# ClickHouse Input Plugin

This plugin gathers statistics data from a [ClickHouse server][clickhouse].
Users on Clickhouse Cloud will not see the Zookeeper metrics as they may not
have permissions to query those tables.

⭐ Telegraf v1.14.0
🏷️ server
💻 all

[clickhouse]: https://github.com/ClickHouse/ClickHouse

## Global configuration options <!-- @/docs/includes/plugin_config.md -->

In addition to the plugin-specific configuration settings, plugins support
additional global and plugin configuration settings. These settings are used to
modify metrics, tags, and field or create aliases and configure ordering, etc.
See the [CONFIGURATION.md][CONFIGURATION.md] for more details.

[CONFIGURATION.md]: ../../../docs/CONFIGURATION.md#plugins

## Configuration

```toml @sample.conf
# Read metrics from one or many ClickHouse servers
[[inputs.clickhouse]]
  ## Username for authorization on ClickHouse server
  username = "default"

  ## Password for authorization on ClickHouse server
  # password = ""

  ## HTTP(s) timeout while getting metrics values
  ## The timeout includes connection time, any redirects, and reading the
  ## response body.
  # timeout = 5s

  ## List of servers for metrics scraping
  ## metrics scrape via HTTP(s) clickhouse interface
  ## https://clickhouse.tech/docs/en/interfaces/http/
  servers = ["http://127.0.0.1:8123"]

  ## Server Variant
  ## When set to "managed", some queries are excluded from being run. This is
  ## useful for instances hosted in ClickHouse Cloud where certain tables are
  ## not available.
  # variant = "self-hosted"

  ## If "auto_discovery"" is "true" plugin tries to connect to all servers
  ## available in the cluster with using same "user:password" described in
  ## "user" and "password" parameters and get this server hostname list from
  ## "system.clusters" table. See
  ## - https://clickhouse.tech/docs/en/operations/system_tables/#system-clusters
  ## - https://clickhouse.tech/docs/en/operations/server_settings/settings/#server_settings_remote_servers
  ## - https://clickhouse.tech/docs/en/operations/table_engines/distributed/
  ## - https://clickhouse.tech/docs/en/operations/table_engines/replication/#creating-replicated-tables
  # auto_discovery = true

  ## Filter cluster names in "system.clusters" when "auto_discovery" is "true"
  ## when this filter present then "WHERE cluster IN (...)" filter will apply
  ## please use only full cluster names here, regexp and glob filters is not
  ## allowed for "/etc/clickhouse-server/config.d/remote.xml"
  ## <yandex>
  ##  <remote_servers>
  ##    <my-own-cluster>
  ##        <shard>
  ##          <replica><host>clickhouse-ru-1.local</host><port>9000</port></replica>
  ##          <replica><host>clickhouse-ru-2.local</host><port>9000</port></replica>
  ##        </shard>
  ##        <shard>
  ##          <replica><host>clickhouse-eu-1.local</host><port>9000</port></replica>
  ##          <replica><host>clickhouse-eu-2.local</host><port>9000</port></replica>
  ##        </shard>
  ##    </my-own-cluster>
  ##  </remote_servers>
  ##
  ## </yandex>
  ##
  ## example: cluster_include = ["my-own-cluster"]
  # cluster_include = []

  ## Filter cluster names in "system.clusters" when "auto_discovery" is
  ## "true" when this filter present then "WHERE cluster NOT IN (...)"
  ## filter will apply
  ##    example: cluster_exclude = ["my-internal-not-discovered-cluster"]
  # cluster_exclude = []

  ## Optional TLS Config
  # tls_ca = "/etc/telegraf/ca.pem"
  # tls_cert = "/etc/telegraf/cert.pem"
  # tls_key = "/etc/telegraf/key.pem"
  ## Use TLS but skip chain & host verification
  # insecure_skip_verify = false
```

## Metrics

- clickhouse_events (see [system.events][] for details)
  - tags:
    - source (ClickHouse server hostname)
    - cluster (Name of the cluster [optional])
    - shard_num (Shard number in the cluster [optional])
  - fields:
    - all rows from [system.events][]

- clickhouse_metrics (see [system.metrics][] for details)
  - tags:
    - source (ClickHouse server hostname)
    - cluster (Name of the cluster [optional])
    - shard_num (Shard number in the cluster [optional])
  - fields:
    - all rows from [system.metrics][]

- clickhouse_asynchronous_metrics (see [system.asynchronous_metrics][]
  for details)
  - tags:
    - source (ClickHouse server hostname)
    - cluster (Name of the cluster [optional])
    - shard_num (Shard number in the cluster [optional])
  - fields:
    - all rows from [system.asynchronous_metrics][]

