For capacity planning it's not worth worrying about whether the MemTables are empty, they will all end up full.Internal caches may refer to either the Row and Key caches or the BloomFilters, not sure which in this case. AaronOn 21 Oct, 2010,at 09:42 AM, CassUser CassUser wrote:I didn't notice the
I didn't notice the number of hot CFs mentioned below. So with data in
them. We are sharing a cluster with others, so I'm trying to get an idea of
what overhead there is for empty CFs if any. What are internal caches?
On Wed, Oct 20, 2010 at 1:17 PM, CassUser CassUser wrote:
> Cool thanks, that
Cool thanks, that helps.
So even if we have defined a column family in the storage-conf and it's
empty, this has some overhead in cassandra and the following rule should
apply:
memtable_throughput_in_mb * 3 * number of hot CFs + 1G + internal caches.
On Wed, Oct 20, 2010 at 12:53 PM, Aaron Mor
Take a look at the section on JVM Heap size here http://wiki.apache.org/cassandra/MemtableThresholdsCF's have a large overhead, Keyspaces have none/little. In general write performance will be affected by the memtable thresholds (also on the link above). Read performance will be affected by the siz
Thanks for the link.
#2 was not meant to be trick question, it just came out like that :). what
i was after is the overhead associated with large number of keyspaces and
column families (i didn't mean empty memtables :). If a few keyspaces that
have 20 or so column families with a percentage of
On Wed, Oct 20, 2010 at 2:47 PM, CassUser CassUser wrote:
> Hey,
>
> As I understand it writes go directly to the commit log. Once a threshold
> has been reached the data is shipped to a memtable, and again to an sstable.
>
> 1. How many memtables are created when a flush happens from a commit lo
Hey,
As I understand it writes go directly to the commit log. Once a threshold
has been reached the data is shipped to a memtable, and again to an sstable.
1. How many memtables are created when a flush happens from a commit log?
One per CF?
2. Is there any space associated with an empty memtab
