71398f3fb4
"
This series cleans up the legacy and common ssatble writer code.
metadata_collector::_ancestors were moved to class sstable
so that the former can be moved out of sstable into file_writer_impl.
Moved setting of replay position and sstable level via
sstable_writer_config so that compaction won't need to access
the metadata_collector via the sstable.
With that, metadata_collector could be moved from class sstable
to sstable_writer::writer_impl along with the column_stats.
That allowed moved "generic" file_writer methods that were actually
k/l format specific into sstable_writer_k_l.
Eventually `file_writer` code is moved into sstables/writer.cc
and sstable_writer_k_l into sstables/kl/writer.{hh,cc}
A bonus cleanup is the ability to get rid of
sstable::_correctly_serialize_non_compound_range_tombstones as
it's now available to the writers via the writer configuration
and not required to be stored in the sstable object.
Fixes #3012
Test: unit(dev)
"
* tag 'cleanup-sstable-writer-v2' of github.com:bhalevy/scylla:
sstables: move writer code away to writer.cc
sstables: move sstable_writer_k_l away to kl/writer
sstables: get rid of sstable::_correctly_serialize_non_compound_range_tombstones
sstables: move writer methods to sstable_writer_k_l
sstables: move compaction ancestors to sstable
sstables: sstable_writer: optionally set sstable level via config
sstables: sstable_writer: optionally set replay position via config
sstables: compaction: make_sstable_writer_config
sstables: open code update_stats_on_end_of_stream in sstable_writer::consume_end_of_stream
sstables: fold components_writer into sstable_writer_k_l
sstables: move sstable_writer_k_l definition upwards
sstables: components_writer: turn _index into unique_ptr
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 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.