5cb3900d90
The driver must see server_c before we stop server_a, otherwise
there will be no live host in the pool when we attempt to drop
the keyspace:
```
@pytest.mark.asyncio
async def test_not_enough_token_owners(manager: ManagerClient):
"""
Test that:
- the first node in the cluster cannot be a zero-token node
- removenode and decommission of the only token owner fail in the presence of zero-token nodes
- removenode and decommission of a token owner fail in the presence of zero-token nodes if the number of token
owners would fall below the RF of some keyspace using tablets
"""
logging.info('Trying to add a zero-token server as the first server in the cluster')
await manager.server_add(config={'join_ring': False},
property_file={"dc": "dc1", "rack": "rz"},
expected_error='Cannot start the first node in the cluster as zero-token')
logging.info('Adding the first server')
server_a = await manager.server_add(property_file={"dc": "dc1", "rack": "r1"})
logging.info('Adding two zero-token servers')
# The second server is needed only to preserve the Raft majority.
server_b = (await manager.servers_add(2, config={'join_ring': False}, property_file={"dc": "dc1", "rack": "rz"}))[0]
logging.info(f'Trying to decommission the only token owner {server_a}')
await manager.decommission_node(server_a.server_id,
expected_error='Cannot decommission the last token-owning node in the cluster')
logging.info(f'Stopping {server_a}')
await manager.server_stop_gracefully(server_a.server_id)
logging.info(f'Trying to remove the only token owner {server_a} by {server_b}')
await manager.remove_node(server_b.server_id, server_a.server_id,
expected_error='cannot be removed because it is the last token-owning node in the cluster')
logging.info(f'Starting {server_a}')
await manager.server_start(server_a.server_id)
logging.info('Adding a normal server')
await manager.server_add(property_file={"dc": "dc1", "rack": "r2"})
cql = manager.get_cql()
await wait_for_cql_and_get_hosts(cql, [server_a], time.time() + 60)
> async with new_test_keyspace(manager, "WITH replication = {'class': 'NetworkTopologyStrategy', 'replication_factor': 2} AND tablets = { 'enabled': true }") as ks_name:
test/cluster/test_not_enough_token_owners.py:57:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
/usr/lib64/python3.14/contextlib.py:221: in __aexit__
await anext(self.gen)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
manager = <test.pylib.manager_client.ManagerClient object at 0x7f37efe00830>
opts = "WITH replication = {'class': 'NetworkTopologyStrategy', 'replication_factor': 2} AND tablets = { 'enabled': true }"
host = None
@asynccontextmanager
async def new_test_keyspace(manager: ManagerClient, opts, host=None):
"""
A utility function for creating a new temporary keyspace with given
options. It can be used in a "async with", as:
async with new_test_keyspace(ManagerClient, '...') as keyspace:
"""
keyspace = await create_new_test_keyspace(manager.get_cql(), opts, host)
try:
yield keyspace
except:
logger.info(f"Error happened while using keyspace '{keyspace}', the keyspace is left in place for investigation")
raise
else:
> await manager.get_cql().run_async("DROP KEYSPACE " + keyspace, host=host)
E cassandra.cluster.NoHostAvailable: ('Unable to complete the operation against any hosts', {<Host: 127.69.108.39:9042 dc1>: ConnectionException('Pool for 127.69.108.39:9042 is shutdown')})
test/cluster/util.py:544: NoHostAvailable
```
Fixes #28011
Closes scylladb/scylladb#28040
(cherry picked from commit 34df158605)
Closes scylladb/scylladb#28073
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.