What are some alternatives to Loggly? I really like being able to aggregate my logs with minimal setup (and cost). I'm logging with Logback (Java), and there is a convenient extension that forwards log statements to Loggly.
Long answer: logback and both appenders can accept pattern formats to adjust how they're formatted. How useful the end result is depends a lot on the receiver, though, and more than that, there's no one implementation that's great for everyone -- that is, there's no right way to "handle large, multi-line log messages," only attempts at making them more useful.
An easy example is searching. Some people want to see the entire message, others want only the matching portion of a stack trace, others want some combination, and others - probably most people - just want something that's useful, however the actual UX works.
In Papertrail's case, our sender-specific context links (think grep -A/-B/-C) were designed for navigating multiline output from a single sender: https://papertrailapp.com/tour/viewer/context. It's basically pivoting from a single entry in a stack trace to the entire stack trace.
There are definitely some like Logentries or Sumologic. But the best I have seen so far is logmatic.io - to be honest I am working for them :). Our objective is to get one tool for all by allying the power of search with true business intelligence. Here is a video of our product as it was 6 months ago: http://bit.ly/logsjava. We are still in private beta and our prices are similar to Loggly and we already have tens of customers.
Background and setup: http://help.papertrailapp.com/kb/configuration/java-logback-...
GitHub repo: https://github.com/papertrail/logback-syslog4j
Papertrail also works with the standard Logback SyslogAppender.