Unable to connect to ScyllaDB 5.4 in self-managed AWS instance

I am trying to setup ScyllaDB 5.4 on my own AWS account but when I try to connect through SSH, nothing happens. It timeouts after awhile.

I followed the guide here: Launch ScyllaDB on AWS | ScyllaDB Docs. These are my exact steps, note that I can connect with the same security groups and subnets when I install a plain AWS AMI instance with a ec2-user as username, so that is configured well:

  1. Launch new instance
  2. Choose ScyllaDB 5.4
  3. Choose instance type ‘i4i.large’
  4. Configure key pair and security groups (everything is open)
  5. I did with and without user data, this was my configuration with user data:

“scylla_yaml”: {
“cluster_name”: “test-cluster”,
“seed_provider”: [{“class_name”: “org.apache.cassandra.locator.SimpleSeedProvider”}],
“post_configuration_script”: “#! /bin/bash\nyum install cloud-init-cfn”,
“start_scylla_on_first_boot”: true

Now I wait until I see 2/2 checks are completed in AWS EC2 instance overview. After that, I tried connecting to both the public IP4 address and Public IPv4 DNS with username scyllaadm, root and ec2-user. They all freeze. I try connecting like this: ssh -i KPNew.pem scyllaadm@

Am I missing something?

This is the system log: gist:c3c31fdbb32f83c1127070a360ac65c9 · GitHub

Hi Jasper

Can you provide the region/ami id you are trying to use?
Did you have the same connection issue with and without your user-data?


Hi Jasper,
Please provide output of “ssh -vvv -i …”