The advice to store the root and metadata table was based on the fact that the root tablet used to rely on DFS file listing to know what files it had. S3 file listings are eventually consistent and not reliable so that could lead to the root tablet missing data. In Accumulo 2.1 the list of root tablet files is stored in zookeeper and it no longer relies on DFS files listing operations to know what files it has. With this change in 2.1 it may be safe to store root and metadata files in S3. However tablet servers write ahead logs probably still need to be stored in a DFS impl that supports reliable sync operations, S3 may not support this.
On Tue, Apr 14, 2026 at 9:13 PM McClure, Bruce MR 2 via user < [email protected]> wrote: > *UNOFFICIAL* > > Hi, > > > > I am just wondering if there is any update since the advice in 2019 that > said Accumulo can run on S3 as long as the root and metadata tables are in > HDFS? > > > > Has any performance benchmarking been done comparing Accumulo running on > S3 versus HDFS? (for comparable hardware/networking configuration). > > > > Thank you, > > > > Bruce. > > >
