/etc/rsyslog.conf

$SystemLogRateLimitInterval 3
$SystemLogRateLimitBurst 40

service rsyslog restart

PollingInterval seconds
Default: 10

This setting specifies how often files are to be polled for new data.
The time specified is in seconds. During each polling interval, all
files are processed in a round-robin fashion.

A short poll interval provides more rapid message forwarding, but
requires more system resources. While it is possible, we stongly
recommend not to set the polling interval to 0 seconds

*.*;auth,authpriv,kern.none   /var/log/syslog
kern.*                        /var/log/kern.log
kern.debug                    stop
*.=debug;
  auth,authpriv.none;
  news.none;mail.none         /var/log/debug