DMS Support for Postgres 17

Based on the information available, it appears that PostgreSQL 17.2 is not currently supported by AWS Database Migration Service (DMS) as a source database. The error message you received for your on-premise PostgreSQL 17.2 database clearly indicates that this version is not supported.

The fact that your AWS PostgreSQL 17.2 target database connection test was reported as successful is interesting, but it's important to note that DMS often has different support levels for source and target databases. It's possible that PostgreSQL 17.2 is supported as a target but not as a source in the current version of DMS.

AWS DMS typically supports PostgreSQL versions that are widely adopted and have been available for some time. As PostgreSQL 17.2 is a very recent release, it's not surprising that it's not yet supported as a source database in DMS.

Unfortunately, there isn't any publicly available information about an ETA for supporting PostgreSQL 17.2 in AWS DMS. AWS typically updates their services to support new database versions over time, but they don't usually provide specific timelines for these updates.

In the meantime, you might consider the following options:

1. Use an earlier version of PostgreSQL that is supported by DMS for your source database.
2. Wait for AWS to update DMS to support PostgreSQL 17.2 as a source.
3. Explore alternative migration methods, such as logical replication or third-party tools that might support PostgreSQL 17.2.

It's recommended to keep an eye on AWS DMS documentation for updates on supported PostgreSQL versions. You could also reach out to AWS Support for more specific information about future plans for PostgreSQL 17.2 support in DMS.
Sources
Using a PostgreSQL database as an AWS DMS source - AWS Database Migration Service
Using a PostgreSQL database as a source for homogeneous data migrations in AWS DMS - AWS Database Migration Service