The server allows for an unlimited number of connections by default, but is restricted by the file descriptor limit on the operating system. If needed, increase the file descriptor limit on the operating system with the following procedure.
If the operating system relies on
systemd, refer to the Linux
operating system documentation for instructions on setting the file descriptor
Display the current
fs.file-maxlimit of the system.
fs.file-maxlimit is the maximum server-wide file limit you can set without tuning the kernel parameters in the proc file system.
Edit the /etc/sysctl.conf file. If there is a line that sets
the value of the
fs.file-maxproperty, make sure that its value is set to at least 1.5 times the per-process limit. If there is no line that sets a value for this property, add the following to the end of the file (100000 is just an example here; specify a value of at least 1.5 times the per-process limit):
fs.file-max = 100000
Display the current hard limit of the system.
open files (-n)value is the maximum number of open files per process limit.
Verify that its value is set to at least 65535.
Edit the /etc/security/limits.conf file. If the file has lines
that set the soft and hard limits for the number of file descriptors, make sure the
values are set to 65535. If the lines are not present, add the following lines to the
end of the file (before “#End of file”), making certain to insert a tab between the
* soft nofile 65535 * hard nofile 65535Note:The number of open file descriptors is limited by the physical memory available to the host. You can determine this limit with the following command.
If the file-max value is significantly higher than the 65535 limit, consider increasing the file descriptor limit to between 10% and 15% of the system-wide file descriptor limit. For example, if the file-max value is 810752, you could set the file descriptor limit to 100000. If the file-max value is lower than 65535, the host is likely not sized appropriately.
Reboot the system, and then use the
ulimitcommand to verify that the file descriptor limit is set to
65535with the following command:
Once the operating system limit is set, the number of file descriptors that the server
will use can be configured by either using a
environment variable, or by creating a
with a single line such as,
NUM_FILE_ DESCRIPTORS=12345. If these are
not set, the default of
65535 is used. This is strictly optional if
wanting to ensure that the server shuts down safely prior to reaching the file
For RedHat 7 or later, modify the
20-nproc.conf file to set both the
open files and max user processes limits:
/etc/security/limits.d/20-nproc.conf Add or edit the following lines if they do not already exist: * soft nproc 65536 * soft nofile 65536 * hard nproc 65536 * hard nofile 65536 root soft nproc unlimited