Bucardo

Bucardo is an open-source, asynchronous replication system built around PostgreSQL databases. It is best suited to teams operating their own Unix-like infrastructure that need selective, multi-way data movement rather than a managed service. Its configurable synchronization and conflict handling are valuable, but schema changes and platform requirements demand careful operational planning.

Overview

Bucardo handles multi-source and multi-target replication, including one-direction master-standby arrangements. You define named syncs that copy chosen tables between a server and one or more other servers, so it can fit selective distribution patterns instead of forcing an all-database copy. That control rewards administrators who understand their data flows; it is less suitable when you want a fully managed, prescriptive replication service.

The project is licensed under BSD and is free to use. Bucardo 5.6.0 is the current published release, with a downloadable archive and signature. Usage questions, bug reports, feature requests and general discussion go through the Bucardo-general mailing list, with an IRC channel also provided. End Point Dev offers professional support, while Bucardo-announce carries release, bug and security notices.

Key features

Selective asynchronous syncs

A Perl daemon listens for PostgreSQL NOTIFY requests, then connects to remote databases to copy data. The asynchronous design suits workloads where replicas do not need every change applied immediately, while named syncs let you target specific table sets across one or many destinations.

Multi-way conflict handling

For multi-source synchronization, Bucardo can use a standard conflict handler or a custom handler assigned per table. This is a practical advantage when different tables need different resolution rules, but it puts the burden of defining safe outcomes for concurrent edits on your database team.

PostgreSQL and truncate constraints

Both the configuration database and replication databases must run PostgreSQL 8.1 or newer. The configuration database also requires PL/pgSQL and PL/PerlU. Truncate replication needs PostgreSQL 8.4 or later and is fully working only for pushdelta syncs, so teams relying on other sync types should verify behavior before designing around truncates.

Bucardo does not replicate DDL or schema changes. Table and schema migrations therefore need a separate process, making it a poor match for environments that expect structural changes to follow data automatically.

Pricing

Bucardo: free (free and open source, BSD license). There is no trial because the software itself is free. This plan fits organizations prepared to install, operate and update their own replication service. It does not provide a hosted tier or remove the Unix-like, PostgreSQL and schema-management responsibilities described above; teams wanting vendor-operated infrastructure should consider a different category of product.

Platforms

Bucardo is self-hosted and runs its daemon on Unix-like systems. It has been tested primarily on Linux and macOS and does not run natively on Windows. Installation options include source code, RPM and Debian packages, and FreeBSD Ports. The replication databases and configuration database are PostgreSQL-based, although the published supported-database list also includes Drizzle, MongoDB, MySQL, MariaDB, Oracle, Redis and SQLite.

Who it's for

Bucardo fits PostgreSQL administrators who need multi-way or master-standby replication, table-level selection and per-table conflict policies, and who can maintain a Unix-like server themselves. It is also a sensible choice when an open-source BSD license and change-data-capture capability matter. Look elsewhere if native Windows operation, automatic schema replication, synchronous guarantees or a managed deployment are requirements.

Pros and cons

Pros

• Flexible topology: Multi-source, multi-target and one-direction master-standby modes cover more than a single primary-replica pattern.
• Focused data movement: Named syncs copy selected tables, helping limit what each destination receives.
• Custom conflict policies: Handlers can be tailored per table for multi-source workloads.
• Open-source cost: The BSD-licensed software is free to run on infrastructure you control.

Cons

• No DDL replication: Schema changes must be coordinated separately.
• Unix-only daemon: Windows hosts cannot run it natively.
• Operational prerequisites: PostgreSQL version, PL/pgSQL and PL/PerlU requirements narrow deployment choices.
• Truncate caveat: Full truncate support is limited to PostgreSQL 8.4-plus environments using pushdelta syncs.

Alternatives

Data Replication Software and Database Replication Software lists provide broader choices.

• SymmetricDS is a freemium option with a free Community plan, free trial and clients spanning mobile, desktop, web and self-hosted platforms.
• MySQL is preferable when you want a database platform with replication and high-availability components, plus API, Windows and self-hosted support.
• Debezium is a free Apache-licensed distributed change-data-capture platform.
• TiCDC is a free open-source choice with no paid plans or usage caps stated.
• Amazon Database Migration Service suits teams wanting an API or web service and an AWS Free Tier with credits valid for up to 12 months.
• Artie offers a hosted/self-hosted freemium approach; its free tier allows up to 1M billable rows per month and two active pipelines.
• Couchbase XDCR is a paid web-based option for Couchbase deployments.
• Estuary provides freemium API, web and self-hosted plans, including a free tier and a $100.00-per-month pay-as-you-go plan.

Verdict

Choose Bucardo when you need free, self-hosted PostgreSQL replication with selective tables, multi-way topologies and configurable conflict rules, and your team can run a Unix-like daemon. Choose another system when native Windows support, automatic schema replication or managed operations outweigh that control.