ebdfa10c8f
The test waited for two "Finished tablet repair" log messages on the
coordinator, expecting one per tablet. But there are two log sources
that emit messages matching this pattern:
repair module (repair/repair.cc:2329):
"Finished tablet repair for table=..."
topology coordinator (topology_coordinator.cc:2083):
"Finished tablet repair host=..."
When the coordinator is also a repair replica (always the case with
RF=3 and 3 nodes), both messages appear in the coordinator log for the
same tablet within 1ms of each other. The test consumed both, thinking
both tablets were done, while the second tablet repair was still running.
From the CI failure logs:
04:08:09.658 Found: repair[...]: Finished tablet repair for table=...
global_tablet_id=e42fd650-3542-11f1-9756-85403784a622:0
04:08:09.660 Found: raft_topology - Finished tablet repair host=...
tablet=e42fd650-3542-11f1-9756-85403784a622:0
Both messages are for tablet :0. Tablet :1 repair had not finished yet.
The test then wrote keys 20-29 while the second tablet repair was still
in progress. That repair flushed the memtable (via
prepare_sstables_for_incremental_repair), including keys 20-29 in the
repair scan, and mark_sstable_as_repaired set repaired_at=2 on the
resulting sstable. This caused the assertion failure on servers[0]:
"should not have post-repair keys in repaired sstables, got:
{20, 21, 22, 23, 24, 25, 26, 27, 28, 29}"
Fix by matching "Finished tablet repair host=" which is unique to the
topology coordinator message and avoids the ambiguity.
Also fix an incorrect comment that said being_repaired=null when at that
point in the test being_repaired is still set to the session_id (the
delay_end_repair_update injection prevents end_repair from running).
Fixes: SCYLLADB-1478
Closes scylladb/scylladb#29444
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.