Although valid for compact tables, non-full (or empty) clustering key prefixes are not handled for row keys when writing sstables. Only the present components are written, consequently if the key is empty, it is omitted entirely. When parsing sstables, the parsing code unconditionally parses a full prefix. This mis-match results in parsing failures, as the parser parses part of the row content as a key resulting in a garbage key and subsequent mis-parsing of the row content and maybe even subsequent partitions. Introduce a new system table: `system.corrupt_data` and infrastructure similar to `large_data_handler`: `corrupt_data_handler` which abstracts how corrupt data is handled. The sstable writer now passes rows such corrupt keys to the corrupt data handler. This way, we avoid corrupting the sstables beyond parsing and the rows are also kept around in system.corrupt_data for later inspection and possible recovery. Add a full-stack test which checks that rows with bad keys are correctly handled. Fixes: https://github.com/scylladb/scylladb/issues/24489 The bug is present in all versions, has to be backported to all supported versions. - (cherry picked from commit92b5fe8983) - (cherry picked from commit0753643606) - (cherry picked from commitb0d5462440) - (cherry picked from commit093d4f8d69) - (cherry picked from commit678deece88) - (cherry picked from commit64f8500367) - (cherry picked from commitb931145a26) - (cherry picked from commit3e1c50e9a7) - (cherry picked from commit46ff7f9c12) - (cherry picked from commitebd9420687) - (cherry picked from commitaae212a87c) - (cherry picked from commit592ca789e2) - (cherry picked from commitedc2906892) Parent PR: #24492 Closes scylladb/scylladb#24744 * github.com:scylladb/scylladb: test/boost/sstable_datafile_test: add test for corrupt data sstables/mx/writer: handler rows with empty keys test/lib/cql_assertions: introduce columns_assertions sstables: add corrupt_data_handler to sstables::sstables tools/scylla-sstable: make large_data_handler a local db: introduce corrupt_data_handler mutation: introduce frozen_mutation_fragment_v2 mutation/mutation_partition_view: read_{clustering,static}_row(): return row type mutation/mutation_partition_view: extract de-ser of {clustering,static} row idl-compiler.py: generate skip() definition for enums serializers idl: extract full_position.idl from position_in_partition.idl db/system_keyspace: add apply_mutation() db/system_keyspace: introduce the corrupt_data table
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.