chmonitorConnection errors
Fix "Test connection" failures in ClickHouse Monitor — host not allowed, invalid URL, authentication failed, missing permissions, DNS, refused, TLS, and timeout errors.
When you add a ClickHouse host and click Test connection, the dashboard classifies any failure into one of the kinds below and links you straight here. Find your error and follow the fix.
Fix your error
Each entry lists the message you saw (the symptom) and the fix. The dashboard shows the raw ClickHouse or network error as technical detail underneath the classified error.
Still stuck?
Reproduce the failure with curl
Test the same URL and credentials outside the dashboard to isolate whether it's a network or a credentials problem:
echo 'SELECT version()' | curl "https://host:8443/?user=monitoring&password=…" --data-binary @-For private clusters, self-host ClickHouse Monitor — the same dashboard, with no public-network requirement.
Related
Troubleshooting
Diagnose connection, auth, performance, and Kubernetes probe failures.
ClickHouse requirements
The least-privilege monitoring user and grants the dashboard needs.
Connect a firewalled ClickHouse
Reach a firewalled cluster from Cloud with a tunnel or dedicated egress IPs.
Self-host
Run ClickHouse Monitor inside your network with no public-address restriction.