4043d95810
REST route removal unregisters handlers but does not wait for requests that already entered storage_service. A request can therefore suspend inside an async operation, restart proceeds to tear the service down, and the coroutine later resumes against destroyed members such as _topology_state_machine, _group0, or _sys_ks — a use-after-destruction bug that surfaces as UBSAN dynamic-type failures (e.g. the crash seen from topology_state_load()). Fix this by holding storage_service::_async_gate from the entry boundary of every externally-triggered async operation so that stop() drains them before teardown begins. The gate is acquired in run_with_api_lock, run_with_no_api_lock, and in individual REST handlers that bypass those wrappers (reload_raft_topology_state, mark_excluded, removenode, schema reload, topology-request waits/abort, cleanup, ring/schema queries, SSTable dictionary training/publish, and sampling). Additionally, fix get_ownership() and abort_topology_request() which forward work to shard 0 but were still referencing the caller-shard's `this` pointer instead of the destination-shard instance, causing silent cross-shard access to shard-local state. Add a cluster regression test that repeatedly exercises the multi-shard ownership REST path to cover the forwarding fix. Fixes: SCYLLADB-1415 Should be backported to all branches, the code has been introduced around 2024.1 release. Closes scylladb/scylladb#29373 * github.com:scylladb/scylladb: storage_service: fix shard-0 forwarding in REST helpers storage_service: gate REST-facing async operations during shutdown storage_service: prepare for async gate in REST handlers
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.