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ScyllaDB is a high-performance NoSQL database system, fully compatible with Apache Cassandra. ScyllaDB is released under the GNU Affero General Public License version 3 and the Apache License, ScyllaDB is free and open-source software.
Scylla Docker support x86_64 for all version, and aarch64 starting from Scylla 4.6. Get it now with Scylla nightly build
To startup a Scylla single-node cluster in developer mode execute:
$ docker run --name some-scylla --hostname some-scylla -d scylladb/scylla --smp 1
This command will start a Scylla single-node cluster in developer mode
(see --developer-mode 1) limited by a single CPU core (see --smp).
Production grade configuration requires tuning a few kernel parameters
such that limiting number of available cores (with --smp 1) is
the simplest way to go.
Multiple cores requires setting a proper value to the /proc/sys/fs/aio-max-nr.
On many non production systems it will be equal to 65K. The formula
to calculate proper value is:
Available AIO on the system - (request AIO per-cpu * ncpus) =
aio_max_nr - aio_nr < (reactor::max_aio + detect_aio_poll + reactor_backend_aio::max_polls) * cpu_cores =
aio_max_nr - aio_nr < (1024 + 2 + 10000) * cpu_cores =
aio_max_nr - aio_nr < 11026 * cpu_cores
where
reactor::max_aio = max_aio_per_queue * max_queues,
max_aio_per_queue = 128,
max_queues = 8.
scylla server instance¶$ docker run --name some-scylla --hostname some-scylla -d scylladb/scylla
nodetool utility¶$ docker exec -it some-scylla nodetool status
Datacenter: datacenter1
=======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
-- Address Load Tokens Owns (effective) Host ID Rack
UN 172.17.0.2 125.51 KB 256 100.0% c9155121-786d-44f8-8667-a8b915b95665 rack1
cqlsh utility¶$ docker exec -it some-scylla cqlsh
Connected to Test Cluster at 172.17.0.2:9042.
[cqlsh 5.0.1 | Cassandra 2.1.8 | CQL spec 3.2.1 | Native protocol v3]
Use HELP for help.
cqlsh>
$ docker run --name some-scylla2 --hostname some-scylla2 -d scylladb/scylla --seeds="$(docker inspect --format='{{ .NetworkSettings.IPAddress }}' some-scylla)"
First, create a docker-compose.yml file with the following contents:
version: '3'
services:
some-scylla:
image: scylladb/scylla
container_name: some-scylla
some-scylla2:
image: scylladb/scylla
container_name: some-scylla2
command: --seeds=some-scylla
some-scylla3:
image: scylladb/scylla
container_name: some-scylla3
command: --seeds=some-scylla
Then, launch the 3-node cluster as follows:
docker-compose up -d
scylla logs¶$ docker logs some-scylla | tail
INFO 2016-08-04 06:57:40,836 [shard 5] database - Setting compaction strategy of system_traces.events to SizeTieredCompactionStrategy
INFO 2016-08-04 06:57:40,836 [shard 3] database - Setting compaction strategy of system_traces.events to SizeTieredCompactionStrategy
INFO 2016-08-04 06:57:40,836 [shard 1] database - Setting compaction strategy of system_traces.events to SizeTieredCompactionStrategy
INFO 2016-08-04 06:57:40,836 [shard 2] database - Setting compaction strategy of system_traces.events to SizeTieredCompactionStrategy
INFO 2016-08-04 06:57:40,836 [shard 4] database - Setting compaction strategy of system_traces.events to SizeTieredCompactionStrategy
INFO 2016-08-04 06:57:40,836 [shard 7] database - Setting compaction strategy of system_traces.events to SizeTieredCompactionStrategy
INFO 2016-08-04 06:57:40,837 [shard 6] database - Setting compaction strategy of system_traces.events to SizeTieredCompactionStrategy
INFO 2016-08-04 06:57:40,839 [shard 0] database - Schema version changed to fea14d93-9c5a-34f5-9d0e-2e49dcfa747e
INFO 2016-08-04 06:57:40,839 [shard 0] storage_service - Starting listening for CQL clients on 172.17.0.2:9042...
INFO 2016-08-04 06:57:40,840 [shard 0] storage_service - Thrift server listening on 172.17.0.2:9160 ...
You can use Docker volumes to improve performance of Scylla.
