3530e80ce1
" This series adds support for the "md" sstable format. Support is based on the following: * do not use clustering based filtering in the presence of static row, tombstones. * Disabling min/max column names in the metadata for formats older than "md". * When updating the metadata, reset and disable min/max in the presence of range tombstones (like Cassandra does and until we process them accurately). * Fix the way we maintain min/max column names by: keeping whole clustering key prefixes as min/max rather than calculating min/max independently for each component, like Cassandra does in the "md" format. Fixes #4442 Tests: unit(dev), cql_query_test -t test_clustering_filtering* (debug) md migration_test dtest from git@github.com:bhalevy/scylla-dtest.git migration_test-md-v1 " * tag 'md-format-v4' of github.com:bhalevy/scylla: (27 commits) config: enable_sstables_md_format by default test: cql_query_test: add test_clustering_filtering unit tests table: filter_sstable_for_reader: allow clustering filtering md-format sstables table: create_single_key_sstable_reader: emit partition_start/end for empty filtered results table: filter_sstable_for_reader: adjust to md-format table: filter_sstable_for_reader: include non-scylla sstables with tombstones table: filter_sstable_for_reader: do not filter if static column is requested table: filter_sstable_for_reader: refactor clustering filtering conditional expression features: add MD_SSTABLE_FORMAT cluster feature config: add enable_sstables_md_format database: add set_format_by_config test: sstable_3_x_test: test both mc and md versions test: Add support for the "md" format sstables: mx/writer: use version from sstable for write calls sstables: mx/writer: update_min_max_components for partition tombstone sstables: metadata_collector: support min_max_components for range tombstones sstable: validate_min_max_metadata: drop outdated logic sstables: rename mc folder to mx sstables: may_contain_rows: always true for old formats sstables: add may_contain_rows ...
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.
- Packaging documentation on how to build Scylla packages for different Linux distributions.
- 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 in ./docs and on the wiki. There is currently no clear definition of what goes where, so when looking for something be sure to check both. 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.