Support for Replication Protocol Version 2

[3n0ugh]

Feature Request: Support for Replication Protocol Version 2

Is your feature request related to a problem? Please describe.

Currently, the go-pq-cdc library supports only replication protocol version 3. This limits its use to PostgreSQL server versions 15 and above. Introducing support for replication protocol version 2 would enable go-pq-cdc to function with PostgreSQL server version 14 as well, thus expanding its compatibility.

Describe the solution you'd like

Implement conditional handling for replication protocols based on the PostgreSQL server version:

1. After establishing a connection, determine the PostgreSQL server version.
   • If the server version is 15 or higher, continue using replication protocol version 3.
   • If the server version is between 14 and 15 (inclusive of 14), switch to using replication protocol version 2.
   • For any server version below 14, return an error indicating that the PostgreSQL version is unsupported.

By adding this logic, go-pq-cdc can support a wider range of PostgreSQL versions while ensuring appropriate protocol compatibility.

Sources

Protocol Versions: https://www.postgresql.org/docs/current/protocol-logical-replication.html#:~:text=Version%202%20is%20supported%20only,streaming%20of%20two%2Dphase%20commits.

go-pq-cdc protocol choose:

go-pq-cdc/pq/replication/replication.go

Line 27 in 0076edc

"proto_version '3'",

Tasks

Beta Give feedback

1. Add PostgreSQL version control
2. Set dynamically replication protocol version by PostgreSQL server version
3. Update integration test for PostgreSQL Server version 14 too
4. Update README.md
5. Update go-pq-cdc-elasticsearch go-pq-cdc version and README.md and production_tutorial docs.