Skip to content

Commit 9ee9c73

Browse files
clone1018clone1018
committed
Adding Postgres & MySQL docs
1 parent e26c070 commit 9ee9c73

File tree

5 files changed

+196
-1
lines changed

5 files changed

+196
-1
lines changed

‎content/en/docs/_overview.md‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -38,7 +38,7 @@ QueryCanary helps you recognize that by letting you:
3838

3939
## How It Works
4040
### 1. Connect your database
41-
We currently support Postgres + SSH tunneling. Our Quickstart will walk you through setting up a read only user.
41+
We currently support [Postgres](/docs/postgresql/) / [MySQL](/docs/mysql/) + [SSH tunneling](/docs/ssh-tunnel/). Our Quickstart will walk you through setting up a read only user.
4242

4343
More database engines will be introduced as requested, if you need one, please email support@querycanary.com
4444

‎content/en/docs/b1.postgresql.md‎

Lines changed: 108 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,108 @@
1+
---
2+
title: Using PostgreSQL with QueryCanary
3+
slug: servers/postgresql
4+
---
5+
QueryCanary fully supports PostgreSQL for production data monitoring. This guide walks you through connecting your database, writing SQL checks, and troubleshooting common issues.
6+
7+
## Overview
8+
9+
QueryCanary connects directly to your PostgreSQL database — with or without SSH tunneling — and allows you to define SQL checks to monitor important conditions in your data (e.g. low signups, null prices, broken joins).
10+
11+
You can:
12+
13+
- Run scheduled SQL queries on your prod database
14+
- Set expectations or anomaly detection on results
15+
- Receive alerts via email or Slack when something looks off
16+
17+
## Requirements
18+
19+
- PostgreSQL version 10 or higher
20+
- A read-only database user
21+
- Access via direct TCP or through an SSH tunnel
22+
23+
We recommend connecting to a replica or using a read-only role for safety.
24+
25+
## Setup
26+
27+
### 1. Create a Read-Only User
28+
29+
In your Postgres server:
30+
31+
```sql
32+
-- 1. Create a dedicated read-only user
33+
CREATE USER querycanary_reader WITH PASSWORD 'your_secure_password';
34+
35+
-- 2. Allow it to connect to your database
36+
GRANT CONNECT ON DATABASE your_database TO querycanary_reader;
37+
38+
-- 3. Grant usage on the schema you want to monitor (typically public)
39+
GRANT USAGE ON SCHEMA public TO querycanary_reader;
40+
41+
-- 4. Grant read-only access to all existing tables
42+
GRANT SELECT ON ALL TABLES IN SCHEMA public TO querycanary_reader;
43+
44+
-- 5. Ensure access to future tables too
45+
ALTER DEFAULT PRIVILEGES IN SCHEMA public
46+
GRANT SELECT ON TABLES TO querycanary_reader;
47+
```
48+
49+
## Connecting to Postgres
50+
51+
### Option 1: Direct Connection
52+
53+
Use this if your database is publicly accessible or hosted on a service like RDS, Supabase, or Fly.io.
54+
55+
You’ll need:
56+
57+
- Hostname (e.g. db.example.com)
58+
- Port (usually 5432)
59+
- Database name
60+
- Username & password
61+
62+
### Option 2: SSH Tunnel (Recommended for Private Networks)
63+
64+
Use this if your DB is in a private VPC and only accessible from a bastion host.
65+
66+
You’ll additionally need:
67+
68+
- Bastion host (hostname/IP)
69+
- SSH username
70+
- SSH public key (we generate one for you securely)
71+
72+
QueryCanary connects via SSH, opens a secure tunnel, and connects to your internal Postgres instance.
73+
74+
## Writing SQL Checks
75+
76+
You can monitor anything you can query. Example:
77+
78+
**Daily Signups Check**
79+
80+
```sql
81+
SELECT COUNT(*) FROM users WHERE created_at >= CURRENT_DATE - INTERVAL '1 day';
82+
```
83+
84+
**Broken Joins Check**
85+
86+
```sql
87+
SELECT COUNT(*) FROM orders o LEFT JOIN users u ON u.id = o.user_id WHERE u.id IS NULL;
88+
```
89+
90+
## Troubleshooting
91+
92+
**Can't connect to database**
93+
94+
- Make sure the hostname and port are reachable
95+
- Check that the user has CONNECT and SELECT permissions
96+
- Confirm no VPN/firewall blocks our IP (contact support if needed)
97+
98+
**SSH tunnel fails**
99+
100+
- Make sure your bastion host is reachable
101+
- Add the provided public key to ~/.ssh/authorized_keys on the bastion
102+
- Check that the bastion user can access the database internally
103+
104+
**Query fails or returns empty**
105+
106+
- Test your query locally with psql or your app first
107+
- Avoid LIMIT, ORDER BY, or formatting functions — we only need values
108+
- Use COUNT, SUM, AVG, or conditional expressions to track value changes

