e588c8667f
Attribute names are now checked against DynamoDB-compatible length limits. When exceeded, Alternator emits exception identical or similar to the DDB one. It might be worth noting that DDB emits more than a single kind of an exception string for some exceptions. The tests' catch clauses handle all the observed kinds of messages from DynamoDB. The validation differentiates between key and non-key attributes and applies the limit accordingly. AWS DDB raises exceptions with somewhat different contents when the get request contains ProjectionExpression, so this case needed separate treatment to emit the corresponding exception string. The length-validating function was declared and defined in expressions.hh/.cc respectively, because that's where the relevant parsing happens. ** Tests The following tests were validated when handling this issue: test_limit_attribute_length_nonkey_good, test_limit_attribute_length_nonkey_bad, test_limit_attribute_length_key_good, test_limit_attribute_length_key_bad, test_limit_attribute_length_gsi_lsi_good, test_limit_attribute_length_gsi_lsi_bad, test_limit_attribute_length_gsi_lsi_projection_bad. Some of the tests were expanded into being more granular. Namely, there is a new test function `test_limit_attribute_length_key_bad_incoherent_names` which groups tests with too long attribute names in the case of incorrect (incoherent) user requests. Similarily, there is a new test function `test_limit_attribute_length_gsi_lsi_bad_incoherent_names` All the tests cover now each combination of the key/keys being too long. Both the new fuctions contain tests that verify that ScyllaDB throws length-related exceptions (instead of the coherency-related), similar to what DynamoDB does. The new test test_limit_gsiu_key_len_bad covers the case of too long attribute name inside GlobalSecondaryIndexUpdates. The new test test_limit_gsiu_key_len_bad_incoherent_names covers the case of incorrect (incoherent) user requests containing too long attribute names and GlobalSecondaryIndexUpdates. test_limit_attribute_length_key_bad was found to have contaned an illegal KeySchema structure. Some of the tests were corrected their match clause. All the tests are stripped of the xfail flag except test_limit_attribute_length_key_bad, which has it changed since it still fails due to Projection in GSI and LIS not implemented in Alternator. The xfail now points to #5036. Fixes scylladb/scylladb#9169 Closes scylladb/scylladb#23097
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.