a7856c3d52
The service level controller relies on `auth::service` to collect information about roles and the relation between them and the service levels (those attached to them). Unfortunately, the service level controller is initialized way earlier than `auth::service` and so we had to prevent potential invalid queries of user service levels (cf.46193f5e79). Unfortunately, that came at a price: it made the maintenance socket incompatible with the current implementation of the service level controller. The maintenance socket starts early, before the `auth::service` is fully initialized and registered, and is exposed almost immediately. If the user attempts to connect to Scylla within this time window, via the maintenance socket, one of the things that will happen is choosing the right service level for the connection. Since the `auth::service` is not registered, Scylla with fail an assertion and crash. A similar scenario occurs when using maintenance mode. The maintenance socket is how the user communicates with the database, and we're not prepared for that either. To avoid unnecessary crashes, we add new branches if the passed user is absent or if it corresponds to the anonymous role. Since the role corresponding to a connection via the maintenance socket is the anonymous role, that solves the problem. Some accesses to `auth::service` are not affected and we do not modify those. Fixes scylladb/scylladb#26816 Backport: yes. This is a fix of a regression. - (cherry picked from commitc0f7622d12) - (cherry picked from commit222eab45f8) - (cherry picked from commit394207fd69) - (cherry picked from commitb357c8278f) Parent PR: #26856 Closes scylladb/scylladb#27034 * github.com:scylladb/scylladb: test/cluster/test_maintenance_mode.py: Wait for initialization test: Disable maintenance mode correctly in test_maintenance_mode.py test: Fix keyspace in test_maintenance_mode.py service/qos: Do not crash Scylla if auth_integration absent
Scylla
What is Scylla?
Scylla is the real-time big data database that is API-compatible with Apache Cassandra and Amazon DynamoDB. Scylla embraces a shared-nothing approach that increases throughput and storage capacity to realize order-of-magnitude performance improvements and reduce hardware costs.
For more information, please see the ScyllaDB web site.
Build Prerequisites
Scylla is fairly fussy about its build environment, requiring very recent versions of the C++23 compiler and of many libraries to build. The document HACKING.md includes detailed information on building and developing Scylla, but to get Scylla building quickly on (almost) any build machine, Scylla offers a frozen toolchain, This is a pre-configured Docker image which includes recent versions of all the required compilers, libraries and build tools. Using the frozen toolchain allows you to avoid changing anything in your build machine to meet Scylla's requirements - you just need to meet the frozen toolchain's prerequisites (mostly, Docker or Podman being available).
Building Scylla
Building Scylla with the frozen toolchain dbuild is as easy as:
$ git submodule update --init --force --recursive
$ ./tools/toolchain/dbuild ./configure.py
$ ./tools/toolchain/dbuild ninja build/release/scylla
For further information, please see:
- Developer documentation for more information on building Scylla.
- Build documentation on how to build Scylla binaries, tests, and packages.
- Docker image build documentation for information on how to build Docker images.
Running Scylla
To start Scylla server, run:
$ ./tools/toolchain/dbuild ./build/release/scylla --workdir tmp --smp 1 --developer-mode 1
This will start a Scylla node with one CPU core allocated to it and data files stored in the tmp directory.
The --developer-mode is needed to disable the various checks Scylla performs at startup to ensure the machine is configured for maximum performance (not relevant on development workstations).
Please note that you need to run Scylla with dbuild if you built it with the frozen toolchain.
For more run options, run:
$ ./tools/toolchain/dbuild ./build/release/scylla --help
Testing
See test.py manual.
Scylla APIs and compatibility
By default, Scylla is compatible with Apache Cassandra and its API - CQL. There is also support for the API of Amazon DynamoDB™, which needs to be enabled and configured in order to be used. For more information on how to enable the DynamoDB™ API in Scylla, and the current compatibility of this feature as well as Scylla-specific extensions, see Alternator and Getting started with Alternator.
Documentation
Documentation can be found here. Seastar documentation can be found here. User documentation can be found here.
Training
Training material and online courses can be found at Scylla University. The courses are free, self-paced and include hands-on examples. They cover a variety of topics including Scylla data modeling, administration, architecture, basic NoSQL concepts, using drivers for application development, Scylla setup, failover, compactions, multi-datacenters and how Scylla integrates with third-party applications.
Contributing to Scylla
If you want to report a bug or submit a pull request or a patch, please read the contribution guidelines.
If you are a developer working on Scylla, please read the developer guidelines.
Contact
- The community forum and Slack channel are for users to discuss configuration, management, and operations of ScyllaDB.
- The developers mailing list is for developers and people interested in following the development of ScyllaDB to discuss technical topics.