Server Settings

Text index tokens cache policy name.

## text\_index\_tokens\_cache\_size[​](#text_index_tokens_cache_size "Direct link to text_index_tokens_cache_size")

Size of cache for text index tokens. Zero means disabled.

Note

This setting can be modified at runtime and will take effect immediately.

## text\_index\_tokens\_cache\_size\_ratio[​](#text_index_tokens_cache_size_ratio "Direct link to text_index_tokens_cache_size_ratio")

The size of the protected queue (in case of SLRU policy) in the text index tokens cache relative to the cache's total size.

## text\_log[​](#text_log "Direct link to text_log")

Settings for the [text\_log](/docs/operations/system-tables/text_log) system table for logging text messages.

The following settings can be configured by sub-tags:

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Setting Description Default Note|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | `database` Name of the database. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | `table` Name of the system table. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | `engine` [MergeTree Engine Definition](/docs/engines/table-engines/mergetree-family/mergetree#table_engine-mergetree-creating-a-table) for a system table. Cannot be used if `partition_by` or `order_by` defined. If not specified `MergeTree` is selected by default| `partition_by` [Custom partitioning key](/docs/engines/table-engines/mergetree-family/custom-partitioning-key) for a system table. If `engine` is specified for system table, `partition_by` parameter should be specified directly inside 'engine'| `ttl` Specifies the table [TTL](/docs/engines/table-engines/mergetree-family/mergetree#table_engine-mergetree-ttl). If `engine` is specified for system table, `ttl` parameter should be specified directly inside 'engine'| `order_by` [Custom sorting key](/docs/engines/table-engines/mergetree-family/mergetree#order_by) for a system table. Can't be used if `engine` defined. If `engine` is specified for system table, `order_by` parameter should be specified directly inside 'engine'| `storage_policy` Name of the storage policy to use for the table (optional). If `engine` is specified for system table, `storage_policy` parameter should be specified directly inside 'engine'| `settings` [Additional parameters](/docs/engines/table-engines/mergetree-family/mergetree#settings) that control the behavior of the MergeTree (optional). If `engine` is specified for system table, `settings` parameter should be specified directly inside 'engine'| `flush_interval_milliseconds` Interval for flushing data from the buffer in memory to the table. `7500` |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | `max_size_rows` Maximal size in lines for the logs. When the amount of non-flushed logs reaches the max\_size, logs are dumped to the disk. `1048576` |  |  |  |  |  |  |  |  |  |  |  |  | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | `reserved_size_rows` Pre-allocated memory size in lines for the logs. `8192` |  |  |  |  |  |  |  |  | | --- | --- | --- | --- | --- | --- | --- | --- | | `buffer_size_rows_flush_threshold` Threshold for amount of lines. If the threshold is reached, flushing logs to the disk is launched in background. `max_size_rows / 2` |  |  |  |  | | --- | --- | --- | --- | | `flush_on_crash` Sets whether logs should be dumped to the disk in case of a crash. `false`  | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

Additionally:

|  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- |
| Setting Description Default Value|  |  |  | | --- | --- | --- | | `level` Maximum Message Level (by default `Trace`) which will be stored in a table. `Trace` | | | | | |

**Example**

```
<clickhouse>
    <text_log>
        <level>notice</level>
        <database>system</database>
        <table>text_log</table>
        <flush_interval_milliseconds>7500</flush_interval_milliseconds>
        <max_size_rows>1048576</max_size_rows>
        <reserved_size_rows>8192</reserved_size_rows>
        <buffer_size_rows_flush_threshold>524288</buffer_size_rows_flush_threshold>
        <flush_on_crash>false</flush_on_crash>
        <!-- <partition_by>event_date</partition_by> -->
        <engine>Engine = MergeTree PARTITION BY event_date ORDER BY event_time TTL event_date + INTERVAL 30 day</engine>
    </text_log>
</clickhouse>
```

## thread\_pool\_queue\_size[​](#thread_pool_queue_size "Direct link to thread_pool_queue_size")

The maximum number of jobs that can be scheduled on the Global Thread pool. Increasing queue size leads to larger memory usage. It is recommended to keep this value equal to [`max_thread_pool_size`](/docs/operations/server-configuration-parameters/settings#max_thread_pool_size).

Note

A value of `0` means unlimited.

**Example**

```
<thread_pool_queue_size>12000</thread_pool_queue_size>
```

## threadpool\_local\_fs\_reader\_pool\_size[​](#threadpool_local_fs_reader_pool_size "Direct link to threadpool_local_fs_reader_pool_size")

The number of threads in the thread pool for reading from local filesystem when `local_filesystem_read_method = 'pread_threadpool'`.

## threadpool\_local\_fs\_reader\_queue\_size[​](#threadpool_local_fs_reader_queue_size "Direct link to threadpool_local_fs_reader_queue_size")

The maximum number of jobs that can be scheduled on the thread pool for reading from local filesystem.

## threadpool\_remote\_fs\_reader\_pool\_size[​](#threadpool_remote_fs_reader_pool_size "Direct link to threadpool_remote_fs_reader_pool_size")

Number of threads in the Thread pool used for reading from remote filesystem when `remote_filesystem_read_method = 'threadpool'`.

## threadpool\_remote\_fs\_reader\_queue\_size[​](#threadpool_remote_fs_reader_queue_size "Direct link to threadpool_remote_fs_reader_queue_size")

The maximum number of jobs that can be scheduled on the thread pool for reading from remote filesystem.

## threadpool\_writer\_pool\_size[​](#threadpool_writer_pool_size "Direct link to threadpool_writer_pool_size")

Size of background pool for write requests to object storages

## threadpool\_writer\_queue\_size[​](#threadpool_writer_queue_size "Direct link to threadpool_writer_queue_size")

Number of tasks which is possible to push into background pool for write requests to object storages