Overview

The landing page for each ClickHouse host: instant health status, active queries, memory, disk, and CPU at a glance.


Routes	`/overview`
Feature id	`overview`
Default access	`public`
Requires auth	No (set `CHM_FEATURE_OVERVIEW_ACCESS=authenticated` to gate)
System tables	`system.asynchronous_metrics`, `system.metrics`, `system.processes`, `system.disks`, `system.tables`
ClickHouse grants	`SELECT` on the system tables above

What it does

Overview is the first page you land on. It pulls live numbers from several system tables to answer:

Is the server healthy right now?
How many queries are running?
How much memory and disk are in use?
What is CPU load?

The page is organized into tabs: Connections, Queries, Merges, Replication, and System. Each tab shows a small set of charts that auto-refresh. There are no write operations on this page.

Pages

Page	Route	What it shows	System tables
Overview	`/overview`	CPU, memory, disk gauges; active query count; connection count; replication lag indicator	`system.asynchronous_metrics`, `system.metrics`, `system.processes`, `system.disks`, `system.tables`

Permissions & access

Overview is public by default. To restrict it:

## Env var
CHM_FEATURE_OVERVIEW_ACCESS=authenticated

## CHM_CONFIG_FILE (TOML)
[features.overview]
access = "authenticated"

To disable the feature entirely:

CHM_DISABLED_FEATURES=overview
## or
CHM_FEATURE_OVERVIEW_ENABLED=false

When disabled, the route is removed from the nav and a disabled screen is shown on direct visit.

Configuration

No feature-specific configuration. The refresh interval and caching behaviour follow the global settings:

CLICKHOUSE_MAX_EXECUTION_TIME=60   # query timeout in seconds

Notes & limitations

system.asynchronous_metrics values are recalculated by ClickHouse on a background interval (default ~1 s). The values shown are as fresh as that interval allows.
system.disks reports the disks ClickHouse knows about. If you use multiple storage policies or remote disks (S3, HDFS), all configured disks appear.
system.tables is queried to derive a table count. On clusters with many databases this can be slow; increase CLICKHOUSE_MAX_EXECUTION_TIME if overviews time out.
The Replication tab shows replication lag only when replicated tables exist on the host. The tab still appears even if there are none.