9daed59af9
The mechanics of the restore is like this - A /storage_service/tablets/restore API is called with (keyspace, table, endpoint, bucket, manifests) parameters - First, it populates the system_distributed.snapshot_sstables table with the data read from the manifests - Then it emplaces a bunch of tablet transitions (of a new "restore" kind), one for each tablet - The topology coordinator handles the "restore" transition by calling a new RESTORE_TABLET RPC against all the current tablet replicas - Each replica handles the RPC verb by - Reading the snapshot_sstables table - Filtering the read sstable infos against current node and tablet being handled - Downloading and attaching the filtered sstables This PR includes system_distributed.snapshot_sstables table from @robertbindar and preparation work from @kreuzerkrieg that extracts raw sstables downloading and attaching from existing generic sstables loading code. This is first step towards SCYLLADB-197 and lacks many things. In particular - the API only works for single-DC cluster - the caller needs to "lock" tablet boundaries with min/max tablet count - not abortable - no progress tracking - sub-optimal (re-kicking API on restore will re-download everything again) - not re-attacheable (if API node dies, restoration proceeds, but the caller cannot "wait" for it to complete via other node) - nodes download sstables in maintenance/streaming sched gorup (should be moved to maintenance/backup) Other follow-up items: - have an actual swagger object specification for `backup_location` Closes #28436 Closes #28657 Closes #28773 Closes scylladb/scylladb#28763 * github.com:scylladb/scylladb: test: Add test for backup vs migration race test: Restore resilience test sstables_loader: Fail tablet-restore task if not all sstables were downloaded sstables_loader: mark sstables as downloaded after attaching sstables_loader: return shared_sstable from attach_sstable db: add update_sstable_download_status method db: add downloaded column to snapshot_sstables db: extract snapshot_sstables TTL into class constant test: Add a test for tablet-aware restore tablets: Implement tablet-aware cluster-wide restore messaging: Add RESTORE_TABLET RPC verb sstables_loader: Add method to download and attach sstables for a tablet tablets: Add restore_config to tablet_transition_info sstables_loader: Add restore_tablets task skeleton test: Add rest_client helper to kick newly introduced API endpoint api: Add /storage_service/tablets/restore endpoint skeleton sstables_loader: Add keyspace and table arguments to manfiest loading helper sstables_loader_helpers: just reformat the code sstables_loader_helpers: generalize argument and variable names sstables_loader_helpers: generalize get_sstables_for_tablet sstables_loader_helpers: add token getters for tablet filtering sstables_loader_helpers: remove underscores from struct members sstables_loader: move download_sstable and get_sstables_for_tablet sstables_loader: extract single-tablet SST filtering sstables_loader: make download_sstable static sstables_loader: fix formating of the new `download_sstable` function sstables_loader: extract single SST download into a function sstables_loader: add shard_id to minimal_sst_info sstables_loader: add function for parsing backup manifests split utility functions for creating test data from database_test export make_storage_options_config from lib/test_services rjson: Add helpers for conversions to dht::token and sstable_id Add system_distributed_keyspace.snapshot_sstables add get_system_distributed_keyspace to cql_test_env code: Add system_distributed_keyspace dependency to sstables_loader storage_service: Export export handle_raft_rpc() helper storage_service: Export do_tablet_operation() storage_service: Split transit_tablet() into two tablets: Add braces around tablet_transition_kind::repair switch
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.