I've often thought about this. Here are some of the features I'd want in a pega log analyzer/viewer tool:
1) Be able to handle behemoths
2) Easy to see what date/time range this log file encompasses (one day's worth ? a whole week ?)
3) Easy to jump to a particular time spot. (for example, I want to see what happened close to 1 pm but I can't just search for 1 pm because maybe nothing happened)
4) Easy to find out how many times errors "like this one" occurred. perhaps I highlight an error of interest and then ask the tool to tell me how many times errors "like this one" occurred.
5) Easy to filter out the thousands of ones "like this" that I'm not interested in.
6) Color coding, for example one color for time stamps, one color for severe errors, one for infos.
7) Some good handling of the extremely wide lines that tend to prevail in log files. Maybe ability to collapse middles of the lines, since sometimes the timestamps and ends of the lines are of more interest.
8) Ability to handle multiple log files simultaneously. Maybe we've got logs for 8 nodes and we don't know which node has what we're looking for. Or maybe we want to see things interleaved in chronological order from multiple nodes to see a story such as "user imported a rule on node A and then pulse on node B picked it up )