Apache Accumulo 4.0.0
02 Oct 2026
Please view the latest release notes.
About
Apache Accumulo 4.0.0 is a non-LTM major version release that contains a large number of internal changes that allow a lot of flexibility in the way that Accumulo is deployed with a small number of API changes. A high level overview of some of the changes are described in this blog post.
User Guide
The 4.x user guide, located here, is being updated. It will be in draft state until the final 4.0.0 release.
Notable Changes
- Some change here
Known Issues
- None
Upgrading
View the Upgrading Accumulo documentation for guidance as the upgrade procedure has changed. Note that during the upgrade all user tablets will be set to have on-demand tablet availability. Users will need to change the tablet availability post-upgrade for tablets that they want always or never hosted on a tablet server. The upgrade process also sets the tablet mergeability to never for all existing tablets to preserve any user created split points. Tablet mergeability can be set when adding new splits and will be set to always when the split is created by the system based on user settings.
Useful Links
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