Server Settings

```
<clickhouse>
    <error_log>
        <database>system</database>
        <table>error_log</table>
        <flush_interval_milliseconds>7500</flush_interval_milliseconds>
        <collect_interval_milliseconds>1000</collect_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>
    </error_log>
</clickhouse>
```

**Disabling**

To disable `error_log` setting, you should create the following file `/etc/clickhouse-server/config.d/disable_error_log.xml` with the following content:

```
<clickhouse>
    <error_log remove="1" />
</clickhouse>
```

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`  | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

## filesystem\_caches\_path[​](#filesystem_caches_path "Direct link to filesystem_caches_path")

This setting specifies the cache path.

**Example**

```
<filesystem_caches_path>/var/lib/clickhouse/filesystem_caches/</filesystem_caches_path>
```

## format\_parsing\_thread\_pool\_queue\_size[​](#format_parsing_thread_pool_queue_size "Direct link to format_parsing_thread_pool_queue_size")

The maximum number of jobs that can be scheduled on thread pool for parsing input.

Note

A value of `0` means unlimited.

## format\_schema\_path[​](#format_schema_path "Direct link to format_schema_path")

The path to the directory with the schemes for the input data, such as schemas for the [CapnProto](/docs/interfaces/formats/CapnProto) format.

**Example**

```
<!-- Directory containing schema files for various input formats. -->
<format_schema_path>/var/lib/clickhouse/format_schemas/</format_schema_path>
```

## global\_profiler\_cpu\_time\_period\_ns[​](#global_profiler_cpu_time_period_ns "Direct link to global_profiler_cpu_time_period_ns")

Period for CPU clock timer of global profiler (in nanoseconds). Set 0 value to turn off the CPU clock global profiler. Recommended value is at least 10000000 (100 times a second) for single queries or 1000000000 (once a second) for cluster-wide profiling.

## global\_profiler\_real\_time\_period\_ns[​](#global_profiler_real_time_period_ns "Direct link to global_profiler_real_time_period_ns")

Period for real clock timer of global profiler (in nanoseconds). Set 0 value to turn off the real clock global profiler. Recommended value is at least 10000000 (100 times a second) for single queries or 1000000000 (once a second) for cluster-wide profiling.

## google\_protos\_path[​](#google_protos_path "Direct link to google_protos_path")

Defines a directory containing proto files for Protobuf types.

**Example**

```
<google_protos_path>/usr/share/clickhouse/protos/</google_protos_path>
```

## graphite[​](#graphite "Direct link to graphite")

Sending data to [Graphite](https://github.com/graphite-project).

Settings:

- `host` – The Graphite server.
- `port` – The port on the Graphite server.
- `interval` – The interval for sending, in seconds.
- `timeout` – The timeout for sending data, in seconds.
- `root_path` – Prefix for keys.
- `metrics` – Sending data from the [system.metrics](/docs/operations/system-tables/metrics) table.
- `events` – Sending deltas data accumulated for the time period from the [system.events](/docs/operations/system-tables/events) table.
- `events_cumulative` – Sending cumulative data from the [system.events](/docs/operations/system-tables/events) table.
- `asynchronous_metrics` – Sending data from the [system.asynchronous\_metrics](/docs/operations/system-tables/asynchronous_metrics) table.

You can configure multiple `<graphite>` clauses. For instance, you can use this for sending different data at different intervals.