Hello, I'd like to open a vote (7 days, ending August 24 at 3:10 PST) to merge the HADOOP-13345 feature branch into trunk.
This branch contains the new S3Guard feature which adds metadata consistency features to the S3A client. Formatted site documentation can be found here: https://github.com/apache/hadoop/blob/HADOOP-13345/hadoop-tools/hadoop-aws/src/site/markdown/tools/hadoop-aws/s3guard.md The current patch against trunk is posted here: https://issues.apache.org/jira/browse/HADOOP-13998 The branch modifies the s3a portion of the hadoop-tools/hadoop-aws module: - The feature is off by default, and care has been taken to insure it has no impact when disabled. - S3Guard can be enabled with the production database which is backed by DynamoDB, or with a local, in-memory implementation that facilitates integration testing without having to pay for a database. - getFileStatus() as well as directory listing consistency has been implemented and thoroughly tested, including delete tracking. - Convenient Maven profiles for testing with and without S3Guard. - New failure injection code and integration tests that exercise it. We use timers and a wrapper around the Amazon SDK client object to force consistency delays to occur. This allows us to assert that S3Guard works as advertised. This will be extended with more types of failure injection to continue hardening the S3A client. Outside of hadoop-tools/hadoop-aws's s3a directory there are some minor changes: - core-default.xml defaults and documentation for s3guard parameters. - A couple additional FS contract test cases around rename. - More goodies in LambdaTestUtils - A new CLI tool for inspecting and manipulating S3Guard features, including the backing MetadataStore database. This branch has seen extensive testing as well as use in production. This branch makes significant improvements to S3A's test toolkit as well. Performance is typically on par with, and in some cases better than, the existing S3A code without S3Guard enabled. This feature was developed with contributions and feedback from many people. I'd like to thank everyone who worked on HADOOP-13345 as well as all of those who contributed feedback and work on the original design document. This is the first major Apache Hadoop project I've worked on from start to finish, and I've really enjoyed it. Please shout if I've missed anything important here or in the VOTE process. Cheers, Aaron Fabbri
