AM
To: user@cassandra.apache.org
Subject: RE: Much more native memory used by Cassandra then the configured JVM
heap size
Seems like my only recourse is to remove jna.jar and just take the
performance/swapping pain?
Obviously can't have the entire box lock up. I can provide a pmap etc
, June 13, 2012 10:53 AM
To: user@cassandra.apache.org
Subject: RE: Much more native memory used by Cassandra then the configured
JVM heap size
Seems like my only recourse is to remove jna.jar and just take the
performance/swapping pain?
Obviously can’t have the entire box lock up. I
We suppose the cached memory will be released by OS, but from /proc/meminfo
, the cached memory is in Active status, so I am not sure if it will be
release by OS.
And for low memory, because we found Unable to reduce heap usage since
there are no dirty column families in system.log, and then
Low OS memory
Low OS memory is not the same as low JVM memory. Normally the JVM allocates and
locks all the memory is needs at start up.
impact by our configuration: memtable_flush_writers=32,
memtable_flush_queue_size=12
increasing flush writers will impact on IO, increasing the queue size
...@thelastpickle.com]
Sent: Tuesday, June 12, 2012 4:08 AM
To: user@cassandra.apache.org
Subject: Re: Much more native memory used by Cassandra then the configured JVM
heap size
see http://wiki.apache.org/cassandra/FAQ#mmap
which cause the OS low memory.
If the memory is used for mmapped access the os can get
@cassandra.apache.org
Subject: RE: Much more native memory used by Cassandra then the configured JVM
heap size
I have experienced the same issue. The Java heap seems fine but eventually the
OS runs out of heap. In my case it renders the entire box unusable without a
hard reboot. Console shows
actually, this is without jna.jar. I will add and see if still have same issue
From: Poziombka, Wade L
Sent: Wednesday, June 13, 2012 10:53 AM
To: user@cassandra.apache.org
Subject: RE: Much more native memory used by Cassandra then the configured JVM
heap size
Seems like my only recourse
@cassandra.apache.org
*Subject:* RE: Much more native memory used by Cassandra then the
configured JVM heap size
** **
Seems like my only recourse is to remove jna.jar and just take the
performance/swapping pain?
** **
Obviously can’t have the entire box lock up. I can provide
see http://wiki.apache.org/cassandra/FAQ#mmap
which cause the OS low memory.
If the memory is used for mmapped access the os can get it back later.
Is the low free memory causing a problem ?
Cheers
-
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com
Btw. I suggest you spin up JConsole as it will give you much more detai
kon what your VM is actually doing.
On Mon, Jun 11, 2012 at 9:14 PM, Jason Tang ares.t...@gmail.com wrote:
Hi
We have some problem with Cassandra memory usage, we configure the JVM
HEAP 6G, but after runing Cassandra
See my post, I limit the HVM heap 6G, but actually Cassandra will use more
memory which is not calculated in JVM heap.
I use top to monitor total memory used by Cassandra.
=
-Xms6G -Xmx6G -Xmn1600M
2012/6/12 Jeffrey Kesselman jef...@gmail.com
Btw. I suggest you
Hi
I found some information of this issue
And seems we can have other strategy for data access to reduce mmap usage,
in order to use less memory.
But I didn't find the document to describe the parameters for Cassandra
1.x, is it a good way to use this parameter to reduce shared memory usage
and
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