Garbage collection issues after 1.2.1 to 1.4.1 upgrade

Hello Elasticsearch community (again)

Following my previous post, that might have been quite unclear, i open this
one because i think i have located the problem (not its source nor its
solution sadly).

So i have an issue with super duper long garbage collectors after upgrading
from 1.2.1 to 1.4.1 . I narrowed the problem down to this looking at the GC
graphs, cluster is running a lot of "full" garbage collectors, taking a lot
(and i mean a lot) of time.
Mmemory used by "old" gc spikes very often ( 5Gb to 32Gb almost instantly )
triggering "stop the world" GC very often.
My memory consumption went from 24 steady gigs to 5, here is the graph
Here is a spike : (i know right ?, it's a spike) It
happens while there is a "full gc" running.
My java version is "1.7.0_51"

Just so you can see how bad the situation is , see one of the WARN garbage
collector message
[2015-02-28 16:03:48,064][WARN ][monitor.jvm ] [node00]
[gc][old][97830][713] duration [29.6s], collections [2]/[29.6s], total
[29.6s]/[1.8h], memory [5gb]->[4.8gb]/[31.8gb], all_pools {[young]
[74.6mb]->[1.4mb]/[865.3mb]}{[survivor] [0b]->[0b]/[108.1mb]}{[old]

I'm neither a sysadmin nor an elastic search expert (and not even a java
dev), so please, ask me for relevant information if you have ANY idea
regarding this problem.

Thank you

You received this message because you are subscribed to the Google Groups "elasticsearch" group.
To unsubscribe from this group and stop receiving emails from it, send an email to
To view this discussion on the web visit
For more options, visit