Open Files Limit
Riak KV can accumulate a large number of open file handles during operation. The creation of numerous data files is normal, and the backend performs periodic merges of data file collections to avoid accumulating file handles.
To accomodate this you should increase the open files limit on your system. We recommend setting a soft limit of 65536 and a hard limit of 200000.
Superuser or root access may be required to perform these steps.
Changing Limit For Current Session
Most operating systems can change the open-files limit for the current shell session using the ulimit -n command:
ulimit -n 200000
Debian & Ubuntu
Start by checking the current open file limit values with:
ulimit -Hn # Hard limit
ulimit -Sn # Soft limit
If you installed Riak KV from a binary package, you will need to the add the following settings to the /etc/security/limits.conf file for the riak user:
riak soft nofile 65536
riak hard nofile 200000
If you use initialization scripts to start Riak KV, you can create a /etc/default/riak file and add the following to specify a limit:
ulimit -n 200000
This file is automatically sourced from the initialization script, and the Riak KV process will inherit this setting. Since initialization scripts are always run as the root user, there’s no need to set limits in /etc/security/limits.conf.
Enable PAM-Based Limits for Debian & Ubuntu
You can enable PAM-based user limits so that non-root users, such as the riak user, may specify a higher value for maximum open files.
For example, follow these steps to enable PAM-based limits for all users to allow a maximum of 200000 open files.
1/. Edit /etc/pam.d/common-session and add the following line:
session required pam_limits.so
2/. Save and close the file. If /etc/pam.d/common-session-noninteractive exists, append the same line as above.
3/. Edit /etc/security/limits.conf and append the following lines to the file:
* soft nofile 65536
* hard nofile 200000
4/. Save and close the file.
5/. (Optional) If you will be accessing the Riak KV nodes via secure shell (SSH), you should also edit /etc/ssh/sshd_config and uncomment the following line:
#UseLogin no
And set its value to yes as shown here:
UseLogin yes
6/. Restart the machine so the limits take effect and verify that the new limits are set with the following command:
ulimit -a
In the above examples, the open files limit is raised for all users of the system. The limit can be specified for the riak user only by substituting the
two asterisks (*) in the examples with riak.
CentOS & Red Hat
Start by checking the current open file limit values with:
ulimit -Hn # Hard limit
ulimit -Sn # Soft limit
If you installed Riak KV from a binary package, you will need to the add the following settings to the /etc/security/limits.conf file for the riak user:
riak soft nofile 65536
riak hard nofile 200000
If you use initialization scripts to start Riak KV, you can create a /etc/default/riak file and add the following to specify a limit:
ulimit -n 200000
This file is automatically sourced from the initialization script, and the Riak KV process will inherit this setting. Since initialization scripts are always run as the root user, there’s no need to set limits in /etc/security/limits.conf.
Enable PAM-Based Limits for CentOS and Red Hat
You can enable PAM-based user limits so that non-root users, such as the riak user, may specify a higher value for maximum open files.
For example, follow these steps to enable PAM-based limits for all users to allow a maximum of 200000 open files.
1/. Edit /etc/pam.d/login and add the following line:
session required pam_limits.so
2/. Save and close /etc/pam.d/login
3/. Edit /etc/security/limits.conf and append the following lines to the file:
* soft nofile 65536
* hard nofile 200000
4/. Save and close the /etc/security/limits.conf file.
5/. Restart the machine so that the limits to take effect and verify that the new limits are set with the following command:
ulimit -a
In the above examples, the open files limit is raised for all users of the system. The limit can be specified for the riak user only by substituting the
two asterisks (*) in the examples with riak.
Solaris
To increase the open file limit on Solaris, add the following line to the /etc/system file:
set rlim_fd_max=200000
macOS Sierra and High Sierra
Start by checking the current open file limit values with:
launchctl limit maxfiles
The response should look something like this:
maxfiles 65536 65536
The first column is the soft limit and the last column is the hard limit.
To change the open files limits on macOS Sierra or High Sierra, perform the following steps:
1/. Add the following line to your .bash/_profile or analogous file:
ulimit -n 65536 200000
2/. Save and close the file. Next create the file /Library/LaunchDaemons/limit.maxfiles.plist (owned by root in the group wheel with the mode 0644). In it place the following XML:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN"
"http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>limit.maxfiles</string>
<key>ProgramArguments</key>
<array>
<string>launchctl</string>
<string>limit</string>
<string>maxfiles</string>
<string>65536</string>
<string>200000</string>
</array>
<key>RunAtLoad</key>
<true/>
<key>ServiceIPC</key>
<false/>
</dict>
</plist>
3/. Save and close the file.
4/. Restart your computer and enter ulimit -n into your terminal. If your system is configured correctly, you should see that maxfiles has been set to 200000.
Mac OS X El Capitan
Start by checking the current open file limit values with:
launchctl limit maxfiles
The response should look something like this:
maxfiles 65536 65536
The first column is the soft limit and the last column is the hard limit.
To change the open files limits on Mac OS X El Capitan, perform the following steps:
1/. Add the following line to your .bash_profile or analogous file:
ulimit -n 65536 200000
2/. Save and close the file. Next open /etc/sysctl.conf (or create it if it doesn’t already exist) and add the following settings:
kern.maxfiles=200000
kern.maxfilesperproc=200000
4/. Restart your computer and enter ulimit -n into your terminal. If your system is configured correctly, you should see that maxfiles has been set to 200000.
Mac OS X Yosemite
Start by checking the current open file limit values with:
launchctl limit maxfiles
The response should look something like this:
maxfiles 65536 65536
The first column is the soft limit and the last column is the hard limit.
To change the open files limits on Mac OS X Yosemite, perform these steps:
1/. Add the following line to your .bash_profile or analogous file:
ulimit -n 65536 200000
2/. Save and close the file. Next edit the /etc/launchd.conf file and add:
limit maxfiles 200000
3/. Save and close the file.
4/. After restarting, verify the new limits by running:
launchctl limit maxfiles
The response output should look something like this:
maxfiles 65536 200000
Mac OS X Older Versions
Start by checking the current open file limit values with:
launchctl limit maxfiles
The response should look something like this:
maxfiles 10240 10240
The first column is the soft limit and the last column is the hard limit.
To adjust the maximum open file limits in OS X 10.7 (Lion) up to but not including OS X Yosemite, perform the following steps:
1/. Edit (or create) /etc/launchd.conf and increase the limits by adding:
limit maxfiles 65536 200000
2/. Save the file and restart the system for the new limits to take effect.
3/. After restarting, verify the new limits by running:
launchctl limit maxfiles
The response output should look something like this:
maxfiles 65536 200000