Can Orion Syslog be configured to reject some syslog messages based on type?

Yes,

the syslog 'viewer' on the solarwinds application server can be configured to take action on the incoming messages before they reach the database to discard them

Thank you Richard - I actually just discovered that and configured a rule to discard the useless noise.  I thought the rules would only filter my view of the database, but the discard function is awesome!

we are also building a new event (syslog, trap) correlation engine that should help you in using logs for troubleshooting of network issues. You may have a look on sample of our UI NPM unified and syslog search preview and leave us a comment (or download a beta and try). we are using new fast full-text search database which we hope will solve the problems with viewing & processing such big amount of logs you have.

Thanks Michal. We are looking at a variety of solutions for dealing with syslog. We’ve currently disabled syslog in Orion. The sheer volume was destroying performance, during my most recent test I logged over 200,000 entries to the syslog table in just over 60 seconds. I’m happy to report that Orion is humming along quite nicely now.