AWS EC2 terminal session terminated with "Plugin with name Standard_Stream not found"

Question

I was streaming Kafka on AWS EC2 CentOS 7. My Session Manager Idle Timeout is set to 60min. And yet, after running for much less than that, the terminal got frozen, saying My session has been terminated. Of course, the Kafka streaming for disrupted as well.

When I tried to restart a new session with a new terminal, I got this error popup

Your session has been terminated for the following reasons: Plugin with name Standard_Stream not found. Step name: Standard_Stream

and I am still unable to restart a terminal.

What does this error mean and how to resolve it? Thanks.

Answer 1

• So far you need to access the EC2 using SSH with key-pem to debug (ask your admin)

Running tail -f got issue

tail: inotify resources exhausted
tail: inotify cannot be used, reverting to polling

• Restart ssm-agent service also got issue No space left on device but it's not about disk space

  [root@env-test ec2-user]# systemctl restart amazon-ssm-agent.service Error: No space left on device

  [root@env-test ec2-user]# df -h |grep dev devtmpfs 32G 0 32G 0% /dev tmpfs 32G 0 32G 0% /dev/shm /dev/nvme0n1p1 100G 82G 18G 83% /

• So the error itself means that system is getting low on inotify watches, that enable programs to monitor file/dirs changes. To see the currently set limit (including output on my machine)

  $ cat /proc/sys/fs/inotify/max_user_watches

  8192

Check which processes using inotify to improve your apps or increase max_user_watches

for foo in /proc/*/fd/*; do readlink -f $foo; done | grep inotify | sort | uniq -c | sort -nr
5 /proc/1/fd/anon_inode:inotify
2 /proc/7126/fd/anon_inode:inotify
2 /proc/5130/fd/anon_inode:inotify
1 /proc/4497/fd/anon_inode:inotify
1 /proc/4437/fd/anon_inode:inotify
1 /proc/4151/fd/anon_inode:inotify
1 /proc/4147/fd/anon_inode:inotify
1 /proc/4028/fd/anon_inode:inotify
1 /proc/3913/fd/anon_inode:inotify
1 /proc/3841/fd/anon_inode:inotify
1 /proc/31146/fd/anon_inode:inotify
1 /proc/2829/fd/anon_inode:inotify
1 /proc/21259/fd/anon_inode:inotify
1 /proc/1934/fd/anon_inode:notify

• Notice that the above inotify list include PID of ssm-agent processes, it explains why we got issue with SSM when max_user_watches reached limit

ps -ef | grep ssm-ag

root      3841     1  0 00:02 ?        00:00:05 /usr/bin/amazon-ssm-agent
root      4497  3841  0 00:02 ?        00:00:33 /usr/bin/ssm-agent-worker

• Final Solution: Permanent solution (preserved across restarts)

echo "fs.inotify.max_user_watches=1048576" >> /etc/sysctl.conf sysctl -p

• Verify:

  $ aws ssm start-session --target i-123abc456efd789xx --region ap-northeast-2

Starting session with SessionId: userdev-03ccb1a04a6345bf5

sh-4.2$

• This issue comes from EC2 instance not about SSM agent Go to link to undestanding SSM agent.

optional link