:51
  version:        0
  cversion:       47
  aversion:       0
  ephemeralOwner: 0
  dataLength:     0
  numChildren:    7
  pzxid:          987021031383
  path:           /clickhouse/tables/01-08/visits/replicas

  Row 2:
  ──────
  name:           example01-08-2.yandex.ru
  value:
  czxid:          933002738135
  mzxid:          933002738135
  ctime:          2015-03-27 16:57:01
  mtime:          2015-03-27 16:57:01
  version:        0
  cversion:       37
  aversion:       0
  ephemeralOwner: 0
  dataLength:     0
  numChildren:    7
  pzxid:          987021252247
  path:           /clickhouse/tables/01-08/visits/replicas