- clickhouse_tables
  - tags:
    - source (ClickHouse server hostname)
    - table
    - database
    - cluster (Name of the cluster [optional])
    - shard_num (Shard number in the cluster [optional])
  - fields:
    - bytes
    - parts
    - rows

- clickhouse_zookeeper (see [system.zookeeper][] for details)
  - tags:
    - source (ClickHouse server hostname)
    - cluster (Name of the cluster [optional])
    - shard_num (Shard number in the cluster [optional])
  - fields:
    - root_nodes (count of node where path=/)

- clickhouse_replication_queue (see [system.replication_queue][] for details)
  - tags:
    - source (ClickHouse server hostname)
    - cluster (Name of the cluster [optional])
    - shard_num (Shard number in the cluster [optional])
  - fields:
    - too_many_tries_replicas (count of replicas which have `num_tries > 1`)

- clickhouse_detached_parts (see [system.detached_parts][] for details)
  - tags:
    - source (ClickHouse server hostname)
    - cluster (Name of the cluster [optional])
    - shard_num (Shard number in the cluster [optional])
  - fields:
    - detached_parts (total detached parts for all tables and databases
      from [system.detached_parts][])

- clickhouse_dictionaries (see [system.dictionaries][] for details)
  - tags:
    - source (ClickHouse server hostname)
    - cluster (Name of the cluster [optional])
    - shard_num (Shard number in the cluster [optional])
    - dict_origin (xml Filename when dictionary created from *_dictionary.xml,
      database.table when dictionary created from DDL)
  - fields:
    - is_loaded (0 - when dictionary data not successful load, 1 - when
      dictionary data loading fail
    - bytes_allocated (bytes allocated in RAM after a dictionary loaded)

- clickhouse_mutations (see [system.mutations][] for details)
  - tags:
    - source (ClickHouse server hostname)
    - cluster (Name of the cluster [optional])
    - shard_num (Shard number in the cluster [optional])
  - fields:
    - running - gauge which show how much mutation doesn't complete now
    - failed - counter which show total failed mutations from first
      clickhouse-server run
    - completed - counter which show total successful finished mutations
      from first clickhouse-server run

- clickhouse_disks (see [system.disks][] for details)
  - tags:
    - source (ClickHouse server hostname)
    - cluster (Name of the cluster [optional])
    - shard_num (Shard number in the cluster [optional])
    - name (disk name in storage configuration)
    - path (path to disk)
  - fields:
    - free_space_percent - 0-100, gauge which show current percent of
      free disk space bytes relative to total disk space bytes
    - keep_free_space_percent - 0-100, gauge which show current percent
      of required keep free disk bytes relative to total disk space bytes

- clickhouse_processes (see [system.processes][] for details)
  - tags:
    - source (ClickHouse server hostname)
    - cluster (Name of the cluster [optional])
    - shard_num (Shard number in the cluster [optional])
  - fields:
    - percentile_50 - float gauge which show 50% percentile (quantile 0.5) for
      `elapsed` field of running processes
    - percentile_90 - float gauge which show 90% percentile (quantile 0.9) for
      `elapsed` field of running processes
    - longest_running - float gauge which show maximum value for `elapsed`
      field of running processes

- clickhouse_text_log (see [system.text_log][] for details)
  - tags:
    - source (ClickHouse server hostname)
    - cluster (Name of the cluster [optional])
    - shard_num (Shard number in the cluster [optional])
    - level (message level, only messages with level less or equal Notice are
      collected)
  - fields:
    - messages_last_10_min - gauge which show how many messages collected

