Occursions
Fast customizable time series web database for big data like log files
... have `just too many' log files?
Occursions asynchronously tails log files and indexes the individual lines in each log file as each line is written to disk so you don't even have to wait for a second after an event happens to search for it.
Occursions uses custom disk backed data structures to create and search its indexes so it is very efficient at using CPU, memory and disk.
You can extend Occursions with shared libraries to support your own file formats, even binary file formats!