54b76e82bc
" There are few places left that call for migration manager by global reference. This set patches all those places and makes the migration manager a service that locally lives in main(). Surprisingly, the largest changes are to get rid of global migration manager calls from ... the migration manager itself. Two tricks here. First, repair code gets its private global migration manager pointer. That's not nice, but it aligned with current repair design -- all its references are now "global". Some day they all will be moved into sharded repair service, for now these globals just describe the real dependencies of the repair code. Second is storage proxy that needs to call migration manager to get schema. Proper layering makes migration manager sit on top of storage proxy, so the direct back-reference is not nice. To overcome this the proxy gets migration manager's shared_from_this() pointer and drops all of them on stop. This makes sure that by the time migration manager stops no references from proxy exist. tests: unit(dev), start-stop, start-drain-stop " * 'br-turn-migration-manager-local' of https://github.com/xemul/scylla: (21 commits) migration_manager: Make it main-local tests: Have own migration manager instances tests: Use migration_manager from cql_test_env migration_manager: Call maybe_sync from this migration_manager: Make get_schema_for_... methods migration_manager: Hide get_schema_definition streaming: Keep migration_manager ptr in rpc lambdas storage_proxy: Keep migration_manager ptr in rpc lambdas streaming: Get migration_manager shared_ptr in messaging storage_proxy: Get migration_manager shared_ptr in messaging migration_manager: Make maybe_sync a method migration_manager: Open-code merge lambda migration_manager: Turn do_announce_new_type non-static migration_manager: Make announce() non-static method storage_servive: Use local migration manager storage_service: Keep migration manager on board migration_manager: Use 'this' where appropriate repair: Use private migration manager pointer repair: Keep private sharded migration manager pointer redis: Carry sharded migration manager over init ...
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++20 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 APIs - CQL and Thrift. 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 users mailing list and Slack channel are for users to discuss configuration, management, and operations of the ScyllaDB open source.
- The developers mailing list is for developers and people interested in following the development of ScyllaDB to discuss technical topics.