Tried the following
sysctl net.core.somaxconn
net.core.somaxconn = 4096
sudo sysctl -w net.core.somaxconn=8192
but without a success.
Finally fixed this error with
ulimit -n 65535
The command sets the maximum number of descriptors, a process run within current BASH session can use.
socket.accept error 24: To many open files
https://stackoverflow.com/questions/2569620/socket-accept-error-24-to-many-open-files