cfa3910509
This PR consists of two changes. The first fixes the flat_mutation_reader and flat_mutation_reader_v2, so that they can be destructed without being closed (if no action has been initiated). This has been discussed in the referenced issue. The second one changes scanning and flush readers so that they implement the second version of the API. It also contains unit test fixes, dealing with flat mutation reader assertions (where the v1 asserter failed to consume range tombstones intelligently enough in some flows) and several sstable_3_x tests (where sstables that contain range tombstones were expected to be byte-by-byte equivalent to a reference, aside from semantic validation). Fixes #9065. Closes #9669 * github.com:scylladb/scylla: flat_reader_assertions: do not accumulate out-of-range tombstones flat_reader_assertions: refactor resetting accumulated tombstone lists flat_mutation_reader_test: fix "test_flat_mutation_reader_consume_single_partition" memtable::make_flush_reader(): return flat_mutation_reader_v2 memtable::make_flat_reader(): return flat_mutation_reader_v2 flat_mutation_reader_v2: add consume_partitions() introduce the MutationConsumer concept mutation_source: clone shortcut constructors for flat_mutation_reader_v2 flat_mutation_reader_v2: add delegating_reader_v2 memtable: upgrade scanning_reader and flush_reader to v2 flat_mutation_reader: allow destructing readers which are not closed and didn't initiate any IO. tests: stop comparing sstables with range tombstones to C* reference tests: flat_reader_assertions: improve range tombstone checking
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.