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a6fb067a75
* Corrected en files * Split system-tables.md into separate files * Fixed links. * Fixed links. * Fixed links. * Fixed links. * Add ref to original article * Fixed links * Add toc_folder_title and translate * Add stack_trace.md, correct toc-title * Fixed links * Hypothesis testing * Hypothesis testing * Update run.sh, thanks @azat Co-authored-by: Anna Devyatova <annadevyatova@yandex-team.ru> Co-authored-by: Sergei Shtykov <bayonet@yandex-team.ru> Co-authored-by: alexey-milovidov <milovidov@yandex-team.ru>
2.5 KiB
2.5 KiB
system.zookeeper
The table does not exist if ZooKeeper is not configured. 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.
The 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:
name(String) — The name of the node.path(String) — The path to the node.value(String) — Node value.dataLength(Int32) — Size of the value.numChildren(Int32) — Number of descendants.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 deleted or added descendants.ctime(DateTime) — Time of node creation.mtime(DateTime) — Time of the last modification of the node.version(Int32) — Node version: the number of times the node was changed.cversion(Int32) — Number of added or removed descendants.aversion(Int32) — Number of changes to the ACL.ephemeralOwner(Int64) — For ephemeral nodes, the ID of the session that owns this node.
Example:
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