How to Raise Bondy's Open File Limit

Bondy can accumulate a large number of open file handles during operation — the storage backend's periodic merges of data files are normal and expected, but they mean a low open-files limit will eventually block Bondy from creating new files it needs.

Prerequisites: shell access to the host or container running Bondy, with permission to change system limits (root, or sudo, for a permanent change).

Steps

1. Check the current limit.

   ulimit -Hn # Hard limit
   ulimit -Sn # Soft limit

2. Raise it for the current shell session.

   ulimit -n 200000

   WARNING

   This only lasts for the current shell session. To make the change permanent, follow the OS-specific steps below.

3. Make the change permanent, following whichever of these matches your deployment:

On most Linux distributions, the total limit for open files is controlled by sysctl.

If Bondy runs as the bondy user, add the following settings to the /etc/security/limits.conf file:

bondy soft nofile 65536
bondy hard nofile 200000

Enable PAM-based user limits so that non-root users, such as the bondy user, may specify a higher value for maximum open files.

Edit /etc/pam.d/common-session and add the following line:

session required pam_limits.so

Save and close the file. If /etc/pam.d/common-session-noninteractive exists, append the same line as above.

Then, edit /etc/security/limits.conf and append the following lines to the file:

soft nofile 65536
hard nofile 200000

Save and close the file.

(Optional) If you will be accessing the Bondy nodes via secure shell (SSH), also edit /etc/ssh/sshd_config and set the following line:

UseLogin yes

Restart the machine so the limits take effect and verify the new limits are set:

ulimit -a

Docker's own ulimit caps a container's resource use, independently of the guest OS limits above.

1. Connect to the desired worker node and check the current value:

systemctl show docker

Look for NOFILE in the output.

2. If it shows 1024, edit /etc/sysconfig/docker and replace:

OPTIONS="--default-ulimit nofile=1024:4096"

with:

OPTIONS="--default-ulimit nofile=2000000:2000000"

3. Restart the Docker daemon:

sudo systemctl restart docker

Set the ulimit directly on docker run:

docker run --ulimit nofile=2000000:2000000 ...

Result

Bondy's process can hold open a soft limit of 65536 files and a hard limit of 200000, surviving both a shell restart and (where configured) a Docker daemon or container restart. Confirm with ulimit -a (or, for a running Bondy process, by inspecting /proc/<pid>/limits on Linux).

See also

• Configuration Basics — locating and writing bondy.conf.