972b24a969
... and drop usage of global storage proxy from several places of mutate_MV().
This is the last dependency loop around storage proxy left as long as the last user of the global storage proxy. The trouble is that while proxy naturally depends on database, the database SUDDENLY requires proxy to push view updates from the guts of database::do_apply().
Similar loop existed in a form of database -> { large_data_handler, compaction manager } -> system keyspace -> database and it was cut in 917fdb9e53 (Cut database-system_keyspace circular dependency) by introducing a soft dependency link from l. d. handler / compaction manager to system keyspace. The similar solution is proposed here.
The database instance gets a soft dependency (shared_ptr) to view_update_generator instance. On start the link is nullptr and pushing view updates is not possible until view_updates_generator starts and plugs itself to the database. The plugging happens naturally, because v.u.generator needs proxy as explicit dependency and, thus, can reach database via proxy. This (seems to) works because tables that need view updates don't start being mutated until late enough, as late as v.u.generator starts.
As a nice side effect this allows removing a bunch of global storage proxy usages from mutate_MV() which opens a pretty short way towards de-globalizing proxy (after it only qctx, tracing and schema registry will be left).
Closes #13367
* github.com:scylladb/scylladb:
view: Drop global storage_proxy usage from mutate_MV()
view: Make mutate_MV() method of view_update_generator
table: Carry v.u.generator down to populate_views()
table: Carry v.u.generator down to do_push_view_replica_updates()
view: Keep v.u.generator shared pointer on view_builder::consumer
view: Capture v.u.generator on view_updating_consumer lambda
view: Plug view update generator to database
view: Add view_builder -> view_update_generator dependency
view: Add view_update_generator -> sharded<storage_proxy> dependency
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 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 the ScyllaDB open source.
- The developers mailing list is for developers and people interested in following the development of ScyllaDB to discuss technical topics.