## Example Output

```text
clickhouse_events,cluster=test_cluster_two_shards_localhost,host=kshvakov,source=localhost,shard_num=1 read_compressed_bytes=212i,arena_alloc_chunks=35i,function_execute=85i,merge_tree_data_writer_rows=3i,rw_lock_acquired_read_locks=421i,file_open=46i,io_buffer_alloc_bytes=86451985i,inserted_bytes=196i,regexp_created=3i,real_time_microseconds=116832i,query=23i,network_receive_elapsed_microseconds=268i,merge_tree_data_writer_compressed_bytes=1080i,arena_alloc_bytes=212992i,disk_write_elapsed_microseconds=556i,inserted_rows=3i,compressed_read_buffer_bytes=81i,read_buffer_from_file_descriptor_read_bytes=148i,write_buffer_from_file_descriptor_write=47i,merge_tree_data_writer_blocks=3i,soft_page_faults=896i,hard_page_faults=7i,select_query=21i,merge_tree_data_writer_uncompressed_bytes=196i,merge_tree_data_writer_blocks_already_sorted=3i,user_time_microseconds=40196i,compressed_read_buffer_blocks=5i,write_buffer_from_file_descriptor_write_bytes=3246i,io_buffer_allocs=296i,created_write_buffer_ordinary=12i,disk_read_elapsed_microseconds=59347044i,network_send_elapsed_microseconds=1538i,context_lock=1040i,insert_query=1i,system_time_microseconds=14582i,read_buffer_from_file_descriptor_read=3i 1569421000000000000
clickhouse_asynchronous_metrics,cluster=test_cluster_two_shards_localhost,host=kshvakov,source=localhost,shard_num=1 jemalloc.metadata_thp=0i,replicas_max_relative_delay=0i,jemalloc.mapped=1803177984i,jemalloc.allocated=1724839256i,jemalloc.background_thread.run_interval=0i,jemalloc.background_thread.num_threads=0i,uncompressed_cache_cells=0i,replicas_max_absolute_delay=0i,mark_cache_bytes=0i,compiled_expression_cache_count=0i,replicas_sum_queue_size=0i,number_of_tables=35i,replicas_max_merges_in_queue=0i,replicas_max_inserts_in_queue=0i,replicas_sum_merges_in_queue=0i,replicas_max_queue_size=0i,mark_cache_files=0i,jemalloc.background_thread.num_runs=0i,jemalloc.active=1726210048i,uptime=158i,jemalloc.retained=380481536i,replicas_sum_inserts_in_queue=0i,uncompressed_cache_bytes=0i,number_of_databases=2i,jemalloc.metadata=9207704i,max_part_count_for_partition=1i,jemalloc.resident=1742442496i 1569421000000000000
clickhouse_metrics,cluster=test_cluster_two_shards_localhost,host=kshvakov,source=localhost,shard_num=1 replicated_send=0i,write=0i,ephemeral_node=0i,zoo_keeper_request=0i,distributed_files_to_insert=0i,replicated_fetch=0i,background_schedule_pool_task=0i,interserver_connection=0i,leader_replica=0i,delayed_inserts=0i,global_thread_active=41i,merge=0i,readonly_replica=0i,memory_tracking_in_background_schedule_pool=0i,memory_tracking_for_merges=0i,zoo_keeper_session=0i,context_lock_wait=0i,storage_buffer_bytes=0i,background_pool_task=0i,send_external_tables=0i,zoo_keeper_watch=0i,part_mutation=0i,disk_space_reserved_for_merge=0i,distributed_send=0i,version_integer=19014003i,local_thread=0i,replicated_checks=0i,memory_tracking=0i,memory_tracking_in_background_processing_pool=0i,leader_election=0i,revision=54425i,open_file_for_read=0i,open_file_for_write=0i,storage_buffer_rows=0i,rw_lock_waiting_readers=0i,rw_lock_waiting_writers=0i,rw_lock_active_writers=0i,local_thread_active=0i,query_preempted=0i,tcp_connection=1i,http_connection=1i,read=2i,query_thread=0i,dict_cache_requests=0i,rw_lock_active_readers=1i,global_thread=43i,query=1i 1569421000000000000
clickhouse_tables,cluster=test_cluster_two_shards_localhost,database=system,host=kshvakov,source=localhost,shard_num=1,table=trace_log bytes=754i,parts=1i,rows=1i 1569421000000000000
clickhouse_tables,cluster=test_cluster_two_shards_localhost,database=default,host=kshvakov,source=localhost,shard_num=1,table=example bytes=326i,parts=2i,rows=2i 1569421000000000000
```

[system.asynchronous_metrics]: https://clickhouse.tech/docs/en/operations/system-tables/asynchronous_metrics/
[system.detached_parts]: https://clickhouse.tech/docs/en/operations/system-tables/detached_parts/
[system.dictionaries]: https://clickhouse.tech/docs/en/operations/system-tables/dictionaries/
[system.disks]: https://clickhouse.tech/docs/en/operations/system-tables/disks/
[system.events]: https://clickhouse.tech/docs/en/operations/system-tables/events/
[system.metrics]: https://clickhouse.tech/docs/en/operations/system-tables/metrics/
[system.mutations]: https://clickhouse.tech/docs/en/operations/system-tables/mutations/
[system.processes]: https://clickhouse.tech/docs/en/operations/system-tables/processes/
[system.replication_queue]:https://clickhouse.com/docs/en/operations/system-tables/replication_queue/
[system.text_log]: https://clickhouse.tech/docs/en/operations/system-tables/text_log/
[system.zookeeper]: https://clickhouse.tech/docs/en/operations/system-tables/zookeeper/