One of the highlights of the syslog-ng 4.3.0 release is #parallelize().

https://www.syslog-ng.com/community/b/blog/posts/accelerating-single-tcp-connections-in-syslog-ng-parallelize

It allows #syslog_ng to process log messages from a single high-traffic #TCP connection in multiple threads, thus increasing processing #performance on multi-core machines.