cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From rohit bhatia <>
Subject Re: Cassandra out of Heap memory
Date Wed, 13 Jun 2012 13:35:54 GMT
To clarify things

Our setup contains of 8 nodes of 32 gb ram...
with a heap_max size of 12gb
and heap new size of 1.6 gb

The load on our nodes is write/read ratio of 10 with 6 main Column Families.
Although the flushes of column families occur every hour with sstables
sizes of around 50-100 mb. The memtable size for those seems to be
around 500mb. (Is this 10-20 times overhead expected).

Also This is the first time I'm seeing max Heap size reached
Exceptions. Could there be a significant reason to this other than
that the cassandra server were running without restarting for 2

On Wed, Jun 13, 2012 at 6:30 PM, rohit bhatia <> wrote:
> Hi
> My cassandra node went out of heap memory with this message
> " 88): Heap is .9934 full." Is this expected? or
> should I adjust my flush_largest_memtable_at variable.
> Also one change I did in my cluster was add 5 Column Families which are empty
> Should empty ColumnFamilies cause significant increase in cassandra heap usage?
> Thanks
> Rohit

View raw message