07ff659849
They don't really have to be noexcept. And "action" may actually throw, leading to abort. It was observed to throw when creating memtable readers: terminate called after throwing an instance of 'utils::memory_limit_reached' what(): kill limit triggered on semaphore sl:users by permit xxx Aborting on shard 4, in scheduling group sl:users. std::terminate() at ??:0 __clang_call_terminate at main.cc:0 replica::storage_group::for_each_compaction_group(std::function<void (seastar::lw_shared_ptr<replica::compaction_group> const&)>) const at ./replica/table.cc:920 (inlined by) replica::table::add_memtables_to_reader_list(std::vector<mutation_reader, std::allocator<mutation_reader>>&, seastar::lw_shared_ptr<schema const> const&, reader_permit const&, interval<dht::ring_position> const&, query::partition_slice const&, tracing::trace_state_ptr const&, seastar::bool_class<streamed_mutation::forwarding_tag>, seastar::bool_class<mutation_reader::partition_range_forwarding_tag>, std::function<void (unsigned long)>) const at ./replica/table.cc:196 (inlined by) replica::table::make_reader_v2(seastar::lw_shared_ptr<schema const>, reader_permit, interval<dht::ring_position> const&, query::partition_slice const&, tracing::trace_state_ptr, seastar::bool_class<streamed_mutation::forwarding_tag>, seastar::bool_class<mutation_reader::partition_range_forwarding_tag>) const at ./replica/table.cc:243 (inlined by) replica::table::as_mutation_source() const::$_0::operator()(seastar::lw_shared_ptr<schema const>, reader_permit, interval<dht::ring_position> const&, query::partition_slice const&, tracing::trace_state_ptr, seastar::bool_class<streamed_mutation::forwarding_tag>, seastar::bool_class<mutation_reader::partition_range_forwarding_tag>) const at ./replica/table.cc:3673 (inlined by) mutation_reader std::__invoke_impl<mutation_reader, replica::table::as_mutation_source() const::$_0&, seastar::lw_shared_ptr<schema const>, reader_permit, interval<dht::ring_position> const&, query::partition_slice const&, tracing::trace_state_ptr, seastar::bool_class<streamed_mutation::forwarding_tag>, seastar::bool_class<mutation_reader::partition_range_forwarding_tag>>(std::__invoke_other, replica::table::as_mutation_source() const::$_0&, seastar::lw_shared_ptr<schema const>&&, reader_permit&&, interval<dht::ring_position> const&, query::partition_slice const&, tracing::trace_state_ptr&&, seastar::bool_class<streamed_mutation::forwarding_tag>&&, seastar::bool_class<mutation_reader::partition_range_forwarding_tag>&&) at /usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/bits/invoke.h:61 (inlined by) std::enable_if<is_invocable_r_v<mutation_reader, replica::table::as_mutation_source() const::$_0&, seastar::lw_shared_ptr<schema const>, reader_permit, interval<dht::ring_position> const&, query::partition_slice const&, tracing::trace_state_ptr, seastar::bool_class<streamed_mutation::forwarding_tag>, seastar::bool_class<mutation_reader::partition_range_forwarding_tag>>, mutation_reader>::type std::__invoke_r<mutation_reader, replica::table::as_mutation_source() const::$_0&, seastar::lw_shared_ptr<schema const>, reader_permit, interval<dht::ring_position> const&, query::partition_slice const&, tracing::trace_state_ptr, seastar::bool_class<streamed_mutation::forwarding_tag>, seastar::bool_class<mutation_reader::partition_range_forwarding_tag>>(replica::table::as_mutation_source() const::$_0&, seastar::lw_shared_ptr<schema const>&&, reader_permit&&, interval<dht::ring_position> const&, query::partition_slice const&, tracing::trace_state_ptr&&, seastar::bool_class<streamed_mutation::forwarding_tag>&&, seastar::bool_class<mutation_reader::partition_range_forwarding_tag>&&) at /usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/bits/invoke.h:114 (inlined by) std::_Function_handler<mutation_reader (seastar::lw_shared_ptr<schema const>, reader_permit, interval<dht::ring_position> const&, query::partition_slice const&, tracing::trace_state_ptr, seastar::bool_class<streamed_mutation::forwarding_tag>, seastar::bool_class<mutation_reader::partition_range_forwarding_tag>), replica::table::as_mutation_source() const::$_0>::_M_invoke(std::_Any_data const&, seastar::lw_shared_ptr<schema const>&&, reader_permit&&, interval<dht::ring_position> const&, query::partition_slice const&, tracing::trace_state_ptr&&, seastar::bool_class<streamed_mutation::forwarding_tag>&&, seastar::bool_class<mutation_reader::partition_range_forwarding_tag>&&) at /usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/bits/std_function.h:290 (inlined by) std::function<mutation_reader (seastar::lw_shared_ptr<schema const>, reader_permit, interval<dht::ring_position> const&, query::partition_slice const&, tracing::trace_state_ptr, seastar::bool_class<streamed_mutation::forwarding_tag>, seastar::bool_class<mutation_reader::partition_range_forwarding_tag>)>::operator()(seastar::lw_shared_ptr<schema const>, reader_permit, interval<dht::ring_position> const&, query::partition_slice const&, tracing::trace_state_ptr, seastar::bool_class<streamed_mutation::forwarding_tag>, seastar::bool_class<mutation_reader::partition_range_forwarding_tag>) const at /usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/bits/std_function.h:591 (inlined by) mutation_source::make_reader_v2(seastar::lw_shared_ptr<schema const>, reader_permit, interval<dht::ring_position> const&, query::partition_slice const&, tracing::trace_state_ptr, seastar::bool_class<streamed_mutation::forwarding_tag>, seastar::bool_class<mutation_reader::partition_range_forwarding_tag>) const at ././readers/mutation_source.hh:143 query::querier_base::querier_base(seastar::lw_shared_ptr<schema const>, reader_permit, interval<dht::ring_position>, query::partition_slice, mutation_source const&, tracing::trace_state_ptr, query::querier_base::querier_config) at ././querier.hh:91 (inlined by) query::querier::querier(mutation_source const&, seastar::lw_shared_ptr<schema const>, reader_permit, interval<dht::ring_position>, query::partition_slice, tracing::trace_state_ptr, query::querier_base::querier_config) at ././querier.hh:164 (inlined by) replica::table::query(seastar::lw_shared_ptr<schema const>, reader_permit, query::read_command const&, query::result_options, std::vector<interval<dht::ring_position>, std::allocator<interval<dht::ring_position>>> const&, tracing::trace_state_ptr, query::result_memory_limiter&, std::chrono::time_point<seastar::lowres_clock, std::chrono::duration<long, std::ratio<1l, 1000000000l>>>, std::optional<query::querier>*) at ./replica/table.cc:3583 replica::database::query(seastar::lw_shared_ptr<schema const>, query::read_command const&, query::result_options, std::vector<interval<dht::ring_position>, std::allocator<interval<dht::ring_position>>> const&, tracing::trace_state_ptr, std::chrono::time_point<seastar::lowres_clock, std::chrono::duration<long, std::ratio<1l, 1000000000l>>>, std::variant<std::monostate, db::per_partition_rate_limit::account_only, db::per_partition_rate_limit::account_and_enforce>)::$_0::operator()(reader_permit) const at ./replica/database.cc:1533 (inlined by) seastar::noncopyable_function<seastar::future<void> (reader_permit)>::indirect_vtable_for<replica::database::query(seastar::lw_shared_ptr<schema const>, query::read_command const&, query::result_options, std::vector<interval<dht::ring_position>, std::allocator<interval<dht::ring_position>>> const&, tracing::trace_state_ptr, std::chrono::time_point<seastar::lowres_clock, std::chrono::duration<long, std::ratio<1l, 1000000000l>>>, std::variant<std::monostate, db::per_partition_rate_limit::account_only, db::per_partition_rate_limit::account_and_enforce>)::$_0>::call(seastar::noncopyable_function<seastar::future<void> (reader_permit)> const*, reader_permit) (.llvm.13537529942037499926) at ././seastar/include/seastar/util/noncopyable_function.hh:158 seastar::noncopyable_function<seastar::future<void> (reader_permit)>::operator()(reader_permit) const at ././seastar/include/seastar/util/noncopyable_function.hh:215 (inlined by) reader_concurrency_semaphore::execution_loop() (.resume) at ./reader_concurrency_semaphore.cc:980 std::__n4861::coroutine_handle<seastar::internal::coroutine_traits_base<void>::promise_type>::resume() const at /usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/coroutine:242 (inlined by) seastar::internal::coroutine_traits_base<void>::promise_type::run_and_dispose() at ./build/release/seastar/./seastar/include/seastar/core/coroutine.hh:122 (inlined by) seastar::reactor::run_tasks(seastar::reactor::task_queue&) at ./build/release/seastar/./seastar/src/core/reactor.cc:2627 (inlined by) seastar::reactor::run_some_tasks() at ./build/release/seastar/./seastar/src/core/reactor.cc:3099 seastar::reactor::do_run() at ./build/release/seastar/./seastar/src/core/reactor.cc:3267 seastar::smp::configure(seastar::smp_options const&, seastar::reactor_options const&)::$_0::operator()() const at ./build/release/seastar/./seastar/src/core/reactor.cc:4591 (inlined by) void std::__invoke_impl<void, seastar::smp::configure(seastar::smp_options const&, seastar::reactor_options const&)::$_0&>(std::__invoke_other, seastar::smp::configure(seastar::smp_options const&, seastar::reactor_options const&)::$_0&) at /usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/bits/invoke.h:61 (inlined by) std::enable_if<is_invocable_r_v<void, seastar::smp::configure(seastar::smp_options const&, seastar::reactor_options const&)::$_0&>, void>::type std::__invoke_r<void, seastar::smp::configure(seastar::smp_options const&, seastar::reactor_options const&)::$_0&>(seastar::smp::configure(seastar::smp_options const&, seastar::reactor_options const&)::$_0&) at /usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/bits/invoke.h:111 (inlined by) std::_Function_handler<void (), seastar::smp::configure(seastar::smp_options const&, seastar::reactor_options const&)::$_0>::_M_invoke(std::_Any_data const&) at /usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/bits/std_function.h:290 std::function<void ()>::operator()() const at /usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/bits/std_function.h:591 Fixes #27475 Co-authored-by: bhalevy <20910904+bhalevy@users.noreply.github.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++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.