Expert incident response for ClickHouse

Our founding team picks up your incident, and Polylane's agents dig through your logs, metrics, traces and code with them.

Real engineers who've carried the pager The team has been on-call at Cloudflare, Webflow, Groq, Twilio, and Robinhood. They've been where you are right now.
Multi-cloud incident response Polylane investigates incidents across AWS, Cloudflare, Vercel, Kubernetes and the rest of your stack, from the edge to the database.
Unified context & investigation Logs, metrics, traces, deploys and code in one context graph. Connect in minutes, not weeks.
Least-privilege access New cloud accounts connect read-only, with scoped credentials. Nothing in production changes unless you allow it.

My ClickHouse database is failing. What should I do?

On ClickHouse Cloud, check status.clickhouse.com first. Then read the error code: MEMORY_LIMIT_EXCEEDED (241) means a query needs more memory than allowed, TOO_MANY_SIMULTANEOUS_QUERIES (202) means you hit the concurrency limit, and TOO_MANY_PARTS (252) means inserts arrive in batches too small to merge. system.query_log and system.errors show what fails.

1 Check ClickHouse Cloud's status status.clickhouse.com lists incidents by cloud and region. If yours shows one, the problem is upstream.
2 Read the error code MEMORY_LIMIT_EXCEEDED (241) is a query that needs too much memory, TOO_MANY_SIMULTANEOUS_QUERIES (202) the concurrency limit, and TOO_MANY_PARTS (252) too many small inserts.
3 Find the queries system.query_log has every query with its duration, memory and exception, and system.processes shows what is running right now.
4 Line it up with your last change Compare the start of the errors with recent schema changes, new materialized views and changes to how often you insert. A materialized view runs on every insert into its source table.

Guides for the errors you're seeing

ClickHouse Code 117 “Expected end of line”: causes and fixes

How we resolve active incidents

1 Rapid onboarding A Polylane engineer reaches out, connects Polylane to your clouds, code and telemetry, and confirms what's affected.
2 Investigation & mitigation Polylane's agents investigate across logs, metrics, traces and recent changes, and an engineer works with you on the right mitigation.
3 Remediation, validation & monitoring The fix lands in your repo for your team to review. Polylane checks that things are back to normal and keeps watching every deploy after it.

Why teams choose Polylane

Every cloud in one graph AWS, Cloudflare, Vercel, Kubernetes and more, mapped into one context graph with your code.

Connected in minutes Connect with OAuth or the CLI. No agents to install, no code changes.

Real engineers on the other end Your report goes straight to the people who build Polylane.

Evidence for every claim Every finding links to the log line, metric or deploy behind it.

You stay in control Read-only by default. Nothing writes to production unless you allow it, and you can switch it off at any time.

Works with your coding agents Claude Code, Cursor and other agents reach Polylane over MCP, so they can dig in with you.

“When I installed polylane for the first time my expectations were pretty low. Couple weeks in I’m speechless - it just works everything is all of a sudden fully autonomous”

Jason @Jasonpraful

Common questions

Is ClickHouse Cloud down or is it my app?

Check status.clickhouse.com. If it shows no incident, the error code and system.query_log usually point at your own queries or inserts.

What does TOO_MANY_PARTS mean?

Inserts are creating parts faster than ClickHouse can merge them, usually from many small inserts. Batch them into fewer, larger inserts, or turn on async inserts.

What does MEMORY_LIMIT_EXCEEDED mean?

A query needed more memory than its limit allows. Find it in system.query_log and look at its large GROUP BY or JOIN steps.

Who will help me with a ClickHouse incident?

Our founding team, engineers who have carried the pager for production systems at scale, working with Polylane's agents across your ClickHouse services, code and telemetry.