Interpreting Advanced Monitoring Stats

Hi there,
I've been trying to find information about how to interpret the advanced monitoring section in kibana. However I haven't been able to find in it ES doc.

How do you know a "normal" GC Count or GC Duration. We seem to have these peaks during the day, that I guess that are messing with the overall platform (timeouts and such). During a day they range between 23 and 250 on the Young, and old is always 0. The durations range from 1.5s to 13s.

We also have around the same time, some very high indexing times (compared to the rest of the day).

Any insight, pointers and information would be highly appreciated.

Have a nice day,

Jordi