48c78ade33
This patch adds comprehensive cql-pytest tests for checking the validation
of strings - ASCII or UTF-8 - in CQL. Strings can be represented in CQL
using several methods - a strings can be a string literal as
part of the statement, can be encoded as a blob (0x...), or
can be a binding parameter for a prepared statement, or returned
by user-defined functions - and these tests check all of them.
We already have low-level unit tests for UTF-8 parsing in
test/boost/utf8_test.cc, but the new tests here confirms that we really
call these low-level functions in the correct way. Moreover, since these
are CQL tests, they can also be run against Cassandra, and doing that
demonstrated that Scylla's UTF-8 parsing is *stricter* than Cassandra's -
Scylla's UTF-8 parser rejects the following sequences which Cassandra's
accepts:
1. \xC0\x80 as another non-minimal representation of null. Note that other
non-minimal encodings are rejected by Cassandra, as expected.
2. Characters beyond the official Unicode range (or what Scylla considers
the end of the range).
3. UTF-16 surrogates - these are not considered valid UTF-8, but Cassandra
accepts them, and Scylla does not.
In the future, we should consider whether Scylla is more correct than
Cassandra here (so we're fine), or whether compatibility is more important
than correctness (so this exposed a bug).
The ASCII tests reproduces issue #5421 - that trying to insert a
non-ASCII string into an "ascii" column should produce an error on
insert - not later when fetching the string. This test now passes,
because issue 5421 was already fixed.
These tests did not exposed any bug in Scylla (other than the differences
with Cassandra mentioned a bug), so all of them pass on Scylla. Two
of the tests fail on Cassandra, because Cassandra does not recognize
some invalid UTF-8 (according to Scylla's definition) as invalid.
Refs #5421.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
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.