Mesos Log Format: What Does it All Mean?
When you’re using Mesos, sooner or later you’re going to need to look in the logs to figure something out. Inevitably, you’ll be greeted by a line like this:
I0909 22:47:01.240617 21904 master.cpp:3600] Sending 1 offers to framework {id}
Uh… what? How do I read that? What are all those arguments? What even is I0909?
Mesos uses glog, the Google logging module. The arguments break down like this:
- The first character (
Iin our example) is one ofI(info),W(warning),E(error), orF(fatal). It indicates the severity of the message that follows. 0909 22:47:01.240617is the timestamp. In order: month, day, hour, minute, second, and microsecond.21904is the thread IDmaster.cpp:3600is the filename and line on which the log line occurs- then we have a bracket and a space, which are purely decorational
- the rest of the line is a human-readable message
That’s it!
Now from this you can tell what level the line is, when it occurred, where to look if you need to find the source, and what actually happened on the line.
To make it a little easier, here’s a cheat sheet:
