Hi Samrat, +1 from me. I think this would be a brilliant contribution. The Hadoop libraries are often full of CVEs and updating them can be, IMHO, one of the hardest chores in the Flink code base. So from a purely maintenance POV I think this work would be valuable. Also having the most up to date AWS Java SDK means we keep up with all the auth requirements and opens up more options for using advanced features in future.
Frankly, I think in the long term, Flink would be better off moving away from Hadoop altogether (but that is a much bigger discussion). Thanks, Tom Cooper @tomcooper.dev | https://tomcooper.dev On Tuesday, 14 October 2025 at 19:19, Samrat Deb <[email protected]> wrote: > Hi All, > > Poorvank (cc'ed) and I are writing to start a discussion about a potential > improvement for Flink, creating a new, native S3 filesystem independent of > Hadoop/Presto. > > The goal of this proposal is to address several challenges related to > Flink's S3 integration, simplifying flink-s3-filesystem. If this discussion > gains positive traction, the next step would be to move forward with a > formalised FLIP. > > The Challenges with the Current S3 Connectors > Currently, Flink offers two primary S3 filesystems, flink-s3-fs-hadoop[1] > and flink-s3-fs-presto[2]. While functional, this dual-connector approach > has few issues: > > 1. The flink-s3-fs-hadoop connector adds an additional dependency to > manage. Upgrades like AWS SDK v2 are more dependent on Hadoop/Presto to > support first and leverage in flink-s3-filesystem. Sometimes it's > restrictive to leverage features directly from the AWS SDK. > > 2. The flink-s3-fs-presto connector was introduced to mitigate the > performance issues of the Hadoop connector, especially for checkpointing. > However, it lacks a RecoverableWriter implementation. > Sometimes it's confusing for Flink users, highlighting the need for a > single, unified solution. > > Proposed Solution: > A Native, Hadoop-Free S3 Filesystem > > I propose we develop a new filesystem, let's call it flink-s3-fs-native, > built directly on the modern AWS SDK for Java v2. This approach would be > free of any Hadoop or Presto dependencies. I have done a small prototype to > validate [3] > > This is motivated by trino<>s3 [4]. The Trino project successfully > > undertook a similar migration, moving from Hadoop-based object storage > clients to their own native implementations. > > The new Flink S3 filesystem would: > > 1. Provide a single, unified connector for all S3 interactions, from state > backends to sinks. > > 2. Implement a high-performance S3RecoverableWriter using S3's Multipart > Upload feature, ensuring exactly-once sink semantics. > > 3. Offer a clean, self-contained dependency, drastically simplifying setup > and eliminating external dependencies. > > A Phased Migration Path > To ensure a smooth transition, we could adopt a phased approach on a very > high level : > > Phase 1: > Introduce the new native S3 filesystem as an optional, parallel plugin. > This would allow for community testing and adoption without breaking > existing setups. > > Phase 2: > Once the native connector achieves feature parity and proven stability, we > will update the documentation to recommend it as the default choice for all > S3 use cases. > > Phase 3: > In a future major release, the legacy flink-s3-fs-hadoop and > flink-s3-fs-presto connectors could be formally deprecated, with clear > migration guides provided for users. > > I would love to hear the community's thoughts on this. > > A few questions to start the discussion: > > 1. What are the biggest pain points with the current S3 filesystem? > > 2. Are there any critical features from the Hadoop S3A client that are > essential to replicate in a native implementation? > > 3. Would a simplified, non-dependent S3 experience be a valuable > improvement for Flink use cases? > > > Cheers, > Samrat > > > [1] > https://github.com/apache/flink/tree/master/flink-filesystems/flink-s3-fs-hadoop > [2] > https://github.com/apache/flink/tree/master/flink-filesystems/flink-s3-fs-presto > [3] https://github.com/Samrat002/flink/pull/4 > [4] https://github.com/trinodb/trino/tree/master/lib/trino-filesystem-s3
