Any one know of any good log summary/monitoring tools

I'm looking for a (preferable) opens source tool that gives me daily/hourly summaries of log files. It have multiple log files on multiple machines and I would like a email every day with a list of all the error for each of these. Does anyone know if there is something like that out there. We had one at my previous Job but it was built i开发者_运维百科n house and I don't want to reinvent the wheel if there is already something like that out there.

Use a database appender, then create a script that will extract, aggregate, summarize the send the resulting document by email.