Cannot run nodetool commands and cqlsh to Scylla in Docker

I am new to Scylla and I am following the instructions to try it in a container as per this page: https://hub.docker.com/r/scylladb/scylla/.

The following command ran fine.

docker run --name some-scylla --hostname some-scylla -d scylladb/scylla

I see the container is running.

CONTAINER ID   IMAGE             COMMAND                  CREATED          STATUS          PORTS                                                            NAMES
e6c4e19ff1bd   scylladb/scylla   "/docker-entrypoint.…"   14 seconds ago   Up 13 seconds   22/tcp, 7000-7001/tcp, 9042/tcp, 9160/tcp, 9180/tcp, 10000/tcp   some-scylla

However, I'm unable to use nodetool or cqlsh. I get the following output.

$ docker exec -it some-scylla nodetool status
Using /etc/scylla/scylla.yaml as the config file
nodetool: Unable to connect to Scylla API server: java.net.ConnectException: Connection refused (Connection refused)
See 'nodetool help' or 'nodetool help <command>'.

and

$ docker exec -it some-scylla cqlsh
Connection error: ('Unable to connect to any servers', {'172.17.0.2': error(111, "Tried connecting to [('172.17.0.2', 9042)]. Last error: Connection refused")})

Any ideas?

Update

Looking at docker logs some-scylla I see some errors in the logs, the last one is as follows.

2021-10-03 07:51:04,771 INFO spawned: 'scylla' with pid 167
Scylla version 4.4.4-0.20210801.69daa9fd0 with build-id eb11cddd30e88ef39c32c847e70181b5cf786355 starting ...
command used: "/usr/bin/scylla --log-to-syslog 0 --log-to-stdout 1 --default-log-level info --network-stack posix --developer-mode=1 --overprovisioned --listen-address 172.17.0.2 --rpc-address 172.17.0.2 --seed-provider-parameters seeds=172.17.0.2 --blocked-reactor-notify-ms 999999999"
parsed command line options: [log-to-syslog: 0, log-to-stdout: 1, default-log-level: info, network-stack: posix, developer-mode: 1, overprovisioned, listen-address: 172.17.0.2, rpc-address: 172.17.0.2, seed-provider-parameters: seeds=172.17.0.2, blocked-reactor-notify-ms: 999999999]
ERROR 2021-10-03 07:51:05,203 [shard 6] seastar - Could not setup Async I/O: Resource temporarily unavailable. The most common cause is not enough request capacity in /proc/sys/fs/aio-max-nr. Try increasing that number or reducing the amount of logical CPUs available for your application
2021-10-03 07:51:05,316 INFO exited: scylla (exit status 1; not expected)
2021-10-03 07:51:06,318 INFO gave up: scylla entered FATAL state, too many start retries too quickly

Update 2

The reason for the error was described on the docker hub page linked above. I had to start container specifying the number of CPUs with --smp 1 as follows.

docker run --name some-scylla --hostname some-scylla -d scylladb/scylla --smp 1

According to the above page:

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. ...