MySQL

This topic describes how to migrate your MySQL database to SerenDB Postgres using pgloader.

The pgloader utility transforms data to a Postgres-compatible format as it is read from your MySQL database. It uses the COPY Postgres protocol to stream the data into your Postgres database.

Prerequisites

Before you begin, make sure that you have the following:

  • A SerenDB account and a project. See Sign up.

  • A properly named database. For example, if you are migrating a database named sakila, you might want to create a database of the same name in SerenDB. See Create a database for instructions.

  • SerenDB's Free plan supports 0.5 GB of data. If your data size is more than 0.5 GB, you'll need to upgrade to one of SerenDB's paid plans. See SerenDB plans for more information.

Also, a close review of the Pgloader MySQL to Postgres Guide guide is recommended before you start. This guide will provide you with a good understanding of pgloader capabilities and how to configure your pgloader configuration file, if necessary.

Retrieve Your MySQL database credentials

Before starting the migration process, collect your MySQL database credentials:

  1. Log into your MySQL database provider.

  2. Identify and record the following details or grab your MySQL database connection string.

    • Hostname or IP address

    • Database name

    • Username

    • Password

Keep your MySQL database connection details handy for later use.

Retrieve your SerenDB database connection string

Log in to the SerenDB Console. Find the connection string for your database by clicking the Connect button on your Project Dashboard. It should look similar to this:

postgresql://alex:AbC123dEf@ep-cool-darkness-123456.us-east-2.aws.serendb.com/dbname?sslmode=require&channel_binding=require

Now, modify the connection string as follows to pass your endpoint ID (ep-cool-darkness-123456 in this example) to SerenDB with your password using the endpoint keyword, as shown here:

postgresql://alex:endpoint=ep-cool-darkness-123456;AbC123dEf@ep-cool-darkness-123456.us-east-2.aws.serendb.com/dbname?sslmode=require&channel_binding=require

Passing the `endpoint ID` with your password is a required workaround for some Postgres drivers, including the one used by `pgloader`. For more information about this workaround and why it's required, refer to our [connection workaround](/docs/connect/connection-errors#d-specify-the-endpoint-id-in-the-password-field) documentation.

Keep your SerenDB connection string handy for later use.

Install pgloader

Here's how you can set up pgloader for your database migration:

  1. Install the pgloader utility using your preferred installation method. Debian (apt), RPM package, and Docker methods are supported, as well as Homebrew for macOS (brew install pgloader). If your macOS has an ARM processor, use the Homebrew installation method.

    See Installing pgloader for Debian (apt), RPM package, and Docker installation instructions.

  2. Create a pgloader configuration file (e.g., config.load). Use your MySQL database credentials to define the connection string for your database source. Use the SerenDB database connection string you retrieved and modified in the previous step as the destination.

    If you need to specify an SSL mode in your connection string, the following format is recommended: `sslmode=require`. Other formats may not work.

    Example configuration in config.load:

    load database
     from mysql://user:password@host/source_db?sslmode=require
     into postgresql://alex:endpoint=ep-cool-darkness-123456;AbC123dEf@ep-cool-darkness-123456.us-east-2.aws.serendb.com/dbname?sslmode=require&channel_binding=require;

Run the migration with pgloader

To initiate the migration process, run:

pgloader config.load

The command output will look similar to this:

LOG report summary reset
             table name     errors       rows      bytes      total time
-----------------------  ---------  ---------  ---------  --------------
        fetch meta data          0          2                     0.727s
         Create Schemas          0          0                     0.346s
       Create SQL Types          0          0                     0.178s
          Create tables          0          2                     0.551s
         Set Table OIDs          0          1                     0.094s
-----------------------  ---------  ---------  ---------  --------------
    "db-test".dbname             0          1     0.0 kB          0.900s
-----------------------  ---------  ---------  ---------  --------------
COPY Threads Completion          0          4                     0.905s
 Index Build Completion          0          1                     0.960s
         Create Indexes          0          1                     0.257s
        Reset Sequences          0          0                     1.083s
           Primary Keys          0          1                     0.263s
    Create Foreign Keys          0          0                     0.000s
        Create Triggers          0          0                     0.169s
        Set Search Path          0          1                     0.427s
       Install Comments          0          0                     0.000s
-----------------------  ---------  ---------  ---------  --------------
      Total import time          ✓          1     0.0 kB          4.064s

SSL verify error

If you encounter an SSL verify error: 20 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY error while attempting the instructions described above using pgloader from a Docker container, try the solution identified in this GitHub issue, which involves specifying sslmode=allow in the Postgres connection string and using the --no-ssl-cert-verification option with pgloader.

The following configuration file and Docker command were verified to work with Docker on Windows but may apply generally when using pgloader in a Docker container. In your pgloader config file, replace the MySQL and Postgres connection string values with your own. In the Docker command, specify the path to your pgloader config file, and replace the container ID value (the long alphanumeric string) with your own.

pgloader config.load file:

load database
  from mysql://user:password@host/source_db?sslmode=require&channel_binding=require
  into postgresql://alex:endpoint=ep-cool-darkness-123456;AbC123dEf@ep-cool-darkness-123456.us-east-2.aws.serendb.com/neondb?sslmode=allow;

Docker command:

docker run -v C:\path\to\config.load:/config.load d183dc100d3af5e703bd867b3b7826c117fa16b7ee2cd360af591dc895b121dc pgloader --no-ssl-cert-verification /config.load

References

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