Bucardo vs Couchbase XDCR

Bucardo is a free, open-source system for asynchronous PostgreSQL replication in multi-source and multi-target arrangements. It supports multi-way synchronization and one-direction master-standby replication. Users define named syncs that copy selected tables between a server and other servers. A Perl daemon listens for NOTIFY requests and connects to remote databases to copy data. Multi-source setups can use a standard conflict handler or a custom handler assigned per table. Configuration and replication databases require PostgreSQL 8.1 or later, while the configuration database also needs PL/pgSQL and PL/PerlU. The daemon needs a Unix-like operating system, is tested mainly on Linux and macOS, and does not run natively on Windows. Installation is available from source, RPM or Debian packages, and FreeBSD Ports. Bucardo does not replicate DDL or schema changes. The listed latest release is 5.6.0.

Couchbase XDCR is a web-based service for replicating database changes between clusters. It supports change data capture and bidirectional synchronization, allowing changes to move in both directions. The deployment model is hybrid. Couchbase lists plans with hourly per-node billing, cluster minimums, and backup intervals. Basic is $0.15 a month, billed from $0.15/hr per node, with a one-node minimum and a 24-hour backup interval. Developer Pro is $0.35 a month, billed from $0.35/hr per node, with a one-node minimum, three nodes for multiple cluster availability zones, and backup intervals up to one hour. Enterprise is $0.49 a month, billed from $0.49/hr per node, with a three-node minimum and backup intervals up to one hour. Couchbase Enterprise is $0.66 a month, billed from $0.66/hr per node through cloud marketplaces, and includes Couchbase Server 8. A Free plan is described as one node and 8GB, although the pricing facts mark no free plan. Couchbase was founded in 2011 and is headquartered in San Jose.