Rsyslog is a multi-threaded implementation of syslogd (a system utility providing support for message logging), with features that include: * reliable syslog over TCP, SSL/TLS and RELP * on-demand disk buffering * email alerting * writing to MySQL or PostgreSQL databases (via separate output plugins) * permitted sender lists * filtering on any part of the syslog message * on-the-wire message compression * fine-grained output format control * failover to backup destinations * enterprise-class encrypted syslog relaying

It is the default syslogd on Debian systems.