Comment 0 for bug 1780164

horizon version 13.0.0-1.el7 (Queens)

After some time working on the dashboard, it stops working and throw this error in the error log

[Wed Jul 04 22:49:33.744241 2018] [:error] [pid 23924] [remote 10.144.187.237:52] IOError: [Errno 24] Too many open files: '/usr/share/openstack-dashboard/openstack_dashboard/templates/500.html'

if we check the open files of this process 23924

 ls -l /proc/23924/fd | wc -l
1023

even if we increase the nofile limit of this process, it doesn't help as the open files is always increasing
the problem is cleared if we restart the httpd process, but then the open files will increase again

how to reproduce

1- login to the dashboard
2- get the pid from the error_log file
[Wed Jul 04 22:50:58.620832 2018] [:error] [pid 23924] INFO openstack_auth.forms Login successful for user "demo" using domain "default"
3- browse the dashboard different menus, specially the network topology tab
4- monitor the open files no. with ls -l /proc/<pid>/fd | wc -l

observation
the no. is always increasing