Monitor ClickHouse from your Mac's notch

What CoIsland watches in ClickHouse

Each monitor kind brings its own query and its own card in the notch.

Custom SQL

Any SELECT, WITH or SHOW, sent with readonly=1. Alert on new rows, or when the row count crosses a number.
Validation

A table, a column and a rule such as is null. CoIsland writes the SQL and shows it.
Failed queries

Each query that fails, from system.query_log: who ran it, the error and the SQL. Every replica with a cluster.
Long-running queries

A query still running past a time, from system.processes.
Stuck mutations

An ALTER UPDATE or DELETE not done after a time, and why it keeps failing.
Too many parts

A partition with more active parts than a number, before inserts slow down or fail.
Replication lag

A replica behind by more than a time, from system.replicas.
Low disk space

A disk with less free space than a share, from system.disks.

How to monitor ClickHouse from your Mac’s notch

A CoIsland monitor runs on its own schedule and opens the notch only when the answer changes: a new failed query, a mutation that stopped moving, a new row, or a count crossing a line.

-- name: Queries failing on any replica
-- kind: clickhouse.failed-queries
-- connector: events
-- every: 5m

lookback:1h cluster:default

Connect ClickHouse covers every field, the grants and each error. PostgreSQL and MySQL work the same way for SQL; all connectors share one page.

Connect it in three steps

Get the service's HTTPS address, a user and its password: ClickHouse Cloud shows them under Connect.
Add a ClickHouse connector. Test connector says who you are, the version, and which system tables the health monitors can read.
Pick a kind or an example: SQL checks every 15 minutes, failed and long queries and replication every 5, unless you change it.

Built for ClickHouse

Every query is sent with readonly=1, so the server itself refuses a write; a second statement or a write word is refused before it is sent.
The password stays in the macOS Keychain and goes only in a header, over HTTPS (plain HTTP only to a server on your Mac).
The server waits for the end of each query before it answers, so a failure is never read as half a result.
A user without access to a system table is told which grant a health monitor needs.

Then hand it to an agent

A click on the alert opens the agent in a terminal under it, with the whole alert as its first message.

Claude Code

Anthropic's coding agent, in its own CLI.
Codex

OpenAI's coding agent, in its own CLI.
Cortex Code

Snowflake's coding agent, in its own CLI.

ClickHouse questions

Can CoIsland change anything in ClickHouse?

No. Every query carries readonly=1, which makes the server refuse writes and setting changes whatever the user may do. SQL that writes, or holds a second statement, is refused before anything is sent.

Does a check wake an idle ClickHouse Cloud service?

Yes: any query wakes an idle service, which then stays on until it idles again. Check less often, or watch a service that does not idle.

Which grants do the health monitors need?

SELECT on the system table each one reads: system.query_log, system.processes, system.mutations, system.parts, system.replicas or system.disks. Test connector lists the ones the user cannot read.

Other connectors

Gmail

Hear about the emails that matter, not every email. Unread mail, chosen senders, labels, Drive comments and invitations reach your Mac's notch, and nothing is marked read.
Calendar

The calendars Calendar.app already shows (iCloud, Google, Exchange, subscriptions), or a calendar's secret ICS feed, in your Mac's notch. A countdown to your next meeting, a warning before it starts with one click to join, and news of invitations and changes.
Dock badges

One watch over every app that badges its Dock icon. Slack, Microsoft Teams, Outlook, Mail, Messages, Discord, WhatsApp or any other app tells the notch when its count goes up, with no account or token for any of them.
Apple Mail

Every account Mail already has, iCloud, Exchange, Gmail or any IMAP, in your Mac's notch. New unread mail in your inboxes, or only from the people and domains you pick, with no password given to CoIsland.
GitHub

Monitor GitHub for what needs you, not everything that moves. Reviews, failed Actions runs, releases and security alerts, on github.com or GitHub Enterprise.
Vercel

Watch Vercel deployments, stuck builds and project domains. A failed build reaches your Mac's notch with its error, and the alert shows the failing step and the end of the build log.
GitLab

Watch GitLab on gitlab.com or a self-managed instance. A review request, a failed pipeline or a new to-do reaches your Mac's notch, and the alert shows the merge request with its description and comments, or the jobs that failed.
Cloudflare

Watch Cloudflare Pages deployments, Worker errors and your zones. A failed build reaches your Mac's notch with its failing step, and the alert shows the end of the build log.
Render

Watch the deploys of your Render services and whether they are suspended. A failed deploy reaches your Mac's notch with its commit, and a suspended service says who suspended it.
Jira

