Managing Distributed Transactions in PostgreSQL and Golang using two phase commit

If you're building a distributed system with PostgreSQL as the database backend, you might have encountered issues with managing transactions across multiple nodes. When a transaction spans multiple databases, ensuring atomicity and consistency can be a challenge. That's where gosql2pc comes in.

gosql2pc is a Golang library for implementing 2 phase commit transactions in PostgreSQL, ensuring atomicity and consistency across distributed systems. With gosql2pc, you can manage transactions across multiple databases, ensuring that all changes are committed or rolled back atomically.

Getting Started

To get started with gosql2pc, you need to have a working knowledge of Golang and PostgreSQL. You also need to have PostgreSQL installed, as gosql2pc relies on the PostgreSQL 2-phase commit protocol.

Once you have PostgreSQL installed, you can install gosql2pc using the following command:

go get github.com/gosom/gosql2pc

Then, use the library's API to create participants for your distributed transaction.

Here's an example of using gosql2pc to create a simple distributed transaction that inserts a new user and order into two separate databases:

// Create the participants for the 2 phase commit
p1 := twophase.NewParticipant(db1, func(ctx context.Context, tx *sql.Tx) error {
    _, err := tx.ExecContext(ctx, "INSERT INTO users (id, name) VALUES ($1, $2)", userID, name)
    return err
})

p2 := twophase.NewParticipant(db2, func(ctx context.Context, tx *sql.Tx) error {
    _, err := tx.ExecContext(ctx, "INSERT INTO orders (id, user_id, amount) VALUES ($1, $2, $3)", orderID, userID, amount)
    return err
})

// setup the parameters for the transaction
params := twophase.Params{
    Participants: []gosql2pc.Participant{p1, p2},
}

// run the transaction
if err := twophase.Do(context.Background(), params); err != nil {
    panic(err)
}

You can find more examples in the library's example directory.

Notes

It's worth noting that distributed transactions can be tricky to manage, and gosql2pc is no exception. PostgreSQL has disabled prepared transactions by default for a good reason, and enabling them can lead to orphaned transactions and data inconsistencies if not monitored carefully.

Nevertheless, gosql2pc provides a useful tool for simplifying the implementation of distributed transactions. If you find a bug or want to suggest a new feature, contributions are always welcome.

To learn more about gosql2pc, including how to enable prepared transactions and monitor for orphaned transactions, check out the library's README file and the accompanying blog posts.