‎content/en/docs/b2.mysql.md‎

Lines changed: 85 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,85 @@
1+
---
2+
title: Using MySQL with QueryCanary
3+
slug: mysql
4+
---
5+
QueryCanary fully supports MySQL for production data monitoring. This guide walks you through connecting your database, writing SQL checks, and troubleshooting common issues.
6+
7+
## Overview
8+
9+
QueryCanary connects directly to your MySQL database — with or without SSH tunneling — and allows you to define SQL checks to monitor important conditions in your data (e.g. low signups, null prices, broken joins).
10+
11+
You can:
12+
13+
- Run scheduled SQL queries on your prod database
14+
- Set expectations or anomaly detection on results
15+
- Receive alerts via email or Slack when something looks off
16+
17+
## Requirements
18+
19+
- MySQL or MariaDB
20+
- A read-only database user
21+
- Access via direct TCP or through an SSH tunnel
22+
23+
We recommend connecting to a replica or using a read-only role for safety.
24+
25+
## Setup
26+
27+
### 1. Create a Read-Only User
28+
29+
In your MySQL server, create a dedicated read-only user, grant it SELECT access to the database you want to monitor, and flush privileges to apply changes.
30+
31+
```sql
32+
-- 1. Create a dedicated read-only user
33+
CREATE USER 'querycanary_reader'@'%' IDENTIFIED BY 'your_secure_password';
34+
35+
-- 2. Grant read-only access to the database you want to monitor
36+
GRANT SELECT ON your_database.* TO 'querycanary_reader'@'%';
37+
38+
-- 3. Flush privileges to apply changes
39+
FLUSH PRIVILEGES;
40+
```
41+
42+
## Connecting to MySQL
43+
44+
### Option 1: Direct Connection
45+
46+
Use this if your database is publicly accessible or hosted on a service like RDS, PlanetScale, or DigitalOcean.
47+
48+
You’ll need:
49+
50+
- Hostname (for example, db.example.com)
51+
- Port (usually 3306)
52+
- Database name
53+
- Username and password
54+
55+
### Option 2: SSH Tunnel (Recommended for Private Networks)
56+
57+
Use this if your database is in a private VPC and only accessible from a bastion host.
58+
59+
You’ll additionally need:
60+
61+
- Bastion host (hostname or IP)
62+
- SSH username
63+
- SSH public key (we generate one for you securely)
64+
65+
QueryCanary connects via SSH, opens a secure tunnel, and connects to your internal MySQL instance.
66+
67+
## Writing SQL Checks
68+
69+
You can monitor anything you can query. For example, you might check the number of daily signups by counting users created in the last day, or look for broken joins by counting orders without a matching user.
70+
71+
**Daily Signups Check**
72+
```sql
73+
SELECT COUNT(*) FROM users WHERE created_at >= CURDATE() - INTERVAL 1 DAY;
74+
```
75+
76+
**Broken Joins Check**
77+
```sql
78+
SELECT COUNT(*) FROM orders o LEFT JOIN users u ON u.id = o.user_id WHERE u.id IS NULL;
79+
```
80+
81+
## Troubleshooting
82+
83+
If you can't connect to the database, make sure the hostname and port are reachable, the user has SELECT permissions, and no VPN or firewall blocks our IP.
84+
If the SSH tunnel fails, ensure your bastion host is reachable, the provided public key is added to authorized keys on the bastion, and the bastion user can access the database internally.
85+
If a query fails or returns empty, test your query locally with the MySQL CLI or your app first. Avoid using LIMIT, ORDER BY, or formatting functions — QueryCanary only needs values. Use COUNT, SUM, AVG, or conditional expressions to track value changes.

content/en/docs/b2.ssh-tunnel.md renamed to content/en/docs/b3.ssh-tunnel.md

File renamed without changes.

‎data/en/docs/sidebar.yml‎

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -8,4 +8,6 @@
88

99
- title: Servers
1010
pages:
11+
- title: PostgreSQL
12+
- title: MySQL
1113
- title: SSH Tunnel

0 commit comments

Comments
 (0)