RHEL 7 and CentOS 7 syslog Rate Limit
In RHEL 7 there is rate-limiting both in systemd-journald and in rsyslog's imjournal module
Lower Ratelimit IntervalLower the interval for rate-limiting and increase the burst level in order to minimize the possibility of losing log messages when the threshold is reached for the specified number of messages logged within the specified interval. Rate-limiting is specific to each process, so there's usually no reason to change this. It is also inadvisable to disable this feature entirely!
grep -i rate /etc/systemd/journald.conf #RateLimitInterval=30s #RateLimitBurst=1000 RateLimitInterval=10s RateLimitBurst=3000
grep -i rate /etc/rsyslog.conf #$imjournalRatelimitInterval 600 <--default $imjournalRatelimitInterval 300 $imjournalRatelimitBurst 30000