There has been some really interesting work on distributed streaming queries for monitoring/diagnostics eg http://p2.berkeley.intel-research.net/papers/EuroSys2

There has been some really interesting work on distributed streaming queries for monitoring/diagnostics eg http://p2.berkeley.intel-research.net/papers/EuroSys2006-debugging.pdf http://p2.berkeley.intel-research.net/papers/EuroSys2006-deb...