Settings

Audit ClickHouse configuration without SQL — see every server setting with non-default values highlighted, plus MergeTree and Replicated MergeTree engine settings.

What it does

The Settings section has two distinct purposes.

• ClickHouse server settings (at /settings) queries system.settings to list all server-level configuration values. The table highlights values that have been changed from their defaults, making it easy to audit non-default configuration. Use it to spot unexpected overrides or verify that a setting change took effect.
• MergeTree settings (at /mergetree-settings) queries system.merge_tree_settings to show engine-specific settings for MergeTree tables. The Replicated MergeTree settings page (at /replicated-merge-tree-settings) queries system.replicated_merge_tree_settings.

Pages

Using it

• Open /settings to review all server settings; non-default values are highlighted so you can spot unexpected overrides or confirm a change took effect.
• Open /mergetree-settings to inspect MergeTree engine settings, and /replicated-merge-tree-settings for Replicated MergeTree settings with changed-from-default values flagged.
• Open /settings-diff to compare system.settings and system.merge_tree_settings across saved hosts (env, per-user, and browser connections), or node vs node on the current cluster. One saved host compares against setting defaults — add another host to diff a second node. Two or more hosts keep an all-hosts matrix, with an optional pair picker. The comparison table supports search, filters, sort, column resize and reorder, density, and CSV export.
• To change a setting, use ClickHouse SQL (SET, ALTER TABLE ... MODIFY SETTING) or edit the server config — these pages are read-only. chmonitor never writes config.xml.

Permissions & access

All three pages share the settings feature id.

CHM_FEATURE_SETTINGS_ACCESS=authenticated

CHM_FEATURE_SETTINGS_ENABLED=false

[features.settings]
enabled = true
access = "authenticated"

Configuration

No feature-specific environment variables. The pages are read-only — chmonitor never writes to ClickHouse settings.

Notes & limitations

• system.settings reflects the settings in effect for the connection user, not global defaults. User-level overrides via profiles can differ from server defaults.
• system.merge_tree_settings and system.replicated_merge_tree_settings are available on all recent ClickHouse versions (23.x+). On older versions they may be absent, in which case the page shows an empty state.
• These pages are read-only. To change a setting, use ClickHouse SQL (SET, ALTER TABLE ... MODIFY SETTING) or edit the server config.

Related