Create a Scylla data directory /var/lib/scylla on the host, which is used by Scylla container to store all data:
$ sudo mkdir -p /var/lib/scylla/data /var/lib/scylla/commitlog /var/lib/scylla/hints /var/lib/scylla/view_hints
Launch Scylla using Docker’s --volume command line option to mount the created host directory as a data volume in the container and disable Scylla’s developer mode to run I/O tuning before starting up the Scylla node.
$ docker run --name some-scylla --volume /var/lib/scylla:/var/lib/scylla -d scylladb/scylla --developer-mode=0
The Scylla docker image defaults to running on overprovisioned mode and won’t apply any CPU pinning optimizations, which it normally does in non-containerized environments.
For better performance, it is recommended to configure resource limits for your Docker container using the --smp, --memory, and --cpuset command line options, as well as
disabling the overprovisioned flag as documented in the section “Command-line options”.
The Docker image uses supervisord to manage Scylla processes. You can restart Scylla in a Docker container using
docker exec -it some-scylla supervisorctl restart scylla
The Scylla image supports many command line options that are passed to the docker run command.
--seeds SEEDS¶The -seeds command line option configures Scylla’s seed nodes.
If no --seeds option is specified, Scylla uses its own IP address as the seed.
For example, to configure Scylla to run with two seed nodes 192.168.0.100 and 192.168.0.200.
$ docker run --name some-scylla -d scylladb/scylla --seeds 192.168.0.100,192.168.0.200
--listen-address ADDR¶The --listen-address command line option configures the IP address the Scylla instance listens on for connections from other Scylla nodes.
For example, to configure Scylla to use listen address 10.0.0.5:
$ docker run --name some-scylla -d scylladb/scylla --listen-address 10.0.0.5
Since: 1.4
--alternator-address ADDR¶The --alternator-address command line option configures the Alternator API listen address. The default value is the same as --listen-address.
Since: 3.2
--alternator-port PORT¶The --alternator-port command line option configures the Alternator API listen port. The Alternator API is disabled by default. You need to specify the port to enable it.
For example, to configure Scylla to listen to Alternator API at port 8000:
$ docker run --name some-scylla -d scylladb/scylla --alternator-port 8000
Since: 3.2
--alternator-https-port PORT¶The --alternator-https-port option is similar to --alternator-port, just enables an encrypted (HTTPS) port. Either the --alternator-https-port or --alternator-http-port, or both, can be used to enable Alternator.
Note that the --alternator-https-port option also requires that files /etc/scylla/scylla.crt and /etc/scylla/scylla.key be inserted into the image. These files contain an SSL certificate and key, respectively.
Since: 4.2
--alternator-write-isolation policy¶The --alternator-write-isolation command line option chooses between four allowed write isolation policies described in docs/alternator/alternator.md. This option must be specified if Alternator is enabled - it does not have a default.
Since: 4.1
--broadcast-address ADDR¶The --broadcast-address command line option configures the IP address the Scylla instance tells other Scylla nodes in the cluster to connect to.
For example, to configure Scylla to use broadcast address 10.0.0.5:
$ docker run --name some-scylla -d scylladb/scylla --broadcast-address 10.0.0.5
--broadcast-rpc-address ADDR¶The --broadcast-rpc-address command line option configures the IP address the Scylla instance tells clients to connect to.
For example, to configure Scylla to use broadcast RPC address 10.0.0.5:
$ docker run --name some-scylla -d scylladb/scylla --broadcast-rpc-address 10.0.0.5
--smp COUNT¶The --smp command line option restricts Scylla to COUNT number of CPUs.
The option does not, however, mandate a specific placement of CPUs.
See the --cpuset command line option if you need Scylla to run on specific CPUs.
For example, to restrict Scylla to 2 CPUs:
$ docker run --name some-scylla -d scylladb/scylla --smp 2
--memory AMOUNT¶The --memory command line option restricts Scylla to use up to AMOUNT of memory.
The AMOUNT value supports both M unit for megabytes and G unit for gigabytes.
For example, to restrict Scylla to 4 GB of memory:
$ docker run --name some-scylla -d scylladb/scylla --memory 4G
--reserve-memory AMOUNT¶The --reserve-memory command line option configures Scylla to reserve the AMOUNT of memory to the OS.
The AMOUNT value supports both M unit for megabytes and G unit for gigabytes.
For example, to reserve 4 GB of memory to the OS:
$ docker run --name some-scylla -d scylladb/scylla --reserve-memory 4G
--overprovisioned ENABLE¶The --overprovisioned command line option enables or disables optimizations for running Scylla in an overprovisioned environment.
If no --overprovisioned option is specified, Scylla defaults to running with optimizations enabled. If --overprovisioned is
not specified and is left at its default, specifying --cpuset will automatically disable --overprovisioned
For example, to enable optimizations for running in an statically partitioned environment:
$ docker run --name some-scylla -d scylladb/scylla --overprovisioned 0
--io-setup ENABLE¶The --io-setup command line option specifies if the scylla_io_setup script is run when the container is started for the first time.
This is useful if users want to specify I/O settings themselves in environments such as Kubernetes, where running iotune is problematic.
The default of --io-setup is 1, which means I/O setup is run.
For example, to skip running I/O setup:
$ docker run --name some-scylla -d scylladb/scylla --io-setup 0
Since: 4.3
--cpuset CPUSET¶The --cpuset command line option restricts Scylla to run on only on CPUs specified by CPUSET.
The CPUSET value is either a single CPU (e.g. --cpuset 1), a range (e.g. --cpuset 2-3), or a list (e.g. --cpuset 1,2,5), or a combination of the last two options (e.g. --cpuset 1-2,5).
For example, to restrict Scylla to run on physical CPUs 0 to 2 and 4:
$ docker run --name some-scylla -d scylladb/scylla --cpuset 0-2,4
--developer-mode ENABLE¶The --developer-mode command line option enables Scylla’s developer mode, which relaxes checks for things like XFS and enables Scylla to run on unsupported configurations (which usually results in suboptimal performance).
If no --developer-mode command line option is defined, Scylla defaults to running with developer mode enabled.
It is highly recommended to disable developer mode for production deployments to ensure Scylla is able to run with maximum performance.
For example, to disable developer mode:
$ docker run --name some-scylla -d scylladb/scylla --developer-mode 0
--experimental ENABLE¶The --experimental command line option enables Scylla’s experimental mode
If no --experimental command line option is defined, Scylla defaults to running with experimental mode disabled.
It is highly recommended to disable experimental mode for production deployments.
For example, to enable experimental mode:
$ docker run --name some-scylla -d scylladb/scylla --experimental 1
Since: 2.0
--disable-version-check¶The --disable-version-check disable the version validation check.
Since: 2.2
--authenticator AUTHENTICATOR¶The --authenticator command lines option allows to provide the authenticator class Scylla will use. By default Scylla uses the AllowAllAuthenticator which performs no credentials checks. The second option is using the PasswordAuthenticator parameter, which relies on username/password pairs to authenticate users.
Since: 2.3
JMX Scylla service is initialized from the /scylla-jmx-service.sh on
container startup. By default the script uses /etc/sysconfig/scylla-jmx
to read default configuration. It then can be overridden by setting
an environmental parameters.
An example:
docker run -d -e "SCYLLA_JMX_ADDR=-ja 0.0.0.0" -e SCYLLA_JMX_REMOTE=-r --publish 7199:7199 scylladb/scylla
Scylla JMX listening port.
Default value:
SCYLLA_JMX_PORT="-jp 7199"
Scylla API port for JMX to connect to.
Default value:
SCYLLA_API_PORT="-p 10000"
Scylla API address for JMX to connect to.
Default value:
SCYLLA_API_ADDR="-a localhost"
JMX address to bind on.
Default value:
SCYLLA_JMX_ADDR="-ja localhost"
For example, it is possible to make JMX available to the outer world
by changing its bind address to 0.0.0.0:
docker run -d -e "SCYLLA_JMX_ADDR=-ja 0.0.0.0" -e SCYLLA_JMX_REMOTE=-r --publish 7199:7199 scylladb/scylla
cassandra-stress requires direct access to the JMX.
A JMX service configuration file path.
Example value:
SCYLLA_JMX_FILE="-cf /etc/scylla.d/scylla-user.cfg"
The location of the JMX executable.
Example value:
SCYLLA_JMX_LOCAL="-l /opt/scylladb/jmx
Allow JMX to run remotely.
Example value:
SCYLLA_JMX_REMOTE="-r"
Enable debugger.
Example value:
SCYLLA_JMX_DEBUG="-d"
For bug reports, please use Scylla’s issue tracker on GitHub. Please read the How to report a Scylla problem page before you report bugs.
For general help, see Scylla’s documentation. For questions and comments, use Scylla’s mailing lists.
Want to scratch your own itch and contribute a patch. We are eager to review and merge your code. Please consult the Contributing on Scylla page