MySQL and MariaDB proxy

The MySQL proxy sits between your application and a real MySQL or MariaDB database. Your application connects to FlowReactor instead of the database; FlowReactor passes everything on, and shows you each query.

Your application keeps its own user, password and database. Only the host and port change.

Add the proxy#

1. + Add › MySQL.
2. Set Real database host and its Port (default localhost, 3306).
3. Check FlowReactor listens on 127.0.0.1, port (default 13306).
4. Choose Add MySQL proxy, then Start.

Connect your application#

Point your connection at 127.0.0.1 and the proxy's port, without requiring TLS. Configuration › Connect your application has these with copy buttons.

// MySqlConnector or MySql.Data
var connectionString =
    "Server=127.0.0.1;Port=13306;User ID=app;Password=secret;Database=shop;" +
    "SslMode=Preferred;AllowPublicKeyRetrieval=true";

// mysql2: leave out the ssl option
import mysql from 'mysql2/promise'

const pool = mysql.createPool({
  host: '127.0.0.1',
  port: 13306,
  user: 'app',
  password: 'secret',
  database: 'shop',
})

# PyMySQL: don't pass ssl options
import pymysql

conn = pymysql.connect(
    host="127.0.0.1", port=13306, user="app", password="secret", database="shop"
)

Java uses jdbc:mysql://127.0.0.1:13306/shop?sslMode=PREFERRED&allowPublicKeyRetrieval=true, and the mysql command line and other tools take mysql://app:[email protected]:13306/shop.

Inspect forwarded requests#

Each query and each execution of a prepared statement appears in the Activity timeline. Other commands, such as USE or PING, appear only when they fail. The Operation is the SQL's first keyword.

• Query shows the SQL, a prepared statement's parameters, and the rows affected, last insert ID and warnings.
• Results shows up to 20 rows of each result set.
• Timing separates the database's time from any pause or injected latency.

A prepared statement created before FlowReactor saw the connection shows as EXECUTE with statement N, because its SQL is unknown.

Configure latency and failures#

• Slow every query: set Latency under Faults. See Test how your app handles a slow database.
• Drop a connection: Active connections › Drop.
• Pause and fail one query: add a breakpoint, then Return error… with a MySQL error number.

You can enter any error number from 1000 to 9999 and your own message. FlowReactor sends the matching SQLSTATE, such as 40001 for a deadlock.

When it can't connect#

If the real database can't be reached, the timeline says Could not reach upstream, with the reason. If the database refuses the login, it says Login refused by the server, with the server's message. See Troubleshooting.