:23
To: user@cassandra.apache.org
Subject: Re: Garbage collection freezes cassandra node
On node 172.16.107.46, I see the following:
21:53:27.192+0100: 1335393.834: [GC 1335393.834: [ParNew (promotion failed):
319468K-324959K(345024K), 0.1304456 secs]1335393.964: [CMS:
6000844K-3298251K
Thanks for this very helpful info. It is indeed a production site which I
cannot easily upgrade. I will try the various gc knobs and post any positive
results.
*IF* your data size, or at least hot set, is small enough that you're
not extremely reliant on the current size of page cache, and
to decrease the CMSInitiatingOccupancyFraction setting?
Thanks!
Rene
-Original Message-
From: sc...@scode.org [mailto:sc...@scode.org] On Behalf Of Peter Schuller
Sent: dinsdag 20 december 2011 6:38
To: user@cassandra.apache.org
Subject: Re: Garbage collection freezes cassandra node
I
the CMSInitiatingOccupancyFraction
setting?
Thanks!
Rene
-Original Message-
From: sc...@scode.org [mailto:sc...@scode.org] On Behalf Of Peter Schuller
Sent: dinsdag 20 december 2011 6:38
To: user@cassandra.apache.org
Subject: Re: Garbage collection freezes cassandra node
I should add: If you
On node 172.16.107.46, I see the following:
21:53:27.192+0100: 1335393.834: [GC 1335393.834: [ParNew (promotion failed):
319468K-324959K(345024K), 0.1304456 secs]1335393.964: [CMS:
6000844K-3298251K(8005248K), 10.8526193 secs] 6310427K-3298251K(8350272K),
[CMS Perm :
] On Behalf Of Peter Schuller
Sent: dinsdag 20 december 2011 6:36
To: user@cassandra.apache.org
Subject: Re: Garbage collection freezes cassandra node
During the garbage collections, Cassandra freezes for about ten seconds. I
observe the following log entries:
“GC for ConcurrentMarkSweep
Increasing memory in this case may not solve the problem. Share some
information about your workload. Cluster configuration, cache sizes etc.
You can also try getting java heap historgram to get more info on what's on
the heap.
On Mon, Dec 19, 2011 at 7:35 AM, Rene Kochen
During the garbage collections, Cassandra freezes for about ten seconds. I
observe the following log entries:
“GC for ConcurrentMarkSweep: 11597 ms for 1 collections, 1887933144 used; max
is 8550678528”
Ok, first off: Are you certain that it is actually pausing, or are you
assuming that
I should add: If you are indeed actually pausing due to promotion
failed or concurrent mode failure (which you will see in the GC log
if you enable it with the options I suggested), the first thing I
would try to mitigate is:
* Decrease the occupancy trigger (search for occupancy) of CMS to a