Monitor Jira with the JQL you already write. New matches, status changes, comments, SLAs near a breach and sprint scope reach your Mac's notch, from Jira Cloud or Data Center.
Linear

Monitor Linear with its own issue filters. New matches, status changes, issues in triage, SLAs at risk, your mentions and projects going off track reach your Mac's notch.
Confluence

Monitor Confluence Cloud without the email digest. Mentions, page edits, new comments, your tasks and any CQL reach your Mac's notch, signed in with the same API token as Jira.
Asana

Know what landed on your plate and what is late. Tasks assigned to you, due dates, new tasks in a project and comments on your tasks reach your Mac's notch, read with your own Asana token.
ClickUp

Know what is yours and what is late. Tasks assigned to you, their status and due dates, and new tasks in a list reach your Mac's notch, read with your own ClickUp token.
Todoist

Know what is due before it is late. Tasks due today or overdue, new tasks in a project, or any filter you already use reach your Mac's notch, read with your own Todoist token.
Notion

Know when a Notion row lands on you, a page you care about changes, or someone comments. Read with your own personal access token, straight from your Mac.
Shortcut

Know when a story lands on you, moves to review, or an iteration is about to end with work still open. Read with your own Shortcut API token.
Airtable

Know when a record starts matching a formula, or someone edits one, without keeping the base open. Read with a personal access token scoped to the bases you pick.
Reminders

The reminders Reminders.app already has, iCloud or Exchange, in your Mac's notch. A warning before one is due, another when it is overdue, and news when someone adds to a list you share.
Sentry

Monitor Sentry with the searches you already write. New errors, regressions, issues assigned to you, failing crons, sites down and new releases reach your Mac's notch, from sentry.io or your own Sentry.
PagerDuty

Know at a glance whether you have to move. Incidents assigned to you, your teams' incidents and your on-call shifts reach your Mac's notch, read with your own PagerDuty token.
Datadog

Know when a Datadog monitor fires without living in the dashboard. Monitors in alert, incidents and metric thresholds reach your Mac's notch, read with your own application key.
New Relic

Run the NRQL you already trust, and see New Relic's alert issues the moment they open, in your Mac's notch, with your own User key.
Langfuse

Your LLM app fails, overspends or gets a thumbs down, and the notch says so. Langfuse's errors, cost, latency and scores reach your Mac, read with a project's key pair on Langfuse Cloud or your own Langfuse.
Snowflake

Monitor Snowflake with read-only SQL. A failed task, a row that breaks a rule or a sudden spike reaches your Mac's notch, and Cortex Code, Claude Code or Codex can take it from there.
Databricks

Monitor Databricks from your Mac's notch. A failed job run, a failed pipeline update or a triggered SQL alert reaches you for free, and read-only SQL on a warehouse watches the data itself.
dbt

Monitor dbt from your Mac's notch. A job run that fails, a run that takes too long or a source that goes stale reaches you, with the failing step's log one click away.
PostHog

Monitor PostHog from your Mac's notch. A HogQL query that finds something, an insight crossing a number or an exception seen for the first time reaches you without opening a dashboard.
Supabase

Monitor Supabase from your Mac's notch. A paused or unhealthy project, a new security lint or a row your SQL finds reaches you, with nothing but a personal access token.
PostgreSQL

Monitor PostgreSQL from your Mac's notch. A read-only query checks your database on a schedule, and each new row it finds reaches you once.
MySQL

Monitor MySQL and MariaDB from your Mac's notch. A read-only query checks your database on a schedule, and each new row it finds reaches you once.
HTTP / JSON

Point CoIsland at any address. A JSON value that changes or crosses a threshold, a new element of a JSON list, or a page that goes down or starts saying "In stock" reaches your Mac's notch.
RSS / Atom

Watch any feed. A new GitHub release, a new post on a blog, or a Hacker News story that says your keyword reaches your Mac's notch, with the article one click away.
Status pages

Know when a service you depend on is down before your users tell you. Incidents, their updates, components going down and the page's overall status reach your Mac's notch.
Shell command

Run a command or a script on your Mac on a schedule. A new line it prints, a new object in its JSON, or a failure reaches the notch once.
Stripe

Watch failed payments, disputes, subscriptions, payouts and your balance with a read-only restricted key. A declined card reaches your Mac's notch with the amount, the customer and the bank's reason.

Put your work stack in the notch

~~Regular price: $59.99~~ Early bird price: $19.99 once, for 2 Macs. Native for Apple Silicon, macOS 14 and later.

Early bird price until October 25

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What CoIsland watches in ClickHouse

Custom SQL

Validation

Failed queries

Long-running queries

Stuck mutations

Too many parts

Replication lag

Low disk space