I got the below messages in the log .

imuxsock begins to drop messages from pid due to rate-limiting
imuxsock lost xxx messages from pid due to rate-limiting


I tried added the below line to rsyslog.conf , then the size of the log will be growth very fast.

$SystemLogRateLimitInterval 0
$SystemLogRateLimitBurst 0
$IMUXSockRateLimitInterval 0
$IMUXSockRateLimitBurst 0

I tried to change it to below , then the openldap service will run slow .

$SystemLogRateLimitInterval 2
$SystemLogRateLimitBurst 50

Would advise what can I do for this case , what setting should I use so that no messages will be prompt to the log ?

thanks

As with several of your other threads, you NEED TO START DOING YOUR OWN RESEARCH. Putting the error into Google leads you to:
http://www.rsyslog.com/tag/rate-limiting/

...the rsylog site, which tells you how to set/test these things, and how to put a 'failsafe' file in place to ensure you don't drop any messages. In short, there is no 'perfect' answer, since it depends on how fast/much things are logging. Adjust the settings, and keep trying until you get it right.