Load balancer will recognize decommissioning nodes and will move tablet replicas away from such nodes with highest priority. Topology changes have now an extra step called "tablet draining" which calls the load balancer. The step will execute tablet migration track as long as there are nodes which require draining. It will not do regular load balancing. If load balancer is unable to find new tablet replicas, because RF cannot be met or availability is at risk due to insufficient node distribution in racks, it will throw an exception. Currently, topology change will retry in a loop. We should make this error cause topology change to be aborted. There is no infrastructure for aborts yet, so this is not implemented. Closes #15197 * github.com:scylladb/scylladb: tablets, raft topology: Add support for decommission with tablets tablet_allocator: Compute load sketch lazily tablet_allocator: Set node id correctly tablet_allocator: Make migration_plan a class tablets: Implement cleanup step storage_service, tablets: Prevent stale RPCs from running beyond their stage locator: Introduce tablet_metadata_guard locator, replica: Add a way to wait for table's effective_replication_map change storage_service, tablets: Extract do_tablet_operation() from stream_tablet() raft topology: Add break in the final case clause raft topology: Fix SIGSEGV when trace-level logging is enabled raft topology: Set node state in topology raft topology: Always set host id in topology
ScyllaDB Documentation
This repository contains the source files for ScyllaDB Open Source documentation.
- The
devfolder contains developer-oriented documentation related to the ScyllaDB code base. It is not published and is only available via GitHub. - All other folders and files contain user-oriented documentation related to ScyllaDB Open Source and are sources for docs.scylladb.com.
To report a documentation bug or suggest an improvement, open an issue in GitHub issues for this project.
To contribute to the documentation, open a GitHub pull request.
Key Guidelines for Contributors
- Follow the ScyllaDB Style Guide.
- The user documentation is written in reStructuredText (RST) - a plaintext markup language similar to Markdown. If you're not familiar with RST, see ScyllaDB RST Examples.
- The developer documentation is written in Markdown. See Basic Markdown Syntax for reference.
Creating Knowledge Base Articles
The kb/ directory holds source files for knowledge base articles in the Knowledge Base section of the ScyllaDB documentation.
The kb/kb_common subdirectory contains a template for knowledge base articles to help you create new articles.
To create a new knowledge base article (KB):
- Copy the
kb-article-template.rstfile from/kb/kb_commonto/kband rename it with a unique name. - Open the new file and fill in the required information.
- Remove what is not needed.
- Run
make previewto build the docs and preview them locally. - Send a PR with "KB" in its title.
Building User Documentation
Prerequisites
- Python 3. Check your version with
$ python --version. - poetry 1.12 or later
- make
Mac OS X
You must have a working Homebrew in order to install the needed tools.
You also need the standard utility make.
Check if you have these two items with the following commands:
brew help
make -h
Linux Distributions
Building the user docs should work out of the box on most Linux distributions.
Windows
Use "Bash on Ubuntu on Windows" for the same tools and capabilities as on Linux distributions.
Building the Docs
- Run
make previewto build the documentation. - Preview the built documentation locally at http://127.0.0.1:5500/.
Cleanup
You can clean up all the build products and auto-installed Python stuff with:
make pristine
Information for Contributors
If you are interested in contributing to Scylla docs, please read the Scylla open source page at http://www.scylladb.com/opensource/ and complete a Scylla contributor agreement if needed. We can only accept documentation pull requests if we have a contributor agreement on file for you.
Third-party Documentation
-
Do any copying as a separate commit. Always commit an unmodified version first and then do any editing in a separate commit.
-
We already have a copy of the Apache license in our tree, so you do not need to commit a copy of the license.
-
Include the copyright header from the source file in the edited version. If you are copying an Apache Cassandra document with no copyright header, use:
This document includes material from Apache Cassandra.
Apache Cassandra is Copyright 2009-2014 The Apache Software Foundation.