managing-cluster-settings（管理集群设置）

Managing Cluster Settings

Reviews, audits, and modifies CockroachDB cluster settings. Before providing procedures, this skill gathers context to determine which settings are available and which modification approach to recommend for the operator's tier.

When to Use This Skill

• Auditing cluster configuration for production readiness
• Identifying settings that deviate from defaults
• Tuning performance, replication, or admission control
• Verifying settings after an upgrade or incident
• Understanding which settings are modifiable on your tier
• Managing enterprise license installation and renewal (Self-Hosted)

For version management: Use upgrading-cluster-version — do not change settings during an upgrade. For health checks: Use reviewing-cluster-health.

Step 1: Gather Context

Required Context

Additional Context (by tier)

If Self-Hosted:

If Advanced or BYOC:

If Standard or Basic: No additional context needed — settings access is limited. Session variables are the primary tuning mechanism.

Context-Driven Routing

Audit Queries (All Tiers)

These read-only queries work on Self-Hosted and Advanced/BYOC. Standard and Basic may have restricted visibility — see tier-specific sections below.

Non-Default Settings

SELECT variable, value, setting_type, description
FROM [SHOW ALL CLUSTER SETTINGS]
WHERE value != default_value ORDER BY variable;

Production-Critical Settings

SELECT variable, value FROM [SHOW ALL CLUSTER SETTINGS]
WHERE variable IN (
  'kv.rangefeed.enabled', 'sql.stats.automatic_collection.enabled',
  'server.time_until_store_dead', 'admission.kv.enabled',
  'gc.ttlseconds', 'cluster.preserve_downgrade_option',
  'sql.defaults.idle_in_transaction_session_timeout'
) ORDER BY variable;

Search by Keyword

SELECT variable, value, description FROM [SHOW ALL CLUSTER SETTINGS]
WHERE variable LIKE '%<keyword>%' OR description LIKE '%<keyword>%'
ORDER BY variable;

See sql-queries reference for additional audit queries. See recommended-values reference for production-recommended settings.

Self-Hosted Settings

Applies when: Tier = Self-Hosted

Full control over all cluster settings and node-level start flags.

Modify a Setting

SHOW CLUSTER SETTING <name>;          -- Document current value first
SET CLUSTER SETTING <name> = <value>; -- Apply
SHOW CLUSTER SETTING <name>;          -- Verify

Reset to Default

RESET CLUSTER SETTING <name>;

Node-Level Settings (require node restart)

Node-level settings are cockroach start flags and cannot be changed at runtime. To change: drain the node, stop the process, update flags, restart. See performing-cluster-maintenance.

See node-level-settings reference for the complete list of start flags.

License Management

CockroachDB Self-Hosted requires an enterprise license for features like backup/restore, changefeeds, encryption at rest, and multi-region capabilities. The license is stored as a cluster setting.

Check current license:

SHOW CLUSTER SETTING cluster.organization;
SHOW CLUSTER SETTING enterprise.license;

Install or renew a license:

SET CLUSTER SETTING cluster.organization = '<organization-name>';
SET CLUSTER SETTING enterprise.license = '<license-key>';

Verify license is active:

SELECT * FROM [SHOW CLUSTER SETTING enterprise.license];

License expiry: Expired licenses do not cause data loss or cluster unavailability. Enterprise features (backups, CDC, EAR) stop working until renewed. Core features remain available. Monitor license expiry proactively.

CockroachDB Core (free): If running without an enterprise license, no license management is needed. Core features are always available.

Advanced / BYOC Settings

Applies when: Tier = Advanced or BYOC

Most SQL-level cluster settings are modifiable. Infrastructure-level settings are managed by Cockroach Labs.

Modifiable (common examples)

SET CLUSTER SETTING sql.defaults.idle_in_transaction_session_timeout = '300s';
SET CLUSTER SETTING sql.defaults.statement_timeout = '30s';
SET CLUSTER SETTING kv.rangefeed.enabled = true;
-- gc.ttlseconds is a zone configuration parameter, not a cluster setting
ALTER RANGE default CONFIGURE ZONE USING gc.ttlseconds = 86400;

Restricted (managed by CRL)

Settings managed by Cockroach Labs that cannot be modified:

• server.time_until_store_dead
• kv.snapshot_rebalance.max_rate
• cluster.preserve_downgrade_option (use Cloud Console for upgrades)
• Node-level flags (--cache, --max-sql-memory) — managed by CRL

If a modification is rejected, the error will indicate the setting is managed by CockroachDB Cloud. Use Cloud Console or contact support.

License: Enterprise license is managed automatically by Cockroach Labs on Advanced/BYOC. No customer action needed.

See cloud-restricted-settings reference for the full list.

Standard Settings

Applies when: Tier = Standard

Standard is a multi-tenant managed service. Most cluster settings are not modifiable because changes could affect other tenants. Use session variables as the primary tuning mechanism.

Session Variables (recommended approach)

-- Per-session
SET statement_timeout = '30s';

-- Default for all sessions (preferred over sql.defaults.*)
ALTER ROLE ALL SET statement_timeout = '30s';
ALTER ROLE ALL SET idle_in_transaction_session_timeout = '300s';

What You Can Configure

• Session-level timeouts and defaults via SET and ALTER ROLE
• SQL-level behavior through session variables

What Is Managed by CRL

• All infrastructure settings (replication, admission control, storage)
• Compute and networking — configured via Cloud Console

Note: SHOW ALL CLUSTER SETTINGS may return a limited set of settings on Standard.

Basic Settings

Applies when: Tier = Basic

Basic is a serverless offering with minimal settings access. Infrastructure is fully managed and auto-scales. Use session variables for SQL-level tuning.

Session Variables

SET statement_timeout = '30s';
ALTER ROLE ALL SET statement_timeout = '30s';

Cloud Console Configuration

• Spending limits
• IP allowlists
• Region selection

All other configuration is managed by Cockroach Labs. If more control over settings is needed, consider upgrading to Standard or Advanced.

Safety Considerations

Read-only queries are safe on all tiers.

Before modifying any setting:

1. Document the current value (for rollback)
2. Verify you are NOT mid-upgrade
3. Understand the impact (check description field)
4. Change one setting at a time
5. Monitor for 15-30 minutes before making additional changes

Risk levels:

• Low: sql.defaults.statement_timeout, diagnostics.reporting.enabled
• Medium: gc.ttlseconds, kv.snapshot_rebalance.max_rate
• High: cluster.preserve_downgrade_option, admission.kv.enabled

Critical: Never change settings during a rolling upgrade. Cluster settings affect ALL workloads on the cluster — prefer session variables for narrower scope when possible.

See safety-guide reference for detailed risk assessments per setting.

Troubleshooting

References

Skill references:

• SQL audit queries
• Recommended production values
• Node-level settings (start flags)
• Cloud-restricted settings
• Safety guide

Related skills:

• reviewing-cluster-health
• upgrading-cluster-version

Official CockroachDB Documentation:

• Cluster Settings
• SET CLUSTER SETTING
• Production Checklist