Supressing repeating log messages with Syslog-ng

Again today I was hit by Stunnel's excessive logging behaviour, causing my log files to grow rapidly with messages like:

stunnel: warning: can't get client address: Bad file descriptor


Which is caused by my Wifi going offline, I fail to see why Stunnel should log hundreds of lines each second if the network is unavailable....

In my five minute search I couldn't really see how I could get Stunnel to change logging behaviour, without disable logging alltogether.

However I finally figured out how to suppress repeat messages with Syslog-ng, like Metalog did back in the old days when I used that. Stunnel from 2.1.1 and up has a suppress(X) option that is not documented very good. With the suppress option Syslog-ng will apparently suppress repeat messages in X second intervals. You can use it simply like this:

destination messages { file("/var/log/messages" suppress(30)); };


So with a bit of luck I should not be hit by Stunnel logging again.